JPH04137744U - Electrostatic precipitator for paint booth - Google Patents

Abstract

(57) [Summary] [Purpose] To efficiently remove solvents, paint mist, etc. from exhaust gas while reducing size and cost. [Structure] A gas-liquid contact part (7) is provided in the dust collection passage (2) in the casing (1) to bring the exhaust gas into gas-liquid contact with an absorption liquid capable of dissolving a solvent. 7)
An electrostatic precipitator (10) is provided behind the.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to an electrostatic precipitator for a paint booth.

0002

[Conventional technology]

For example, in a paint booth, a Venturi system removes paint mist generated inside the painting room. It is collected by gas-liquid contact using a vacuum cleaner (normal collection efficiency is 95-98%).

0003 By the way, recently, stricter exhaust gas regulations ( For example, exhaust gas regulations and VOC regulations in the United States are being implemented. Therefore, it takes In order to comply with VOC regulations, etc., exhaust gas that has been primarily treated with a venturi device, etc. , a bag fume is installed before an activated carbon adsorption device (for example, a honeycomb deodorization device) for VOC treatment. It has been proposed to filter with a filter or the like (target collection efficiency of 80 to 90%).

0004 However, if the paint in the exhaust gas is collected using a bag filter, etc., the bag filter Paint may adhere to filters, etc., causing them to become clogged early. Things to do If this occurs, the passage of exhaust gas becomes difficult (that is, pressure loss increases), and the exhaust gas The amount of processing will decrease. In addition, once the paint adheres to bag filters, etc., it has a strong adhesive. Due to its nature, it cannot be easily removed and maintenance is very time consuming.

[0005] Therefore, in order to eliminate the above-mentioned drawbacks, the primary treated exhaust gas is subjected to wet electrostatic electrolysis. Secondary treatment using dust collectors is being considered.

[0006] Below, we will first explain the general configuration of a wet electrostatic precipitator, and then We will explain the secondary treatment of exhaust gas using

[0007] Figure 4 shows the schematic configuration of a wet electrostatic precipitator.

[0008] In the figure, 5 is a thin wire-shaped discharge electrode, and multiple lines are stretched in the direction perpendicular to the paper surface in the figure. ing. In addition, 6 is a flat dust collecting electrode, which is arranged a predetermined distance d from the discharge electrode 5. has been done. A high voltage is applied between the discharge electrode 5 and the dust collection electrode 6 to emit corona. An electric field field is formed.

[0009] However, paint particles in exhaust gas G that has been primarily treated using a venturi device etc. is charged with a constant polarity when passing through the discharge electric field formed between the electrodes 5 and 6. It adheres to the dust collection electrode 6. At this time, the dust collection electrode 6 is used to remove paint particles that have adhered to it. Water, etc. is sprinkled on the surface to clean it.

0010

[Problem that the idea aims to solve]

By the way, as mentioned above, wet type is used for secondary treatment of exhaust gas G from the paint booth. When using an electrostatic precipitator, the paint once attached to the dust collection electrode 6 is sticky. requires large amounts of water to effectively remove the paint.

Here, there is a limit to reducing the distance d between the discharge electrode 5 and the dust collection electrode 6 (generally 20 cm or less) because it is necessary to spray a large amount of water on the dust collection electrode 6 to prevent leakage. (difficult). As described above, since the distance d cannot be made small, the voltage applied between the electrodes 5 and 6 must be made extremely large in order to form a sufficient discharge electric field area between the electrodes 5 and 6. This results in high costs. In addition, since the amount of dust collected per unit area passing through the dust collection electrode 6 decreases, the equipment must become larger to treat the exhaust gas of 500 to 2000 m ³ /min that is normally discharged from one zone of a painting booth. Put it away.

0012 Furthermore, electrostatic precipitators cannot remove solvents from exhaust gas, so static As mentioned above, an activated carbon adsorption device (honeycomb deodorization device, etc.) is installed after the electrostatic precipitator. Because of this, the exhaust gas treatment equipment becomes larger and costs increase.

[0013] In view of the above circumstances, the purpose of this invention is to reduce exhaust gas while reducing size and cost. Electrostatic for paint booths that can efficiently remove solvents and paint mist inside. The purpose is to provide a dust collector.

