JP2001038242A - Electrostatic dust collector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic duct collector capable of preventing sparking while keeping dust collecting efficiency. SOLUTION: Flat-plate non-dust-collecting electrodes 3 made of a semi- insulating resin having a volume resistivity of not less than 108 Ω cm and flat- plate dust-collecting electrodes 5 made of a conductive material are alternately laminated parallel. The non-dust-collecting electrodes 3 are supported by a first support member 11 made of a material having the same function as that of the non-dust-collecting electrodes 3 in such a manner not to be in contact with the dust-collecting electrodes 5, and are connected to a first power source. The dust-collecting electrodes 5 are supported by second support members 15 made of a material having the same function as that of the dust-collecting electrodes 5 in such a manner not to be in contact to the non-dust-collecting electrodes 3, and are connected to a second power source.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic precipitator, and more particularly, to an electrostatic precipitator having a feature in a support interval and a feeding pitch of an electrode plate constituting a dust collecting portion. is there.

[0002]

2. Description of the Related Art Conventionally, dust in the air ionized by corona discharge of a charging unit is connected to a power supply to form an electric field between a non-dust collecting electrode and a dust collecting electrode. There is known an electrostatic dust collector which collects the dust on a dust collecting electrode.

In such a dust collecting device, for example, a positive corona discharge space is formed in the charging section, and dust in the air is positively charged, and the dust particles are relatively moved from the non-dust collecting electrode of the dust collecting section. The dust is collected electrostatically on a dust collecting electrode connected to the negative power supply or the ground potential. Also, a power supply is connected so that the dust is collected on the dust collecting electrode even when a negative discharge is caused in the charging unit.

In such an electrostatic precipitator, metal has been used as an electrode. However, when a metal is used for the electrode, a spark is generated when the potential difference between the non-dust collecting electrode and the dust collecting electrode is increased, or when the collected dust accumulates on the dust collecting electrode and the resistance decreases as a result. Discharge or sparking was inevitable. In addition, if the insulating portion holding the electrodes, the spacers, and the like become dirty, a collector leak current flows, and there is a disadvantage that the potential difference decreases and the collecting performance decreases. Further, as shown in Japanese Utility Model Registration No. 30331345, for example, in FIG. 8, a comb-shaped charging rod for supporting the non-dust collecting side electrode 101 and supplying power to the non-dust collecting side electrode 101. 103 is formed of a semi-insulating resin, and the dust collecting side electrode 105 is inserted into a comb-like ground rod 107 so as not to contact the non-dust collecting side electrode 101.

[0005]

However, in such a conventional technique, there is a problem that sparks still tend to occur because the electrodes are made of metal.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrostatic precipitator capable of preventing the occurrence of a spark while maintaining the collection efficiency. It is in.

[0007]

In order to achieve the above object, an electrostatic precipitator according to the first aspect of the present invention is capable of removing dust in the air ionized by corona discharge of a charging unit. An electrostatic precipitator that electrostatically collects in an electric field generated between an electrode and a precipitating electrode, wherein the non-precipitating electrode has a volume resistivity of 10 ⁸ Ωcm or more. A power feeding member which is a thin plate-shaped electrode made of resin, and which is arranged in parallel so that the non-dust collecting electrode and the thin plate-shaped dust collecting electrode do not alternately contact with each other, and is made of a functional material similarly to the non-dust collecting electrode. And connecting the non-dust collecting electrode to a power supply.

Accordingly, the thin plate-shaped non-dust collecting electrode made of a semi-insulating resin having a volume resistivity of 10 ⁸ Ωcm or more and the thin plate-shaped dust collecting electrode are arranged in parallel so as not to contact alternately. The dust collecting electrode is similarly connected to a power supply by a power supply member that is a semi-insulating resin.

According to a second aspect of the present invention, an electrostatic precipitator is provided.
2. The electrostatic dust collector according to claim 1, wherein a pitch P (mm) between the power supply members is equal to an applied voltage V (kV). 3.
It is characterized in that P ≦ 2.05 · V ² −17.7 · V + 96.4.

