JP2780130B2 - Exhaust gas purification device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an exhaust gas purifying apparatus for purifying exhaust gas by corona discharge in an engine mounted on a vehicle and a ship, an engine for private power generation, and the like. More particularly, the present invention relates to an exhaust gas purifying apparatus having a scrubber corona generating portion capable of stably generating a scrubber corona discharge for a long period of time.

[Prior Art] Conventionally, as this kind of technique, there has been one disclosed in Japanese Patent Application Laid-Open No. 57-20510. According to the conventional technology,
It is composed of a cylindrical dust collecting tube formed into a corrugated shape, and a desired number of discharge wires stretched in a hollow portion of the cylindrical dust collecting tube. For example, fine particles such as tar particles and graphite are removed. In other words, fine particles floating in the exhaust gas are attracted to and adhered to the inner wall of the dust collecting cylinder by the action of a strong electrostatic field generated between the cylindrical dust collecting cylinder and the discharge line to remove dust.

[Problems to be Solved by the Invention] However, according to the above-described conventional technology, there is a risk that the discharge wire is disconnected when a spark discharge occurs between the dust collection tube and the discharge wire.

Further, the purifying ability is weak and insufficient for removing harmful gases such as NO _x and CO _x in the exhaust gas.

As an effective discharge generation mode for activating and removing such harmful gases, a recent corona discharge was considered, but the expected value could not be secured by a general corona discharge phenomenon.

Therefore, it is necessary to generate a peculiar corona, that is, a flat corona, in order to put the technology for removing harmful gas by the corona discharge into practical use, and it is necessary to secure an increased number of flat coronas.

Furthermore, in order to stably generate the scrub corona for a long period of time, it is necessary to eliminate the influence of, for example, the adhesion of carbonized particles or the like on the generation of the scrub corona.

[Means for Solving the Problems] The present invention has been made in view of the above problems, and has a first electrode having a convex portion on its surface, a second electrode opposed to the first electrode, An insulating portion attached to at least a surface of the second electrode on the first electrode side; a scrubber corona generating portion including a high-voltage power supply connected between the two electrodes; and a fuel liquid injected into the scrubber corona generating portion An exhaust gas purifying apparatus comprising: an injecting means for supplying the fuel liquid flowing out of the brushing corona generating section to the engine;

The present invention is intended to stably generate a scrubber corona by the above-mentioned constitutional means, and to purify exhaust gas by the scrubber corona for a long period of time. It is intended to be reused as engine fuel.

[Operation] The exhaust gas purifying apparatus having the above-described configuration according to the present invention operates as follows.

First, in the scrubber corona generating section, when a high voltage is applied between the first electrode and the second electrode, the scrubber corona is attached to the inner surface of the second electrode. Occurs.

This situation is shown in FIGS. 3 to 5 and will be described below.

FIG. 3 shows a state in which a positive voltage is applied to the first electrode 1 and a negative voltage is applied to the second electrode 2 by the high voltage power supply 4.

The arrow indicated by E0 in FIG. 3 indicates the direction of the electric field generated by the high voltage applied between the first electrode 1 and the second electrode 2, and the arrow indicated by ES is covered by the fuel liquid 5. The direction of the reverse electric field generated by the electric charge accumulated on the surface of the insulating part 3 is shown, P shows the positive electric charge accumulated on the surface of the insulating part 3, and C1 shows the positive corona. Shows the most grown Cormorant Corona.

In the state shown in FIG. 3, the wiper corona C1 is generated and at the same time, the positive charges P are accumulated on the surface of the insulating portion 3, and the reverse electric field ES increases according to the amount of the positive charges P to suppress the wiper corona C1. As time elapses, the brush corona C1 changes and attenuates to a brush corona or a film corona generated only in the vicinity of the first electrode 1.

This change decay phenomenon of the brush corona C1 eventually occurs because the accumulated amount of the positive charge P becomes too large.
By taking measures to reduce the excess positive charge P, the brush corona C1 increases and grows.

