CN101542080A - Gas purifying device, gas purifying system and gas purifying method - Google Patents

Gas purifying device, gas purifying system and gas purifying method Download PDF

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Publication number
CN101542080A
CN101542080A CNA2007800430741A CN200780043074A CN101542080A CN 101542080 A CN101542080 A CN 101542080A CN A2007800430741 A CNA2007800430741 A CN A2007800430741A CN 200780043074 A CN200780043074 A CN 200780043074A CN 101542080 A CN101542080 A CN 101542080A
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gas
mentioned
electric field
unit
cleaning plant
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田中元史
安井祐之
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Toshiba Corp
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Toshiba Corp
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Abstract

A gas purifying device (10) comprises a first electric field forming means that forms discharging electric field in a gas flow path (36) where gas to be purified EG flows to generate discharge plasma P, and charges and burns PMs contained in the gas to be purified EG by the action of the discharge plasma P, a second electric field forming means that forms a precipitating electric field for capturing the charged PMs by an electric precipitating function and pulling out the discharge plasma P to the gas flow path side, and a charging electrode (35) that charges the flowing gas to be purified EG on the upstream side of the positions where the first electric field forming means and the second electric field forming means are respectively installed.

Description

Gas cleaning plant, gas purge system and method for gas purification
Technical field
The gas cleaning plant, gas purge system and the method for gas purification that the present invention relates to from the purification object gas that comprises harmful matter such as particle-like substance, remove harmful matter and purify.
Background technique
In the past, as the gas cleaning plant that is used for purifying particle-like substance harmful matters such as (PM:Particulate Matter) from the discharge gas that discharge gases such as engine take place to discharge in the source, have in the gas flow path of the discharge gas that contains PM the PM filter is set, and utilize this PM filter to catch the device of PM.For example, in Japanese kokai publication hei 11-062558 communique record, following gas cleaning plant is disclosed: material such as the charcoal that contains among the PM that uses the heater burning to catch by the PM filter and removing, and make the functional regeneration of PM filter.
In this gas cleaning plant, owing in the seizure of PM, use mechanical control of dust, thus exist the pressure loss of discharging gas bigger, and uprise such problem at the load in discharge gases such as engine generation source.
In addition, because by removing the materials such as charcoal that contain among the PM that catches by the PM filter, so the temperature of gas need be heated to about 600 ℃ with the combustion reaction of oxygen.Therefore, need append external heater, back washing mechanism etc. are set, need append to spray and be used for burnt fuel, especially under effluent air temp is the situation of low temperature (especially below 200 ℃), be difficult to remove effectively PM.
Therefore, for example, in TOHKEMY 2005-320895 communique, disclose with the flow direction of discharging gas and carried out coronal discharge and the gas cleaning plant of purifying exhaust gas across.In this gas cleaning plant, can on dielectric or sparking electrode, catch charged PM by the discharge plasma that takes place according to coronal discharge, need not heating and remove, thus purifying exhaust gas.
But at the purification plant that uses in the past, under situation about handling from the discharge gas of the violent actual engine of load change, unburned is to the greatest extent and pile up sometimes for the PM that is caught by dielectric or sparking electrode.Thus, coronal discharge becomes unstable, maybe can't produce coronal discharge sometimes.And, also produce following problem sometimes, promptly PM piles up and discharges the stream sectional area that gas stream crosses and diminish, and discharges the problems such as pressure loss rising in the gas flow path.
Patent documentation 1: Japanese kokai publication hei 11-062558 communique
Patent documentation 2: TOHKEMY 2005-320895 communique
Summary of the invention
The object of the present invention is to provide a kind of gas cleaning plant, gas purge system and method for gas purification, need not the PM that is caught is heated and can remove efficiently, purify thereby will purify object gas.
According to a mode of the present invention, a kind of gas cleaning plant is provided, it is characterized in that, utilize first electric field to form the unit, in purifying the mobile gas flow path of object gas, form the electric field of discharge usefulness and generate discharge plasma, effect by above-mentioned discharge plasma makes the particle-like substance that is contained in the above-mentioned purification object gas charged and carry out combustion disposal, utilize second electric field to form the unit, catch above-mentioned charged particle-like substance and be formed for above-mentioned discharge plasma is drawn out to the electric field that the control of dust of above-mentioned gas stream side is used by the electrostatic precipitation function, wherein, being provided with the upstream side that above-mentioned first electric field forms the position of unit and above-mentioned second electric field formation unit, possesses the charged electrode of using that makes mobile purification object gas charged.
In addition, according to a mode of the present invention, a kind of gas cleaning plant is provided, it is characterized in that, utilize first electric field to form the unit, in purifying the mobile gas flow path of object gas, form the electric field of discharge usefulness and generate discharge plasma, effect by above-mentioned discharge plasma makes the particle-like substance that is contained in the above-mentioned purification object gas charged and carry out combustion disposal, utilize second electric field to form the unit, catch above-mentioned charged particle-like substance and be formed for above-mentioned discharge plasma is drawn out to the electric field that the control of dust of above-mentioned gas stream side is used by the electrostatic precipitation function, wherein, be provided with the internal face of above-mentioned gas stream that above-mentioned first electric field forms a side of unit, be provided with the internal face of above-mentioned gas stream that above-mentioned second electric field forms a side of unit, constitute the sparking electrode that above-mentioned first electric field forms the unit, and the control of dust that constitutes above-mentioned second electric field formation unit forms male and fomale(M﹠F) with any one surface at least in the electrode.
In addition, according to a mode of the present invention, a kind of gas cleaning plant is provided, it is characterized in that, utilize first electric field to form the unit, in purifying the mobile gas flow path of object gas, form the electric field of discharge usefulness and generate discharge plasma, effect by above-mentioned discharge plasma makes the particle-like substance that is contained in the above-mentioned purification object gas charged and carry out combustion disposal, utilize second electric field to form the unit, catch above-mentioned charged particle-like substance and be formed for above-mentioned discharge plasma is drawn out to the electric field that the control of dust of above-mentioned gas stream side is used by the electrostatic precipitation function, wherein, be provided with the internal face of above-mentioned gas stream that above-mentioned first electric field forms a side of unit, be provided with the internal face of above-mentioned gas stream that above-mentioned second electric field forms a side of unit, constitute the sparking electrode that above-mentioned first electric field forms the unit, the control of dust that constitutes above-mentioned second electric field formation unit is formed with catalyst layer with any one surface at least in the electrode.
And, according to a mode of the present invention, a kind of gas cleaning plant is provided, it is characterized in that, utilize first electric field to form the unit, in purifying the mobile gas flow path of object gas, form the electric field of discharge usefulness and generate discharge plasma, effect by above-mentioned discharge plasma makes the particle-like substance that is contained in the above-mentioned purification object gas charged and carry out combustion disposal, utilize second electric field to form the unit, catch above-mentioned charged particle-like substance and be formed for above-mentioned discharge plasma is drawn out to the electric field that the control of dust of above-mentioned gas stream side is used by the electrostatic precipitation function, wherein, being provided with the upstream side that above-mentioned first electric field forms the position of unit and above-mentioned second electric field formation unit, possesses the interpolation gas feed unit that supply can generate the interpolation gas of oxidation base.
In addition, according to a mode of the present invention, a kind of method for gas purification is provided, it is characterized in that, it is the method for gas purification of gas cleaning plant, this gas cleaning plant possesses: first electric field forms the unit, forms the electric field of discharge usefulness and generate discharge plasma in purifying the gas flow path that object gas flows, and the effect by above-mentioned discharge plasma makes the particle-like substance that is contained in the above-mentioned purification object gas charged and carry out combustion disposal; Second electric field forms the unit, catches above-mentioned charged particle-like substance and is formed for above-mentioned discharge plasma is drawn out to the electric field that the control of dust of above-mentioned gas stream side is used by the electrostatic precipitation function; And control unit, above-mentioned first electric field formation unit and above-mentioned second electric field formation unit are controlled, wherein, above-mentioned control unit detects the relevant information of the combustion disposal with particle-like substance that above-mentioned first electric field forms in the unit, according to this detected information, the operating state that above-mentioned first electric field is formed unit and/or above-mentioned second electric field formation unit is controlled.
In addition, according to a mode of the present invention, a kind of method for gas purification is provided, it is characterized in that, be the method for gas purification of serial or parallel connection when having disposed a plurality of gas cleaning plant, this gas cleaning plant possesses: first electric field forms the unit, forms the electric field of discharge usefulness and generate discharge plasma in purifying the gas flow path that object gas flows, and the effect by above-mentioned discharge plasma makes the particle-like substance that is contained in the above-mentioned purification object gas charged and carry out combustion disposal; Second electric field forms the unit, catches above-mentioned charged particle-like substance and is formed for above-mentioned discharge plasma is drawn out to the electric field that the control of dust of above-mentioned gas stream side is used by the electrostatic precipitation function; And control unit, above-mentioned first electric field formation unit and above-mentioned second electric field formation unit are controlled, wherein, above-mentioned control unit detects the relevant information of the combustion disposal with particle-like substance that above-mentioned first electric field in above-mentioned each gas cleaning plant forms in the unit, according to this detected information, the operating state that above-mentioned first electric field in above-mentioned each gas cleaning plant is formed unit and/or above-mentioned second electric field formation unit is controlled.
Description of drawings
Fig. 1 is the block diagram of the gas purge system of the schematically illustrated gas cleaning plant that possesses first mode of execution of the present invention.
Fig. 2 is the figure of section of the gas cleaning plant of schematically illustrated first mode of execution of the present invention.
Fig. 3 is the figure that near the section the sparking electrode of appearance of generation of the discharge plasma that is used to illustrate the sparking electrode vicinity is shown.
Fig. 4 is the block diagram of gas purge system of other structures of the schematically illustrated gas cleaning plant that possesses first mode of execution.
Fig. 5 is the figure of section of the gas cleaning plant of schematically illustrated second mode of execution of the present invention.
Fig. 6 is the figure of section of the gas cleaning plant of schematically illustrated the 3rd mode of execution of the present invention.
The block diagram of the gas purge system of Fig. 7 is schematically illustrated arranged in series two gas cleaning plants of the present invention.
Fig. 8 is the block diagram that the gas purge system of two gas cleaning plants of the present invention has been disposed in schematically illustrated parallel connection.
Fig. 9 is the block diagram of gas purge system of the method for gas purification of the schematically illustrated gas cleaning plant that is used for illustrating the 5th mode of execution of the present invention.
Figure 10 is the figure of section of the gas cleaning plant of schematically illustrated the 5th mode of execution of the present invention.
Figure 11 is the schematically illustrated block diagram that possesses the gas purge system of adding gas supply device and oxygen concentration detecting apparatus.
Figure 12 is the block diagram of gas purge system of the method for gas purification of the schematically illustrated gas cleaning plant that is used for illustrating the 6th mode of execution of the present invention.
Figure 13 is the block diagram of gas purge system of the method for gas purification of the schematically illustrated gas cleaning plant that is used for illustrating the 7th mode of execution of the present invention.
Figure 14 is the figure of section of the gas cleaning plant of schematically illustrated the 8th mode of execution of the present invention.
Symbol description
31 dielectrics, 32 sparking electrodes, 33 discharges of 10 gas cleaning plants, 30 exoelectrical reaction portions use electrical system EG to purify object gas P discharge plasma with electrical system 60 controls of dust with power supply 61 controls of dust with power supply 51 discharges with counter electrode 35 charged discharges with electrode 36 gas flow paths 50 with counter electrode 34 controls of dust
Embodiment
Below, with reference to accompanying drawing, embodiments of the present invention are described.
(first mode of execution)
Fig. 1 is the block diagram of the gas purge system of the schematically illustrated gas cleaning plant 10 that possesses first mode of execution of the present invention.Fig. 2 is the figure of section of the gas cleaning plant 10 of schematically illustrated first mode of execution of the present invention.Fig. 3 illustrates the figure that is used to illustrate near the section the sparking electrode 32 of appearance of discharge plasma P takes place in sparking electrode 32 vicinity.
As shown in Figure 1, gas cleaning plant 10 for example is arranged on from the engine 20 of automobile in the exhaust flow path 21 that the purification object gas EG such as discharge gas that discharge are passed through.As shown in Figure 2, this gas cleaning plant 10 possesses: be arranged at the exoelectrical reaction portion 30 on the stream that purifies object gas EG; Via the discharge power supply 50 that discharges and be connected with this exoelectrical reaction portion 30 with electrical system 51; And the control of dust usefulness power supply 60 that is connected with exoelectrical reaction portion 30 with electrical system 61 via control of dust.
Exoelectrical reaction portion 30 possesses: dielectric 31; Sparking electrode 32; The discharge counter electrode 33 that is provided with across dielectric 31 and this sparking electrode 32 subtends ground; Control of dust counter electrode 34 across stream that purifies object gas EG and the setting of sparking electrode 32 subtends ground; And the charged electrode 35 of using of using the upstream side setting of counter electrode 34 in discharge with counter electrode 33, control of dust.
Dielectric 31 is for example flat board or the cylindrical shells that are made of dielectric material, for example is arranged on the stream of the purification object gas EG such as discharge gas that discharge from the engine of automobile.Therefore, in dielectric 31 inside, be imported into the gas flow path 36 that purifies object gas EG and form purification object gas EG.As dielectric material, for example can use resins such as special teflon (Teflon) (TM trade mark), epoxy, KAPTON, perhaps potteries such as glass, aluminium oxide, aluminium nitride at this.In addition, situation about handling from the discharge gas of the engine of reality is being needed under the situation of the processing under the high temperature like that, it is effective using pottery, when considering the temperature characteristic of dielectric material, from the viewpoint that reduces power consumption use the little material of dielectric loss under the high temperature for example aluminium oxide etc. be effective.Especially, the dielectric loss under 300 ℃ by measuring under 1kHz is the material of tan δ＜0.1, can access good purifying property.If the relative dielectric constant of dielectric 31 is made as 0.1～1000, the thickness of dielectric 31 is made as about 0.01mm～10mm, then can easily trigger creeping discharge described later (creepingdischarge).
At the internal face of this gas flow path 36, be provided with to subtend sparking electrode 32 and control of dust counter electrode 34 mutually.Sparking electrode 32 is for example with the shape formation of a plurality of thin tabular electrodes with almost parallel ground, the interval configuration of regulation and a distolateral comb shape that is electrically connected with electrical system 51 with discharge respectively.And, so that each tabular electrode becomes the form of approximate vertical with respect to the main flow direction of the purification object gas EG that flows through gas flow path 36, dispose sparking electrode 32.This sparking electrode 32 is by object gas EG has corrosion resistance, stable on heating conductive material constitutes, and for example uses stainless steel etc. for purifying.For example also can be at the internal face of gas flow path 36, directly print and form this sparking electrode 32.In addition, control of dust has writing board shape with counter electrode 34, with sparking electrode 32 similarly, for example object gas EG has corrosion resistance, stable on heating conductive material constitutes for purifying by stainless steel etc.This control of dust with counter electrode 34 also with sparking electrode 32 similarly, for example also can with the directly printing and forming of the internal face of the gas flow path 36 of the position subtend that disposes sparking electrode 32.In addition, have corrosion resistance, heat resistance with counter electrode 34 in order to make sparking electrode 32, control of dust, on the surface of metal film with have corrosion resistance, stable on heating coating coats also is effective.For example, by stainless steel, wolfram steel electrode being carried out the nickel plating or the alumina-coated of 1 μ m～100 μ m thickness, the corrosion in the real gas environment such as discharge gas that can suppress for example from the engine of automobile, to discharge.In addition, necessarily the becoming vertically towards need not of the electrode of comb shape with respect to main flow direction, also can be made as with respect to main flow becomes direction parallel or that tilt.
And, the discharge of exoelectrical reaction portion 30 with counter electrode 33 across dielectric 31, in other words clip dielectric 31 and the configuration of sparking electrode 32 subtends.Discharge is for example formed by thin flat conductive material with counter electrode 33.Discharge with counter electrode 33 also can with sparking electrode 32 similarly, with the directly printing and being provided with of the outer wall of the gas flow path 36 of the dielectric 31 of sparking electrode 32 subtends.
In addition, sparking electrode 32, discharge are not limited to above-mentioned shape with counter electrode 33 and control of dust with the shape of counter electrode 34 but arbitrarily, but the shape of sparking electrode 32 for example is preferably wire, point-like, slit-shaped or mesh-shape except above-mentioned comb shape.Become these shapes by the shape that makes sparking electrode 32, it is close that near the line of electric force the sparking electrode 32 becomes, and can easily generate discharge plasma, so be resultful.And, can catch a lot of particle-like substances harmful matters such as (PM:Particulate Matter), can efficiently harmful matter, particularly PM be burnt and remove.In addition, control of dust also is not limited to planar with the shape of counter electrode 34, also can similarly be made as slit-shaped or mesh-shape etc. with sparking electrode 32.
