JPH10113577A - Charging part of air cleaning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a charging part which is of a small size and has a high charging efficiency and a low pressure loss, and can be cleaned and operated at a low running cost. SOLUTION: The charging part of an air cleaning device is provided on the upstream side of a gas flow as the charging part of the device consisting of a dust collecting part on the downstream side. In addition, an air-permeable grounding electrode 3 arranged spaced with a specified void from a discharge electrode 5 to which high voltage is applied, is of such a trapezoidal shape that the cross section of the grounding electrode 3 is bottomless. Further, the discharging part of the discharge electrode 5 is set in closest proximity to, at least, three or more points on the trapezoidal grounding electrode 3. Besides, the parts equivalent to the trapezoidal bottom parts of the grounding electrode 3 whose cross section is bottomless are combined by butting the parts to each other in a mutually opposite position, so that the grounding electrode 3 is arranged spaced with a specified void from the discharge electrode 5. Alternatively, the parts equivalent to the trapezoidal bottom parts are combined by butting the parts to each other in a mutually opposite position and are set in closest proximity to, at least, three or more points on one trapezoidal grounding electrode 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging section of an air cleaning apparatus using an electric dust collection system.

[0002]

2. Description of the Related Art In a conventional charging section shown in FIG. 2, a grounded counter electrode facing a needle electrode is arranged so as to be perpendicular to a vertical direction, and dust particles entering a charging section 13 by a gas flow are removed. A method of charging in an ion atmosphere formed between a needle electrode and a ground electrode has been used.

The charging section 13 of this electric dust collector is thin,
Although it was able to satisfy low pressure loss, it was possible to charge particles by corona discharge only in a small space between the tip of the needle electrode and the opposing electrode due to the thinness, so that dust entering the gas flow The probability of charging the particles was low and the amount of charged dust particles was not sufficient.

Further, since the counter electrode is located at a position orthogonal to the needle electrode, the transition of the discharge point at the needle tip at the time of corona discharge generated between the needle electrode and the counter electrode is small, and the decay of the discharge current with respect to the elapsed time is small. Large and stable charging space cannot be obtained for a long time.

As a method of increasing the amount of charged particles in the charging unit 13 to increase the probability of charged particles and increase dust collection efficiency, a method of increasing the number of needle electrodes and widening the space in which an electric field works is used. However, there are structural limitations and a problem that the amount of ozone generated during discharge increases.

[Problems to be solved by the invention]

The present invention is an improvement of the above-mentioned prior art, and realizes high charging efficiency, miniaturization, low pressure loss, and cleaning and recyclable air of low running cost, which are the propositions of the charging system of an electrostatic precipitator. A charging unit of the cleaning device is provided.

[Means for Solving the Problems]

The cross section of the discharge electrode to which a high voltage is applied and the air-permeable ground electrode provided through a certain gap are trapezoidal without a lower bottom.

[0008] The cross section of the discharge electrode to which a high voltage is applied and the air-permeable ground electrode disposed through a certain gap is trapezoidal without a lower bottom, and the discharge portion of the discharge electrode has at least three points of the ground electrode. And the closest.

[0009] As the charging portion, a trapezoidal lower-bottom-corresponding portion having a trapezoidal cross section having no lower bottom and having a cross section of a discharge electrode to which a high voltage is applied and a gas-permeable ground electrode provided through a constant gap is opposed to and opposed to each other. Combined.

The cross section of the air-permeable ground electrode provided with a certain gap therebetween has at least three points of a trapezoidal ground electrode, which is combined with the trapezoidal ground electrode having a trapezoidal shape having no lower bottom and opposed to each other. Closest.

[0011]

In an air purifying apparatus provided with a charged portion on the upstream side of a gas flow and a dust collecting portion on the downstream side, ventilation provided as a charged portion through a discharge electrode 1 to which a high voltage is applied and a fixed gap. The operation in the case where the cross section of the ground electrode having the property is a trapezoid having no lower bottom will be described below with reference to FIG.