In the present invention, the generation of the scraper corona C1 is ensured by neutralizing and reducing the excess positive charge P through the steps shown in FIGS. 4 and 5 described later.

FIG. 4 shows a so-called zero point state where the polarity of the output of the high-voltage power supply 4 is switched. In the state shown in FIG. 4, the generation of corona is temporarily stopped.

FIG. 5 has a polarity opposite to that of the state shown in FIG. 3,
A negative voltage is applied to the first electrode 1 by the high voltage power supply 4,
The state where the plasma voltage is applied to the second electrode 2 is shown.

In FIG. 5, e indicates an electron, and C2 indicates a negative corona.

In the state shown in FIG. 5, the negative electrode corona C2 and the electrons e are generated from the first electrode 1, and the electrons e are combined with the positive charges P accumulated on the surface of the insulating portion 3 and neutralized.

As a result, the excess positive charge P is reduced, and when the state again proceeds to the state shown in FIG. 3, the scraper corona C1 is generated again.

As described above, the scourer corona C1 is continuously generated by the repetition of the states shown in FIGS. 3 to 5 at the scrubber corona generating portion. However, carbonized particles adhere to the insulating portion 3 and the surface of the insulating portion 3 When irregularities occur on the surface, the brush corona C1 disappears, and the state shifts to spark discharge. However, in the present invention, the fuel liquid 5 is injected into the slender corona generating section 6 by the injection means, and the deposits on the surface of the insulating section 3 are always washed by the fuel liquid 5. Therefore, in the spreader corona generating section 6, the spreader corona C1 is stably generated for a long period of time.

When aerated with exhaust gas to the hossu corona generator 6, NO _x in the exhaust gas, SO _x, harmful gases such as CO _x is oxidized by O ₃ (ozone) generated by hossu corona in the stable gas It is cleaned by being changed or adsorbed by the wiping corona generating section 6 by ion wind.

First Embodiment FIG. 1 is a vertical sectional view showing a first embodiment of the present invention.

In FIG. 1, reference numeral 6 denotes a brush corona generating section for generating a brush corona C1 by applying a high voltage power supply 4, and includes a first electrode 1, a second electrode 2, an insulating section 3, a high voltage power supply 4, and a support. It is constituted by the unit 7.

More specifically, the first electrode 1 is, for example, a stainless steel rod that is spirally processed like a screw. As the spiral working, a method using a cutting machine such as a milling machine or a method using a mold working machine such as sintering may be appropriately selected. Then, by changing the pitch of the screw thread, a convex portion having a triangular cross section or a trapezoidal cross section on the surface of the first electrode 1 is formed.

Next, the first electrode 1 is supported at the center of a cylindrical insulating member 3 made of a material such as ceramics by a supporting member 7 made of an insulating material.

Then, the second electrode 2 is formed on the outside of the insulating portion 3.

The second electrode 2 is formed by printing a metal paste on the surface of an insulating portion 3 made of, for example, ceramics and baking it. Alternatively, the second electrode 2 is prepared in advance with a metal pipe, and then the surface of the second electrode 2 is enameled with an organic glass or the like to form the insulating portion 3. Further, it may be a simple combination of an insulating pipe and a metal pipe.

The first electrode 1 and the second electrode 2 are each electrically connected to a high-voltage power supply 4. The high-voltage power supply 4 is a circuit that generates positive and negative high voltages at a certain frequency, and its waveform may be any of a sine wave and a pulse wave.

The above-mentioned frequency is a constant frequency or a frequency synchronized with the engine speed such as the output of an ignition coil.

5 is a fuel liquid. The fuel liquid 5 only needs to be suitable for cleaning the deposits on the insulating portion 3 of the slender corona generating portion 6, and for example, viscous oil such as engine oil, light oil, or the like can be used.

8 is an injection means. The injection means 8 is for injecting the fuel liquid 5 into the surface of the insulating portion 3 on the first electrode 1 side, and has a drip hole 8a.