In addition, discharge is connected with the sparking electrode 32 of exoelectrical reaction portion 30 with electrical system 51 via discharge with a utmost point of power supply 50, and another utmost point is connected with counter electrode 33 with discharge with electrical system 51 via discharge.Discharge for example is made of the power supply of primary side and primary side with power supply 50.As the power supply of primary side, use the ac power supply of AC 100V and Φ 50Hz or Φ 60Hz, perhaps the DC electrical source of DC12V or DC 24V.In addition, the output voltage of the power supply of primary side for example be made as have pulse type (positive polarity, negative polarity, positive negative bipolar), exchange the output voltage of shape (sinusoidal wave, intermittent sine wave) waveform.In addition, the power supply of primary side and the power supply of primary side can also be made as integrative-structure, but are used as primary side by the power supplys such as battery that will be equipped in the automobile usually, thereby need not newly to be provided with the power supply of primary side, have realized the miniaturization of device.And the power supply of primary side can constitute: possess transformer, will utilize signal about several V～hundreds of V of shapings such as inverter to boost to the output voltage of several kV～tens kV by transformer.In order to shorten the distance of high voltage wiring as far as possible, preferably power supply and the exoelectrical reaction portion 30 with primary side closely is provided with.In addition, the situation etc. that is in high temperature in exoelectrical reaction portion 30 down, in order to prevent electronic circuit such as inverter because heat is damaged, preferred employing, only closely is provided with transformer and exoelectrical reaction portion 30 the transformer portion independent structures from the power supply of primary side.
So, utilization is discharged with 50 pairs of sparking electrodes 32 of power supply and is discharged with the voltage that applies between the counter electrode 33 about for example a few kV to tens kV, thereby discharge when in gas flow path 36, forming electric field, at the gas flow path 36 inner discharge plasma P that generate.At this moment, being situated between between sparking electrode 32 and discharge are with counter electrode 33 has dielectric 31, and dielectric 31 is provided with contiguously with sparking electrode 32, so the discharge in the gas flow path 36 becomes along the creeping discharge of dielectric 31 formation.
Form first electric field with power supplys 50, sparking electrode 32 and discharge with counter electrode 33 with electrical system 51 interconnective discharges via discharge and form the unit by above-mentioned.
On the other hand, control of dust is connected with counter electrode 34 with the control of dust of exoelectrical reaction portion 30 with electrical system 61 via control of dust with a utmost point of power supply 60, and another utmost point is connected with the sparking electrode 32 of exoelectrical reaction portion 30 with electrical system 61 via control of dust.Control of dust for example is made of the power supply of primary side and primary side with power supply 60.As the power supply of primary side, use the ac power supply of AC 100V and Φ 50Hz or Φ 60Hz, perhaps the DC electrical source of DC 12V or DC 24V.In addition, the output voltage of the power supply of primary side for example is made as the output voltage of direct current shape (positive polarity, negative polarity, positive negative bipolar), pulse type (positive polarity, negative polarity, positive negative bipolar), rectified waveform (single ripple rectified waveform, double wave rectified waveform).
So, constitute by from control of dust with 60 pairs of sparking electrodes 32 of power supply and control of dust with the voltage that applies between the counter electrode 34 about for example several kV, thereby can in gas flow path 36, form electric field.Form second electric field with power supplys 60, sparking electrode 32 and control of dust with counter electrode 34 with electrical system 61 interconnective controls of dust via control of dust and form the unit by above-mentioned.At this, improve to sparking electrode 32 and control of dust with counter electrode 34 between (distance D) apply voltage V the time, discharging between generation space, finally causes producing spark.When becoming such state, the conductivity in the gas flow path rises, and is drawn out to unipolarity movement of electric charges degree in the gas flow path and uprises and absorbed with counter electrode 34 by sparking electrode 32 or control of dust, thereby can't make PM charged efficiently.For fear of such state, preferably use the voltage V that is applied in the scope of between sparking electrode 32 and control of dust are with counter electrode 34, discharging unautogenously, for example preferably will be made as 1～30kV/cm with the average field intensity of V/D regulation.
In addition, chargedly be arranged at discharge with counter electrode 33, control of dust upstream side (left side in Fig. 2), and on direction, cross gas flow path 36 and be provided with respect to the main flow direction approximate vertical that purifies object gas EG with counter electrode 34 with electrode 35.This is charged for example to have bar-shaped shape with electrode 35, and under situation about forming with cylinder, its diameter forms about 0.3～10mm.In addition, this charged with electrode 35 by object gas EG has corrosion resistance, stable on heating conductive material constitutes, and for example uses stainless steel etc. for purifying.These charged two ends with electrode 35 can be connected with power supply 50 with discharge with electrical system 51 via above-mentioned discharge respectively, also can be connected with power supply 60 with control of dust with electrical system 61 via above-mentioned control of dust.In addition, the charged power supply of using with electrode that applies voltage with electrode 35 to charged also can be set separately.To the charged voltage that applies with electrode 35 both can be that to exchange also can be direct current.
To discharge with power supply 50 as under the situation of the charged power supply of using with electrode, as mentioned above, the output voltage of the power supply of primary side for example become have pulse type (positive polarity, negative polarity, positive negative bipolar), exchange the output voltage of shape (sinusoidal wave, intermittent sine wave) waveform, with between the two ends of electrode 35, apply the voltage about for example a few kV to tens kV charged.Thus, produce coronal discharge on electrode 35 charged, at the charged purification object gas EG that flows around with electrode 35 by charged.In addition, control of dust is being used as under the situation of the charged power supply of using with electrode with power supply 60, as mentioned above, the output voltage of the power supply of primary side becomes the output voltage of direct current shape (positive polarity, negative polarity, positive negative bipolar), pulse type (positive polarity, negative polarity, positive negative bipolar), rectified waveform (single ripple rectified waveform, double wave rectified waveform), with between the two ends of electrode 35, apply the voltage about for example several kV charged.Thus, produce coronal discharge on electrode 35 charged, at the charged purification object gas EG that flows around with electrode 35 by charged.
In addition, in Fig. 2, show an example of the structure of the exoelectrical reaction portion 30 that possesses a charged usefulness electrode 35, but also can be provided with a plurality of charged with electrodes 35.Charged configuration example as this moment with electrode 35, for example, enumerate the upstream side of using counter electrode 34 in discharge with counter electrode 33, control of dust, on direction, separate a plurality of charged examples of using electrode 35 of arranged spaced of regulation etc. with respect to the main flow direction approximate vertical that purifies object gas EG.The interval of regulation is set at least in the adjacent charged degree that does not produce sparkover between with electrode 35.In addition, use electrode 35 under the situation of direction (above-below direction among Fig. 2) arrangement of using counter electrode 34 from sparking electrode 32 towards control of dust when each is charged, both can arrange point-blank, also can be adjacent chargedly to be configured in the different such non-directional arrangement in position mutually with electrode 35.A plurality of charged with electrodes 35 by such configuration, spread all over the section of gas flow path 36 by roughly charged equably as the PM of the harmful matter that contains among the purification object gas EG that in gas flow path 36, flows.
Next, the effect of gas cleaning plant 10 is described.
At first, the purification object gas EG such as discharge gas that discharge from the engine of automobile etc. are directed in the gas flow path 36 that forms in the exoelectrical reaction portion 30, and flow in the exoelectrical reaction portion 30.
At this, to be provided with in the ingress of exoelectrical reaction portion 30 charged apply with electrode 35 have pulse type (positive polarity, negative polarity, positive negative bipolar), exchange the output voltage of shape (sine wave, intermittent sine wave) or rectified waveform (single ripple rectified waveform, double wave rectified waveform) waveform.Thus, produce coronal discharge charged on electrode 35, the PM that contains in the purification object gas EG that flows around it is by charged.
Comprise by the purification object gas EG of charged PM inflow sparking electrode 32 and control of dust and use between the counter electrode 34.Herein, from discharge with 50 pairs of sparking electrodes 32 of power supply with discharge with applying pulse type (positive polarity, negative polarity, positive negative bipolar) between the counter electrode 33 or exchanging the voltage of shape (sine wave, intermittent sine wave).Thus, with between the counter electrode 33, particularly near sparking electrode 32, the concentrated area forms electric field and causes along the creeping discharge of dielectric 31 in sparking electrode 32 and discharge, follows this creeping discharge and produces discharge plasma P.
At this, discharge is pulse type (positive polarity, negative polarity, positive negative bipolar) or the output voltage that exchanges shape (sinusoidal wave, intermittent sine wave) with the output voltage of the primary side of power supply 50, even the dielectric 31 of dielectricity is arranged so be situated between, also can on the surface of dielectric 31, not put aside surface charge and discharge is stopped or discharge and shift to be Arc Discharge, so produce stable discharge plasma P equally.
On the other hand, from control of dust with 60 pairs of sparking electrodes 32 of power supply and control of dust with the voltage that applies direct current shape (positive polarity, negative polarity, positive negative bipolar), pulse type (positive polarity, negative polarity, positive negative bipolar) or rectified waveform (single ripple rectified waveform, double wave rectified waveform) between the counter electrode 34.That is, polarity can not change such voltage and is applied to sparking electrode 32 and control of dust with between the counter electrode 34 from control of dust with power supply 60 on the time, at sparking electrode 32 and control of dust with the same electric field of formation between the counter electrode 34.
Its result, by being formed at the effect of electric field between sparking electrode 32 and the control of dust usefulness counter electrode 34, discharge plasma P is drawn out to gas flow path 36 inside from sparking electrode 32 in large quantities.So, the PM that contains among the purification object gas EG that in gas flow path 36, flows since with by the collision of electronics that discharge plasma P generated that is drawn out to gas flow path 36 inside in large quantities or ion by charged.That is, PM passes through the above-mentioned charged electrode 35 of using by charged, and then passes through discharge plasma P also by charged.In addition, as mentioned above, discharge plasma P is drawn out to gas flow path 36 inside from sparking electrode 32 in large quantities, thereby spreads all over the sectional area expansion of gas flow path 36, so the probability that contacts with the purification object gas EG that flows in gas flow path 36 improves.Thus, being contained in the PM that purifies among the object gas EG is improved by charged ratio.
In addition, as mentioned above, by the output voltage characteristic of control of dust with power supply 60, being formed at sparking electrode 32 and control of dust and can not changing in time with the direction of the electric field between the counter electrode 34, is the discharge plasma P with a kind of polarity in the plus or minus so be drawn out to the discharge plasma P of gas flow path 36 inside.Thus, PM's most also is with plus or minus.Therefore, by the track of charged PM because the Coulomb force that the electric field that forms from the effect that forms the unit by second electric field is subjected to and bending.Crooked direction is by the direction decision with electric field of electric charge that PM had, so because the polarity of electric charge, produce to the PM of sparking electrode 32 lateral bending songs and use the PM of counter electrode 34 lateral bending songs to control of dust.
Thus, also add the electric force of discharge plasma P on by the electrostatic precipitation function that acts on the electric field that sparking electrode 32 and control of dust form between with counter electrode 34 of control of dust with power supply 60, charged a kind of PM attracted to sparking electrode 32 sides in gas flow path 36, thereby is caught in the surface of sparking electrode 32 or near the surface of the dielectric 31 the sparking electrode 32.In addition, the charged polarity another kind of PM different with a kind of PM is caught in the surface of control of dust usefulness counter electrode 34 or near the surface of the dielectric 31 the control of dust usefulness counter electrode 34.That is, the PM of band plus or minus electricity is subjected to electric force by the effect of electric field and unipolar discharge plasma P on same direction, be caught in sparking electrode 32 sides or control of dust counter electrode 34 sides.
As mentioned above, PM passes through the charged electrode 35 of using by charged, and then pass through discharge plasma P also by charged, thereby has sufficient carried charge, be subjected to electric force by acting on the same direction of electric field and unipolar discharge plasma P, thereby be caught in sparking electrode 32 sides or control of dust counter electrode 34 sides efficiently.Like this, because the effect of drawing of discharge plasma P improves the effect of charged efficient of the PM in the gas flow path 36, also have provides electric force and the effect of catching with counter electrode 34 sides at sparking electrode 32 sides or control of dust efficiently to charged PM to the electric field that forms with the effect of power supply 60 by control of dust except having.At this, improve to sparking electrode 32 and control of dust with counter electrode 34 between (distance D) apply voltage V the time, discharging between generation space, finally causes producing spark.When becoming such state, the conductivity in the gas flow path rises, and is drawn out to unipolarity movement of electric charges degree in the gas flow path and uprises and absorbed with counter electrode 34 by sparking electrode 32 or control of dust, thereby can't make PM charged efficiently.For fear of such state, preferably use the voltage V that is applied in the scope of between sparking electrode 32 and control of dust are with counter electrode 34, discharging unautogenously, for example preferably will be made as 1～30kV/cm with the average field intensity of V/D regulation.
At this,, the appearance that produces discharge plasma P in sparking electrode 32 vicinity is described with reference to Fig. 3.
In exoelectrical reaction portion 30, possess, for example, a plurality of thin tabular electrodes with almost parallel ground, the interval configuration of regulation and one distolateral respectively with the sparking electrode 32 of discharge with the electrical system 51 electric comb shapes that engage.And this sparking electrode 32 is configured to, and the electrode of each tabular (width W) becomes approximate vertical with respect to the main flow direction of the purification object gas EG that flows in gas flow path 36.In addition, the time interval at this electrode that each is tabular is S.That is, the part that is provided with sparking electrode 32 becomes the state that the dielectric of the electrode of width W and width S alternately exposes, and PM is caught on this part.
Generally, for example, constituting under the situation of sparking electrode 32 by a flat board, so owing to exist discharge plasma P PM burned to high-density at the two end part of sparking electrode 32, but near the central authorities of sparking electrode 32, the density step-down of discharge plasma P, PM is burned and pile up.Like this, if PM piles up, then coronal discharge is become unstable or because the accumulation of PM and the sectional area of gas flow path 36 reduces, the pressure losses in the gas flow path 36 increase, and can't make the gas cleaning plant runs steadily by obstruction.
On the other hand, as mentioned above the shape of sparking electrode 32 for example is being made as comb shape and this sparking electrode 32 has been applied under the voltage condition, discharge plasma P is from the highest triple point 80 of electric field (contact of tabular electrode and dielectric and air) development, and to the part that is provided with the sparking electrode 32 of catching PM, be that the part that the dielectric of electrode and the width S of width W alternately exposes is expanded (with reference to Fig. 3).Thus, PM is burnt reliably, the accumulation of PM is prevented from.For discharge plasma P is developed equably, width W and width S are preferably about 0.1～20mm.In addition, be made as netted, mesh-shape, can access the same action effect of situation with the sparking electrode 32 of above-mentioned comb shape by shape with sparking electrode 32.In addition, even under the situation of the sparking electrode 32 that has used comb shape, the width W of each comb, the interval between comb (being equivalent to S) also need not constant, for example also can make W, S short near the inlet that purifies object gas EG, make W, S long near the outlet that purifies object gas EG.Thus, discharged power is concentrated near the high inlet of the concentration of PM, PM is burnt efficiently.In addition, the height of each comb also need not constant, for example also can make highly lowly near the inlet that purifies object gas EG, makes highly high near outlet.Thus, constant by making with respect to becoming from the outlet that enters the mouth towards the position of the discharge in the boundary layer of the stream of outlet expansion relation from inlet, thus can make the processing homogenization.In addition, the discharge plasma P that takes place in sparking electrode 32 sides is drawn out to control of dust with counter electrode 34 sides by control of dust with the effect of power supply 60 as previously mentioned, spreads all over the section of the regulation of gas flow path 36 and expands.
In addition, in the gas flow path 36 in exoelectrical reaction portion 30, the high-energy electron that is generated by discharge plasma P collides with purifying object gas EG, thereby generates O, OH, O 3, O 2-Deng oxidation base or NO 2Deng.Oxidation base further produces other active hydrocarbon molecules with purifying the hydrocarbon reaction among the object gas EG.In addition, NO 2Produce combustion reaction with PM, PM is decomposed and oxidation.
Swarm into PM in this discharge plasma P and need not to implement heating and wait processing, and interim ground combustion reaction and being decomposed and oxidation finally becomes carbon monoxide, carbon dioxide etc.At this, swarm into the part of the PM among the highdensity discharge plasma P and decompose in the space, near the surface of the dielectric 31 of the residue surface of sparking electrode 32, sparking electrode 32 or control of dust are captured with near the surface collision of the dielectric 31 of counter electrode 34 with the surface of counter electrode 34, control of dust.The PM that catches on each surface with the reacting field of oxidation base in be detained for a long time, need not to implement heating and wait processing, and interim real estate is estranged separates and combustion reaction such as oxidation by the effect of oxidation base in during this period, finally becomes carbon monoxide, carbon dioxide etc.Therefore, always keep peace and quiet in the exoelectrical reaction portion 30, can prevent the phenomenon that discharge plasma P reduces or the electrostatic precipitation function reduces owing to be subjected to their pollution.Especially, creeping discharge is triggered in the vicinity of the PM that catches on the surface, it is near that thereby the distance of oxidation base and PM becomes, and can the oxidation base that the life-span is shorter effectively utilizes in the combustion reaction of materials such as the charcoal that contains in PM, hydrocarbon, thereby can handle more efficiently.
The purification object gas EG that utilizes exoelectrical reaction portion 30 to remove PM like this is discharged to the outside of exoelectrical reaction portion 30.
In addition, in the above description, even capture under the situation of PM with the surface of counter electrode 34 or control of dust surface with near the dielectric the counter electrode 34 31 at control of dust, as mentioned above, because discharge plasma P also expands with counter electrode 34 sides to control of dust, so the PM that is caught is decomposed and oxidation interimly.At this, further burn efficiently with the surface of counter electrode 34, the PM that control of dust is caught with near the surface of the dielectric 31 the counter electrode 34 in order to make at control of dust, also can be for example as putting down in writing, Figure 13 of TOHKEMY 2005-320895 communique constitutes: replace being provided with control of dust with counter electrode 34, and sparking electrode is set at internal face with the dielectric 31 of sparking electrode 32 subtends, in a side discharge counter electrode is set across dielectric 31 and this sparking electrode subtend.That is, also can adopt sparking electrode that is provided with two groups of subtends and the structure of discharging the usefulness counter electrode.