FIG. 3A is a schematic diagram of the dust collection system of the present invention, and FIG. 3B is an enlarged view of the discharge unit 2 of the charging unit 13 and the trapezoidal ground electrode 3 of FIG. 3A. is there. The gas flow 11 is, for example, a flow of gas generated by a fan or the like to be processed by an air purifier and contains dust. The dust carried on the gas flow 11 enters the charging unit 13 of the present invention, which is constituted by the discharge electrode 1 and the trapezoidal ground electrode 3. A high voltage is applied to the discharge electrode 1 by a power supply 4 for a charging unit having a positive electrode grounded, and a negative corona discharge generated in a gap between the discharge part 2 of the discharge electrode 1 and the trapezoidal ground electrode 3 causes
The dust particles having the ion atmosphere and entering the charging unit 13 riding on the gas flow 11 are charged in the ion atmosphere (hereinafter, the charged dust particles are referred to as charged particles 15).

The ion atmosphere formed by the charging unit 13 is as follows:
Since the trapezoidal ground electrode 3 is arranged so as to surround the discharge part 2, the time during which the dust particles stay in the ion atmosphere becomes apparently long, so that the dust particles are charged with an extremely high probability.

Most of the dust particles are charged with a high probability by the charging unit 13 to become charged particles 15, for example, the charged particles 15
Focusing on “a”, the charged particles 15 a
Despite the movement in the vector direction 6a, the discharge portion 2 causes the trapezoidal ground electrode oblique side 3a (hereinafter oblique side 3a).
The charged particles 15a are deflected in the direction of the combination 16c of the two vectors and move toward the hypotenuse 3a by receiving the force of the vector 16b combined by the Coulomb force due to the electric field acting in the direction of the electric field and the action of the lines of electric force. Collected. In addition, even if attention is paid to the charged particles 15c, the charged particles 15c are collected by the hypotenuse portion 3c by substantially the same mechanism as that of the charged particles 15a.

Focusing on the charged particles 15a, Coulomb force and electric force are generated by a vector 16a due to the gas flow 11 and an electric field acting in a gap between the discharge portion 2 and the trapezoidal ground electrode top bottom 3b (hereinafter referred to as top bottom 3b). The force 16b is received by the action of the line, and is collected toward the upper bottom 3b by the force represented by the combined vector 16c of the two vectors.

In this region in which the direction of the vector 16a of the gas flow 11, the force applied by the electric field acting in the gap between the discharge part 2 and the trapezoidal ground electrode 3, and the direction of the vector 16b are almost equal, the two combined vectors 16c become large. Charged particle 1
The mobility of 5a increases. Therefore, the collection efficiency of the charged particles 15b is not necessarily higher than that of the region where the charged particles 15a exist. However, this region also has the effect of improving the collection efficiency of the entire charging unit.

As described above, it is possible to simultaneously increase a charged space effective for charging particles and a space having an electric field intensity effective for collection, and to reduce dust particles entering the charging unit 13 with a high probability. It can be charged and further collected on the ground electrode 3.

The charged particles not collected by the charging unit 13 ride on the gas flow 11, pass through the trapezoidal ground electrode 3 having air permeability, and enter the dust collecting unit 14. The charged particles 16 that have reached the dust collecting part 14 pass through the collecting electrode 5 and have a positive polarity opposite to that of the repulsion electrode 7 to which a negative high voltage is applied from the dust collecting part power supply 7. The charged particles are efficiently collected by the non-permeable portion 6 of the collecting electrode gas flow due to the Coulomb force acting between them.

With the above-described charged particle collecting mechanism, the dust collecting portion according to the present invention can obtain extremely high dust collecting efficiency and a dust particle charging effect.

In describing the operation of the present invention,
Although described with reference to the configuration of FIG. 3, it is not always necessary to stick to this configuration. For example, the discharge electrode 1 may be a wire electrode, or may be a positive charge having the opposite charge electrode property.

In an air purifying apparatus provided with a charged portion on the upstream side of the gas flow and a dust collecting portion on the downstream side, the charged portion is provided with a discharge electrode 1 to which a high voltage is applied and a ventilation provided via a fixed gap. FIG. 4 shows an operation in the case where the cross section of the grounding electrode having a trapezoidal shape without a lower bottom and the discharge part 2 of the discharge electrode 1 is closest to at least three points of the grounding electrode.
This will be described with reference to FIG.