Reference numeral 9 denotes a sub-tank, which constitutes a liquid storage means 11 together with a main tank 10 described later. The subtan 79 is
A cap 12 for discharging the sediment 5b is screwed into the cap, and the supply means 13 is connected to the circulation pipe 14. The supply means 13 supplies the fuel liquid 5 stored in the sub tank 9 to the engine
In order to supply the oil to the engine 15, it is constituted by a pipe connecting the sub tank 9 and the engine 15. Engine 15 is a diesel engine. The circulation pipe 14 supplies the fuel liquid 5 stored in the sub tank 9 to the main tank 10 by the pump 16.
The sub-tank 9 and the main tank 10 are connected in order to recirculate.

And each tip of the supply means 13 and the circulation pipe 14
13a and 14a are set slightly higher than the bottom surface 9a of the sub-tank 9 to prevent the suction of the precipitate 5b. Further, the sub-tank 9 has a collision plate 9b for separating mist such as a fuel liquid contained in the exhaust gas.

10 is a main tank. The main tank 10 is a tank which can be easily refueled from the outside, and is connected to the injection means 8 together with the additive tank 17. The additive tank 17 is a tank for adding an additive such as a cleaning dispersant to the fuel liquid 5. The detergent / dispersant referred to here is to disperse the deposit precursor or the oil oxide in the fuel liquid 5 in a neutralized or fine particle state.

18 is a lower duct and 19 is an upper duct. The lower duct 18 and the upper duct 19 are exhaust gas passages,
The lower duct 18 is connected to the sub tank 9 and the upper duct 19 is connected to the engine 15. And with the lower duct 18,
Between the upper ducts 19, the wiper corona generator 6 is sandwiched. More specifically, the lower part of the scraper corona generating part 6 is pressed against the lower duct 18 via a silicone rubber packing 20a, and the upper part is similarly set via the packing 20b.
It is pressed against 1. Further, the set member 21 is fixed to the upper duct 19 by screws 21a.

The set member 21 is a metal member, and facilitates removal and mounting of the slender corona generator 6 during maintenance.

Between the lower duct 18 and the upper duct 19, there is provided an earth plate 22 through which a plurality of brush corona generators 6 are inserted. The earth plate 22 is a member for grounding the second electrode 2 of each brush core corona generator 6 together with one end of the high-voltage power supply 4, and the earth plate 22 is connected to the second electrode 2 through a contact member 23. 2 is electrically connected. The contact member 23 is a member formed of a metal material such as beryllium, copper alloy material or the like, which is formed in a substantially U-shape, and is detached and attached at the time of maintenance of the spreader corona generator 6. Is easy.

Next, the operation of the exhaust gas purifying device having the above-described components will be described with reference to FIG.

First, the exhaust gas sent from the engine 15 through the inlet hole 24 into the upper duct 19 as shown by the arrow B passes through the plurality of scraper corona generators 6 as shown by the arrow C. At this time, in the inside of the scourer corona generating section 6, the scrubber coronas C1 are arranged in a row due to a discharge phenomenon, and all of the exhaust gas passes through the atmosphere of the scrubber corona C1.

The exhaust gas contains harmful gases such as nitrogen compounds (NO _x ), and these harmful gases are removed from the exhaust gas by ozone, ion wind, etc. generated in the scraper corona generator 6.

The exhaust gas that has passed through the scraper corona generator 6 is purified, reaches the lower duct 18 as shown by the arrow D, and is discharged to the exhaust hole 25 through the sub-tank 9 as shown by the arrows E and F.

On the other hand, the fuel liquid 5 is dropped from the main tank 10 through the injection means 8 and the dropping hole 8a into the scraper corona generator 6.

The fuel liquid 5 dropped into the scourer corona generating unit 6 receives Coulomb force or is diffused and adsorbed on the surface of the insulating unit 3 by ionic wind between the two electrodes where the scrubber corona C1 is generated.

