KR100600504B1 - Continuous kiln with unit of dealing with discharge gas - Google Patents

Abstract

A problem is to provide a continuous firing furnace equipped with an exhaust gas treatment unit capable of inhaling atmospheric gases in a furnace containing binder volatiles generated from a fired substance and oxidizing (burning) the binder volatiles with a catalyst and exhausting them. Shall be.

The present invention provides a tubular or elongated box-shaped gas suction member (3) in which a plurality of holes (3a) or slits for sucking gas containing binder volatiles generated from an object to be fired (W) are formed over approximately the entire length. ) Is installed at the upper part in the furnace body 1 in the direction perpendicular to the conveying direction of the to-be-fired object W, or is installed in the direction parallel to the conveying direction of the to-be-fired object W at the side part in the furnace body 2, and this gas suction is carried out. In the middle of the exhaust pipe passage 4 drawn out of the furnace body 1 from the member 3, an exhaust gas treatment unit 5 containing a ventable catalyst support 5a for supporting a catalyst for oxidatively decomposing the binder volatiles is provided. It is a continuous firing furnace in which the exhaust gas treatment unit of the installed structure is installed.

Description

CONTINUOUS KILN WITH UNIT OF DEALING WITH DISCHARGE GAS

1 is a schematic cross-sectional view of a continuous firing furnace in which an exhaust gas treating unit according to an embodiment of the present invention is installed.

2 is a schematic cross-sectional view of a continuous kiln in which an exhaust gas treating unit according to another embodiment of the present invention is installed.

3 is a side view of a continuous firing furnace in which the exhaust gas treating unit is installed.

4 is a schematic cross-sectional view of a continuous firing furnace in which an exhaust gas treating unit according to another embodiment of the present invention is installed.

5 is a side view of a continuous firing furnace in which the exhaust gas treating unit is installed.

The present invention relates to a continuous kiln in which an exhaust gas treating unit for treating a gas containing binder volatiles generated from an object to be fired is installed.

In a continuous firing furnace for firing a to-be-fired product containing a binder containing an organic substance as a main component, a binder is volatilized from the to-be-fired product in an intermediate temperature rise region (a region of about 300 to 400 ° C). Since the binder volatiles adversely affect the firing, gas (ambient gas in the furnace) containing the binder volatiles is discharged out of the furnace through the exhaust pipe. However, when the temperature of the exhaust gas in the exhaust pipe is lowered, the binder volatiles solidify and adhere to the inner wall of the exhaust pipe, which adversely affects the exhaust system of the kiln or the factory exhaust duct.

In order to cope with such a problem, measures such as keeping the exhaust pipe passage warm or heating to prevent solidification of binder volatiles have been adopted. In this case, maintenance and repair of the exhaust pipe is cumbersome, and the discharged gas is harmful to the human body. There is a problem that causes odor.

Therefore, by forming an exhaust hole in the furnace wall of the region where the furnace temperature of the continuous kiln is equal to or higher than the activation temperature of the predetermined catalyst, and embedding a structure for supporting the catalyst in the exhaust hole, binder volatiles generated from the fired substance are removed. When discharging the contained gas from the exhaust hole, a continuous sintering furnace has been proposed in which the binder volatiles are burned with an activated catalyst to decompose and deodorize the exhaust gas (see Patent Document 1, for example).

(Patent Document 1)

Japanese Patent Laid-Open No. 2001-241862 (2 pages, Fig. 1)

However, a structure in which exhaust holes are formed in a furnace wall in a region where the activation temperature of a predetermined catalyst is equal to or higher than a predetermined catalyst like the above-mentioned continuous kiln, and a structure supporting the catalyst therein contains binder volatiles generated from a fired substance. Since it is difficult to discharge a gas from the exhaust hole without leaving it, the gas containing the binder volatiles contaminates the atmosphere in the furnace, deteriorating the quality of the object to be treated, agglomerates at the low temperature surface in the furnace, or the fired product of the continuous firing furnace. There was a problem of being dissipated to some extent from the exit. In addition, the combustion of the binder volatiles by incorporating a structure for supporting the catalyst in the exhaust hole formed in the furnace wall like this continuous firing furnace also has a problem that the combustion state of the binder volatiles cannot be grasped and adjusted so as to obtain a high combustion efficiency. there was.

It is an object of the present invention to provide a continuous firing furnace equipped with an exhaust gas treatment unit capable of solving the above problem.

In order to achieve the above object, the continuous firing furnace in which the exhaust gas treating unit of the present invention is installed has a tubular shape in which a plurality of holes or slits for sucking gas containing binder volatiles generated from a fired product are formed over approximately the entire length or An elongated box-shaped gas suction member is provided in the furnace body in a direction orthogonal to the conveying direction of the to-be-baked object at the upper part of the furnace, or is installed in a direction parallel to the conveying direction of the workpiece to be removed from the side in the furnace body, and out of the furnace body from the gas suction member. On the way to the exhaust pipe, it is characterized in that the exhaust gas treatment unit is provided with a permeable catalyst carrier (catalyst carrier) for supporting the catalyst for oxidative decomposition of the binder volatiles.

Like this continuous firing furnace, a tubular or elongated box-shaped gas suction member in which a plurality of holes or slits are formed over approximately the entire length is provided in a direction perpendicular to the conveying direction of the to-be-fired object in the upper part of the furnace, or If the side portion is installed in the direction parallel to the conveying direction of the to-be-fired object, the gas in the furnace containing the binder volatiles generated from the to-be-fired material is sucked from each hole or slit of the gas suction member over a wide range, and thus, It does not pollute the atmosphere and there is no fear that the gas containing the binder volatiles is released from the outlet of the furnace body. Then, when the gas containing the binder volatiles sucked from the gas suction member passes through the catalyst support built into the exhaust gas treatment unit on the way to the exhaust pipe, the binder volatilizes in the exhaust pipe furnace contained in the exhaust gas and connected to the outdoors. There is no fear of water coagulation or odor.

In the continuous firing furnace of the present invention, it is preferable to include an auxiliary heater for heating the exhaust gas above the activation temperature of the catalyst on the gas inlet side rather than the catalyst support of the exhaust gas processing unit. If such an auxiliary heater is incorporated, even when the temperature of the exhaust gas introduced into the exhaust gas treatment unit is lower than the activation temperature of the catalyst, by heating the exhaust gas with the auxiliary heater above the activation temperature, the binder volatiles in the exhaust gas with the activated catalyst Oxidative decomposition (combustion) can be surely performed, and when oxidative decomposition is not sufficient, the temperature of the exhaust gas can be further increased by an auxiliary heater to promote oxidative decomposition.

In the continuous firing furnace of the present invention, a first temperature sensor for controlling the temperature of the exhaust gas heated by the auxiliary heater is provided on the gas inlet side rather than the catalyst support of the exhaust gas treatment unit, and the exhaust gas treatment is performed. It is preferable to provide a second temperature sensor on the gas outlet side rather than the catalyst support of the unit for monitoring the temperature of the exhaust gas after the treatment. If the first temperature sensor and the second temperature sensor are provided in this way, the temperature of the exhaust gas before the treatment detected by the first temperature sensor (the temperature of the exhaust gas before the treatment heated by the auxiliary heater) and the treatment detected by the second temperature sensor By comparing the temperature of subsequent exhaust gas, the state of the oxidative decomposition treatment (combustion) of the binder volatiles by a catalyst can be grasped. In other words, if the temperature of the exhaust gas after the treatment is higher than the temperature of the exhaust gas before the treatment, it can be judged that the oxidative decomposition treatment (combustion) of the binder volatiles by the catalyst is being performed. It can be judged that it is performed efficiently and efficiently. On the other hand, when the temperature of the exhaust gas after the treatment is lower than the temperature of the exhaust gas heated by the heater before the treatment, it can be determined that the oxidative decomposition treatment of the binder volatiles by the catalyst is not performed. Therefore, when it is determined that the oxidative decomposition treatment of the binder volatiles is not performed or is determined to be insufficient, the heating temperature of the exhaust gas before the treatment is increased with an auxiliary heater, or as described later, the air of the exhaust gas treatment unit is also changed. By adding or subtracting the amount of air introduced from the inlet, the oxidative decomposition treatment of the binder volatiles by the catalyst can be surely and sufficiently performed.

In the continuous firing furnace of the present invention, it is preferable to form an air inlet which can adjust the flow rate on the gas inlet side rather than the auxiliary heater of the exhaust gas treatment unit. The air can promote oxidative decomposition of the binder volatiles, and the efficiency of oxidative decomposition can be improved by adjusting the amount of air introduced.

Further, in the continuous kiln of the present invention, it is preferable to incorporate a filter on the side of the auxiliary heater rather than the catalyst support of the exhaust gas treatment unit, so that clogging of the catalyst support can be prevented by the filter.

EMBODIMENT OF THE INVENTION Hereinafter, specific embodiment of this invention is described in detail with reference to drawings.

1 is a schematic cross-sectional view showing one embodiment of a continuous firing furnace in which an exhaust gas treating unit according to the present invention is installed.