As mentioned above, in the gas cleaning plant 10 of first mode of execution, be provided with charged with electrode 35 with counter electrode 33, control of dust with the upstream side of counter electrode 34 in discharge, making the harmful matter that contains among the purification object gas EG that flow into exoelectrical reaction portion 30 is that PM is charged, and make this PM charged, thereby can make PM possess sufficient carried charge by the discharge plasma P that forms the unit generation by first electric field.Thus, this PM is subjected to electric force by the effect of the electric field that formed the unit by second electric field and take place and unipolar discharge plasma P on same direction, the surface or the control of dust of near can be on the surface of sparking electrode 32, the sparking electrode 32 dielectric 31 are caught with near the surface of the dielectric the counter electrode 34 31 efficiently with surface, the control of dust of counter electrode 34.And the PM that is caught need not heating, and with discharge plasma P in the oxidation base combustion reaction and be removed, purify so can purify object gas.In addition, remove, so, also can bring into play sufficient performance even for example under the situation that the discharge gas of the actual engine violent from load change is handled owing to catching PM efficiently.
In addition, at this, the gas purge system of other structures of the gas cleaning plant 10 that possesses first mode of execution is described.
Fig. 4 is the block diagram of gas purge system of other structures of the schematically illustrated gas cleaning plant 10 that possesses first mode of execution.
The gas purge system of other structures is in gas purge system shown in Figure 1, gas cleaning plant 10 is provided with the system that adds gas supply device 100, and this interpolation gas supply device 100 is used for the exhaust flow path 21 of the upstream side that purifies object gas EG inflow is supplied with the interpolation gases.
This interpolation gas supply device 100 is supplied with and can be generated above-mentioned O, OH, O 3, O 2-Deng oxidation base or NO 2Deng for example oxygen or water vapour etc. add gas.Link by pipe arrangement between this interpolation gas supply device 100 and the exhaust flow path 21, be added and be mixed among the purification object gas EG that exhaust flow path 21, flows from the interpolation gas that adds gas supply device 100 discharges, flow in the exoelectrical reaction portion 30.
Like this, add gas supply device 100, can increase the growing amount of oxidation base, promote the combustion reaction of PM by being provided with.Thus, can make the surface that is caught in sparking electrode 32, near the surface or the control of dust of the dielectric 31 the sparking electrode 32 use near the PM on the surface of the dielectric 31 the counter electrode 34 to decompose more efficiently and oxidation, can purify purifying object gas with surface, the control of dust of counter electrode 34.
In addition, only adding the combustion reaction that gas supply device 100 can promote PM by being provided with, and can constitute gas cleaning plant 10 with electrode 35 to purifying under the situation that object gas purifies, also can not be provided with possess in the gas cleaning plant 10 charged.
(second mode of execution)
The gas cleaning plant 150 of second mode of execution of the present invention charged in the gas cleaning plant 10 that does not possess first mode of execution is with electrode 35 and disposing sparking electrode 32 and the control of dust shape difference with the internal face of the gas flow path 36 of a side of counter electrode 34, identical with the structure of the gas cleaning plant 10 of first mode of execution, so the structure that these are different mainly is described at this.
Fig. 5 is the figure of section of the gas cleaning plant 150 of schematically illustrated second mode of execution of the present invention.In addition, to the identical part of structure of the gas cleaning plant 10 of first mode of execution, additional same-sign and omit or simplify the explanation of repetition.
As shown in Figure 5, the gas cleaning plant 150 of second mode of execution possesses: be arranged at the exoelectrical reaction portion 30 on the stream that purifies object gas EG; Via the discharge power supply 50 that discharges and be connected with this exoelectrical reaction portion 30 with electrical system 51; And the control of dust usefulness power supply 60 that is connected with exoelectrical reaction portion 30 with electrical system 61 via control of dust.
Exoelectrical reaction portion 30 possesses: dielectric 31; Sparking electrode 32; The discharge counter electrode 33 that is provided with across dielectric 31 and this sparking electrode 32 subtends ground; And the control of dust counter electrode 34 that is provided with across stream and the sparking electrode 32 subtends ground of purification object gas EG.
Dielectric 31 is for example flat board or the cylindrical shells that are made of dielectric material, for example is arranged on the stream of the purification object gas EG such as discharge gas that discharge from the engine of automobile.Therefore, in dielectric 31 inside, be imported into the gas flow path 36 that purifies object gas EG and form purification object gas EG.In addition, at the internal face of this gas flow path 36, be provided with to subtend sparking electrode 32 and control of dust counter electrode 34 mutually.And, as shown in Figure 5, be provided with sparking electrode 32 and control of dust with the internal face of the gas flow path 36 of a side of counter electrode 34 and these sparking electrodes 32 and control of dust with near the internal face the counter electrode 34, be formed with jog 151,152 along the main flow direction that purifies object gas EG.In addition, the formation direction of jog 151,152 is not limited to form along the main flow direction that purifies object gas EG, for example also can on direction, form near the internal face sparking electrode 32 and the control of dust usefulness counter electrode 34 with respect to the main flow direction approximate vertical that purifies object gas EG.In addition, the height of jog 151,152 need not constant, for example also can make highly lowly near the inlet that purifies object gas EG, makes highly high near outlet.Thus, constant by making with respect to exporting from entering the mouth to towards the position of the jog 151,152 in the boundary layer of the stream of outlet expansion relation from inlet, thus can make the processing homogenization.In addition, also can adopt sparking electrode 32, control of dust itself to form concavo-convex structure, the structure of for example comb shape with respect to plane internal face with counter electrode 34.
And, also can be with sparking electrode 32 and control of dust surface with counter electrode 34, with above-mentioned sparking electrode 32 and control of dust with near the internal face of counter electrode 34 similarly, be made as concaveconvex structure along the main flow direction that purifies object gas EG.In addition, concaveconvex structure is not limited to form along the main flow direction that purifies object gas EG, for example also can form on the direction with respect to the main flow direction approximate vertical that purifies object gas EG.
For example, as shown in Figure 5, near sparking electrode 32 and control of dust usefulness counter electrode 34 internal face, formed under the situation of jog 151,152 along the main flow direction that purifies object gas EG, purify object gas EG and generally perpendicularly collide, form circular flow in the positive downstream side of protuberance to the protuberance of 151,152 ones of jogs.Be involved in PM by this circular flow, can catch more PM.In addition, in that sparking electrode 32 and control of dust similarly are made as under the situation of concaveconvex structure along the main flow direction that purifies object gas EG with near the internal face the counter electrode 34 with the surface of counter electrode 34 and above-mentioned sparking electrode 32 and control of dust, also obtain same action effect.In addition, owing to compared by the situation that the plane forms with internal face, the surface area of internal face increases, and the catching rate of PM also improves thus.
On the other hand, near sparking electrode 32 and control of dust usefulness counter electrode 34 internal face, formed under the situation of jog 151,152 along direction, on the main flow direction that purifies object gas EG, be formed with slot part by jog 151,152 with respect to the main flow direction approximate vertical that purifies object gas EG.Purifying object gas EG flows through along this slot part.In this case, compare by the situation that the plane forms, increased the surface area of internal face, thereby can catch more PM with internal face.
As mentioned above, in the gas cleaning plant 150 of second mode of execution, form jog 151,152 at sparking electrode 32 and control of dust with near the internal face the counter electrode 34, thereby can increase surface area, can catch more PM and remove.In addition, become on the surface that makes sparking electrode 32 and control of dust with counter electrode 34 under the situation of concaveconvex structure, owing to surface area also can increase, so also can obtain same action effect.
In addition, forming under the situation of jog 151,152, forming circular flow, be involved in PM to this circular flow, thereby can catch more PM in the positive downstream side of protuberance along the main flow direction that purifies object gas EG.In addition, become under the situation of concaveconvex structure along the main flow direction that purifies object gas EG on the surface that makes sparking electrode 32 and control of dust with counter electrode 34, owing to also can form circular flow in the positive downstream side of protuberance, so also can access same action effect.
At this, replace that jog 151,152 is set and also can constitute: these sparking electrodes 32 and the control of dust surface layer with near the internal face of counter electrode 34 is constituted with the cavernous porous layer that is for example formed by dielectric material.In addition, replace making sparking electrode 32 and control of dust to become concaveconvex structure, also sparking electrode 32 and control of dust for example can be constituted with the porous layer that is made of the foam metal that has corrosion resistance, heat resistance, electric conductivity for purification object gas EG etc. with the surface of counter electrode 34 with the surface of counter electrode 34.
Like this, under the surface layer or sparking electrode 32 and surface layer the situation with porous layer formation of control of dust with near the internal face the counter electrode 34 with counter electrode 34 with sparking electrode 32 and control of dust, surface area increases, and can catch more PM and removes.In addition, PM to sparking electrode 32, control of dust with near the internal face collision of counter electrode 34, these electrodes and be captured, but by making these faces become porous layer, the knock-on in the time of can preventing the PM collision and improve catching rate.
In addition, in the gas cleaning plant 150 of mode of execution 2, the charged electrode 35 of using that possesses in the gas cleaning plant 10 of first mode of execution can be set also.Thus, the action effect in the gas cleaning plant 150 of above-mentioned second mode of execution, can also obtain the identical action effect of action effect with the gas cleaning plant 10 of first mode of execution.
And, in the gas purge system of the gas cleaning plant 150 that possesses second mode of execution, also can with the gas purge system of the gas cleaning plant 10 that possesses first mode of execution similarly, be provided with and add gas supply device 100.Thus, can increase the growing amount of oxidation base, promote the combustion reaction of PM, the PM that is caught is decomposed and oxidation more efficiently.
(the 3rd mode of execution)
Charged in the gas cleaning plant 10 that does not possess first mode of execution possesses on sparking electrode 32 and the control of dust internal face with the gas flow path 36 of a side of counter electrode 34 catalyst layer 201,202 with electrode 35 and disposing the gas cleaning plant 200 of the 3rd mode of execution of the present invention, identical with the structure of the gas cleaning plant 10 of first mode of execution, at this, the structure that these are different is described mainly.
Fig. 6 is the figure of section of the gas cleaning plant 200 of schematically illustrated the 3rd mode of execution of the present invention.In addition, to the identical part of structure of the gas cleaning plant 10 of first mode of execution, additional same-sign and omit or simplify the explanation of repetition.
As shown in Figure 6, the gas cleaning plant 200 of the 3rd mode of execution possesses: be arranged at the exoelectrical reaction portion 30 on the stream that purifies object gas EG; Via the discharge power supply 50 that discharges and be connected with this exoelectrical reaction portion 30 with electrical system 51; And the control of dust usefulness power supply 60 that is connected with exoelectrical reaction portion 30 with electrical system 61 via control of dust.
Exoelectrical reaction portion 30 possesses: dielectric 31; Sparking electrode 32; The discharge counter electrode 33 that is provided with across dielectric 31 and this sparking electrode 32 subtends ground; And the control of dust counter electrode 34 that is provided with across stream and the sparking electrode 32 subtends ground of purification object gas EG.
Dielectric 31 is for example flat board or the cylindrical shells that are made of dielectric material, for example is arranged on the stream of the purification object gas EG such as discharge gas that discharge from the engine of automobile.Therefore, in dielectric 31 inside, be imported into the gas flow path 36 that purifies object gas EG and form purification object gas EG.In addition, at the internal face of this gas flow path 36, be provided with to subtend sparking electrode 32 and control of dust counter electrode 34 mutually.And, as shown in Figure 6, be provided with sparking electrode 32 and control of dust with the internal face of the gas flow path 36 of a side of counter electrode 34 and these sparking electrodes 32 and control of dust with near the surface of the internal face the counter electrode 34, be formed with catalyst layer 201,202.
This catalyst layer the 201, the 202nd forms with near the internal face coating catalyst the counter electrode 34 at sparking electrode 32 and control of dust.In addition, catalyst layer 201,202 also can constitute at the laminal porous plastid that sparking electrode 32 and control of dust have carried catalyzer with near the internal face setting the counter electrode 34.As catalyzer, can use following catalyzer: the oxidation catalyst of platinum class; Three-way catalyst; Used the catalyzer more than any one that select metal, particularly Pt from 8 families, 1B family, 2B family, 3B family, 4B family, Fe, Co, Ni, Cu, Zn, Ga, In, the Sn; Utilized with they with from Al, Ti, Zr, Si, select any one more than the composite oxides or the oxide solid solution that use simultaneously; Utilized the catalyzer of the mixture of two or more metallic oxides; The catalyzer etc. that presents the reaction mechanism of non-Langmuir type (non-Langmuir type).
Next, decomposition and the oxidation of PM in the exoelectrical reaction portion 30 are described.
Because the discharge plasma P that is drawn out to gas flow path 36 inside is the discharge plasma P with a kind of polarity in the plus or minus, thus PM most also by the band plus or minus.Therefore, by the bending of the track of charged PM owing to the Coulomb force that is subjected to from the formed electric field of effect that forms the unit by second electric field.Crooked direction is by the direction decision with electric field of electric charge that PM had, so the polarity by electric charge produces to the PM of sparking electrode 32 lateral bending songs with to the PM of control of dust usefulness counter electrode 34 lateral bending songs.
Swarm into the part of the PM among the highdensity discharge plasma P and decompose in the space, near catalyst layer 201 or the control of dust of the residue surface of sparking electrode 32, sparking electrode 32 collides with near counter electrode 34 catalyst layers 202 with surface, the control of dust of counter electrode 34 and is captured.
At this, usually, because catalyzer is at high temperature brought into play its catalyst action, so for example under the situation that effluent air temp is low when the automobile low speed driving etc., catalyzer is not activated, and can't make the PM oxidation efficiently.Generally, catalyst reaction is the reaction of high order that is made of a plurality of reactions that cause on catalyst surface, and some reactions wherein become speed decision reaction and the regulation reaction velocity.
In the present invention, constitute: generate the generation material that becomes its speed decision reaction by the plasma chemical reaction that purifies among the object gas EG, and supply with to catalyst surface from the outside.Thus, the catalyst reaction that the activate energy is low is promoted.So, need not to be heated to the temperature of catalyst action performance, and, decompose efficiently and oxidation thereby make by the PM of catalyst layer 201,202 seizure by making the coexistence of discharge plasma P and catalyzer, finally become carbon monoxide, carbon dioxide etc.In addition, even under the situation that effluent air temp is low when the automobile low speed driving etc., PM is decomposed and oxidation.
In addition, under the situation that effluent air temp is high when galloping etc., because catalyst reaction fully promoted by this burning gas temperature, so can reduce the voltage that applies that first electric field that is used for generating discharge plasma P forms the unit.Thus, can suppress to form the electric power that the unit consumes by first electric field.
In addition, even being caught in control of dust at PM uses under the surface of counter electrode 34, the situation of control of dust with near the surface of the dielectric 31 the counter electrode 34, by making the coexistence of discharge plasma P and catalyzer as mentioned above, the PM that is caught by catalyst layer 202 is decomposed and oxidation efficiently, but, for example also can adopt the structure that Figure 13 put down in writing of TOHKEMY 2005-320895 communique for it is burnt more efficiently.That is, also can constitute: replace being provided with control of dust with counter electrode 34, and sparking electrode is set, the discharge counter electrode is set in a side across dielectric 31 and this sparking electrode subtend at internal face with the dielectric 31 of sparking electrode 32 subtends.
As mentioned above, in the gas cleaning plant 200 of the 3rd mode of execution, by forming catalyst layer 201,202 with near the internal face the counter electrode 34 at sparking electrode 32 and control of dust, and discharge plasma P and catalyzer are coexisted, thereby need not to be heated to the temperature of catalyst action performance, the PM that is caught by catalyst layer 201,202 is decomposed and oxidation efficiently.Thus, can from purify object gas EG, remove PM, can purify purifying object gas EG.
In addition, in the above-described embodiment, show at sparking electrode 32 and control of dust and be provided with an example of catalyst layer 201,202, but also can with the surface of counter electrode 34 catalyst layer 201,202 be set at sparking electrode 32 and control of dust with near the surface of the internal face the counter electrode 34.Thus, also obtain the action effect same with above-mentioned action effect.
In addition, under the situation that catalyst layer 201,202 is constituted with porous layer, surface area increases, and can catch more PM and removes.And, PM to sparking electrode 32, control of dust with near the internal face collision of counter electrode 34, these electrodes and be captured, but by making these faces become porous layer, the knock-on in the time of can preventing the PM collision and improve catching rate.
In addition, in the gas cleaning plant 200 of mode of execution 3, the charged electrode 35 of using that possesses in the gas cleaning plant 10 of first mode of execution can be set also.Thus, the action effect in the gas cleaning plant 200 of above-mentioned the 3rd mode of execution, can also obtain the identical action effect of action effect with the gas cleaning plant 10 of first mode of execution.
And, in the gas purge system of the gas cleaning plant 200 that possesses the 3rd mode of execution, also can with the gas purge system of the gas cleaning plant 10 that possesses first mode of execution similarly, be provided with and add gas supply device 100.Thus, can increase the growing amount of oxidation base, promote the combustion reaction of PM, the PM that is caught is decomposed and oxidation more efficiently.
(the 4th mode of execution)
At this, illustrate the gas purge system of gas cleaning plant 10,150,200 arranged in series of the present invention and the gas purge system of configuration in parallel.
The block diagram of the gas purge system of Fig. 7 is schematically illustrated arranged in series two gas cleaning plant 10a, 10b of the present invention.Fig. 8 is the block diagram that the gas purge system of two gas cleaning plant 10a, 10b of the present invention has been disposed in schematically illustrated parallel connection.In addition, gas cleaning plant 10a, 10b also can be made of in the gas cleaning plant 10,150,200 in above-mentioned first～the 3rd mode of execution any one as used herein.