[0014]

[Means to solve the problem]

This invention is a dust collector for passing exhaust gas containing solvents etc. discharged from a painting booth. It has a casing in which a passage is formed, and in the dust collection passage in this casing, A gas-liquid contact portion is provided for bringing the exhaust gas into gas-liquid contact with an absorption liquid capable of dissolving the solvent. In both cases, an electrostatic precipitator is provided behind this gas-liquid contact part, and the electrostatic precipitator collects the discharge voltage. pole, and a spaced apart from this discharge electrode by a predetermined distance and with respect to the discharge electrode. A dust collecting electrode made of a movable endless porous conductive material, and this dust collecting electrode A discharge electric field area is provided between a drive mechanism for moving the pole and the discharge electrode and the dust collection electrode. a high voltage generator for supplying a high voltage sufficient to form a dust-collecting electrode; Container containing paint stripper that can remove paint that has come into contact with the electrode and has adhered to the electrode. It is characterized by having a configuration including the following.

[0015]

[Effect]

In this invention, the paint is discharged from the painting room of the painting booth, etc., and is discharged using a Venturi device, etc. The solvent in the primary treated exhaust gas is absorbed by the gas-liquid contact section before entering the electrostatic precipitator. Gas-liquid contact with liquid. At this time, the absorbing liquid can dissolve the solvent, so the exhaust gas The solvent in the gas can be effectively collected.

[0016] In this way, the exhaust gas from which the solvent has been removed is transferred to the discharge electrode and the dust collection electrode of the electrostatic precipitator. When passing through the discharge electric field formed between the particles, it is charged with a constant polarity and is effective as a dust collection electrode. Attach to.

[0017] In this way, the dust collection electrode with the paint in the exhaust gas is continuously or If the dust collecting electrode is moved intermittently, the dust collecting electrode may be partially immersed in the paint stripping liquid inside the container. be done. Then, the paint is peeled off from the dust collecting electrode immersed in the paint stripper.

[0018] Performing such a movement operation of the dust collection electrode for a predetermined cycle (for example, one cycle) As a result, paint is thoroughly removed from the dust collecting electrode.

[0019] In this way, paint adhering to the dust collection electrode can be removed without running water through the electrode. The distance between the discharge electrode and the dust collection electrode can be shortened (for example, the distance between the discharge electrode and the dust collection electrode can be shortened). 5cm apart). Thereby, miniaturization can be easily achieved. Also, between both electrodes It is possible to efficiently collect paint in exhaust gas without particularly increasing the applied voltage. This makes it easy to reduce costs. Furthermore, if the distance between both electrodes is shortened, The distance that paint particles travel in the discharge electric field until they are attached to the dust collection electrode is generally Since the length is shorter, the collection is more efficient.

[0020] Furthermore, as mentioned above, the solvent in the exhaust gas comes into contact with gas and liquid before entering the electrostatic precipitator. Since it is removed by the contact part, an activated carbon adsorption device is not required.

[0021] Therefore, it is possible to reduce the amount of solvent and paint contained in exhaust gas while reducing size and cost. It is possible to efficiently remove strikes and the like.

[0022]

【Example】

An embodiment of the present invention will be described based on the drawings.

[0023] The electrostatic precipitator for a paint booth according to this embodiment has a casing as shown in Figures 1 to 3. 1, a gas-liquid contact section 7, and an electrostatic precipitator 10.

[0024] Here, inside the casing 1, there is exhaust gas containing solvent etc. discharged from the painting booth. A dust collection passage 2 is formed for passing the dust. Here, the exhaust gas is usually treated as It is managed. In other words, the exhaust gas is collected using a Venturi device, etc. to remove paint mist. It is collected with a certain collection efficiency (for example, 98%).

[0025] Further, the gas-liquid contact part 7 is provided in the dust collection passage 2 of the casing 1, and This is a means for bringing gas and liquid into gas-liquid contact with an absorbing liquid capable of dissolving a solvent.

[0026] In this embodiment, the gas-liquid contact section 7 is a dust collector near the inlet section 1e of the casing 1. It consists of a shower device 8 provided in the passage 2. The shower device 8 is The absorbing liquid is sprayed in a mist onto the exhaust gas passing through the dust collection passage 2 to separate the exhaust gas and gas liquid. It is configured to make contact.

[0027] Here, examples of substances that can be used as the absorption liquid include polyhydric alcohol, polyhydric alcohol Examples include polymers of alcohols, etherification products, and esterification products thereof. example For example, polyethylene glycol, polypropylene glycol, or and aryl or aryl ethers or esters. preferred Examples are diethylene glycol monomethyl ether, diethylene glycol monomethyl ether, Tyl ether, diethylene glycol monopropyl ether, diethylene glyco monobutyl ether (BDG), triethylene glycol monomethyl ether triethylene glycol monoethyl ether, triethylene glycol monoethyl ether Propyl ether, triethylene glycol monobutyl ether, triethylene Glycol monophenyl ether, etc.