The continuous firing furnace provided with this exhaust gas treatment unit is a rectangular parallelepiped furnace body formed of a bottom wall 1a, an upper wall 1b, and left and right side walls 1c and 1c made of a thick plate-shaped hard heat insulating material vacuum-forming ceramic fibers ( 1) is formed and the inside of the furnace body is heated by a plurality of electric heaters 1d embedded in the upper wall 1b and the like.

The furnace 1 is elongated in the front-rear direction (the direction perpendicular to the ground in FIG. 1), and a plurality of conveying rollers 2 penetrating the furnace 1 to the left and right are arranged at regular intervals in the front-rear direction. have. Both ends of each conveyance roller 2 are rotatably bearing, and the sprocket 2a of the roller end is engaged with the common drive chain (not shown). Therefore, when a common drive chain is started, each conveyance roller 2 rotates at the predetermined rotational speed all at once, and can convey the to-be-baked material W at a fixed speed in the front-back direction.

On the upper portion of the intermediate temperature raising region in the furnace 1 in which binder volatiles are generated from the to-be-fired object W, the tubular gas suction member 3 is orthogonal to the conveying direction (front and rear direction) of the to-be-fired object W, That is, it is provided over substantially the full width in the left-right width direction of the furnace 1. The gas suction member 3 has a plurality of holes 3a for sucking the atmospheric gas in the furnace 1 containing the binder volatiles generated from the workpiece W, over approximately the entire length of the tubular body with both ends closed. ) Is formed. Instead of the tubular gas suction member 3, an elongated box-shaped gas suction member 30 having a slit to be described over the entire length may be provided in the upper part of the furnace 1.

The gas suction member 3 is connected to a plurality of exhaust pipe passages 4 branched into three pieces (three in FIG. 1) through the upper wall 1b of the furnace body 1 and out of the furnace body 1. . These branched exhaust pipe passages 4 are collected in one exhaust pipe passage, connected to the injector 4a using the Venturi effect, and exhausted by the injector 4a. Instead of the injector 4a, the exhaust pipe passage 4 may be connected to an exhaust blower for exhausting.

An exhaust gas treatment unit 5 is provided in the middle of the exhaust pipe passage 4, and the exhaust pipe passage 4 branched from the exhaust gas treatment unit 5 on the side of the furnace body 1 is kept warm with the heater 4b for thermal insulation. It is double-coated by the heat insulating material 4c for. Therefore, the temperature decrease does not occur until the gas containing the binder volatiles sucked from the gas suction member 3 is introduced into the processing unit 5, and there is no fear that the binder volatiles will solidify. These heat keeping heaters 4b and the heat insulating material 4c keep the processing unit 5 close to the furnace body 1 so that the distance of the exhaust pipe passage 4 from the furnace body 1 to the processing unit 5 is reduced. In the case of shortening, it is unnecessary.

The exhaust gas treatment unit 5 includes a permeable catalyst support 5a for supporting a catalyst for oxidatively decomposing binder volatiles in a hermetic unit case so as to be detachable and replaceable, rather than this catalyst support 5a. On the gas inlet side, an auxiliary heater 5b for heating the exhaust gas above the activation temperature of the catalyst is incorporated, and a first temperature sensor 5c for controlling the temperature of the exhaust gas heated by the auxiliary heater 5b. And a second temperature sensor 5d for monitoring the temperature of the exhaust gas after the treatment is provided on the gas outlet side than the catalyst support 5a. Further, a filter 5e for preventing the catalyst support 5a from clogging is incorporated in the auxiliary heater 5b side more detachably than the catalyst support 5a, and the gas inlet side is provided from the auxiliary heater 5b side. The air inlet port 5g with the flow control valve 5f is formed at the bottom. As the catalyst support 5a, an oxide catalyst such as Pt, Pd, Ag ₂ O, etc., having an activation temperature in the range of 200 to 350 ° C., is dispersed on a honeycomb-supported ceramic or heat-resistant metal support having a large contact area. What is attached (supported) is used preferably.

In the continuous firing furnace in which the exhaust gas treatment unit having the above structure is installed, a glass substrate for plasma display, for example, is mounted on a setter as a to-be-fired material W containing a binder, and the conveying roller 2 And heating while conveying the inside of the furnace body 1, the binder volatiles are generated from the unfired object W when the intermediate temperature in the furnace body 1 is reached, but the furnace body 1 containing the binder volatiles Atmospheric gas (air) in the () is sucked from the plurality of holes (3a) of the tubular gas suction member 3 over a wide range, so that the atmospheric gas containing the binder volatiles from the outlet of the furnace 1 There is no fear of release.