Accordingly, the power feeding member, for the pitch P (mm) is the applied voltage V (kV), P ≦ 2.05 · V 2 -1
The non-dust collecting electrode is supported at a pitch of 7.7 · V + 96.4.

[0011] According to a third aspect of the present invention, there is provided an electrostatic precipitator.
3. The electrostatic precipitator according to claim 1, wherein the non-precipitating electrode and the power supply member are in a range of 10 ¹⁰ to 10 ¹³ Ωc.
m.

Therefore, the non-dust collecting electrode and the power supply member are composed of 1
It is formed from a member having a volume resistivity of 0 ¹⁰ to 10 ¹³ Ωcm.

According to a fourth aspect of the present invention, there is provided an electrostatic precipitator.
An electrostatic precipitator that electrostatically collects dust in air ionized by corona discharge of a charging unit in an electric field generated between a non-precipitating electrode and a precipitating electrode, The dust collecting electrode is a plate-shaped electrode made of a semi-insulating resin having a volume resistivity of 10 ⁸ Ωcm or more, and the dust collecting electrode is a plate-shaped electrode made of a conductive material. The electrode and the dust collecting electrode are stacked in parallel so as not to contact alternately, and are made of the same functional material as the non-dust collecting electrode, and support the non-dust collecting electrode in a state of not contacting the dust collecting electrode. A first support member connected to a power supply, and a second support member formed of a functional material similar to the dust collection electrode and supporting the dust collection electrode in a state not in contact with the non-dust collection electrode and connected to a second power supply. And a support member.

Therefore, the plate-shaped non-dust collecting electrode made of a semi-insulating resin having a volume resistivity of 10 ⁸ Ωcm or more and the plate-shaped dust collecting electrode made of a conductive material do not alternately contact each other. The non-dust collection electrodes are stacked in parallel, and the non-dust collection electrodes are supported by a first support member made of a material having a similar function so as not to contact the dust collection electrodes, and are simultaneously connected to the first power supply. The dust collecting electrode is supported by a second support member made of a material having a similar function so as not to contact the non-dust collecting electrode, and is simultaneously connected to the second power supply.

According to a fifth aspect of the invention, there is provided an electrostatic dust collecting apparatus.
The electrostatic precipitator according to claim 4, wherein the first support member and the second support member are disposed so as to penetrate the dust collection electrode and the non-dust collection electrode. Is what you do.

Therefore, the first support member is arranged so as to penetrate so as not to contact the dust collecting electrode, and the second support member is arranged so as to penetrate so as not to contact the non-dust collecting electrode.

According to a sixth aspect of the present invention, there is provided an electrostatic dust collecting apparatus comprising:
The electrostatic dust collector according to claim 4 or 5, wherein a pitch Y (mm) between the first support members is 70 mm or less.

Therefore, the first support member is provided at the pitch Y (m
m) supports the non-dust collecting electrode in a range of 70 mm or less.

According to a seventh aspect of the present invention, an electrostatic precipitator is provided.
7. The electrostatic precipitator according to claim 6, wherein a pitch Y (mm) between the first support members is Y ≦ 2.05 · V ² −17.7 · V + 96. 4 is a feature.

Therefore, the first support member has a pitch Y (m
m) is Y ≦ 2.05 · V with respect to the applied voltage V (kV).
^The non-dust collecting electrode is supported within the range of 2−17.7 · V + 96.4.

[0021] The electrostatic dust collecting apparatus of the invention according to claim 8 is as follows.
The electrostatic precipitator according to any one of claims 4 to 7, wherein the non-dust precipitating electrode and the first support member are 10 ¹⁰
From 10 ¹³ Ωcm to 10 ¹³ Ωcm.

Therefore, the non-dust collecting electrode and the first support member are formed of a material having a volume resistivity of 10 ¹⁰ to 10 ¹³ Ωcm.

According to a ninth aspect of the present invention, there is provided an electrostatic precipitator,
The electrostatic precipitator according to claim 4 or 5, wherein the precipitating electrode and the second support member have a volume resistivity of less than 10 ⁸ Ωcm.

