JPH0647250A - Exhaust gas treating device - Google Patents

Abstract

PURPOSE:To drastically reduce an investment, a running cost and an installation space, etc., of the device without reducing the treating ability of the exhaust gas treating device which removes the org. solvent contained in the exhaust gas. CONSTITUTION:When one folding screen-like filter 2R facing other filter across the evacuating flow passage 1 advanced into the evacuating flow passage 1 to absorb the org. solvent in the exhaust gas, the org. solvent absorbed to the other folding screen-like filter 2L housed in the filter recovering room 3R which lefts from the evacuating flow passage 1 is swept off by the hot air blowed into the filter recovering room 3R, and blown to the solvent removing device 14 in the state contained at high concn. in the hot air.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust treatment device for purifying exhaust gas containing an organic solvent discharged from a coating booth or the like.

[0002]

2. Description of the Related Art Since the exhaust gas of a coating booth contains an organic solvent that causes environmental pollution, it must be passed through a direct combustion or catalytic combustion deodorizing device before it is released into the atmosphere. Although the organic solvent component is combusted and decomposed, the catalytic combustion type deodorizing device uses an expensive catalyst, which increases the facility cost and the fuel cost of the burner that heats the catalyst to a predetermined reaction temperature. The direct combustion type deodorizing device has a drawback that the fuel cost is further increased as compared with the catalytic combustion type because the large amount of exhaust gas is directly heated by the flame of the burner. In addition, since the concentration of the organic solvent contained in the exhaust gas of the coating booth is extremely low, a considerably high temperature is required to burn and decompose the organic solvent, resulting in a huge fuel cost.

For this reason, recently, the organic solvent contained in the exhaust gas is once collected by a rotor-type solvent recovery machine, and the collected organic solvent is removed from the rotor-type solvent recovery machine by hot air and concentrated. Means for feeding to the above deodorizing device is used. Further, the present applicant uses an activated carbon deodorizing device that adsorbs and removes organic solvent components in the exhaust with an activated carbon layer as an alternative to the above deodorizing device, and this deodorizing device is included in the exhaust gas of a coating booth. Since the moisture adheres to the surface of the activated carbon layer and loses its adsorption function in a short period of time, the moisture in the exhaust is removed in advance by a rotor type dehumidifier to prevent the function of the activated carbon deodorizing device from deteriorating. 63-88076).

[0004]

However, the rotor-type solvent recovery machine for increasing the solvent concentration in the exhaust gas and the rotor-type dehumidifier for removing the water content in the exhaust gas have a honeycomb structure drum having a large number of vent holes. Since it is a large-scale device that rotates the rotor with a motor, it requires a considerably large installation space and its equipment cost is still high. Therefore, it is a technical object of the present invention to further reduce the equipment cost, running cost, and installation space without lowering the processing capacity of the exhaust gas processing device.

[0005]

In order to solve the above problems, the present invention provides an exhaust treatment device for purifying exhaust gas by means of a folding screen filter in which a plurality of filter plates for adsorbing an organic solvent are foldably connected. A pair of folding screen filters, which are alternately opposed to the exhaust flow path, are disposed at positions facing each other across the exhaust flow path, and the folding screen filters retreating from the exhaust flow path are disposed. A filter regeneration chamber for accommodating and regenerating is provided, and in the filter regeneration chamber, a hot air supply pipe for sending hot air to wipe the organic solvent component adsorbed on the surface of the folding screen filter into the chamber, and an organic gas from the chamber It is characterized in that a solvent discharge pipe is connected to discharge hot air containing a solvent component and send it to the solvent removing device.

[0006]

According to the present invention, while one folding screen filter advances into the exhaust passage to adsorb the organic solvent contained in the exhaust gas, it exits from the exhaust passage and enters the filter regeneration chamber. The other folding screen filter housed is regenerated by wiping off the organic solvent component and water adsorbed on the surface by the high heat of the hot air sent into the filter regenerating chamber. Then, when the folding screen filter advancing to the exhaust passage adsorbs a certain amount or more of the organic solvent contained in the exhaust gas and the moisture that inhibits the adsorption of the organic solvent, the folding screen filter is withdrawn from the exhaust passage. At the same time as the filter is housed in the filter regeneration chamber, the regenerated folding screen filter previously housed in the filter regeneration chamber is advanced to the exhaust passage instead of the filter. As a result, since the folding screen filter having a good adsorption efficiency of the organic solvent can be always interposed in the exhaust passage, the organic solvent contained in the exhaust can be reliably removed.