The discharge unit 2 is positioned at three points closest to the trapezoidal ground electrode 3 and at equal distances 12 to the adjacent points A, B, and C, respectively.
They are installed through a, b, and c. A negative high voltage is applied to the discharge electrode 2 from the charging unit power supply 4 having the positive electrode grounded, and the trapezoidal ground electrode 3 is connected to the opposite positive polarity. Corona discharge occurs due to the uneven electric field at the adjacent points, and the gap between the discharge part 2 and the trapezoidal ground electrode 3 becomes a uniform ion atmosphere. The dust particles that have entered the charging unit 13 due to the gas flow 11 are negatively charged in the uniform ion atmosphere gap between the discharging unit 2 and the trapezoidal ground electrode 3 to become charged particles.

Since the trapezoidal grounding electrode 3 is disposed at equal distances 12a, b, and c from the discharge part 2, the electric field strength from the discharge part 2 becomes uniform, and the discharge point of the discharge part 2 Therefore, the discharge point can be easily moved, so that the decay of the discharge current can be eased and a high charging efficiency can be obtained for dust particles for a long period of time.

Although the operation of the present invention has been described with reference to the configuration of FIG. 4, it is not always necessary to stick to this configuration. For example, the discharge electrode 1 may be a wire electrode, The opposite positive charge may be used.

In an air purifying apparatus provided with a charging section on the upstream side of the gas flow and a dust collecting section on the downstream side, the air permeability provided by a high-voltage-applied discharge electrode as the charging section and a certain gap is provided. The operation in the case where the trapezoidal bottom corresponding to a trapezoid having a cross section of the ground electrode having no lower bottom is opposed to each other and combined with each other will be described with reference to FIG.

The lower and upper portions of the two trapezoidal grounding electrodes are arranged so as to abut against the upper and lower portions of the gas flow so as to surround the discharge portion 2 to which the high voltage is applied. An electric field acts on the gap between the trapezoidal ground electrode 17a and the trapezoidal ground electrode 17b on the downstream side, and the space of the ion atmosphere is greatly increased despite the same applied voltage as the above-mentioned system, which is effective for charging dust particles. Dust particles entering the charging unit 13 are charged with extremely high efficiency.

Further, the upstream trapezoidal ground electrode 17a and the downstream trapezoidal ground electrode 17a are discharged from the discharge portion 2 by the action of the electric field.
Both the Coulomb force generated toward b and the space and area on which the lines of electric force act become large, and the charged particles can be more efficiently collected by the upstream and downstream trapezoidal ground electrodes 17a and 17b.

In an air purifying apparatus provided with a charging section on the upstream side of the gas flow and a dust collecting section on the downstream side, the charging section is provided with a discharge electrode to which a high voltage is applied and a gas permeable member provided through a fixed gap. The cross-section of the ground electrode having a trapezoidal shape having no trapezoidal bottom is matched with the bottom of the trapezoid, and the discharge part 2 of the discharge electrode is brought closest to at least three points of one trapezoidal grounding electrode having no trapezoidal bottom. The operation in the case of this will be described with reference to FIG.

The discharge unit 2 to which the high voltage is applied has a distance A12d from the upper trapezoidal ground electrode upper bottom 18 via the distance A12b equal to the downstream trapezoidal ground electrode upper bottom 20.
At two points where the upper and lower trapezoidal ground electrodes 17a and 17b are in contact with each other, the gas flow 11 and the discharge unit 2 are arranged via a gap having the same distance A12a and c in the direction orthogonal to the orthogonal direction.

The upper and lower trapezoidal ground electrodes 17a and 17b and the discharge portion 2
Are closest to each other in a gap equal to or more than three points, the discharge point of the discharge part 2 easily transitions, the attenuation of the discharge current can be eased, and high charging efficiency can be obtained for dust particles for a long time.