In gas purge system shown in Figure 7, the discharge gas of discharging from the engine 20 of automobile etc. purify object gas EG via exhaust flow path 21, at first are directed among the gas cleaning plant 10a of upstream side of arranged in series.Next, the purification object gas EG that discharges from the gas cleaning plant 10a of upstream side is directed among the gas cleaning plant 10b in downstream side, is deflated afterwards.
In gas purge system shown in Figure 8, the discharge gas of discharging from the engine 20 of automobile etc. purify object gas EG by exhaust flow path 21, and then by among bypass vent stream 21a, the 21b of exhaust flow path 21 branches any one, be directed among gas cleaning plant 10a or the gas cleaning plant 10b, be deflated afterwards.In addition, on the branching portion of exhaust flow path 21, be equipped with the switching valve 250 that is used for the switching of purification object gas EG stream is flow into gas cleaning plant 10a or gas cleaning plant 10b.
In the above-mentioned gas cleaning system, for example, can distinguish first electric field set respectively in each gas cleaning plant and form unit and second electric field and form the operating condition of unit and turn round.In addition, the gas cleaning plant of serial or parallel connection configuration is not limited to two, also can dispose more than three.In addition, under each gas cleaning plant 10a, 10b to parallel connection configuration circulate the situation of branch's gas simultaneously, also can not possess switching valve 250.Gas cleaning plant 10a, the 10b of serial or parallel connection configuration for example also can constitute the assembly (unit) that is made of stacked a plurality of units gas cleaning plant.Also can constitute the further serial or parallel connection of these assemblies.In addition, also can control simultaneously, but can realize handling more efficiently by control is next independently respectively for these assemblies.In addition, the holdup time of the discharge gas by each gas cleaning plant 10a, 10b is preferably set to the scope of 100 μ sec (μ second)～1sec (second).
(the 5th mode of execution)
Fig. 9 is the block diagram of gas purge system of the method for gas purification of the schematically illustrated gas cleaning plant 10 that is used for illustrating the 5th mode of execution of the present invention.Figure 10 is the figure of section of the gas cleaning plant 10 of schematically illustrated the 5th mode of execution of the present invention.In addition, to the identical part of structure of the gas cleaning plant 10 of above-mentioned mode of execution, additional same-sign.
As shown in Figure 9, gas cleaning plant 10 for example is arranged at from the engine 20 of automobile in the exhaust flow path 21 that the purification object gas EG such as discharge gas that discharge are passed through.In addition, possess first detection device 22 at the upstream side of the gas cleaning plant 10 of exhaust flow path 21,22 pairs of information relevant with the combustion disposal of particle-like substance (PM:Particulate Matter) of this first detection device detect.In addition, possess second detection device 23 in the downstream side of the gas cleaning plant 10 of exhaust flow path 21,23 pairs of information relevant with the combustion disposal of PM of this second detection device detect.In addition, as the device that the information relevant with the combustion disposal of PM is detected, possess in above-mentioned first detection device 22, second detection device 23 any one gets final product at least.In addition, gas cleaning plant 10, first detection device 22, second detection device 23 are electrically connected with control device 24.In addition, in Fig. 9, omitted the connecting line of each device with control device 24 for making drawings clear.
At this, in the information relevant, comprise with the combustion disposal of PM in following at least any one: for example, gas componant (CO, NOx, HC, the CO of the purification object gas EG in the inlet of gas cleaning plant 10, inside or outlet port 2, O 2Deng) or its variation, the inlet of gas cleaning plant 10, inner, the pressure of the purification object gas EG in outlet port, the pressure loss in the above-mentioned gas purification plant 10, the inlet of gas cleaning plant 10, temperature or its variation of the purification object gas EG in inside or outlet port, first electric field described later forms the voltage that applies in unit or second electric field formation unit, electric current, apply the relevant information of state of ratio (applying voltage/current) etc. with the gas cleaning plant 10 of voltage and electric current; The aperture of the timing of the emitted dose of the pressure of engine speed, moment of torsion, air fuel ratio, suction air or flow, fuel or consumption, injection, the pressure of fuel, engine internal pressure, Aspirating valves, outlet valve or EGR valve, the temperature of engine, the information relevant such as temperature of cooling water with the state of engine.
First detection device 22 and second detection device 23 for example are made of the pressure metering device that the pressure to the purification object gas EG that flows in exhaust flow path 21 carries out instrumentation.According to the instrumentation result in this pressure metering device, can obtain the pressure loss value in the gas cleaning plant 10.In addition, first detection device 22 and second detection device 23 for example comprise: the gas composition analysis device that the gas componant of the purification object gas EG that discharges from gas cleaning plant 10 is analyzed; The temperature of the purification object gas EG of discharge from gas cleaning plant 10 is carried out the temperature metering device of instrumentation; And form voltmeter or the galvanometer that discharge that unit or second electric field form the unit is carried out instrumentation with the output end voltage or the electric current of power supply to driving first electric field described later.In addition, first detection device 22 and second detection device 23 by in above-mentioned each device any one constitutes and gets final product at least.
In addition, in the gas composition analysis device, the concentration of the carbon dioxide among the purification object gas EG, hydrocarbon, oxygen etc. is carried out instrumentation.In addition, above-mentioned voltmeter or galvanometer are electrically connected with power supply 60 with the control of dust that power supply 50, second electric field form the unit with the discharge that first electric field forms the unit.
Control device 24 for example is made of computer that the program that action of being used for gas cleaning plant 10 etc. controls has been installed etc., possesses input device, information processor, storage device, display unit and the input/output interface etc. of regulation.
At this, input device is made of input units such as indicator equipment such as keyboard, mouses, accepts literal input etc. and supplies with and give information processor.Information processor has: the arithmetic elements such as CPU of carrying out inner various calculation process; By the nonvolatile memories such as ROM that store system information etc., can upgrade the storage unit that the semiconductor memories such as RAM of ground stored information constitute; And send to the exercises in the inside, with outside information and to receive the control unit controlled etc., information processor is used for core that the action of gas cleaning plant 10 etc. is controlled according to carrying out various processing from the content of the input of input device, the program of being installed etc., bearing.Storage device continues to keep these information as required by the file of the program of being installed, the storage unit such as hard disk that various data file information such as (for example managing the file of the database of various data with database structure) is preserved are constituted.Display unit is made of display units such as liquid crystal display, CRT monitor, printers, and the information of stipulating under the control of information processor shows.Input/output interface is born the input output of information, for example import from relevant information such as the combustion disposal with PM of each instrumentation equipment etc., the information relevant with the operating condition of engine, the discharge that output is used for control gaseous purification plant 10 is with power supply 50 and the control of dust signal with power supply 60 etc.
As shown in figure 10, gas cleaning plant 10 possesses: be arranged at the exoelectrical reaction portion 30 on the stream that purifies object gas EG; Via the discharge power supply 50 that discharges and be connected with this exoelectrical reaction portion 30 with electrical system 51; And the control of dust usefulness power supply 60 that is connected with exoelectrical reaction portion 30 with electrical system 61 via control of dust.
Exoelectrical reaction portion 30 possesses: dielectric 31; Sparking electrode 32; The discharge counter electrode 33 that is provided with across dielectric 31 and this sparking electrode 32 subtends ground; And the control of dust counter electrode 34 that is provided with across stream and the sparking electrode 32 subtends ground of purification object gas EG.
Dielectric 31 is for example flat board or the cylindrical shells that are made of dielectric material, for example is arranged on the stream of the purification object gas EG such as discharge gas that discharge from the engine of automobile.Therefore, in dielectric 31 inside, be imported into the gas flow path 36 that purifies object gas EG and form purification object gas EG.As dielectric material, for example can use resins such as special teflon (Teflon) (TM trade mark), epoxy, KAPTON, perhaps potteries such as glass, aluminium oxide, aluminium nitride at this.In addition, situation about handling from the discharge gas of the engine of reality is being needed under the situation of the processing under the high temperature like that, it is effective using pottery, when considering the temperature characteristic of dielectric material, from the viewpoint that reduces power consumption use the little material of dielectric loss under the high temperature for example aluminium oxide etc. be effective.Particularly, the dielectric loss under 300 ℃ by measuring under 1kHz is the material of tan δ＜0.1, can access good purifying property.If the relative dielectric constant of dielectric 31 is made as 0.1～1000, the thickness of dielectric 31 is made as about 0.01mm～10mm, then can easily trigger creeping discharge described later.
At the internal face of this gas flow path 36, be provided with to subtend sparking electrode 32 and control of dust counter electrode 34 mutually.Sparking electrode 32 for example constitute a plurality of thin tabular electrodes with almost parallel ground, the interval configuration of regulation and one distolateral respectively with the shape of the comb shape that is electrically connected with electrical system 51 of discharging.And, so that each tabular electrode becomes the form of approximate vertical with respect to the main flow direction of the purification object gas EG that flows through gas flow path 36, dispose sparking electrode 32.This sparking electrode 32 is by object gas EG has corrosion resistance, stable on heating conductive material constitutes, and for example uses stainless steel etc. for purifying.For example also can form this sparking electrode 32 in the direct printing of the internal face of gas flow path 36.In addition, control of dust has writing board shape with counter electrode 34, with sparking electrode 32 similarly, for example object gas EG has corrosion resistance, stable on heating conductive material constitutes for purifying by stainless steel etc.This control of dust with counter electrode 34 also with sparking electrode 32 similarly, for example also can with the directly printing and forming of the internal face of the gas flow path 36 of the position subtend that disposes sparking electrode 32.In addition, have corrosion resistance, heat resistance with counter electrode 34 in order to make sparking electrode 32, control of dust, on the surface of metal film with have corrosion resistance, stable on heating coating coats also is effective.For example, by stainless steel, wolfram steel electrode being carried out nickel plating, the alumina-coated of 1 μ m～100 μ m thickness, the corrosion in the real gas environment such as discharge gas that can suppress for example from the engine of automobile, to discharge.In addition, necessarily the becoming vertically towards need not of the electrode of comb shape with respect to main flow direction, also can be made as with respect to main flow becomes direction parallel or that tilt.
And, the discharge of exoelectrical reaction portion 30 with counter electrode 33 across dielectric 31, in other words clip dielectric 31 and the configuration of sparking electrode 32 subtends.Discharge is for example formed by thin flat conductive material with counter electrode 33.Discharge with counter electrode 33 also can with sparking electrode 32 similarly, with the directly printing and being provided with of the outer wall of the gas flow path 36 of the dielectric 31 of sparking electrode 32 subtends.
In addition, sparking electrode 32, discharge are not limited to above-mentioned shape with counter electrode 33 and control of dust with the shape of counter electrode 34 but arbitrarily, but the shape of sparking electrode 32 for example is preferably wire, point-like, slit-shaped or mesh-shape except above-mentioned comb shape.Become these shapes by the shape that makes sparking electrode 32, it is close that near the line of electric force the sparking electrode 32 becomes, and can easily generate discharge plasma, so be resultful.And, can catch a lot of particle-like substances harmful matters such as (PM:Particulate Matter), can efficiently harmful matter, particularly PM be burnt and remove.In addition, control of dust also is not limited to planar with the shape of counter electrode 34, also can similarly be made as slit-shaped or mesh-shape etc. with sparking electrode 32.
In addition, discharge is connected with the sparking electrode 32 of exoelectrical reaction portion 30 with electrical system 51 via discharge with a utmost point of power supply 50, and another utmost point is connected with counter electrode 33 with discharge with electrical system 51 via discharge.Discharge for example is made of the power supply of primary side and primary side with power supply 50.As the power supply of primary side, use the ac power supply of AC 100V and Φ 50Hz or Φ 60Hz, perhaps the DC electrical source of DC12V or DC 24V.In addition, the output voltage of the power supply of primary side for example be made as have pulse type (positive polarity, negative polarity, positive negative bipolar), exchange the output voltage of shape (sinusoidal wave, intermittent sine wave) waveform.In addition, the power supply of primary side and the power supply of primary side can also be made as integrative-structure, but are used as primary side by the power supplys such as battery that will be equipped in the automobile usually, thereby need not newly to be provided with the power supply of primary side, have realized the miniaturization of device.And the power supply of primary side can constitute: possess transformer, make signal about several V～hundreds of V that utilizes shapings such as inverter boost to the output voltage of several kV～tens kV by transformer.In order to shorten the distance of high voltage wiring as far as possible, preferably power supply and the exoelectrical reaction portion 30 with primary side closely is provided with.In addition, the situation etc. that is in high temperature in exoelectrical reaction portion 30 down, in order to prevent electronic circuit such as inverter because heat is damaged, preferred employing, only closely is provided with transformer and exoelectrical reaction portion 30 the transformer portion independent structures from the power supply of primary side.
So, utilization is discharged with 50 pairs of sparking electrodes 32 of power supply and is discharged with the voltage that applies between the counter electrode 33 about for example a few kV to tens kV, thereby discharge when in gas flow path 36, forming electric field, at the gas flow path 36 inner plasma discharging P that generate.At this moment, being situated between between sparking electrode 32 and discharge are with counter electrode 33 has dielectric 31, and dielectric 31 is provided with contiguously with sparking electrode 32, so the discharge in the gas flow path 36 becomes along the creeping discharge of dielectric 31 formation.
Form first electric field with power supplys 50, sparking electrode 32 and discharge with counter electrode 33 with electrical system 51 interconnective discharges via discharge and form the unit by above-mentioned.This first electric field formation unit makes the PM that is contained among the purification object gas EG charged by the effect of discharge plasma, and bears the combustion disposal that makes PM decomposition and oxidation.
On the other hand, control of dust is connected with counter electrode 34 with the control of dust of exoelectrical reaction portion 30 with electrical system 61 via control of dust with a utmost point of power supply 60, and another utmost point is connected with the sparking electrode 32 of exoelectrical reaction portion 30 with electrical system 61 via control of dust.Control of dust for example is made of the power supply of primary side and primary side with power supply 60.As the power supply of primary side, use the ac power supply of AC 100V and Φ 50Hz or Φ 60Hz, perhaps the DC electrical source of DC 12V or DC 24V.In addition, the output voltage of the power supply of primary side for example is made as the output voltage of direct current shape (positive polarity, negative polarity, positive negative bipolar), pulse type (positive polarity, negative polarity, positive negative bipolar), rectified waveform (single ripple rectified waveform, double wave rectified waveform).
So, constitute by from control of dust with 60 pairs of sparking electrodes 32 of power supply and control of dust with the voltage that applies between the counter electrode 34 about for example several kV, thereby can in gas flow path 36, form electric field.Form second electric field with power supplys 60, sparking electrode 32 and control of dust with counter electrode 34 with electrical system 61 interconnective controls of dust via control of dust and form the unit by above-mentioned.This second electric field form unit bear by the electrostatic precipitation function catch charged PM, and be formed for drawing the effect of electric field that the control of dust of discharge plasma P is used to gas flow path 36 sides.At this, improve to sparking electrode 32 and control of dust with counter electrode 34 between (distance D) apply voltage V the time, discharging between generation space, finally causes producing spark.When becoming such state, the conductivity in the gas flow path rises, and is drawn out to unipolarity movement of electric charges degree in the gas flow path and uprises and absorbed with counter electrode 34 by sparking electrode 32 or control of dust, thereby can't make PM charged efficiently.For fear of such state, preferably use the voltage V that is applied in the scope of between sparking electrode 32 and control of dust are with counter electrode 34, discharging unautogenously, for example preferably will be made as 1～30kV/cm with the average field intensity of V/D regulation.
In addition, the structure of gas cleaning plant 10 only is an example, and is not limited to said structure.
Next, the effect of gas cleaning plant 10 is described.
At first, the purification object gas EG such as discharge gas that discharge from the engine of automobile etc. flow into sparking electrode 32 and control of dust with between the counter electrode 34.At this, use between the counter electrode 33 with 50 pairs of sparking electrodes 32 of power supply and control of dust from discharge, apply the voltage of pulse type (positive polarity, negative polarity, positive negative bipolar) or interchange shape (sinusoidal wave, intermittent sine wave).Thus, sparking electrode 32 and discharge with between the counter electrode 33, particularly sparking electrode 32 near, the concentrated area forms electric field and causes along the creeping discharge of dielectric 31, follows creeping discharge and produces discharge plasma P.
At this, discharge is pulse type (positive polarity, negative polarity, positive negative bipolar) or the output voltage that exchanges shape (sinusoidal wave, intermittent sine wave) with the output voltage of the primary side of power supply 50, even the dielectric 31 of dielectricity is arranged so be situated between, yet can discharge be stopped or discharging to shift to be Arc Discharge, so produce stable discharge plasma P equally in the surface of dielectric 31 savings surface charge.
On the other hand, from control of dust with 60 pairs of sparking electrodes 32 of power supply and control of dust with the voltage that applies direct current shape (positive polarity, negative polarity, positive negative bipolar), pulse type (positive polarity, negative polarity, positive negative bipolar) or rectified waveform (single ripple rectified waveform, double wave rectified waveform) between the counter electrode 34.That is, polarity can not change such voltage and is applied to sparking electrode 32 and control of dust with between the counter electrode 34 from control of dust with power supply 60 on the time, at sparking electrode 32 and control of dust with the same electric field of formation between the counter electrode 34.