[0028] In this embodiment, BDG (diethylene glycol monobutyl ether) is used. That is, the BD in the storage section 51 G is configured to be supplied to the shower device 8 via piping 9 and the like. In addition, The absorption liquid (BDG) that is sprayed by the shower device 8 and absorbs the solvent in the exhaust gas is It is configured to be collected into a storage section 51.

[0029] On the other hand, the electrostatic precipitator 10 has an eliminator in the dust collection passage 2 behind the gas-liquid contact part 7. It is separated by a discharge electrode 11, a dust collection electrode 21, and a drive mechanism. 31, a high voltage generator 61, a housing section 51, and the like.

[0030] Here, a plurality of discharge electrodes 11 are arranged at a predetermined pitch in the dust collection passage 2 in the casing 1. At intervals, through the insulating member 12 and the supporting members 13, 14, etc., It is extended in the direction.

[0031] Further, the dust collecting electrode 21 is made of an endless porous conductive material, and is made of an endless porous conductive material. While leaving the discharge electrode 11 by a predetermined distance (5 cm in this example), It is movable relative to the pole 11. In this embodiment, the dust collection electrode 21 is An endless roller stretched between a large number of support rollers 32, rollers 33, and pressing rollers 34 It is formed from a mesh-like conductive member.

[0032] Further, the drive mechanism 31 is a means for moving the dust collecting electrode 21. Main implementation In the example, the drive mechanism 31 includes the plurality of support rollers 32 and rollers 33 described above. , a belt 35 for interlocking and rotating the support roller 32, etc. in a predetermined direction; A pressure roller 34 and a predetermined support roller 32 for applying a predetermined tension to 35 The structure includes a drive motor (not shown) for rotationally driving the motor.

[0033] Furthermore, the high voltage generator 61 provides a discharge voltage between the discharge electrode 11 and the dust collecting electrode 21. This is a means of supplying a high enough voltage to form a field.

[0034] Furthermore, the accommodating part 51 comes into contact with a part of the dust collection electrode 21 and adheres to the electrode 21. It is configured to contain a paint stripping solution capable of stripping the painted paint.

[0035] In this embodiment, the accommodating portion 51 includes a partition plate 52 on the bottom surface 1b of the casing 1. The storage section 51 contains a paint stripping liquid. Ru.

[0036] Polyhydric alcohols, polyhydric alcohols, Examples include polymers of alcohols, etherification products, and esterification products thereof. example For example, polyethylene glycol, polypropylene glycol, or and aryl or aryl ethers or esters. preferred Examples are diethylene glycol monomethyl ether, diethylene glycol monomethyl ether, Tyl ether, diethylene glycol monopropyl ether, diethylene glyco monobutyl ether (BDG), triethylene glycol monomethyl ether triethylene glycol monoethyl ether, triethylene glycol monoethyl ether Propyl ether, triethylene glycol monobutyl ether, triethylene Glycol monophenyl ether, etc.

[0037] In this example, BDG (diethylene glycol monobutyl ether) was used. It will be done.

[0038] Although the BDG stock solution selected as the paint stripper is flammable, it is a water-soluble solution. is not flammable. Therefore, a water-soluble solution of BDG is used as the paint stripper. It is desirable that However, when using the undiluted BDG solution, the BD If residual G is sent to the discharge electrode 11, the discharge electrode 11 will generate sparks, etc. There is no guarantee that it will not burst into flames if A water tank section 55 is provided for washing off BDG from the dust electrode 21. difference Furthermore, on the downstream side of the water tank section 55, there is collected water that has been washed with the washing water in the water tank section 55. A cleaning nozzle 56 is provided for spraying fresh water onto the dust electrode 21 portion. .

[0039] Next, the effect will be explained.

[0040] It is discharged from the painting room of the painting booth and undergoes primary treatment using a Venturi device, etc. Before entering the electrostatic precipitator 10 through the gas-liquid contact section 7, the solvent in the exhaust gas DG) is brought into gas-liquid contact. At this time, the absorption liquid (BDG) cannot dissolve the solvent. Therefore, the solvent in the exhaust gas can be effectively collected.

[0041] In this way, the exhaust gas from which the solvent has been removed is transferred to the discharge electrode 11 of the electrostatic precipitator 10 and When passing through the discharge electric field formed between the dust collection electrodes 21, the dust is charged with a constant polarity and collected. The dust adheres effectively to the electrode 21.