Further, by the action of the electric field which spreads evenly from the discharge part 2, the upstream trapezoidal ground electrode 17a
The Coulomb force generated toward the trapezoidal ground electrode 17b on the downstream side and the space and the area where the lines of electric force act become large, and the charged particles are more efficiently trapped on the trapezoidal ground electrode 17 on the upstream and downstream sides.
a and b can be collected.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the method of the present invention will be described below in detail with reference to the drawings. Note that the method of the present invention can be implemented in a charging unit of an air purifying apparatus in which a charging unit is provided on an upstream side of a gas flow and a dust collection unit is provided on a downstream side using an electric dust collection method.

FIG. 1 is a cross-sectional view showing the overall configuration of an electric dust collector using a charging unit according to the method of the present invention. The charging unit 13 of the present invention is connected upstream of the gas flow 11 to the negative electrode of the charging unit power supply 4 having a positive electrode grounded using a needle-shaped electrode as the discharging electrode 1, and directed downstream with respect to the gas flow 11. Discharge part 2
Is arranged. The trapezoidal ground electrode 3 has an upper bottom disposed downstream with respect to the gas flow 11 via a constant gap with the discharge unit 2,
The discharge unit 2 is connected to the positive electrode of the charging unit power supply 4 and to the ground 10, and is connected to the discharge unit 2 by the negative high voltage applied to the discharge electrode 1.
And a non-uniform electric field is formed in the gap between the trapezoidal ground electrode 3 and the negative corona discharge is generated in the vicinity of the discharge unit 2 so that the dust particles entering the charging unit 13 by the gas flow 11 are negatively charged. ing.

On the other hand, the dust collecting part 14 is arranged perpendicularly to the collecting electrode gas flow transmitting part 5, which is arranged perpendicular to the gas flow 11, and the collecting electrode gas non-permeable part 6 is arranged at a certain interval. It consists of repulsion electrodes 7 arranged with a constant gap. The repulsion electrode 7 has the same polarity as the polarity of the charging unit 13, is connected to the negative electrode of the power source 9 for the dust collection unit, and the collection electrode gas flow transmission unit 5 and the collection electrode gas flow non-transmission unit 6 collect dust. It is connected to the grounded positive electrode side of the external power supply 9. The trapezoidal ground electrode 3 is formed by punching metal into a trapezoidal shape so that the gas flow 11 can pass therethrough. The pressure loss in the charging unit is as extremely low as 0.7 mmAq at 0.8 m / S, and the charging unit 13 Since the ground electrode is processed into a trapezoidal shape while having an extremely small thickness of 12 mm, the area of the trapezoidal ground electrode 3, that is, the ground electrode area is about 60% wider than that of the conventional system.

Further, in this embodiment, when the dust collection efficiency of the 0.3 μm particle diameter in the charging unit 13 and the dust collection unit 14 was measured using the indoor dust, the gas flow rate was 0.8 m / s.
Showed an extremely high dust collection efficiency of about 75%. Further, according to the configuration of the present embodiment, a water flow or the like at the time of cleaning the inside of the charging unit 13 and the dust collecting unit 14 can be transmitted,
Since the used members can sufficiently withstand the cleaning, the cleaning and regeneration of all the systems can be easily performed, and the running cost of the air cleaning apparatus can be reduced.

In this embodiment, a needle electrode is used as the discharge electrode 1. However, the same effect can be obtained with a wire electrode, and the same effect can be obtained even when the applied voltage is positive.

FIG. 7 shows a third embodiment of the present invention wherein two trapezoidal grounding electrodes 17a and 17b are arranged so as to correspond to the lower bottom portions thereof, and a predetermined distance from the trapezoidal grounding electrodes 17a and 17b. A wire electrode is disposed as the discharge electrode 1 through the intermediary.
As the trapezoidal ground electrodes 17a and 17b, S having an aperture ratio of about 50%
US punching metal is machined into a trapezoidal shape, and the charging unit 13 in this embodiment can effectively use space. Therefore, the area of the ground electrode should be increased about 2.2 times as compared with the conventional system. And gas flow rate of 0.8m / s
Although the pressure loss at the time is extremely low at 1.5 mmAq and the thickness in the gas flow direction is as thin as about 20 mm, the charged portion 1
The dust collection efficiency of only 3 is as high as 50% at a gas flow rate of 0.8 m / s in 0.3 μm atmospheric dust, and a charged part with high dust collection efficiency can be realized. A dust collecting device having a high dust collecting efficiency can be obtained. In addition, trapezoidal ground electrodes 17a,
It is desirable to change the aperture ratio of the punched metal b. In this manner, the trapezoidal ground electrode 17a,
It has the characteristic that the material, shape and type of b can be selected.