Its result, by being formed at the effect of electric field between sparking electrode 32 and the control of dust usefulness counter electrode 34, discharge plasma P is drawn out to gas flow path 36 inside from sparking electrode 32 in large quantities.So, the PM that contains among the purification object gas EG that in gas flow path 36, flows since with by the collision of electronics that discharge plasma P generated that is drawn out to gas flow path 36 inside in large quantities or ion by charged.In addition, as mentioned above, discharge plasma P is drawn out to gas flow path 36 inside from sparking electrode 32 in large quantities, thereby spreads all over the sectional area expansion of gas flow path 36, so the probability that contacts with the purification object gas EG that flows in gas flow path 36 improves.Thus, purifying the PM that is contained among the object gas EG is improved by charged ratio.
In addition, as mentioned above, by the output voltage characteristic of control of dust with power supply 60, being formed at sparking electrode 32 and control of dust and using the direction of the electric field between the counter electrode 34 can the time not go up variation, is the discharge plasma P with a kind of polarity in the plus or minus so be drawn out to the discharge plasma P of gas flow path 36 inside.Thus, PM's most also is with plus or minus.Therefore, by the track of charged PM because the Coulomb force that the electric field that forms from the effect that forms the unit by second electric field is subjected to and bending.Crooked direction is by the direction decision with electric field of electric charge that PM had, so the polarity by electric charge produces to the PM of sparking electrode 32 lateral bending songs and the PM that uses counter electrode 34 lateral bending songs to control of dust.
Thus, also add the electric force of discharge plasma P on by the electrostatic precipitation function that acts on the electric field that sparking electrode 32 and control of dust form between with counter electrode 34 of control of dust with power supply 60, charged a kind of PM attracted to sparking electrode 32 sides in gas flow path 36, thereby is caught in the surface of sparking electrode 32 or near the surface of the dielectric 31 the sparking electrode 32.In addition, the charged polarity another kind of PM different with a kind of PM is caught in the surface of control of dust usefulness counter electrode 34 or near the surface of the dielectric 31 the control of dust usefulness counter electrode 34.That is, on same direction, be subjected to electric force by the effect of electric field and unipolar discharge plasma P, be caught in sparking electrode 32 sides or control of dust counter electrode 34 sides by PM with the plus or minus electricity.
As mentioned above, PM passes through discharge plasma P by charged, have sufficient carried charge, be subjected to electric force, be caught in sparking electrode 32 sides or control of dust counter electrode 34 sides efficiently by acting on the same direction of electric field and unipolar discharge plasma P.Like this, because the effect of drawing of discharge plasma P improves the effect of charged efficient of the PM in the gas flow path 36, also have provides electric force and the effect of catching with counter electrode 34 sides at sparking electrode 32 sides or control of dust efficiently to charged PM to the electric field that forms with the effect of power supply 60 by control of dust except having.At this, improve to sparking electrode 32 and control of dust with counter electrode 34 between (distance D) apply voltage V the time, discharging between generation space, finally causes producing spark.When becoming such state, the conductivity in the gas flow path rises, and is drawn out to unipolarity movement of electric charges degree in the gas flow path and uprises and attracted with counter electrode 34 by sparking electrode 32 or control of dust, thereby can't make PM charged efficiently.For fear of such state, preferably use the voltage V that is applied in the scope of between sparking electrode 32 and control of dust are with counter electrode 34, discharging unautogenously, for example preferably will be made as 1～30kV/cm with the average field intensity of V/D regulation.
In addition, in the gas flow path 36 in exoelectrical reaction portion 30, the high-energy electron that is generated by discharge plasma P collides with purifying object gas EG, thereby generates O, OH, O 3, O 2-Deng oxidation base or NO 2Deng.Oxidation base further reacts with the hydrocarbon that purifies among the object gas EG, produces other active hydrocarbon molecules.In addition, NO 2Produce combustion reaction with PM, PM is decomposed and oxidation.
Swarm into PM in this discharge plasma P and need not to implement heating and wait processing, and interim ground combustion reaction and being decomposed and oxidation finally becomes carbon monoxide, carbon dioxide etc.At this, swarm into the part of the PM among the highdensity discharge plasma P and decompose in the space, near the surface of the dielectric 31 of the residue surface of sparking electrode 32, sparking electrode 32 or control of dust are captured with near the surface collision of the dielectric 31 of counter electrode 34 with the surface of counter electrode 34, control of dust.Be caught in each lip-deep PM with the reacting field of oxidation base in be detained for a long time, thereby need not to implement heating and wait processing, and interim real estate is estranged separates and combustion reaction such as oxidation by the effect of oxidation base in during this period, finally becomes carbon monoxide, carbon dioxide etc.Therefore, always keep peace and quiet in the exoelectrical reaction portion 30, can prevent the phenomenon that discharge plasma P reduces, the electrostatic precipitation function reduces owing to be subjected to their pollution.
The purification object gas EG that utilizes exoelectrical reaction portion 30 to remove PM like this is discharged to the outside of exoelectrical reaction portion 30.
Next, method for gas purification based on the gas cleaning plant 10 of the information relevant with the combustion disposal of PM is described.
The combustion disposal speed of the PM that is captured changes according to the constituent of the gas componant that purifies object gas EG, temperature, PM etc.Oxygen concentration in purifying object gas EG or purify the temperature of object gas EG when low, perhaps the ratio of the charcoal in being contained in PM for a long time, combustion disposal speed reduces.When combustion disposal speed is slow, if caught a large amount of PM, then because the capture velocity of PM is higher than combustion disposal speed, so PM with the surface of counter electrode 34, near these electrodes the accumulations such as surface of dielectric 31, causes the instability of coronal discharge, the rising of the pressure loss in the gas cleaning plant 10 at the sparking electrode 32 of gas cleaning plant 10, control of dust.At this, the combustion disposal speed (g/h) of PM is meant, the removed PM amount of time per unit.At this, the removal of PM is meant, makes PM decomposition and oxidation and becomes carbon dioxide, carbon monoxide, thereby can not exist as PM.
At this, the amount of the PM that will in gas cleaning plant 10, flow into be made as Qi (g/h), with the capturing efficiency of the PM in the gas cleaning plant 10 be made as η, when combustion disposal speed is made as Qb (g/h), by controlling to satisfy following formula (1), PM is piled up, and can stably purify purifying object gas EG.
Qb＞η Qi formula (1)
Wherein, " the η Qi " on the right in the formula (1) means that the PM that time per unit is captured measures, is the capture velocity of PM.In addition, in order to prevent the accumulation of PM, preferably the combustion disposal speed of PM is faster than the capture velocity of PM as satisfying formula (1), but under the combustion disposal speed of PM and situation that the capture velocity of PM equates, the purification that also can reach stable purification object gas EG.In addition, need not to make the relation of formula (1) always to set up, for example during till make regular check on, long-time accumulative total or averaged result such as between riding time of one day car etc., test model on-stream period, if its result's formula (1) is set up, then can carry out stable purification.For example, also can be during certain work under the opposite such condition of the sign of inequality of internal type (1), PM is piled up, and set formula (1) in the moment that finishes during this period and set up such operating condition.Thus, can effectively utilize the ignition heat of the PM that is piled up.
In the method for gas purification of gas cleaning plant 10 of the present invention, according to the state of the combustion disposal of the PM that is piled up, promptly utilize first electric field to form the state of the combustion disposal of carrying out the unit, control first electric field and form the operating state that unit or second electric field form the unit.At this, in fact, owing to be difficult to directly measure the combustion disposal speed of PM, so the conduct of information that will be relevant with the combustion disposal of PM is used to estimate the index of the stacking states of PM.That is, will possess as database with the combustion disposal speed of the related PM of the information relevant shown below, by measuring the information relevant with the combustion disposal of PM can obtain PM from database combustion disposal speed with combustion disposal PM.Wherein, database is stored in the storage unit such as hard disk.As mentioned above, in the information relevant, comprise with the combustion disposal of PM in following at least any one: for example, gas componant (CO, NOx, HC, the CO of the purification object gas EG in the inlet of gas cleaning plant 10, inside or outlet port 2, O 2Deng) or its variation, the inlet of gas cleaning plant 10, inner, the pressure of the purification object gas EG in outlet port, the pressure loss in the above-mentioned gas purification plant 10, the inlet of gas cleaning plant 10, temperature or its variation of the purification object gas EG in inside or outlet port, first electric field described later forms the voltage that applies in unit or second electric field formation unit, electric current, apply the relevant information of state of ratio (applying voltage/current) etc. with the gas cleaning plant 10 of voltage and electric current; The aperture of the timing of the emitted dose of the pressure of engine speed, moment of torsion, air fuel ratio, suction air or flow, fuel or consumption, injection, the pressure of fuel, engine internal pressure, Aspirating valves, outlet valve or EGR valve, the temperature of engine, the information relevant such as temperature of cooling water with the state of engine.Judge according to these information reference data storehouses relevant by control device 24, thereby control the operating state that first electric field forms unit or second electric field formation unit with the combustion disposal of PM.In addition, under the situation of using the information relevant with the state of gas cleaning plant 10, carry out Passive Control that the variation of the state of the gas cleaning plant 10 that causes mainly due to the discharge gas of discharging from engine is obtained, under the situation of using the information relevant, carry out the ACTIVE CONTROL of predicting mainly due to the variation of the state of the gas cleaning plant that causes from the discharge gas of engine discharge with the state of engine.In addition, also can make up these controls.
Then, the control device 24 inputs information relevant with the combustion disposal of PM is carried out such judgement as follows according to this information, controls the operating state that first electric field forms unit or second electric field formation unit.In addition, only a example as follows for judging, and be not limited thereto.
Change in gas componant under the situation of concentration of (for example carbon dioxide, hydrocarbon) based on the purification object gas EG in the inlet of gas cleaning plant 10 and outlet port, when the change in concentration of carbon dioxide, hydrocarbon is that specified value is when above, the decomposition, the oxidation that are judged to be above-mentioned PM are promoted, are judged to be PM and do not pile up.In this case, the control device 24 combustion disposal speed that is judged to be PM is faster or equate than the capture velocity of PM.On the other hand, when the change in concentration of carbon dioxide, hydrocarbon is lower than under the situation of specified value, be judged to be PM and pile up.In this case, it is slower than the capture velocity of PM that control device 24 is judged to be the combustion disposal speed of PM.
In addition, under situation, during the pressure loss more than having specified value, be judged to be PM and pile up and gas flow path 36 is narrowed down based on the pressure loss in the gas cleaning plant 10.In this case, it is slower than the capture velocity of PM that control device 24 is judged to be the combustion disposal speed of PM.On the other hand, when the pressure loss during less than specified value, it is faster than the capture velocity of PM that control device 24 is judged to be the combustion disposal speed of PM.
In addition, under the situation based on the temperature variation of the purification object gas EG in the outlet port of gas cleaning plant 10, when the temperature variation that purifies object gas EG is specified value when above, it is faster than the capture velocity of PM that control device 24 is judged to be the combustion disposal speed of PM.On the other hand, when the temperature that purifies object gas EG during less than specified value, it is slower than the capture velocity of PM that control device 24 is judged to be the combustion disposal speed of PM.
In addition, forming based on first electric field under the situation of the ratio that applies voltage and electric current (applying voltage/current) in the unit, when this ratio is specified value when above, it is faster than the capture velocity of PM that control device 24 is judged to be the combustion disposal speed of PM.On the other hand, when rate value during less than specified value, it is slower than the capture velocity of PM that control device 24 is judged to be the combustion disposal speed of PM.
In addition, forming based on second electric field under the situation of the ratio that applies voltage and electric current (applying voltage/current) in the unit, when this ratio is specified value when above, it is faster than the capture velocity of PM that control device 24 is judged to be the combustion disposal speed of PM.On the other hand, when rate value during less than specified value, it is slower than the capture velocity of PM that control device 24 is judged to be the combustion disposal speed of PM.
Below, illustrate that the situation that does not satisfy formula (1) is that the combustion disposal speed of PM is the example of the combustion disposal speed of PM than the method for gas purification under the fast situation of the capture velocity of PM than slow situation of the capture velocity of PM and the situation that satisfies formula (1).
(under the combustion disposal speed of the PM situation slower) than the capture velocity of PM
Control device 24 is being judged to be according to the information relevant with the combustion disposal of PM under the combustion disposal speed of the PM situation slower than the capture velocity of PM, the discharge that forms the unit to first electric field is used for signal that the past direction that combustion disposal is speeded up such as voltage, frequency, waveform is adjusted with power supply 50 outputs, simultaneously, the control of dust that forms the unit to second electric field is used for signal that voltage, frequency, waveform etc. are adjusted toward the direction that makes the collection effiiency reduction with power supply 60 outputs.At this, for example,, can accelerate combustion disposal speed by increasing the frequency of discharge with power supply 50.In addition, for example,, can reduce collection effiiency by reducing the voltage of control of dust with power supply 60.
By carrying out this control, can satisfy the relation of following formula (1), promptly, make the combustion disposal speed of PM faster than the capture velocity of PM.
(the combustion disposal speed of PM than the fast situation of the capture velocity of PM under)
Control device 24 the combustion disposal speed that is judged to be PM according to the information relevant with the combustion disposal of PM than the fast situation of the capture velocity of PM under, the discharge that forms the unit to first electric field is used for signal that voltage, frequency, waveform etc. are adjusted toward the direction that makes the reduction of combustion disposal speed with power supply 50 outputs, simultaneously, the control of dust that forms the unit to second electric field is used for signal that voltage, frequency, waveform etc. are adjusted toward the direction that makes the collection effiiency raising with power supply 60 outputs.At this, for example,, can reduce combustion disposal speed by reducing the frequency of discharge with power supply 50.In addition, for example,, can improve collection effiiency by improving the voltage of control of dust with power supply 60.
Like this, object lesson as the combustion disposal speed of PM when faster than the capture velocity of PM, can enumerate the high situation of temperature that purifies object gas EG, perhaps the temperature of sedimentation layer rises because of the continuous burning of the PM that piled up, thus the situation that sedimentation layer itself takes fire etc.In these cases, make electric power become " 0 ", also can continue the burning of PM even cut off first electric field to form the voltage of unit.
As mentioned above, in the method for gas purification of the gas cleaning plant 10 of the 5th mode of execution, can be according to the information relevant with the combustion disposal of PM, control first electric field the most rightly and form unit, second electric field and form voltage in the unit, frequency, waveform etc.Thus, the PM that is caught is burnt efficiently, and can from purify object gas EG, remove PM and purify purifying object gas EG.And.Even adding the purification that also can carry out stable purification object gas EG under the violent condition of change.In the method for gas purification of the gas cleaning plant 10 of above-mentioned the 5th mode of execution, according to the information relevant with the combustion disposal of PM, having controlled first electric field the most rightly forms unit, second electric field and forms voltage in the unit, frequency, waveform etc., but the combustion disposal speed that replaces PM, and use in the information relevant any one with the trap state of the electriferous state of the state of drawing of electric charge, PM, PM, also can carry out same control.Thus, the PM that is caught is burnt efficiently, and can from purify object gas EG, remove PM and purify purifying object gas EG.And.Even adding the purification that also can carry out stable purification object gas EG under the violent condition of change.The information that these are relevant with the trap state of the electriferous state of the state of drawing of electric charge, PM, PM is owing to similarly be difficult to direct measurement with the combustion disposal speed of PM, so will be related with information shown below relevant with the trap state of the electriferous state of the state of drawing electric charge, PM, PM information possesses as database, can obtain the combustion disposal speed of PM from database by measuring following information.In addition, database is stored in the storage unit such as hard disk.
In addition, information shown below is identical with the information relevant with the combustion disposal of PM.That is, in this information, comprise in following at least any one: for example, gas componant (CO, NOx, HC, the CO of the purification object gas EG in the inlet of gas cleaning plant 10, inside or outlet port 2, O 2Deng) or its variation, the inlet of gas cleaning plant 10, inner, the pressure of the purification object gas EG in outlet port, the pressure loss in the above-mentioned gas purification plant 10, the inlet of gas cleaning plant 10, temperature or its variation of the purification object gas EG in inside or outlet port, first electric field described later forms the voltage that applies in unit or second electric field formation unit, electric current, apply the relevant information of state of ratio (applying voltage/current) etc. with the gas cleaning plant 10 of voltage and electric current; The aperture of the timing of the emitted dose of the pressure of engine speed, moment of torsion, air fuel ratio, suction air or flow, fuel or consumption, injection, the pressure of fuel, engine internal pressure, Aspirating valves, outlet valve or EGR valve, the temperature of engine, the information relevant such as temperature of cooling water with the state of engine.Judge according to these above-mentioned information reference data storehouses by control device 24, thereby control the operating state that first electric field forms unit or second electric field formation unit.
In addition, the method for gas purification of the gas cleaning plant 10 of the 5th mode of execution of the present invention is not limited to the above-mentioned gas purification method, for example, also can form the upstream side that unit and second electric field form the unit and also possess the gas feed unit of interpolation and gas composition analysis device at first electric field, this interpolation gas feed unit is supplied with the interpolation gas that can generate oxidation base, and this gas composition analysis device detects the gas componant that purifies in the object gas.As the gas composition analysis device, for example, enumerate the oxygen concentration detecting apparatus that oxygen concentration is detected.
Figure 11 is the schematically illustrated block diagram that possesses the gas purge system of adding gas supply device 25 and oxygen concentration detecting apparatus 26.
As shown in figure 11, in exhaust flow path 21, be arranged at oxygen concentration detecting apparatus 26 by the position of adding gas supply device 25 interpolation gases and gather the upstream side of the position that purifies object gas EG.Thus, control device 24 can from oxygen concentration detecting apparatus 26 input with added the purification object gas EG behind the gas the relevant information of oxygen concentration, according to this instrumentation value, the flow from the interpolation gas of interpolation gas supply device 25 supplies is controlled.