Therefore, the dust collecting electrode and the second supporting member are
It is composed of a material having a volume resistivity of less than 10 ⁸ Ωcm.

[0025]

Embodiments of the present invention will be described below in detail with reference to the drawings.

Referring also to FIGS. 1 and 7, in the electrostatic dust collecting apparatus 1 according to the present invention, the non-dust collecting electrode 3 and the dust collecting electrode 5 to which a high voltage is applied are arranged at a predetermined interval. The dust particles in the ionized air are alternately arranged in parallel and pass through the corona discharge space of the charging unit 9 connected to a power supply (not shown), and the dust in the ionized air is connected to the power supply (not shown). An electric field is formed between the electrodes 5, and a dust collecting portion 7 is formed to electrostatically collect the dust on the dust collecting electrode 5. In the following description, a high voltage is applied to the discharge electrode of the charging unit as the first power supply, and the charging unit counter electrode is connected to the ground potential as the second power supply. I have. However, it is needless to say that the contents of the present invention are not limited only to this electrical connection, and can be applied to an electrostatic dust collector having another electrical connection.

The non-dust collecting electrode 3 is at least 10 ⁸ Ωcm (1
(Preferably 0 ¹⁰ to 10 ¹³ Ωcm). Also,
The dust collection electrode 5 is formed in a flat plate shape from a conductive material (or resin) having a volume resistivity of less than 10 ⁸ Ωcm.

Referring to FIG. 1 to FIG.
Is supported by a plurality of first support rods 11 as a first support member made of a semi-insulating resin similar to the non-dust collecting electrode 3, and is supplied with a high voltage by contact. The first support rod 11 has a hole 13 for the dust collection electrode 5.
To prevent contact. The first support bar 11 is connected to a high voltage generator of a power supply (not shown).

The dust collecting electrode 5 is supported by a plurality of second support rods 15 as a second support member made of the same material as the dust collecting electrode 5, but the non-dust collecting electrode 3 is The hole 17 prevents contact. Note that the second support bar 15 is connected to the ground.

Next, from the viewpoint of the bending of the electrodes 3 and 5 and the collection efficiency of the dust collecting section 7, the support pitch (also referred to as the power supply pitch) of the support rods 11 and 15 of the electrodes 3 and 5 is determined. The determination will be described.

When considering the support pitch from the viewpoint of bending, it is naturally advantageous to increase the thickness of the electrode plate in terms of the strength of the electrode itself. However, in order to increase the collection efficiency, that is, to increase the dust collection area, the same volume is required. It is desirable to arrange as many electrodes as possible in the dust collecting portion and to set the thickness as thin as possible in consideration of ventilation resistance. However, when considering from the viewpoint of ensuring the safety of the device, the plate thickness may be inevitably increased in consideration of ensuring the flame retardancy.

For setting the electrode thickness of the dust collecting portion as an actual product, for example, a semi-insulating resin material having hygroscopicity described in Japanese Patent Application Laid-Open No. 8-71451 of the invention which the present applicant has made in the past is used. When the non-dust collection electrode is manufactured by using, for example, 0.2 mm to 3.0 mm in consideration of the above-described contents and the like in various ways.
The thickness was set to about mm, but in the models that were used in the subsequent experiments, 0.5 mm molded with a hygroscopic semi-insulating resin material was used for the non-dust collecting electrode, and molded with a conductive resin material The same thickness was used for the dust collection electrode.

First, an experiment was conducted on the support pitch from the viewpoint of bending of the electrodes 3 and 5. That is, as shown in FIG. 4, the insulating spacer 1 is attached to the two dust collecting electrodes 5 at the ground potential.
The deflection of the charged non-dust collecting electrode 3 sandwiched via 9 is measured. Actually, when the non-dust collecting electrode 3 is located at an equidistant position between the two dust collecting electrodes 5, the non-dust collecting electrode 3 is pulled by the same force from both, so that it is not displaced. And a case where the eccentricity is considered in consideration of the change with time, and set as an experimental model.

Here, assuming that the closer pitch d is, for example, 1 mm and the other is 3.6 mm, the pulling by the electrostatic attraction f1, f2 from both electrodes 3, 5 (f1> f).
According to 2), the non-dust collecting electrode 3 is pulled by the lower dust collecting electrode 5 and displaced downward. FIG. 5A shows the relationship between the support pitch of the insulating spacer and the applied voltage when the electrodes 3 and 5 come into contact with each other. In this graph, the four applied voltages shown are 1.9, 2.5, 3.3, 4.5.
The support pitch at the limit of contact with respect to kV was measured and indicated by a circle.

The circle 4 shown in FIG.
When an approximate expression passing through individual fixed points is obtained, as an example, Y =
^{2.05 · X 2 -17.7 · X +} 96.4 is obtained. When the support pitch Y (mm) for each applied voltage X (kV) is obtained by this approximate expression, a sufficiently close value can be obtained as shown in FIG. Therefore,
If the support pitch Y is determined in the hatched range in FIG. 5A, it is possible to prevent the electrodes 3 and 5 from being bent and coming into contact.

If the applied voltage is 1.9 kV and the supporting pitch is 70 mm or less, and 3.3 kV or less, 60 mm or less, the electrodes 3 and 5 do not come into contact with each other. In a dust collector in which electrodes are arranged at an equal pitch without eccentricity, the potential difference between the two electrodes, that is, the applied voltage is 3 kV in order to obtain a desired value of the collection efficiency.
Considering that there is a case where the above setting is made, it is desirable to select the support pitch Y of about 60 mm or less.

Next, a feed pitch which is allowable from the viewpoint of collection efficiency is obtained. That is, when the dust collecting device 1 is used as a dust collecting device such as a smoke separator, it is required that the dust collecting device 1 be operated at a predetermined collection efficiency immediately after being turned on.

In the non-dust collecting electrode 3 using a semi-insulating material, it takes a long time to charge the entire electrode in the relation of time constant τ = dielectric constant ε × volume resistivity ρ. That is, it is known that it takes time to reach a predetermined collection efficiency. Also, as is clear from the experiment described later, when the power supply pitch exceeds a certain value due to the difference in resistance value affected by the shape of the electrode and the like, the trapping efficiency becomes the desired value even after a long time has elapsed since the start of high voltage application. Values (eg, 90%) were not found to be reached.

For this reason, it is desirable that the arrangement of the first support rods 11 (functioning as a power supply point) for supplying power to the non-dust collecting electrode 3 is such that the interval between the adjacent first support rods 11 is short. On the other hand, when the number increases to reduce the distance between the first support rods 11, the holes 13 for the first support rods 11 in the dust collection electrode 5 are increased.
Increases, the dust collection area decreases, and the dust collection efficiency decreases. Further, pressure loss increases due to an increase in ventilation resistance. Further, an increase in the number of the first support rods 11 causes a problem of increasing the number of assembling steps.

Therefore, the maximum pitch that can reduce the number of the first support rods 11 while maintaining a predetermined collection efficiency is determined. In FIG. 6A, similarly to the above-described support pitch from the viewpoint of bending, the points P0 (42 mm), PB (70 mm), and PC (192) from the point P0 shown in FIG.
mm) for three different distances.

FIG. 6A shows a measurement result of a temporal change in the dust collection efficiency with respect to each of the above-described power supply pitches when a voltage of 4 kV is applied to the non-dust collection electrode 3. FIG. 6B is a graph showing the contents of the table in FIG. 6A.

That is, when the power supply pitch is 42 mm, a predetermined dust collection efficiency (for example, 90%) is satisfied after one minute. In the case of 70 mm, the dust collection efficiency reaches a predetermined dust collection efficiency after 15 minutes.
As shown for 92 mm, the dust collection efficiency does not improve even after 15 minutes. From this, the power supply pitch is 70 m
m or less is desirable.