Further, the hot air for wiping the organic solvent component from the surface of the folding screen filter needs to be fed into the filter regenerating chamber for a certain time only when the folding screen filter is housed in the regenerating chamber. Fuel costs required to generate hot air are low. Furthermore, since the amount of hot air sent from the filter regeneration chamber to the solvent removal device is significantly smaller than the amount of exhaust gas discharged from the painting booth, etc., it can be used as a solvent removal device to remove the organic solvent contained in the hot air. For example, even when a direct combustion type or catalytic combustion type deodorizing device is used, a small deodorizing device is sufficient and the equipment cost and fuel cost are significantly reduced. Further, since hot air is sent to the solvent removing device, even when an activated carbon deodorizing device is used as the solvent removing device, there is a possibility that a problem such as a decrease in the efficiency of removing the organic solvent due to moisture adhering to the activated carbon layer may occur. Absent.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a plan view showing an example of an exhaust treatment device according to the present invention.

In the exhaust treatment apparatus of this example, the exhaust passage 1 for discharging the polluted air containing the organic solvent from the coating booth is located at the opposite positions with respect to each other, and the exhaust passage 1 is alternately arranged from that position. A pair of left and right folding screen filters 2R, 2 that can move forward and backward
A pair of left and right filters in which L is disposed, and the folding screen filters 2R and 2L that have exited from the exhaust passage 1 are accommodated in a folded state and the organic solvent component adsorbed on the surface thereof is wiped off by the high heat of hot air. Regeneration chambers 3R and 3L are provided.

In the folding screen filters 2R and 2L, a plurality of filter plates 4 in which an activated carbon layer (or zeolite layer) 5 for adsorbing an organic solvent contained in the exhaust gas of a coating booth is fitted inside a rectangular frame 6 are hinged. The upper and lower ends of the filter plates 4 are foldably connected to each other by 7 and extend to the inside of the filter regeneration chambers 3R and 3L arranged across the exhaust flow path 1 in the left-right direction. It is slidably supported by the guide rail 18 of.

The filter regeneration chambers 3R and 3L are provided in the exhaust passage 1
The inside of the chamber 9 is formed by a chamber 9 having a filter inlet / outlet 8 opened therein, and a hot air supply pipe 12 for sending hot air of about 120 ° C. into the chamber 9 by a fan 11 from a hot air generator 10 provided in a coating drying oven or the like. A solvent discharge pipe 15 is connected to discharge the hot air sent to the solvent to the solvent removing device 14 by the fan 13. The solvent removing device 14 is a direct combustion type or catalytic combustion type deodorizing device for burning and decomposing and removing the organic solvent component contained in the hot air, or an activated carbon deodorizing device for removing the organic solvent component by adsorbing the organic solvent component on the activated carbon layer. A device or the like is used.

However, either the right or left folding screen filter 2R (or 2L) across the exhaust flow path 1 advances into the flow path 1 so as to close the exhaust flow path 1, and the exhaust gas of the coating booth is exhausted. While the organic solvent contained in the filter plate 4 is being adsorbed by the activated carbon layer 5 of the filter plate 4, the other folding screen filter 2L (or 2R) that has exited from the exhaust passage 1 is stored in a folded state. Hot air of about 120 ° C. is sent into the chamber 9 of the chamber 3L (or 3R) from the hot air generator 10 through the hot air supply pipe 12 for a certain period of time, and the high heat of the hot air causes the surface of the folding filter 2L (or 2R) to flow. Not only the adsorbed organic solvent component but also water that hinders the adsorption of the organic solvent component is wiped off by evaporation, and the entire filter 2L (or 2R) is regenerated to have the best adsorption efficiency.