For example, control device 24 is under the situation that is judged to be the oxygen concentration reduction, to adding the signal that gas supply device 25 outputs are used to increase the adding quantity that adds gas, add gas supply device 25 according to this signal, for example, by opening valve or making method such as pump work, increase the adding quantity that adds gas.The combustion disposal speed of PM is subjected to O, the O by discharge plasma P generation 3, O 2-Influence Deng the concentration of oxidation base etc. increases by the oxygen concentration that purifies among the object gas EG, and the concentration of oxidation base uprises, thereby can accelerate combustion disposal speed.
In addition, also can be arranged at the downstream side that oxygen concentration detecting apparatus 26 is gathered the position that purifies object gas EG by the position of adding gas supply device 25 interpolation gases.Thus, control device 24 according to by oxygen concentration detecting apparatus 26 instrumentations, add the oxygen concentration among the purification object gas EG before the gas, to controlling from the flow that adds the interpolation gas that gas supply device 25 supplies with.
From the interpolation gas that adds gas supply device 25 supplies is to generate above-mentioned O, OH, O 3, O 2-Deng oxidation base or NO 2Gas such as for example oxygen, water vapour etc.Link by pipe arrangement between this interpolation gas supply device 25 and the exhaust flow path 21, be added and be mixed among the purification object gas EG that exhaust flow path 21, flows, flow in the exoelectrical reaction portion 30 from the interpolation gas that adds gas supply device 25 discharges.
Like this, add gas supply device 25 and oxygen concentration detecting apparatus 26, the oxygen concentration that purifies among the object gas EG can be set in the scope of regulation by being provided with.Thus, can increase the growing amount of oxidation base, promote the combustion reaction of PM.In addition, can make the surface that is caught in sparking electrode 32, near the surface or the control of dust of the dielectric 31 the sparking electrode 32 use near the PM on the surface of the dielectric 31 the counter electrode 34 to decompose more efficiently and oxidation, can purify purifying object gas with surface, the control of dust of counter electrode 34.In addition, under the situation that for example is provided with the catalyst layer that constitutes by the oxidation catalyst of platinum class or three-way catalyst etc. at the surface of sparking electrode 32, near the sparking electrode 32 the surface of dielectric 31 or control of dust with the surface of counter electrode 34, control of dust with near the surface of the dielectric the counter electrode 34 31, owing to catalyzer for example the adsorb oxygen molecule produce active oxygen, so can also control reaction velocity in the catalyzer by the control oxygen concentration.
(the 6th mode of execution)
In the method for gas purification in the gas cleaning plant 10 of the 6th mode of execution, the method for gas purification during arranged in series has been described a plurality of gas cleaning plant 10.In addition, at this, example arranged in series is shown two gas cleaning plants 10 situation and describe.
Figure 12 is the block diagram of gas purge system of the method for gas purification of the schematically illustrated gas cleaning plant 10 that is used for illustrating the 6th mode of execution of the present invention.In addition, to the identical part of structure of the gas purge system of the 5th mode of execution, additional same-sign and omit or simplify the explanation of repetition.In addition, in Figure 12, two gas cleaning plants 10 are expressed as gas cleaning plant 10a, gas cleaning plant 10b respectively.
As shown in figure 12, the discharge gas of discharging from the engine 20 of automobile etc. purify object gas EG via exhaust flow path 21, at first are directed among the gas cleaning plant 10a of the upstream side that is connected in series.Next, the purification object gas EG of exhaust from the gas cleaning plant 10a of upstream side is directed among the gas cleaning plant 10b in downstream side, is deflated afterwards.In addition, between the upstream side of the gas cleaning plant 10a of exhaust flow path 21 and gas cleaning plant 10a and gas cleaning plant 10b and the downstream side of gas cleaning plant 10b, possesses first～the 3rd detection device 23,24,27 that the information relevant with the combustion disposal of PM is detected respectively.
At this, in the information relevant, comprise with the combustion disposal of PM, for example, the gas componant of the purification object gas EG in the inlet of gas cleaning plant 10 and outlet port changes, temperature variation, first electric field described later of the purification object gas in the inlet of the pressure loss in the above-mentioned gas purification plant, gas cleaning plant and outlet port form the unit or second electric field form in the ratio that applies voltage and electric current (applying voltage/current) in the unit at least any one.
First detection device 22, second detection device 23 and the 3rd detection device 27 for example are made of the pressure metering device that the pressure to the purification object gas EG that flows in exhaust flow path 21 carries out instrumentation.According to the instrumentation result in this pressure metering device, can access the pressure loss value in the gas cleaning plant 10.In addition, first detection device 22, second detection device 23 and the 3rd detection device 27 for example comprise: the gas composition analysis device that the gas componant of the purification object gas EG that discharges from gas cleaning plant 10 is analyzed; The temperature of the purification object gas EG of discharge from gas cleaning plant 10 is carried out the temperature metering device of instrumentation; And form voltmeter that discharge that unit or second electric field form the unit carries out instrumentation with the output end voltage or the electric current of power supply or galvanometer etc. to driving first electric field described later.In addition, first detection device 22, second detection device 23 and the 3rd detection device 27 by in above-mentioned each device any one constitutes and gets final product at least.
In addition, in the gas composition analysis device, the concentration of the carbon dioxide among the purification object gas EG, hydrocarbon, oxygen etc. is carried out instrumentation.In addition, above-mentioned voltmeter or galvanometer are electrically connected with power supply 60 with the control of dust that power supply 50, second electric field form the unit with the discharge that first electric field forms the unit.In addition, gas cleaning plant 10, first detection device 22, second detection device 23 and the 3rd detection device 27 are electrically connected with control device 24.In addition, in Figure 12,, omitted the connecting line of each device with control device 24 in order to make drawings clear.
In the method for gas purification in the gas cleaning plant 10 of the 6th mode of execution, at first, control device 24 is in the gas cleaning plant 10a of upstream side, the discharge that first electric field of gas cleaning plant 10a is formed the unit is controlled with the voltage in the power supply 60, frequency, waveform etc. with the control of dust of power supply 50 and/or second electric field formation unit, to obtain the high collection effiiency of PM.Below, the setting of the voltage of the high collection effiiency of this PM of obtaining, frequency, waveform etc. is called trap mode.In addition, control device 24 is in the gas cleaning plant 10b in downstream side, the discharge that first electric field of gas cleaning plant 10b is formed the unit is controlled with the voltage in the power supply 60, frequency, waveform etc. with the control of dust of power supply 50 and/or second electric field formation unit, so that the collection effiiency of PM is low and obtain high combustion disposal function.In this case, mainly implement to make the PM that is caught to decompose and the combustion disposal of oxidation.Below, the collection effiiency of this PM is low and setting that obtain the voltage, frequency, waveform etc. of high combustion disposal function is called combustion mode.
At first, when purification object gas EG flow into the gas cleaning plant 10a of upstream side, owing to gas cleaning plant 10a turns round with trap mode, so mainly be to purify the PM that contains among the object gas EG to be captured.Control device 24 is according to the information relevant with combustion disposal PM among the gas cleaning plant 10a, for example being judged to be increases with the pressure loss and is judged as the combustion disposal speed of the above-mentioned PM state slower than the capture velocity of PM when suitable, and the discharge that forms the unit to first electric field of gas cleaning plant 10a forms the control of dust of unit and exports the signal that is used for the operating condition of gas cleaning plant 10a is switched to from trap mode combustion mode with power supply 60 with the power supply 50 and/or second electric field.Switch simultaneously with this, the discharge that control device 24 forms the unit to first electric field of gas cleaning plant 10b forms the unit with the power supply 50 and/or second electric field control of dust is exported the signal that is used for the operating condition of the gas cleaning plant 10b in downstream side is switched to from combustion mode trap mode with power supply 60.
Thus, in the gas cleaning plant 10a of upstream side, mainly be that the PM that caught is burned, become the combustion disposal speed state faster of the PM that satisfies following formula (1) than the capture velocity of PM.So, the PM that piles up decomposition and oxidation and reduce gradually, near the surface of the dielectric 31 the surface of sparking electrode 32, the sparking electrode 32 or control of dust are the state of not piling up PM with the surface of counter electrode 34, control of dust with near the surface recovery of the dielectric 31 of counter electrode 34.In addition, flow into the most of of PM that the purification object gas EG among the gas cleaning plant 10a of upstream side comprised, in the gas cleaning plant 10b in downstream side, be captured directly by gas cleaning plant 10a.
Next, control device 24 is according to the relevant information of the combustion disposal with PM among the gas cleaning plant 10b in downstream side, for example being judged to be increases with the pressure loss and is judged as the combustion disposal speed of the above-mentioned PM state slower than the capture velocity of PM when suitable, and the discharge that forms the unit to first electric field of gas cleaning plant 10b forms the control of dust of unit and exports the signal that is used for the operating condition of gas cleaning plant 10b is switched to from trap mode combustion mode with power supply 60 with the power supply 50 and/or second electric field.Switch simultaneously with this, the discharge that control device 24 forms the unit to first electric field of gas cleaning plant 10a forms the unit with the power supply 50 and/or second electric field control of dust is exported the signal that is used for the operating condition of the gas cleaning plant 10a of upstream side is switched to from combustion mode trap mode with power supply 60.
Thus, in the gas cleaning plant 10b in downstream side, mainly be that the PM that caught is burned, become the combustion disposal speed state faster of the PM that satisfies following formula (1) than the capture velocity of PM.So, the PM that piles up decomposition and oxidation and reduce gradually, near the surface of the dielectric 31 the surface of sparking electrode 32, the sparking electrode 32 or control of dust are the state of not piling up PM with the surface of counter electrode 34, control of dust with near the surface recovery of the dielectric 31 of counter electrode 34.In addition, when purification object gas EG flow into the gas cleaning plant 10a of upstream side, owing to gas cleaning plant 10a turns round with trap mode, so mainly be to purify the PM that contains among the object gas EG to be captured.
After running in, also as mentioned above,, in gas cleaning plant 10a and gas cleaning plant 10b, carry out the running of trap mode and combustion mode repeatedly according to the information relevant with the combustion disposal of PM.
As mentioned above, in the method for gas purification in the gas cleaning plant 10 of the 6th mode of execution, by a plurality of gas cleaning plants of arranged in series, certain gas cleaning plant is turned round with combustion mode, other gas cleaning plants are turned round with trap mode.Thus, turn round with capture function and compare, can bring into play combustion function and capture function function separately more efficiently with in a gas cleaning plant, having both combustion function.In addition, owing to can the operating condition in each gas cleaning plant be switched to trap mode or switch to combustion mode from trap mode from combustion mode according to the information relevant, so can stablize and purify continuously the purification of object gas EG as gas purge system integral body with the combustion disposal of PM.
In addition, the method for gas purification of the gas cleaning plant 10 of the 6th mode of execution of the present invention is not limited to the above-mentioned gas purification method, also can with the 5th mode of execution similarly, for example first electric field in each gas cleaning plant 10a, 10b forms the upstream side that unit and second electric field form the unit, also possesses supply and can generate the interpolation gas feed unit of interpolation gas of oxidation base and the gas composition analysis device that the gas componant that purifies object gas is detected.As the gas composition analysis device, for example, enumerate the oxygen concentration detecting apparatus that oxygen concentration is detected.
At this, combustion disposal speed for PM, can increase by purifying oxygen concentration among the object gas EG, the concentration of oxidation base uprise combustion disposal is speeded up, to add gas be preferred so supply with to the gas cleaning plant of the state that is in combustion mode especially.
Like this, add gas supply device and oxygen concentration detecting apparatus, the oxygen concentration that purifies among the object gas EG can be set in the scope of regulation by being provided with.Thus, can increase the growing amount of oxidation base, promote the combustion reaction of PM.In addition, can make the surface that is caught in sparking electrode 32, near the surface or the control of dust of the dielectric 31 the sparking electrode 32 use near the PM on the surface of the dielectric 31 the counter electrode 34 to decompose more efficiently and oxidation, can purify purifying object gas with surface, the control of dust of counter electrode 34.In addition, under the situation that for example is provided with the catalyst layer that constitutes by the oxidation catalyst of platinum class or three-way catalyst etc. at the surface of sparking electrode 32, near the sparking electrode 32 the surface of dielectric 31 or control of dust with the surface of counter electrode 34, control of dust with near the surface of the dielectric the counter electrode 34 31, owing to catalyzer for example the adsorb oxygen molecule produce active oxygen, so can also control reaction velocity in the catalyzer by the control oxygen concentration.
In addition, in the above-mentioned gas purification method, for example, can distinguish first electric field set respectively among each gas cleaning plant 10a, 10b and form unit and second electric field and form the operating condition of unit and turn round.In addition, the gas cleaning plant of arranged in series is not limited to two, also can dispose more than three.In addition, gas cleaning plant 10a, the 10b of arranged in series for example also can constitute the assembly that is made of stacked a plurality of units gas cleaning plant.Also can constitute the further serial or parallel connection of these assemblies.In addition, also can control simultaneously, but can realize handling more efficiently by control is next independently respectively for these assemblies.
(the 7th mode of execution)
In the method for gas purification in the gas cleaning plant 10 of the 7th mode of execution, method for gas purification when having disposed a plurality of gas cleaning plant 10 in parallel is described.In addition, at this, example illustrates parallel connection and has disposed the situation of two gas cleaning plants 10 and describe.
Figure 13 is the block diagram of gas purge system of the method for gas purification of the schematically illustrated gas cleaning plant 10 that is used for illustrating the 7th mode of execution of the present invention.In addition, to the identical part of structure of the gas purge system of the 5th mode of execution, additional same-sign and omit or simplify the explanation of repetition.In addition, in Figure 13, two gas cleaning plants 10 are expressed as gas cleaning plant 10a, gas cleaning plant 10b respectively.
As shown in figure 13, the discharge gas of discharging from the engine 20 of automobile etc. purify object gas EG by exhaust flow path 21, and then some among the bypass vent stream 21a, the 21b that are branched by exhaust flow path 21, be directed among gas cleaning plant 10a or the gas cleaning plant 10b, be deflated afterwards.In addition, on the branching portion of exhaust flow path 21, possesses the switching valve 70 that is used for the switching of purification object gas EG stream is flow into gas cleaning plant 10a or gas cleaning plant 10b.In addition, upstream side and downstream side at gas cleaning plant 10a, the 10b of bypass vent stream 21a possess first detection device 22 and second detection device 23 that the information relevant with the combustion disposal of PM is detected respectively.
At this, in the information relevant, comprise with the combustion disposal of PM, for example, the gas componant of the purification object gas EG in the inlet of gas cleaning plant 10 and outlet port changes, temperature variation, first electric field described later of the purification object gas in the inlet of the pressure loss in the above-mentioned gas purification plant, gas cleaning plant and outlet port form the unit or second electric field form in the ratio that applies voltage and electric current (applying voltage/current) in the unit at least any one.
In addition, gas cleaning plant 10, first detection device 22, second detection device 23 and switching valve 70 are electrically connected with control device 24.In addition, in Figure 13, omitted the connecting line of each device with control device 24 for making drawings clear.
In the method for gas purification in the gas cleaning plant 10 of the 7th mode of execution, at first, control device 24 is controlled switching valves 70 and is made as the state that object gas EG only flow into side's gas cleaning plant 10a that purifies.And control device 24 is exported signal that the operating condition that be used for make the side gas cleaning plant 10a that allow inflow purification object gas EG become trap mode with the control of dust of power supply 50 and/or second electric field formation unit with power supply 60 to the discharge of first electric field formation unit of gas cleaning plant 10a.On the other hand, control device 24 discharge from the unit to first electric field of gas cleaning plant 10b that the form control of dust that forms the unit with the power supply 50 and/or second electric field is exported the signal that the operating condition that is used for making the opposing party's gas cleaning plant 10b that does not allow to flow into purification object gas EG becomes combustion mode with power supply 60.
At first, when purification object gas EG flow among side's gas cleaning plant 10a, owing to gas cleaning plant 10a is turned round with trap mode, so mainly be to purify the PM that contains among the object gas EG to be captured.Control device 24 is according to the information relevant with combustion disposal PM among the gas cleaning plant 10a, for example being judged to be increases with the pressure loss and is judged as the combustion disposal speed of the above-mentioned PM state slower than the capture velocity of PM when suitable, and the discharge that forms the unit to first electric field of gas cleaning plant 10a forms the control of dust of unit and exports the signal that is used for the operating condition of gas cleaning plant 10a is switched to from trap mode combustion mode with power supply 60 with the power supply 50 and/or second electric field.Switch simultaneously with this, control device 24 control switching valves 70 and be made as the state that object gas EG only flow into the opposing party's gas cleaning plant 10b that purifies, and export the signal that is used for the operating condition of the opposing party's gas cleaning plant 10b is switched to from combustion mode trap mode with power supply 60 to the discharge that first electric field of gas cleaning plant 10b forms the unit forms the unit with the power supply 50 and/or second electric field control of dust.
Thus, in side's gas cleaning plant 10a, the PM that is caught is burned, becomes the combustion disposal speed state faster than the capture velocity of PM of the PM that satisfies following formula (1).In addition, do not supply among side's gas cleaning plant 10a owing to purify object gas EG, so in fact, in formula (1), the amount Qi that flow into the PM of gas cleaning plant 10a becomes " 0 ".So, the PM that piles up decomposition and oxidation and reduce gradually, near the surface of the dielectric 31 the surface of sparking electrode 32, the sparking electrode 32 or control of dust are the state of not piling up PM with the surface of counter electrode 34, control of dust with near the surface recovery of the dielectric 31 of counter electrode 34.In addition, flowing into the PM that the purification object gas EG of the opposing party's gas cleaning plant 10b comprised is caught by this opposing party's gas cleaning plant 10b with the trap mode running.