As a result, the surface of the insulating portion 3 is constantly cleaned and smoothed by the fuel liquid 5. Then, the fuel liquid 5 flowing out of the parlor corona generator 6 is supplied to the lower duct.
The sub tank 9 is reached via 18. At this time, a part of the fuel liquid 5 is contained as mist in the exhaust gas, and the mist collides with a collision plate 9b provided in the sub tank 9, is stalled, and is collected in the sub tank 9. Thereby, the fuel liquid 5 can be effectively used. Then, the fuel liquid 5 accumulated in the sub tank 9 is pumped by the pump 16 into the main tank 10 and is again injected into the brush corona generator 6.

The fuel liquid 5 accumulated in the sub-tank 9 is supplied to a supply unit.
It is also supplied to the engine 15 via 13. That is, as the engine 15 rotates, the feed /
When a pump (Feed Pump, not shown) operates, the feed pump exerts a negative pressure on the supply means 13, thereby sucking up the fuel liquid 5 accumulated in the sub tank 9. Thus,
The fuel liquid 5 that has washed the parlor corona generator 6 is temporarily stored in the sub tank 9 and then supplied to the engine 15 for combustion.

Second Embodiment FIG. 2 is a vertical sectional view showing a second embodiment of the present invention. The second embodiment has substantially the same configuration as the above-described first embodiment. Here, the description of the common parts will be omitted, and different parts will be described.

In the second embodiment, the connection position of the main tank 10 is different from that of the first embodiment. That is, the main tank 10 of the second embodiment is provided in the middle of the supply means 13. The main tank 10 is installed at substantially the same height as the sub tank 9, and
The diameter of the supply means 13 connecting the main tank 10 and the sub tank 9 is set to a relatively large diameter. Therefore, for example, when the vehicle accelerates and brakes, the fuel liquid 5 is subjected to inertial force so that the space between the main tank 10 and the sub tank 9 is conventionally moved, and the fuel liquid 5 in the sub tank 9 is Diluted.

[Effects of the Invention] The present invention has an injection means for injecting a fuel liquid into a slender corona generating section constituting an exhaust gas purifying apparatus,
It is characterized in that it has a supply means for supplying the engine with the fuel liquid flowing out of the scraper corona generating section.

Therefore, the deposits on the surface of the insulating portion on the first electrode side can be washed with the fuel liquid, and the large-scale corona discharge can be stably maintained and secured for a long period of time. Harmful gas in the exhaust gas can be stably removed for a long period of time by passing the vehicle exhaust gas through the corona generating portion, and the fuel liquid can be reused as fuel for the engine. Is excellent.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a first embodiment of the present invention, and FIG. 2 is a vertical sectional view of a second embodiment of the present invention. 3 to 5 are schematic views for explaining a corona generation state of the present invention, FIG. 3 is a view showing a positive corona generation state, FIG. 4 is a view showing a zero point state, FIG. 5 is a view showing a state in which a negative polarity corona is generated. 1... A first electrode, 2... A second electrode, 3.
4 ... High-voltage power supply, 5 ... Fuel liquid, 6 ... Sputter corona generating section, 7 ... Support section, 8 ... Injection means, 8a ... Drip hole, 9
… Sub tank, 10… Main tank, 11… Reservoir means, 13… Supply means, 14… Circulation pipe, 15… Engine, 18 …… Lower duct, 19 …… Upper duct

────────────────────────────────────────────────── ─── Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F01N 3/04-3/38

Claims (1)

(57) [Claims] A first electrode having a convex portion on a surface, a second electrode facing the first electrode, and an insulating portion attached to at least a surface of the second electrode on the first electrode side. A brushing corona generating section comprising a high-voltage power supply connected between the two electrodes; an injection means for injecting the fuel liquid into the brushing corona generating section; and a supply for supplying the fuel liquid flowing out of the brushing corona generating section to the engine. Means, and an exhaust gas purifying apparatus comprising: