JP2997134B2 - Exhaust treatment device - Google Patents

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 painting booth or the like.

[0002]

2. Description of the Related Art Since the exhaust gas from a coating booth contains an organic solvent which causes environmental pollution, the exhaust gas is passed through a deodorizer of a direct combustion type or a catalytic combustion type before being discharged to the atmosphere. Although the organic solvent component is burned and decomposed, the catalytic combustion type deodorizer uses an expensive catalyst, so the equipment cost increases, and at the same time, the fuel cost of a burner for heating the catalyst to a predetermined reaction temperature also increases. The direct-combustion type deodorizer has a drawback in that the large-volume exhaust gas is directly heated by the burner flame, so that the fuel cost is higher than that of the catalytic combustion type. Further, since the concentration of the organic solvent contained in the exhaust gas from the painting booth is extremely low, a considerably high temperature is required to burn and decompose the organic solvent, so that the fuel cost is enormous.

[0003] 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 to obtain a concentrated state. Means for feeding the above deodorizing device is used. In addition, the present applicant uses an activated carbon deodorizing device that adsorbs and removes organic solvent components in exhaust gas with an activated carbon layer as an alternative to the above deodorizing device, and this deodorizing device is included in the exhaust of a painting booth. Since the absorbed water adheres to the surface of the activated carbon layer and loses the adsorption function in a short period of time, the moisture in the exhaust gas is removed in advance by a rotor type dehumidifier to prevent the function of the activated carbon deodorizing device from deteriorating (Japanese Patent Application Laid-Open (JP-A) no. 63-88076).

[0004]

However, a rotor-type solvent recovery machine for increasing the solvent concentration in exhaust gas and a rotor-type dehumidifier for removing water in exhaust gas have a honeycomb-structured drum having a large number of ventilation holes. Since it is a large-scale device for rotating a shaped rotor by a motor, it itself requires a considerably large installation space, and its equipment cost is still at a high level. Therefore, an object of the present invention is to further reduce the equipment cost, the running cost, and the installation space without reducing the processing capacity of the exhaust treatment device.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an exhaust gas treatment apparatus 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. And a pair of screen-like filters that can alternately advance and retreat from the position with respect to the exhaust flow path are provided at positions opposed to each other across the exhaust flow path, and the screen-like filters that have exited the exhaust flow path. A filter regeneration chamber for containing and regenerating the filter is provided, the filter regeneration chamber includes a hot air supply pipe for supplying hot air for wiping the organic solvent component adsorbed on the surface of the folding screen filter into the chamber, and an organic A solvent discharge pipe for discharging hot air containing a solvent component and sending the hot air to a solvent removing device is connected.

[0006]

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

[0007] Further, the hot air for wiping the organic solvent component from the surface of the screen filter only needs to be sent into the filter regeneration chamber for a certain period of time only when the screen filter is accommodated in the filter regeneration chamber. Fuel costs for generating hot air are low. Furthermore, since the amount of hot air sent from the filter regeneration chamber to the solvent removing device is significantly smaller than the amount of exhaust gas discharged from a painting booth or the like, it is used as a solvent removing device for removing the organic solvent contained in the hot air. For example, even when a direct combustion type or catalytic combustion type deodorizing device is used, the deodorizing device need only be a small one, and equipment costs and fuel costs are significantly reduced. In addition, since hot air is sent into the solvent removing device, even when an activated carbon deodorizing device is used as the solvent removing device, there is a possibility that moisture may adhere to the activated carbon layer and the efficiency of removing the organic solvent may be reduced, and the like. Absent.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a plan view showing an example of an exhaust treatment apparatus according to the present invention.

The exhaust treatment apparatus of this embodiment is arranged at positions opposed to each other across an exhaust passage 1 for discharging contaminated air containing an organic solvent from a coating booth, and alternately with respect to the exhaust passage 1 from that position. A pair of left and right folding screen filters 2R, 2A
And a pair of left and right filters for accommodating each of the folding screen filters 2R and 2L having exited from the exhaust passage 1 in a folded state and wiping and removing the organic solvent component adsorbed on the surface thereof by the high heat of the hot air. Reproduction rooms 3R and 3L are provided.

The folding screen filters 2R and 2L are hinged by 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 air of the painting booth is fitted inside a rectangular frame 6. The upper and lower ends of each of the filter plates 4 traverse the exhaust flow path 1 in the left-right direction and extend to a pair of filter regeneration chambers 3R, 3L disposed on both left and right sides thereof. Are slidably supported by the guide rail 18.