Next, control device 24 is according to the relevant information of the combustion disposal with PM among the opposing party's gas cleaning plant 10b, for example being judged to be increases with the pressure loss and is judged as the combustion disposal speed of the above-mentioned PM state slower than the capture velocity of PM when suitable, and the discharge that forms the unit to first electric field of gas cleaning plant 10b forms the control of dust of unit and exports the signal that is used for the operating condition of gas cleaning plant 10b is switched to from trap mode combustion mode with power supply 60 with the power supply 50 and/or second electric field.Switch simultaneously with this, control device 24 control switching valves 70 and be made as the state that object gas EG only flow into side's gas cleaning plant 10a that purifies, and export the signal that is used for the operating condition of side's gas cleaning plant 10a is switched to from combustion mode trap mode with power supply 60 to the discharge that first electric field of gas cleaning plant 10a forms the unit forms the unit with the power supply 50 and/or second electric field control of dust.
Thus, in the opposing party's gas cleaning plant 10b, mainly be that the PM that caught is burned, become the combustion disposal speed state faster of the PM that satisfies following formula (1) than the capture velocity of PM.In addition, do not supply to the opposing party's gas cleaning plant 10b owing to purify object gas EG, so in fact, in formula (1), the amount Qi that flow into the PM of gas cleaning plant 10b becomes " 0 ".So, the PM that piles up decomposition and oxidation and reduce gradually, near the surface of the dielectric 31 the surface of sparking electrode 32, the sparking electrode 32 or control of dust are the state of not piling up PM with the surface of counter electrode 34, control of dust with near the surface recovery of the dielectric 31 of counter electrode 34.In addition, flowing into the PM that the purification object gas EG of side's gas cleaning plant 10a comprised is caught by this side gas cleaning plant 10a with the trap mode running.
After running in, also as mentioned above,, in gas cleaning plant 10a and gas cleaning plant 10b, carry out the running of trap mode and combustion mode repeatedly according to the information relevant with the combustion disposal of PM.
As mentioned above, in the method for gas purification in the gas cleaning plant 10 of the 7th mode of execution, dispose a plurality of gas cleaning plants by parallel connection, certain gas cleaning plant is turned round with combustion mode, other gas cleaning plants are turned round with trap mode.Thus, turn round with capture function and compare, can bring into play combustion function and capture function function separately more efficiently with in a gas cleaning plant, having combustion function concurrently.In addition, because can be according to the information relevant with the combustion disposal of PM, operating condition in each gas cleaning plant is switched to trap mode or switches to combustion mode from trap mode from combustion mode, so can stablize and purify continuously the purification of object gas EG as gas purge system integral body.
In addition, the method for gas purification of the gas cleaning plant 10 of the 7th mode of execution of the present invention is not limited to the above-mentioned gas purification method, also can with the 5th mode of execution similarly, for example first electric field in each gas cleaning plant 10a, 10b forms the upstream side that unit and second electric field form the unit, also possesses supply and can generate the interpolation gas feed unit of interpolation gas of oxidation base and the gas composition analysis device that the gas componant that purifies object gas is detected.As the gas composition analysis device, for example, enumerate the oxygen concentration detecting apparatus that oxygen concentration is detected.
At this, combustion disposal speed for PM, can increase by purifying oxygen concentration among the object gas EG, the concentration of oxidation base uprise combustion disposal is speeded up, to add gas be preferred so supply with to the gas cleaning plant of the state that is in combustion mode especially.
Like this, add gas supply device and oxygen concentration detecting apparatus, the oxygen concentration that purifies among the object gas EG can be set in the scope of regulation by being provided with.Thus, can increase the growing amount of oxidation base, promote the combustion reaction of PM.In addition, can make the surface that is caught in sparking electrode 32, near the surface or the control of dust of the dielectric 31 the sparking electrode 32 use near the PM on the surface of the dielectric 31 the counter electrode 34 to decompose more efficiently and oxidation, can purify purifying object gas with surface, the control of dust of counter electrode 34.In addition, under the situation that for example is provided with the catalyst layer that constitutes by the oxidation catalyst of platinum class or three-way catalyst etc. at the surface of sparking electrode 32, near the sparking electrode 32 the surface of dielectric 31 or control of dust with the surface of counter electrode 34, control of dust with near the surface of the dielectric the counter electrode 34 31, owing to catalyzer for example the adsorb oxygen molecule produce active oxygen, so can also control reaction velocity in the catalyzer by the control oxygen concentration.
In addition, in the above-mentioned gas purification method, for example, can distinguish first electric field set respectively among each gas cleaning plant 10a, 10b and form unit and second electric field and form the operating condition of unit and turn round.In addition, the gas cleaning plant of configuration in parallel is not limited to two, also can dispose more than three.In addition, under each gas cleaning plant 10a, 10b to parallel connection configuration circulate the situation of branch's gas simultaneously, also can not possess switching valve 70.Gas cleaning plant 10a, the 10b of configuration in parallel for example also can constitute the assembly that is made of stacked a plurality of units gas cleaning plant.Also can constitute the further serial or parallel connection of these assemblies.In addition, though also can control simultaneously, can realize handling more efficiently by control is next independently respectively for these assemblies.
(the 8th mode of execution)
Figure 14 is the figure of section of the gas cleaning plant 10 of schematically illustrated the 8th mode of execution of the present invention.In addition, to the identical part of structure of the gas cleaning plant 10 of above-mentioned mode of execution, additional same-sign.
Gas cleaning plant 10 shown in Figure 14 is in the gas cleaning plant 10 of above-mentioned mode of execution, replaces being provided with control of dust and is provided with many groups for example sparking electrode 32a, 32b and discharge counter electrode 33a, the 33b of two groups of subtends with counter electrode 34.Gas cleaning plant 10 shown in Figure 14 is in the gas cleaning plant 10 of the 5th mode of execution shown in Figure 10, replaces being provided with control of dust and is provided with sparking electrode 32a, the 32b of two groups of subtends and the example of discharge counter electrode 33a, 33b with counter electrode 34.In addition, at this, with this gas cleaning plant shown in Figure 14 10 is that an example describes, but in the gas cleaning plant 10 of other mode of executions, can replace also being provided with that control of dust is provided with many groups with counter electrode 34, for example sparking electrode 32a, the 32b of two groups of subtends and discharge be with counter electrode 33a, 33b, obtain the identical action effect of action effect with the gas cleaning plant 10 of this example.
In gas cleaning plant 10, for example the dielectric 31 by flat board or tubular structure forms gas flow path 36.Gas flow path 36 1 sides at dielectric 31, be provided with many groups for example two groups of sparking electrode 32a, 32b (the first sparking electrode 32a and the second sparking electrode 32b), on the other hand in a side opposite, be provided with two groups of discharges with counter electrode 33a, 33b (first discharge with the counter electrode 33a and the second discharge counter electrode 33b) with the gas flow path 36 of dielectric 31.Clip gas flow path 36 mutually and be provided with the first sparking electrode 32a and the second sparking electrode 32b contiguously with dielectric 31 respectively.And, on the position that clips the dielectric 31 and the first sparking electrode 32a subtend, dispose first discharge and use counter electrode 33a, on the position that clips the dielectric 31 and the second sparking electrode 32b subtend, dispose the second discharge counter electrode 33b.
In addition, the first sparking electrode 32a and first discharge constitute with counter electrode 33a: be connected with power supply 50a with first discharge with electrical system 51a via discharge, can discharge with applying pulse type between the counter electrode 33a, exchanging the voltage of shape or bipolar pulse shape to the first sparking electrode 32a and first with power supply 50a by utilizing first discharge, form the electric field of discharge usefulness and cause discharge, and generate discharge plasma P1.
Similarly, the second sparking electrode 32b and second discharge constitute with counter electrode 33b: be connected with power supply 50b with second discharge with electrical system 51b via discharge, can discharge with applying pulse type between the counter electrode 33b, exchanging the voltage of shape or bipolar pulse shape to the second sparking electrode 32b and second with power supply 50b by utilizing second discharge, form the electric field of discharge usefulness and cause discharge, and generate discharge plasma P2.By above-mentioned via discharge with the interconnective discharge of electrical system 51a, 51b with power supply 50a, 50b, sparking electrode 32a, 32b and discharge and form first electric field with counter electrode 33a, 33b and form the unit.
At this moment, owing between the first sparking electrode 32a and first discharges with counter electrode 33a, have dielectric 31, and the first sparking electrode 32a and dielectric 31 close proximity, so caused discharge is stable coronal discharge, near the first sparking electrode 32a, become along the creeping discharge of dielectric 31.The discharge that causes in the second sparking electrode 32b is also identical.
And, the first sparking electrode 32a and the second sparking electrode 32b constitute: be connected with power supply 60 with control of dust with electrical system 61 via control of dust respectively, and can be by the electric field that utilizes the control of dust control of dust that direction is constant on the formation time with applying the voltage of direct current shape, unipolar pulse type, rectified wave shape between the 60 couples first sparking electrode 32a of power supply and the second sparking electrode 32b to use.Form second electric field with electrical system 61 interconnective controls of dust with power supply 60, sparking electrode 32a, 32b via control of dust and form the unit by above-mentioned.
Therefore, in the effect of electric field of using by control of dust and near the first sparking electrode 32a and among near each the discharge plasma P1 that generates the second sparking electrode 32b, the discharge plasma P1 with negative electric charge or positive electric charge is drawn out to gas flow path 36 sides.In addition, at this moment, because the direction of the electric field used of control of dust and the electric field of drawing usefulness that also is used in discharge plasma P1 is constant, so the polarity of each the discharge plasma P1 that draws to gas flow path 36 sides is opposite mutually.
So, since the electrostatic precipitation effect of the electric field that discharge plasma P1 and charged PM use by the control of dust that is formed between the first sparking electrode 32a and the second sparking electrode 32b with the corresponding direction of polarity on be subjected to electric force and be caught in dielectric 31, the first sparking electrode 32a and the second sparking electrode 32b, and the PM that is captured burned processing by near the discharge plasma P1 that the first sparking electrode 32a and the second sparking electrode 32b, generates by creeping discharge.
Promptly, gas cleaning plant 10 constitutes: form the electric field that control of dust is used by making two groups of sparking electrode 32a, the configuration of 32b subtend, the structural element that sparking electrode 32a, 32b have concurrently mutually as the formation of second electric field in the gas cleaning plant shown in Figure 10 10 unit is the function of control of dust with counter electrode 34.
Therefore, according to gas cleaning plant 10, the effect in gas cleaning plant shown in Figure 10 10, can also in wideer scope, generate discharge plasma P1 at the near surface of gas flow path 36 sides of dielectric 31.Be under two the situation for example,, the PM that catches at dielectric 31 can be carried out combustion disposal more efficiently everywhere owing to can generate discharge plasma P1, P2 two positions at sparking electrode as shown in figure 14.
Especially, for example gas cleaning plant 10 as shown in figure 10 is such, when the electric charge of discharge plasma P is unipolarity and generates under such situation from a position, attracted to a side that does not generate discharge plasma P by charged PM and be captured for the polarity identical with the polarity of discharge plasma P.In this case, might the PM that be caught can't be burnt fully.In fact, inventors have confirmed that by experiment the major part of the PM that flows into is attached on the face with a side of discharge plasma P subtend sometimes.
On the other hand, according to gas cleaning plant 10,, also can carry out combustion disposal by discharge plasma P1, P2 even PM electrically is subjected to power and is caught by dielectric 31 on any one direction.
And, in gas cleaning plant 10, the voltage of electric field of discharge usefulness will apply, promptly the first sparking electrode 32a applies with the voltage between the counter electrode 33a with first discharge and the second sparking electrode 32b and second discharges and applies alternately switching and carry out intermittently with the voltage between the counter electrode 33b, then can remove PM more efficiently if will be used to form.
Promptly, suppose to carry out simultaneously that the first sparking electrode 32a and first discharge apply with the voltage between the counter electrode 33a and the second sparking electrode 32b and second discharges applies with the voltage between the counter electrode 33b, then generate discharge plasma P1, P2 respectively simultaneously from the first sparking electrode 32a and the second sparking electrode 32b.But the polarity of each plasma discharging P1, P2 is different mutually, mixes in the core of gas flow path 36 and has discharge plasma P1, the P2 with two kinds of polarity.In addition, near the first sparking electrode 32a and the second sparking electrode 32b, in the little position of the influence that the electric field of being used by control of dust causes, also mix and have discharge plasma P1, P2 with two kinds of polarity.
Therefore, when apply big voltage for discharge, and the many electrostatic precipitation effects that consequently electric field of being used by control of dust produced of the amount of discharge plasma P1, P2 are brought when influencing, mix the zone that exists at discharge plasma P1, P2 with two kinds of polarity, moving of charged PM might be hindered.Especially near the first sparking electrode 32a and the second sparking electrode 32b, greater amount ground generates discharge plasma P1, the P2 with two kinds of polarity, attracted to the possibility height that the mobile quilt of the PM the dielectric 31 near hinders.Therefore, if each sparking electrode 32a, 32b discharge with switching, even then applied bigger voltage for discharge, the control of dust that also can avoid such PM hinders.
In addition, also can make first discharge with power supply 50a and second discharge with power supply 50b sharing, use single discharge to carry out with power supply that the first sparking electrode 32a applies with the voltage between the counter electrode 33a with first discharge and the second sparking electrode 32b and second discharges applies with the voltage between the counter electrode 33b.In addition, first discharge both can be the same or different with power supply 50b output voltage separately with the power supply 50a and second discharge.
Next, method for gas purification in the gas cleaning plant 10 of above-mentioned the 8th mode of execution is described.Be used to the gas purge system of this method for gas purification is described, so describe with reference to Fig. 9 owing to be the structure identical with gas purge system shown in Figure 9.In addition, for the identical part of structure of the gas purge system of the method for gas purification of the gas cleaning plant 10 that is used for illustrating the 5th mode of execution, additional same-sign is omitted or is simplified the explanation that repeats.
In addition, at this, method for gas purification in the gas cleaning plant 10 of the 8th mode of execution is described, but in the gas cleaning plant 10 of other mode of executions, by constituting same gas purge system, also obtain the identical action effect of method for gas purification in the gas cleaning plant 10 with the 8th mode of execution.
As shown in Figure 9, the gas cleaning plant 10 of the 8th mode of execution for example is arranged at from the engine 20 of automobile on the exhaust flow path 21 that the purification object gas EG such as discharge gas that discharge pass through.In addition, the upstream side at the gas cleaning plant 10 of exhaust flow path 21 possesses first detection device 22 that the information relevant with the combustion disposal of particle-like substance (PM:Particulate Matter) is detected.In addition, the downstream side at the gas cleaning plant 10 of exhaust flow path 21 possesses second detection device 23 that the information relevant with the combustion disposal of PM is detected.In addition, about the device that the information relevant with the combustion disposal of PM detects, possess in above-mentioned first detection device 22, second detection device 23 any one gets final product at least.In addition, gas cleaning plant 10, first detection device 22, second detection device 23 are electrically connected with control device 24.In addition, in Fig. 9, omitted the connecting line of each device with control device 24 for making drawings clear.
In this gas purge system, can with form by first electric field that constitutes with counter electrode 33a with power supply 50a, sparking electrode 32a and discharge with the interconnective discharge of electrical system 51a via discharge the unit, and by via discharge with the interconnective discharge of electrical system 51b with power supply 50b, sparking electrode 32b and first electric field that constitutes with counter electrode 33b of discharging form the unit and switch and turn round.At this, switching is meant: can by switch discharges alternately with power supply 50a and discharge with the running of power supply 50b with stop to carry out, also can be by making discharge with power supply 50a and discharge and still keep under the situation of work switching with power supply 50b it applies voltage, applies frequency and carry out.That is, as long as be made as the state that between the quantity of electric charge of discharge plasma P1 different and discharge plasma P2, produces difference with polarity.
At this, can utilize the capturing efficiency η of the amount Qi (g/h), the PM in the gas cleaning plant 10 that flow into the PM in the gas cleaning plant 10, the timing that combustion disposal speed Qb (g/h) decides switching.In addition, carry out switching that above-mentioned two first electric fields form the unit and control and second electric field by control device 24 and form control of unit etc.
For example, make discharge with power supply 50a running, make the time t1 that stops with power supply 50b of discharging during, the PM that is attached to the surface of sparking electrode 32b can not burn and pile up.If the accumulating amount of this PM becomes too much, when then making discharge with power supply 50b running after switching, sparking electrode 32b is covered by PM, thus can't apply electric field effectively, and might can't begin discharge.Because the accumulating amount of PM is proportional with the value of " η * Qi * t1 ", so the situation that discharge when beginning can't be carried out so that its value less than below the certain value and the switching of turning round and stopping, can being avoided discharging by decision t1.Thus, can carry out stable control.
Next, switch discharges make with the operating condition of power supply discharge with power supply 50b running, make the time t2 that stops with power supply 50a of discharging during, need make the PM burning of accumulation, thus set t2 so that the value of " Qb * t2 " greater than the value of " η * Qi * t1 ".
At this, owing in fact can not be directly measure Qi, Qb, thus will possess as database with the information that information shown below is set up related Qi, Qb, and following information is next can to obtain Qi, Qb from database by measuring.In addition, database is stored in the storage unit such as hard disk.In addition, information shown below is identical with the above-mentioned information relevant with the combustion disposal of PM.That is, in this information, comprise, for example, gas componant (CO, NOx, HC, the CO of the purification object gas EG in the inlet of gas cleaning plant 10, inside or outlet port 2, O 2Deng) or its variation, the inlet of gas cleaning plant 10, inner, the pressure of the purification object gas EG in outlet port, the pressure loss in the above-mentioned gas purification plant 10, the inlet of gas cleaning plant 10, temperature or its variation of the purification object gas EG in inside or outlet port, first electric field described later forms the voltage that applies in unit or second electric field formation unit, electric current, apply the relevant information of state of ratio (applying voltage/current) etc. with the gas cleaning plant 10 of voltage and electric current; In the information relevant such as the aperture of the timing of the emitted dose of the pressure of engine speed, moment of torsion, air fuel ratio, suction air or flow, fuel or consumption, injection, the pressure of fuel, engine internal pressure, Aspirating valves, outlet valve or EGR valve, the temperature of engine, the temperature of cooling water with the state of engine at least any one.Judge according to these above-mentioned information reference data storehouses by control device 24, thereby control the operating state that first electric field forms unit or second electric field formation unit.In addition, under the situation of using the information relevant with the state of gas cleaning plant 10, carry out Passive Control that the variation of the state of the gas cleaning plant 10 that causes mainly due to the discharge gas of discharging from engine is obtained, under the situation of using the information relevant, carry out the ACTIVE CONTROL that the variation of the state of the gas cleaning plant that causes mainly due to the discharge gas from the engine discharge is predicted with the state of engine.In addition, also can make up these controls.
In addition, be under the situation of purpose with dielectric jacketed electrode surface in heat resistance, corrosion resistance with the surface of improving sparking electrode 32a, 32b, be effective from the switching controls of other viewpoints.
Under the situation that has coated sparking electrode 32a, 32b with dielectric, make discharge with power supply 50a running, when discharge is stopped with power supply 50b, if electric charge of drawing from discharge plasma P1 or the electric charge that is attached to PM form the formed electric field in unit by second electric field and arrive on the sparking electrode 32b, then the electric charge savings is on the dielectric surface.By the electric field that is formed by this savings electric charge, second electric field forms the formed electric field neutralisation in unit, can't bring into play the effect that second electric field forms the electric field of unit formation along with effluxion.Turn round, make discharge to stop if under this state, making discharge with power supply 50b with power supply 50a, the charge decay of being put aside by near the discharge plasma P2 that sparking electrode 32b, produces then, thus can bring into play the effect that second electric field forms the electric field that the unit forms once more.
On the other hand, begin savings at sparking electrode 32a side electric charge next time, can't bring into play the effect that second electric field forms the electric field of unit formation along with effluxion.Therefore, by with do not lose the time lag switch discharges of effect that second electric field forms the electric field that the unit forms with power supply 50a and discharge with the running of power supply 50b and stop, the effect that second electric field forms the electric field of unit formation can be brought into play fully, and good treatment state can be kept continuously.The savings speed of electric charge can be by being measured flowing into the electric current that second electric field forms the unit, and by this information is input to control device 24, control device 24 can be controlled the timing of the switching of power supply.Even in fact directly do not measure and flow into the electric current that second electric field forms the unit, also can use any one in the above-mentioned information relevant with combustion disposal PM, determine that the person who lives in exile forms the electric current of unit to second electric field, the timing of the switching of power supply is controlled.
As mentioned above, gas cleaning plant 10 according to the 8th mode of execution of the present invention, by be provided with many groups for example sparking electrode 32a, the 32b of two groups of subtends and discharge with counter electrode 33a, 33b, can switch discharges with power supply 50a and discharge with the running of power supply 50b and stop.Thus, can catch PM more efficiently and remove.
More than, utilize a mode of execution to understand the present invention specifically, but the invention is not restricted to these mode of executions, and in the scope that does not break away from its main idea, can carry out various changes.In addition, gas cleaning plant of the present invention, gas purge system and method for gas purification in the exhaust line that is applied to automobile, can also overall application comprise in the motor (motor) of discharge gas of PM in discharge.
Utilizability on the industry
Gas cleaning plant according to the embodiment of the present invention, gas purge system and gas Purification method can catch the PM that is contained in the Exhaust Gas efficiently, need not heating and catches The PM that catches and removing efficiently will purify object gas and purify. Enforcement side of the present invention The gas cleaning plant of formula, gas purge system and method for gas purification are except being applied to automobile Exhaust line in beyond, can also overall application comprise the starting of Exhaust Gas of PM in discharge In the machine.

Claims (24)

1. gas cleaning plant; It is characterized in that; Utilize first electric field to form the unit; In purifying the mobile gas flow path of object gas, form the electric field of discharge usefulness and generate discharge plasma; Effect by above-mentioned discharge plasma makes the charged and processing of burning of particle-like substance contained in the above-mentioned purification object gas; Utilize second electric field to form the unit; Catch above-mentioned charged particle-like substance and be formed for above-mentioned discharge plasma is drawn out to the electric field that the control of dust of above-mentioned gas stream side is used by the electric precipitation function; Wherein
Being provided with the upstream side that above-mentioned first electric field forms the position of unit and above-mentioned second electric field formation unit, possesses the charged electrode of using that makes mobile purification object gas charged.
2. gas cleaning plant according to claim 1 is characterized in that, above-mentioned chargedly be arranged on the direction with respect to the main flow direction approximate vertical of above-mentioned purification object gas with electrode.
3. gas cleaning plant according to claim 1 is characterized in that, separates a plurality of above-mentioned charged electrodes of using of being arranged at intervals with of regulation.
4. gas cleaning plant; It is characterized in that; Utilize first electric field to form the unit; In purifying the mobile gas flow path of object gas, form the electric field of discharge usefulness and generate discharge plasma; Effect by above-mentioned discharge plasma makes the charged and processing of burning of particle-like substance contained in the above-mentioned purification object gas; Utilize second electric field to form the unit; Catch above-mentioned charged particle-like substance and be formed for above-mentioned discharge plasma is drawn out to the electric field that the control of dust of above-mentioned gas stream side is used by the electric precipitation function; Wherein
Be provided with above-mentioned first electric field form the unit a side the above-mentioned gas stream internal face, be provided with above-mentioned second electric field form the unit a side the above-mentioned gas stream internal face, constitute above-mentioned first electric field and form the sparking electrode of unit and constitute the control of dust that above-mentioned second electric field forms the unit and form male and fomale(M﹠F) with any one surface at least in the electrode.
5. gas cleaning plant according to claim 4 is characterized in that, above-mentioned male and fomale(M﹠F) concavo-convex along above-mentioned purification object gas main flow direction and form.
6. gas cleaning plant according to claim 4 is characterized in that, above-mentioned male and fomale(M﹠F) concavo-convex along with respect to the direction of the main flow direction approximate vertical of above-mentioned purification object gas and form.
7. gas cleaning plant; It is characterized in that; Utilize first electric field to form the unit; In purifying the mobile gas flow path of object gas, form the electric field of discharge usefulness and generate discharge plasma; Effect by above-mentioned discharge plasma makes the charged and processing of burning of particle-like substance contained in the above-mentioned purification object gas; Utilize second electric field to form the unit; Catch above-mentioned charged particle-like substance and be formed for above-mentioned discharge plasma is drawn out to the electric field that the control of dust of above-mentioned gas stream side is used by the electric precipitation function; Wherein
Be provided with above-mentioned first electric field form the unit a side the above-mentioned gas stream internal face, be provided with above-mentioned second electric field form the unit a side the above-mentioned gas stream internal face, constitute above-mentioned first electric field and form the sparking electrode of unit and constitute control of dust that above-mentioned second electric field forms the unit with any one surface at least in the electrode, be formed with catalyst layer.
8. gas cleaning plant according to claim 7 is characterized in that above-mentioned catalyst layer is made of the overlay that is coated in above-mentioned lip-deep catalyst material.
9. gas cleaning plant according to claim 7 is characterized in that above-mentioned catalyst layer is made of the porous layer that is arranged on above-mentioned lip-deep bearing catalyst material.
10. gas cleaning plant; It is characterized in that; Utilize first electric field to form the unit; In purifying the mobile gas flow path of object gas, form the electric field of discharge usefulness and generate discharge plasma; Effect by above-mentioned discharge plasma makes the charged and processing of burning of particle-like substance contained in the above-mentioned purification object gas; Utilize second electric field to form the unit; Catch above-mentioned charged particle-like substance and be formed for above-mentioned discharge plasma is drawn out to the electric field that the control of dust of above-mentioned gas stream side is used by the electric precipitation function; Wherein
Being provided with the upstream side that above-mentioned first electric field forms the position of unit and above-mentioned second electric field formation unit, possesses the interpolation gas feed unit that supply can generate the interpolation gas of oxidation base.
11. a gas purge system is characterized in that, serial or parallel connection has disposed at least two described gas cleaning plants of claim 1.
12. a gas purge system is characterized in that, serial or parallel connection has disposed at least two described gas cleaning plants of claim 4.
13. a gas purge system is characterized in that, serial or parallel connection has disposed at least two described gas cleaning plants of claim 7.
14. a gas purge system is characterized in that, serial or parallel connection has disposed at least two described gas cleaning plants of claim 10.
15. gas purge system according to claim 11 is characterized in that, has disposed in parallel connection under the situation of above-mentioned gas purification plant, possesses to switch the switching valve that imports to each gas cleaning plant with purifying object gas stream.
16. gas purge system according to claim 12 is characterized in that, has disposed in parallel connection under the situation of above-mentioned gas purification plant, possesses to switch the switching valve that imports to each gas cleaning plant with purifying object gas stream.
17. gas purge system according to claim 13 is characterized in that, has disposed in parallel connection under the situation of above-mentioned gas purification plant, possesses to switch the switching valve that imports to each gas cleaning plant with purifying object gas stream.
18. gas purge system according to claim 14 is characterized in that, has disposed in parallel connection under the situation of above-mentioned gas purification plant, possesses to switch the switching valve that imports to each gas cleaning plant with purifying object gas stream.
19. method for gas purification, it is characterized in that, it is the method for gas purification of gas cleaning plant, this gas cleaning plant possesses: first electric field forms the unit, form the electric field of discharge usefulness and generate discharge plasma in purifying the gas flow path that object gas flows, the effect by above-mentioned discharge plasma makes the particle-like substance that is contained in the above-mentioned purification object gas charged and carry out combustion disposal; Second electric field forms the unit, catches above-mentioned charged particle-like substance and is formed for above-mentioned discharge plasma is drawn out to the electric field that the control of dust of above-mentioned gas stream side is used by the electrostatic precipitation function; And control unit, above-mentioned first electric field formation unit and above-mentioned second electric field formation unit are controlled, wherein,
Above-mentioned control unit detects the relevant information of the combustion disposal with particle-like substance that above-mentioned first electric field forms in the unit, according to this detected information, the operating state that above-mentioned first electric field is formed unit and/or above-mentioned second electric field formation unit is controlled.
20. method for gas purification, it is characterized in that, be the method for gas purification of serial or parallel connection when having disposed a plurality of gas cleaning plant, this gas cleaning plant possesses: first electric field forms the unit, form the electric field of discharge usefulness and generate discharge plasma in purifying the gas flow path that object gas flows, the effect by above-mentioned discharge plasma makes the particle-like substance that is contained in the above-mentioned purification object gas charged and carry out combustion disposal; Second electric field forms the unit, catches above-mentioned charged particle-like substance and is formed for above-mentioned discharge plasma is drawn out to the electric field that the control of dust of above-mentioned gas stream side is used by the electrostatic precipitation function; And control unit, above-mentioned first electric field formation unit and above-mentioned second electric field formation unit are controlled, wherein,
Above-mentioned control unit detects the relevant information of the combustion disposal with particle-like substance that above-mentioned first electric field in above-mentioned each gas cleaning plant forms in the unit, according to this detected information, the operating state that above-mentioned first electric field in above-mentioned each gas cleaning plant is formed unit and/or above-mentioned second electric field formation unit is controlled.
21. method for gas purification according to claim 19, it is characterized in that, the above-mentioned gas purification plant forms the upstream side of unit and above-mentioned second electric field formation unit at above-mentioned first electric field, also possess supply and can generate the interpolation gas feed unit of interpolation gas of oxidation base and the gas componant detection unit that the gas componant that purifies in the object gas is detected
Above-mentioned control unit basis detected gas componant in above-mentioned gas composition detection unit is controlled above-mentioned interpolation gas feed unit, interpolation gas is adjusted flow and supplied to purify in the object gas.
22. method for gas purification according to claim 20, it is characterized in that, the above-mentioned gas purification plant forms the upstream side of unit and above-mentioned second electric field formation unit at above-mentioned first electric field, also possess supply and can generate the interpolation gas feed unit of interpolation gas of oxidation base and the gas componant detection unit that the gas componant that purifies in the object gas is detected
Above-mentioned control unit basis detected gas componant in above-mentioned gas composition detection unit is controlled above-mentioned interpolation gas feed unit, interpolation gas is adjusted flow and supplied to purify in the object gas.
23. method for gas purification according to claim 19, it is characterized in that, the relevant information of combustion disposal above-mentioned and particle-like substance comprises that the gas componant of the purification object gas in the inlet of gas cleaning plant and outlet port changes, temperature variation, first electric field of the purification object gas in the inlet of the pressure loss in the above-mentioned gas purification plant, gas cleaning plant and outlet port form the unit or second electric field form in the ratio that applies voltage and electric current in the unit at least any one.
24. method for gas purification according to claim 20, it is characterized in that, the relevant information of combustion disposal above-mentioned and particle-like substance comprises that the gas componant of the purification object gas in the inlet of gas cleaning plant and outlet port changes, temperature variation, first electric field of the purification object gas in the inlet of the pressure loss in the above-mentioned gas purification plant, gas cleaning plant and outlet port form the unit or second electric field form in the ratio that applies voltage and electric current in the unit at least any one.
CNA2007800430741A 2006-11-20 2007-11-19 Gas purifying device, gas purifying system and gas purifying method Pending CN101542080A (en)

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Cited By (11)

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CN102906380A (en) * 2010-05-25 2013-01-30 丰田自动车株式会社 Control device for internal combustion engine
CN103894289A (en) * 2014-04-17 2014-07-02 刘晓岳 Air purification method and device based on electrostatic deflection
CN104179552A (en) * 2014-09-10 2014-12-03 中投仙能科技（苏州）有限公司 Automobile tail gas treatment device and method based on low-temperature plasma
CN104289309A (en) * 2014-10-16 2015-01-21 南通市崇川盛源净化器材厂 Electric dust removal device and catalyst coating formula
CN105649714A (en) * 2014-12-02 2016-06-08 丰田自动车株式会社 Exhaust gas purification apparatus
CN107036164A (en) * 2017-03-31 2017-08-11 杭州电子科技大学 A kind of air purification method based on external electromagnetic field
CN108060953A (en) * 2016-11-08 2018-05-22 福特环球技术公司 Gas handling system, device and method
CN108472662A (en) * 2016-06-15 2018-08-31 富士电机株式会社 Particle-like substance burner
CN113351372A (en) * 2021-06-07 2021-09-07 珠海格力电器股份有限公司 Zr-based amorphous coating, preparation process thereof and application thereof in electric purification
CN113356966A (en) * 2021-06-17 2021-09-07 东风小康汽车有限公司重庆分公司 Automobile exhaust particle processor and exhaust treatment device
CN113522527A (en) * 2020-04-17 2021-10-22 宝马股份公司 Electrostatic air filter device, method for operating an electrostatic air filter device, and motor vehicle having an electrostatic air filter device

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Publication number Priority date Publication date Assignee Title
CN102906380A (en) * 2010-05-25 2013-01-30 丰田自动车株式会社 Control device for internal combustion engine
CN102906380B (en) * 2010-05-25 2015-04-29 丰田自动车株式会社 Control device for internal combustion engine
CN103894289B (en) * 2014-04-17 2017-04-05 刘晓岳 Air purification method and air cleaning unit based on electrostatic deflection
CN103894289A (en) * 2014-04-17 2014-07-02 刘晓岳 Air purification method and device based on electrostatic deflection
CN104179552A (en) * 2014-09-10 2014-12-03 中投仙能科技（苏州）有限公司 Automobile tail gas treatment device and method based on low-temperature plasma
CN104289309A (en) * 2014-10-16 2015-01-21 南通市崇川盛源净化器材厂 Electric dust removal device and catalyst coating formula
CN105649714A (en) * 2014-12-02 2016-06-08 丰田自动车株式会社 Exhaust gas purification apparatus
CN105649714B (en) * 2014-12-02 2018-07-20 丰田自动车株式会社 Waste gas purification apparatus
CN108472662A (en) * 2016-06-15 2018-08-31 富士电机株式会社 Particle-like substance burner
CN108060953A (en) * 2016-11-08 2018-05-22 福特环球技术公司 Gas handling system, device and method
CN107036164A (en) * 2017-03-31 2017-08-11 杭州电子科技大学 A kind of air purification method based on external electromagnetic field
CN113522527A (en) * 2020-04-17 2021-10-22 宝马股份公司 Electrostatic air filter device, method for operating an electrostatic air filter device, and motor vehicle having an electrostatic air filter device
CN113351372A (en) * 2021-06-07 2021-09-07 珠海格力电器股份有限公司 Zr-based amorphous coating, preparation process thereof and application thereof in electric purification
CN113351372B (en) * 2021-06-07 2022-09-13 珠海格力电器股份有限公司 Zr-based amorphous coating, preparation process thereof and application thereof in electric purification
CN113356966A (en) * 2021-06-17 2021-09-07 东风小康汽车有限公司重庆分公司 Automobile exhaust particle processor and exhaust treatment device

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