[0042] Therefore, the dust collection electrode 21 to which the paint in the exhaust gas has adhered is removed using the drive mechanism 31. A part of the dust collecting electrode 21 is immersed in the paint stripper (BDG) in the housing part 51 for at least 5 minutes. If the paint is moved continuously or intermittently, the paint stripping action of BDG will cause the paint to peel off. The paint is peeled off from the dust collecting electrode 21 immersed in the BDG.

[0043] Note that the part of the dust collecting electrode 21 from which the paint was peeled off by BDG is As it moves, it is immersed in cleaning water in the water tank section 55, and is further immersed in cleaning water by the cleaning nozzle 56. Washing water is sprayed to completely wash off the BDG.

[0044] Therefore, such a movement operation of the dust collection electrode 21 is performed in a predetermined cycle (for example, one cycle). By doing this, the dust collection electrode 21 can be cleaned without any paint or BDG attached. Facing the discharge electrode 11, the paint in the exhaust gas passing between the electrodes 11 and 21 is efficiently removed. Can be collected (dust collected) well.

[0045] In this way, the paint attached to the dust collecting electrode 21 can be removed without flowing water to the dust collecting electrode 21. Since it can be removed cleanly, the distance between the discharge electrode 11 and the dust collection electrode 21 can be shortened. Wear. Thereby, miniaturization can be easily achieved. In addition, both electrodes 11, 21 To efficiently collect paint in exhaust gas without particularly increasing the voltage applied between This makes it easy to reduce costs. Furthermore, the distance between both electrodes 11 and 21 By shortening, the paint particles moving in the discharge electric field area will not be attached to the dust collection electrode 21. Since the travel distance is shortened, collection can be made more efficiently.

[0046] Furthermore, as mentioned above, the solvent in the exhaust gas is vaporized before entering the electrostatic precipitator 10. Since it is removed by the liquid contact section 7, a conventional activated carbon adsorption device is not required.

[0047] According to this embodiment, the exhaust gas and the dust collecting passage 2 in the casing 1 are A gas-liquid contact portion 7 is provided for bringing the absorbing liquid capable of dissolving the solvent into gas-liquid contact. Since the electrostatic precipitator 10 is provided behind the gas-liquid contact section 7, it is possible to reduce the size and cost. To efficiently remove solvents, paint mist, etc. from exhaust gas while reducing stress. I can do it.

[0048]

[Effect of the idea]

According to the present invention, an absorbent that can dissolve exhaust gas and solvent is provided in the dust collection passage in the casing. A gas-liquid contact part is provided to bring the collected liquid into gas-liquid contact, and a stationary part is provided behind the gas-liquid contact part. The structure is equipped with an electrostatic precipitator, which reduces the size and cost of the exhaust gas. It is possible to efficiently remove solvents, paint mist, etc.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing one embodiment.

FIG. 3 is a side view showing essential parts of an embodiment of the present invention.

FIG. 4 is a diagram showing a schematic configuration of a conventional wet-type electrostatic precipitator.

[Explanation of symbols]

1 Casing 2 Dust collection passage 7 Gas-liquid contact part 10 Electrostatic precipitator 11 Discharge electrode 21 Dust collection electrode 31 Drive mechanism 51 Accommodation section 61 High voltage generator

──────────────────────────────────────────────── ─── Continued from the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location B05C 15/00 6804-4D (72) Creator Shinji Toshimitsu Trinity, 1-9 Kakimoto-cho, Toyota City, Aichi Prefecture Inside Kogyo Co., Ltd.

Claims (1)

[Scope of utility model registration request] Claim 1: A casing having a dust collection passage formed inside the casing for passing exhaust gas containing solvent etc. discharged from a painting booth; A gas-liquid contact portion is provided for bringing the soluble absorbing liquid into gas-liquid contact, and an electrostatic precipitator is provided behind the gas-liquid contact portion, and the electrostatic precipitator connects the discharge electrode and the discharge electrode. a dust collection electrode made of an endless porous conductive member that is separated by a predetermined distance from the discharge electrode and is movable with respect to the discharge electrode; a drive mechanism for moving the dust collection electrode; A high voltage generator for supplying a high voltage sufficient to form a discharge electric field between the electrode and the dust collection electrode, and a paint that comes into contact with a part of the dust collection electrode and is capable of peeling off the paint that has adhered to the electrode. An electrostatic precipitator for a paint booth, characterized in that the electrostatic precipitator for a paint booth is configured to include a storage section containing a paint stripping solution.