From the above results, it can be seen that the first support rod 11 supporting the non-dust collection electrode 3 not only serves as a structural support member but also serves as a power supply, and the second support rod 11 supporting the dust collection electrode 5. Considering that the support rod 15 is also a support member and a ground member (role corresponding to a power supply member), the support rod 15 is supported from the viewpoint of the deflection of the non-dust collecting electrode 3 and the collection efficiency of the dust collecting part 7. The pitch and feed pitch are Y
= 2.05.X ² -17.7.X + 96.4 It can be said that it is desirable to be equal to or less than the approximate curve and 70 mm or less.
Within this range, it is possible to prevent the trapping due to the contact due to the bending of the electrodes 3 and 5 and to obtain a predetermined trapping efficiency in a short time after switching on.

It should be noted that the present invention is not limited to the above-described embodiment of the present invention, but by making appropriate changes.
It can be implemented in other aspects. That is, in the above-described embodiment of the present invention, the relationship between the applied voltage and the limit support pitch is represented by a quadratic equation passing through four fixed points.
Not limited to this. Various curves can be adopted depending on the number of side fixed points and how to obtain an approximate curve.

In the above-described embodiment of the present invention, the case where the dust collecting electrode 5 is made of a conductive resin has been described, but a metal or resin such as iron or aluminum or a resin which has been subjected to plating surface treatment is used. It is also possible.

[0046]

As described above, in the electrostatic precipitator according to the first aspect of the present invention, the volume resistivity value is 10 ⁸ Ωc.
m, a thin plate-shaped non-dust collecting electrode made of a semi-insulating resin
Since the thin dust collecting electrodes are arranged in parallel so as not to contact alternately, and the non-dust collecting electrodes are connected to the power supply by a power supply member which is also a semi-insulating resin, so that sparks can be prevented. .

In the electrostatic dust collecting apparatus according to the second aspect of the present invention, the power supply member has a pitch P (mm) having an applied voltage V (k).
For V), P ≦ 2.05 · V ² −17.7 · V + 9
Since the non-dust collection electrodes are supported at a pitch in the range of 6.4, a predetermined collection efficiency can be obtained in a short time.

In the electrostatic precipitator according to the third aspect of the present invention, the non-precipitating electrode and the power supply member are 10 ¹⁰ to 10 ¹³ Ω.
Since it is formed by a member having a volume specific resistance of cm, spark can be prevented.

According to a fourth aspect of the present invention, there is provided an electrostatic precipitator having a flat non-dust collecting electrode made of a semi-insulating resin having a volume resistivity of 10 ⁸ Ωcm or more, and a flat non-collecting electrode made of a conductive material. The dust collecting electrodes are stacked in parallel without alternate contact, and the non-dust collecting electrodes are supported by the first support member made of a material having a similar function so as not to contact the dust collecting electrodes. Because it is connected to the first power source,
It is possible to prevent sparking, support the non-dust collection electrode, and supply power. The dust collecting electrode is supported by a second support member made of a material having a similar function so as not to contact the non-dust collecting electrode, and is connected to the second power supply at the same time. It can support the dust electrode and supply power.

In the electrostatic precipitator according to the fifth aspect of the present invention, the first support member is disposed so as to penetrate so as not to contact the dust collection electrode, and the second support member is disposed so as not to contact the non-dust collection electrode. Since it is disposed so as to penetrate, sparks can be prevented.

In the electrostatic dust collecting apparatus according to the sixth aspect of the present invention, since the first supporting member supports the non-dust collecting electrode in a range where the pitch Y (mm) is 70 mm or less, the first supporting member supports the non-dust collecting electrode. Spark due to bending can be prevented.

In the electrostatic dust collecting apparatus according to the present invention, the pitch Y (mm) of the first supporting member is equal to the applied voltage V.
(KV), Y ≦ 2.05 · V ² −17.7 · V
The non-dust collecting electrode is supported within the range of +96.4.

In the electrostatic dust collecting apparatus according to the eighth aspect of the present invention, the non-dust collecting electrode and the first supporting member may have a size of 10 ¹⁰ to 10
Since it is formed of a material having a volume resistivity of ¹³ Ωcm, it is possible to prevent sparks between the power supply member and the dust collection electrode.

In the electrostatic precipitator according to the ninth aspect of the present invention, since the precipitating electrode and the second support member are made of a material having a volume resistivity of less than 10 ⁸ Ωcm, the potential of the precipitating electrode is reduced. Can be made uniform.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a supporting state of a non-dust collecting electrode and a dust collecting electrode in an electrostatic dust collecting apparatus according to the present invention.

FIG. 2 is a plan view seen from a direction II in FIG.

FIG. 3 is a front view as viewed from a direction III in FIG. 1;

FIG. 4 is a model used for determining a support pitch.

FIG. 5A is a graph showing the relationship between the support pitch and the applied voltage at the time of contact, and FIG. 5B is a table showing the values.

FIG. 6A is a table showing a relationship between a power supply pitch and dust collection efficiency, and FIG. 6B is a graph thereof.

FIG. 7 is an external view of an electrostatic precipitator according to the present invention.

FIG. 8 is a front view showing a conventional non-collecting electrode and a supporting state of a collecting electrode.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrostatic dust collection device 3 Non-dust collection electrode 5 Dust collection electrode 11 First support rod (first support member) 15 Second support rod (second support member)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Yoshikazu Onoguchi 5-3, Hiroo, Shibuya-ku, Tokyo Midori Safety Co., Ltd. (72) Tsuneyuki Kiuchi Midori, 4-3-3 Hiroo, Shibuya-ku, Tokyo Midori F term in Safety Co., Ltd. (reference) 4D054 AA11 BA02 BC03 BC21 BC22 BC24 BC33 BC34 BC36

Claims (9)

[Claims] 1. An electrostatic precipitator that electrostatically collects dust in air ionized by corona discharge of a charging unit in an electric field generated between a non-precipitating electrode and a precipitating electrode. The non-dust collecting electrode is a thin plate made of a semi-insulating resin having a volume resistivity of 10 ⁸ Ωcm or more, and the non-dust collecting electrode and the thin plate collecting electrode are alternately contacted. An electrostatic precipitator, wherein the non-precipitator is connected to a power supply by a power supply member made of a functional material similar to the non-precipitator. 2. The pitch P (mm) between the power supply members is P ≦ 2.05 · V ² −1 with respect to an applied voltage V (kV).
The electrostatic precipitator according to claim 1, wherein 7.7 · V + 96.4. 3. The method according to claim 2, wherein the non-dust collecting electrode and the power supply member are one.
The electrostatic precipitator according to claim 1 or 2, wherein the electrostatic precipitator has a volume resistivity of 0 ¹⁰ to 10 ¹³ Ωcm. 4. An electrostatic precipitator that electrostatically collects dust in air ionized by corona discharge of a charging unit in an electric field generated between a non-precipitating electrode and a precipitating electrode. The non-dust collection electrode is a flat plate electrode made of a semi-insulating resin having a volume resistivity of 10 ⁸ Ωcm or more, and the dust collection electrode is a flat plate electrode made of a conductive material. The non-collecting electrode and the dust-collecting electrode are stacked in parallel so as not to alternately contact with each other, and are formed of the same functional material as the non-dust-collecting electrode. A first support member supported and connected to the first power source,
A second support member that is made of the same functional material as the dust collecting electrode and supports the dust collecting electrode without being in contact with the non-dust collecting electrode, and is connected to a second power supply. Electrostatic dust collector. 5. The electrostatic device according to claim 4, wherein the first support member and the second support member are arranged so as to penetrate the dust collecting electrode and the non-dust collecting electrode. Type dust collector. 6. A pitch Y (mm) between the first support members.
The electrostatic precipitator according to claim 4 or 5, wherein is less than or equal to 70 mm. 7. A pitch Y (mm) between the first support members.
Indicates that the applied voltage V (kV) is Y ≦ 2.05 · V ² −
The electrostatic precipitator according to claim 6, wherein 17.7 V + 96.4. 8. The electrostatic type according to claim 4, wherein the non-dust collecting electrode and the first support member have a volume resistivity of 10 ¹⁰ to 10 ¹³ Ωcm. Dust collector. 9. The electrostatic precipitator according to claim 4, wherein the precipitating electrode and the second support member have a specific volume resistance of less than 10 ⁸ Ωcm.