FIG. 8 shows a fourth embodiment of the present invention in which two similar trapezoidal grounding electrodes 17a and 17b are opposed to each other and abuttingly arranged. The discharge electrode 1 is arranged at a certain distance so as to be closest to a point or more, and a wire electrode is arranged as the discharge electrode. The trapezoidal ground electrodes 17a and 17b have an aperture ratio of about 5
8% SUS expanded metal is processed into a trapezoidal shape, and the charging section in this embodiment can effectively use space. Therefore, the area of the ground electrode is about 2.3 times larger than that of the conventional system. And the discharge electrode 1
Is closer to at least three or more points of the trapezoidal ground electrodes 17a and 17b, the discharge point easily transitions, and the decay of the discharge current due to corona discharge can be reduced to almost twice the conventional value.

Further, the pressure loss at the gas flow rate of 0.8 m / s in the charging section 13 is extremely low at 1.4 mmAq, and the thickness in the gas flow direction is as thin as about 20 mm. The efficiency is as high as 50% at a gas flow rate of 0.8 m / s in 0.3 μm atmospheric dust, and a charged part with high dust collection efficiency can be realized. Further, the discharge part 2 and the ground electrode 17a,
The ion atmosphere formed by the action of the electric field that spreads uniformly between b spreads widely, and the dust particles are sufficiently charged, and the charged amount of the charged particles increases, so that the dust collection efficiency in the dust collection part also increases,
When combined with the dust collecting section 14, a dust collecting device having an extremely high dust collecting efficiency of 85% or more can be obtained, and all the members can be washed and regenerated, so that the running cost can be kept low.

FIG. 9 shows a system in which a plurality of the embodiments shown in FIG. 8 are combined and stacked. The trapezoidal ground electrode 3 is made of SUS punched metal having an aperture ratio of about 65% in order to reduce the pressure loss. The thickness in the gas flow direction is about 68 mm, but the dust collection efficiency is about 0.
85% at 3m air dust at a gas flow rate of 0.8m / s
As described above, a dust collection device having high dust collection efficiency can be realized. Further, the dust collection efficiency can be further increased by increasing the number of combinations.

In the embodiment shown in FIG. 10, the trapezoidal ground electrode 3 has an upper bottom portion facing the upstream side of the gas flow 11 and a conductive flat ground electrode 20 extending downstream of the gas flow 11. The discharge electrode 1 is arranged at a predetermined distance from the trapezoidal ground electrode 3, which is in contact with a portion corresponding to the lower bottom of the shape ground electrode 3. The discharge electrode 1 has a flat plate-equivalent portion 21 formed by processing a flat plate-equivalent portion extending to the downstream side of the gas flow to be longer, and the flat plate-equivalent portion 21 has a flat plate ground electrode 20 extending from the trapezoidal ground electrode to the downstream side of the gas flow. They are installed in parallel with a certain gap.

Dust particles that have entered the charging unit formed by the trapezoidal ground electrode 3 and the discharge unit 2 by the gas flow 11
In the uniform ion atmosphere formed by the corona discharge formed between the ground electrode 3 and the trapezoidal ground electrode 3, the charged particles 16 are efficiently charged into the charged particles 16 and further extend to the gas flow 11 downstream of the discharge electrode 1. , And into the dust collecting portion formed by the flat plate ground electrode 20 extending from the lower bottom portion corresponding portion of the trapezoidal ground electrode 3 to the downstream side of the gas flow 11. In this region, as shown by the generally used Deutsch equation, the charged particles 16 are efficiently applied to the grounded plate electrode by the Coulomb force acting between the grounded plate electrode and the plate electrode to which a high voltage is applied. Collected.

By arranging the trapezoidal ground electrode 3 at the upper bottom toward the upstream side of the gas flow 11 as described above, the trapezoidal ground electrode 3 can be used as a dust collecting portion in combination with the flat electrode. By increasing the amount of charge of the charged particles 16 using, the dust collection efficiency can be increased and the pressure loss can be suppressed low. Further, since the trapezoidal ground electrode 3 is installed such that the upper bottom portion is on the upstream side, It is possible to use a filter that is usually used to remove large dust, hair, and the like.

[0044]

As described above, according to the present invention, it is possible to provide an air purifying apparatus which realizes high charging efficiency, miniaturization, low pressure loss, and can be reused by washing and has low running cost. Can be.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an air purifying apparatus using a charging unit according to the present invention.

FIG. 2 is a schematic diagram of a conventional electric precipitator using a charging unit.

FIG. 3 is a schematic diagram illustrating the present invention.

FIG. 4 is a schematic diagram of a charging unit of the present invention in which a discharge electrode is closest to at least three points of a trapezoidal ground electrode.

FIG. 5 is a schematic view of a charging section of the present invention in which discharge electrodes are arranged by butt-combining portions corresponding to lower bottom portions of trapezoidal ground electrodes.

FIG. 6 is a schematic diagram of a charging unit according to the present invention in which parts corresponding to the lower bottom of the trapezoidal grounding electrode are butted together and brought closer to at least three or more points with the discharge electrode.

FIG. 7 is a perspective view of the first embodiment of the present invention in which discharge electrodes are arranged by butt-combining portions corresponding to lower bottom portions of trapezoidal ground electrodes.

FIG. 8 is a perspective view of a second embodiment of the present invention in which parts corresponding to the lower bottom portion of the trapezoidal ground electrode are butted together and brought closer to at least three points with the discharge electrode.

FIG. 9 is a schematic view of a third embodiment of the present invention in which a plurality of charging units of the present invention are combined.

FIG. 10 is a schematic view of a fourth embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 discharge electrode 2 discharge part 3 trapezoidal ground electrode 4 power supply for charging part 5 collection electrode gas flow transmission part 6 collection electrode gas flow non-transmission part 7 repulsion electrode 8 electrical connection 9 power supply for dust collection part 10 ground 11 gas Flow 12a Distance A 12b Distance A 12c Distance A 13 Charging part 14 Dust collecting part 15a Charged particle 15b Charged particle 15c Charged particle 16a Gas flow direction vector 16b Gas flow direction vector 16c Gas flow direction vector 17a Upstream trapezoidal ground electrode 17b Downstream Side trapezoidal ground electrode 18 Upper trapezoidal ground electrode top bottom 19 Downstream trapezoidal ground electrode top bottom 20 Flat plate ground electrode 21 Plate equivalent

Claims (4)

[Claims] In an air purifying apparatus provided with a charging section on the upstream side of a gas flow and a dust collecting section on a downstream side, the charging section is disposed via a fixed electrode and a discharge electrode to which a high voltage is applied. A charging section of an air purifying apparatus, wherein a cross section of a ground electrode having air permeability has a trapezoidal shape having no lower bottom. 2. An air purifying apparatus having a charging section provided upstream of a gas flow and a dust collecting section provided downstream thereof, wherein said charging section is disposed via a constant gap with a discharge electrode to which a high voltage is applied. The cross section of the air-permeable ground electrode is trapezoidal with no lower bottom, and the discharge part of the discharge electrode is at least 3
The charging unit of the air purifier, which is closest to the point or higher. 3. An air purifying apparatus having a charging section upstream of a gas flow and a dust collecting section downstream of the gas flow, wherein the charging section is disposed via a constant gap with a discharge electrode to which a high voltage is applied. A charging section of an air purifying device, wherein a section of a trapezoidal bottom having a trapezoidal shape in which a cross section of an air-permeable ground electrode does not have a bottom bottom is opposed to and combined with each other. 4. A cross-section of an air-permeable ground electrode provided with a constant gap as an air-charging unit, wherein a charging unit is provided on an upstream side of a gas flow and a dust collecting unit is provided on a downstream side. A trapezoidal ground electrode having a trapezoidal shape having no lower bottom and having a portion corresponding to a lower bottom portion of the trapezoidal shape facing the bottom portion and closest to at least three points of a trapezoidal ground electrode.