While the filter is being regenerated, hot air from which the organic solvent components and water have been wiped from the surface of the folding screen filter 2L (or 2R) is sent to the solvent removing device 14 through the solvent discharge pipe 15, and the device 14 is used. After removing the organic solvent component, it is returned to the hot air generator 10 to receive the heat, and then the filter regeneration chamber 3L is again fed through the hot air supply pipe 12.
(Or 3R) is circulated in a path fed into the chamber 9. When the filter regeneration is completed, the fan 1
At the same time as stopping 1 and 13, the dampers 16 and 17 interposed in the hot air supply pipe 12 and the solvent discharge pipe 15 are closed to stop the supply of hot air into the chamber 9 and the operation of the solvent removal device 14 is also stopped. To do. If the hot air generator 10 is a dedicated device used only for the exhaust treatment device of this example, the operation of the hot air generator 10 is also stopped.

By doing so, even when a deodorizing device for combusting and decomposing organic solvent components is used as the solvent removing device 14, the deodorizing device needs only a small burner such as a small capacity and the operating time of the device is short. Therefore, the equipment cost and fuel cost can be very low. In addition, since hot air is sent to the solvent removing device 14, even when an activated carbon deodorizing device or a zeolite deodorizing device is used as the device, moisture adheres to the activated carbon layer or the zeolite layer and the removal efficiency of the organic solvent is reduced. That's not it. Therefore, since it is not necessary to provide an expensive and large-scale rotor dehumidifier, the equipment cost, running cost, installation space, etc. of the entire exhaust treatment device can be significantly reduced.

Further, the chamber 9 opening in the exhaust passage 1
If the filter entrance / exit 8 is shielded by an opening / closing door or a partition curtain, the organic solvent and water adsorbed on the surfaces of the folding screen filters 2R, 2L can be sufficiently wiped off by the hot air sent into the chamber 9. The wiped organic solvent can be surely sucked by the solvent discharge pipe 15 and sent to the solvent removing device 14 without being released to the exhaust passage 1.
Further, by connecting the pair of folding screen filters 2R and 2L to each other, when one folding screen filter 2R advancing into the exhaust passage 1 is withdrawn into the filter regeneration chamber 3R, the filter regeneration chamber 3L The other folding screen filter 2L housed in the room can be automatically advanced to the exhaust passage 1. When a direct combustion type or catalytic combustion type deodorizing device is used as the solvent removing device 14, the installation of the hot air generating device 10 can be omitted. That is, if hot deodorizing gas generated by burning and decomposing the organic solvent by the solvent removing device 14 which is a direct combustion type or catalytic combustion type deodorizing device is sent to the filter regeneration chambers 3R, 3L, the hot air generating device 10 Need not be provided separately.

[0016]

As described above, according to the present invention, the equipment cost, running cost, and installation space of the exhaust treatment device can be reduced more than before without lowering the removal efficiency of the organic solvent component contained in the exhaust gas. Has a very excellent effect that it can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of an exhaust treatment device according to the present invention.

[Explanation of symbols]

 1 ... Exhaust flow passage 2R, 2L ... Folding screen filter 3R, 3L ... Filter regeneration chamber 4 ... Filter plate 10 ... Hot air generator 12 ... ..Hot air supply piping 14 ... Solvent removal device 15 ... Solvent discharge piping

Claims (2)

[Claims] 1. An exhaust treatment device for purifying exhaust gas by means of a folding screen filter (2R, 2L) in which a plurality of filter plates (4) for adsorbing an organic solvent are foldably connected to each other. ), A pair of folding screen filters (2R, 2L) capable of alternately advancing and retreating from the position to the exhaust flow path (1) are disposed at positions facing each other. A filter regeneration chamber (3R, 3L) for accommodating and regenerating the retreating folding screen filters (2R, 2L) is provided, and the filter regeneration chamber (3R, 3L) is provided with a folding screen filter (2R, 2L). ) A hot air supply pipe (12) for sending in hot air for wiping off the organic solvent component adsorbed on the surface,
An exhaust treatment device is characterized in that a solvent discharge pipe (15) for discharging hot air containing an organic solvent component from the room and sending it to the solvent removal device (14) is connected. 2. The exhaust treatment device according to claim 1, wherein the solvent removal device (14) is a direct combustion type or catalytic combustion type deodorizing device.