The filter regeneration chambers 3R and 3L are provided in the exhaust passage 1
A hot air supply pipe 12 which is formed by a fan 11 from a hot air generator 10 provided in a coating / drying furnace or the like and sends hot air of about 120 ° C. into the chamber 9; A solvent discharge pipe 15 is connected to discharge the hot air sent into the fan 13 by the fan 13 and feed the hot air to the solvent removing device 14. The solvent removing device 14 is a direct combustion type or catalytic combustion type deodorizing device that removes the organic solvent component contained in the hot air by burning and decomposing, or an activated carbon deodorizing device that removes the organic solvent component by adsorbing it on the activated carbon layer. An apparatus or the like is used.

Thus, one of the left and right folding screen filters 2R (or 2L) with the exhaust flow path 1 interposed therebetween enters the flow path 1 so as to close the exhaust flow path 1 so that the exhaust gas from the painting booth is discharged. Regeneration while containing the other screen-shaped filter 2L (or 2R) that has exited from the exhaust flow path 1 while the organic solvent contained in the filter plate 4 is adsorbed on the activated carbon layer 5 of the filter plate 4 Hot air of about 120 ° C. is sent from the hot air generator 10 through the hot air supply pipe 12 for a certain time into the chamber 9 of the chamber 3L (or 3R), and the high heat of the hot air causes the surface of the folding screen filter 2L (or 2R) to flow. Not only the adsorbed organic solvent component but also moisture that inhibits the adsorption of the organic solvent component is wiped off by evaporation, and the entire filter 2L (or 2R) is regenerated to a state having the best adsorption efficiency.

During the regeneration of the filter, hot air having the organic solvent component and moisture wiped off from the surface of the screen filter 2L (or 2R) is sent to the solvent removing device 14 through the solvent discharge pipe 15, and the device 14 removes the hot air. After removing the organic solvent component, it is returned to the hot air generator 10 to receive heat, and then the filter regeneration chamber 3L is again passed through the hot air supply pipe 12.
(Or 3R) circulates in a path sent into the chamber 9. When the regeneration of the filter is completed, the fan 1
At the same time, the dampers 16 and 17 interposed between the hot air supply pipe 12 and the solvent discharge pipe 15 are closed to stop the supply of the hot air into the chamber 9, and the operation of the solvent removing device 14 is also stopped. I do. Further, when the hot air generator 10 is a dedicated device used only for the exhaust treatment device of the present example, the operation of the hot air generator 10 is also stopped.

In this way, even when a deodorizing device that burns and decomposes organic solvent components is used as the solvent removing device 14, the deodorizing device needs only to be a small one with a small burner capacity and the like, and the operating time of the device is short. Therefore, equipment costs and fuel costs are very low. Further, since hot air is fed into 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 efficiency of removing the organic solvent is reduced. It is not. Therefore, there is no need to provide an expensive and large-scale rotor dehumidifier, so that the equipment cost, running cost, installation space, and the like of the entire exhaust treatment device can be significantly reduced.

A chamber 9 opened in the exhaust passage 1
If the filter entrance 8 is shielded by an opening / closing door or a partition curtain, the hot air sent into the chamber 9 can sufficiently wipe off the organic solvent and moisture adsorbed on the surfaces of the screen filters 2R and 2L. The wiped organic solvent can be surely sucked by the solvent discharge pipe 15 and sent to the solvent removing device 14 without escaping to the exhaust flow path 1 side.
Further, if the pair of folding filters 2R and 2L are connected to each other, when one folding filter 2R that has advanced to the exhaust passage 1 is retreated into the filter regeneration chamber 3R, the filter regeneration chamber 3L is closed. The other folding screen filter 2L accommodated 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 the high-temperature deodorized gas generated by burning and decomposing the organic solvent by the solvent removing device 14 composed of a direct combustion type or catalytic combustion type deodorizing device is sent to the filter regeneration chambers 3R and 3L, the hot air generator 10 It is not necessary to provide a separate.

[0016]

As described above, according to the present invention, the equipment cost, the running cost, and the installation space of the exhaust treatment device can be reduced as compared with the conventional one without reducing the removal efficiency of the organic solvent component contained in the exhaust gas. Has a very excellent effect that it can be greatly reduced.

[Brief description of the 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 path 2R, 2L ... 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)

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