In this way, the gas containing the binder volatiles sucked from the gas suction member 3 is sent to the exhaust gas processing unit 5 without causing a temperature drop through the exhaust pipe passage 4, and to the auxiliary heater 5b. Thereby heating above the activation temperature of the catalyst, preferably above 350 ° C. When passing through the filter 5e, the solids in the exhaust gas and the like are removed, and when passing through the catalyst support 5a, the binder volatiles in the exhaust gas are oxidatively decomposed (burned) by the activated oxidation catalyst and injected. It is exhausted to 4a. Therefore, the binder volatiles in the exhaust gas do not solidify or generate odor as in the prior art. When the temperature of the exhaust gas sent to the exhaust gas treatment unit 5 is sufficiently higher than the activation temperature of the catalyst, it is passed through the catalyst support 5a without being heated by the auxiliary heater 5b and subjected to oxidative decomposition treatment.

When oxidizing and decomposing the binder volatiles contained in the exhaust gas as described above, the temperature of the exhaust gas before the treatment detected by the first temperature sensor 5c and the temperature of the exhaust gas after the treatment detected by the second temperature sensor 5d. By displaying on a monitor or the like to confirm that the oxidative decomposition of the binder volatiles is reliably performed at a temperature higher than the temperature of the exhaust gas before treatment, and the oxidative decomposition is insufficient and the temperature difference between both is small. In this case, by raising the heating temperature of the auxiliary heater (5b) or by adjusting the amount of air introduced from the air inlet (5g) by the flow control valve (5f) to promote the oxidation efficiency of the binder volatiles to improve the treatment efficiency It is preferable to make it.

In the continuous firing furnace provided with the exhaust gas treatment unit shown in FIG. 1, the tubular gas suction member 3 is placed in a direction orthogonal to the conveying direction of the to-be-fired object W in the upper portion of the temperature raising intermediate region in the furnace body 1. Although only the dogs are provided, the plurality of gas suction members 3 are provided at an upper portion of the intermediate temperature raising region at intervals in the conveying direction, whereby suction of atmospheric gas containing binder volatiles generated from the fired matter W is more sure. Needless to say, it may be done.

2 is a schematic cross-sectional view of a continuous kiln in which an exhaust gas treating unit according to another embodiment of the present invention is installed, and FIG. 3 is a side view of the continuous kiln.

Instead of the tubular gas suction member 3 described above, the continuous firing furnace provided with this exhaust gas treatment unit has an elongated box shape in which a gas suction slit 30a (see Fig. 3) is formed over the entire length of the lower surface. The gas suction member 30 is provided in the direction perpendicular to the conveyance direction of the to-be-fired object W in the upper part of the temperature increase intermediate | middle area | region in the furnace body 1. As shown in FIG. Then, exhaust pipe passages 4 and 4 are led out through the left and right side walls 1c and 1c of the furnace body 1 from both ends of the gas suction member 30 to the outside. The exhaust gas treatment units 5 and 5 described above are provided in portions (parts close to the lead portion from the furnace 1). Thus, since the distance from the derivation part of the exhaust pipe paths 4 and 4 to the waste gas processing units 5 and 5 is short, the heat insulation heater and heat insulating material for covering the exhaust pipe paths 4 and 4 are omitted.

Since the other structure of the continuous kiln provided with this waste gas processing unit is the same as the continuous kiln provided with the waste gas processing unit of FIG. 1 mentioned above, the same code | symbol is attached | subjected to FIG. 2, FIG. 3, and description is abbreviate | omitted. .

Even in the continuous firing furnace in which the exhaust gas treatment unit of this embodiment is installed, the atmosphere gas containing the binder volatiles generated from the fired matter W is formed by the elongated box-shaped gas suction member 30 having the slit 30a. It is sucked in a wide range and sent to exhaust gas processing units 5 and 5 via exhaust pipes 4 and 4. The binder volatiles are oxidatively decomposed (burned) when passing through the catalyst supports 5a and 5a, and the treated exhaust gas is exhausted to the injectors 4a and 4a, so that the small component atmosphere can be kept clean and the binder Volatiles do not solidify or cause odor. In addition, the state of oxidative decomposition of the binder volatiles can be grasped by comparing the exhaust gas temperature before the treatment detected by the first temperature sensor 5c and the second temperature sensor 5d with the exhaust gas temperature after the treatment. In this case, the heating temperature of the auxiliary heater 5b may be increased or the amount of air introduced from the air inlet 5g may be adjusted to promote oxidative decomposition to improve processing efficiency.

4 is a schematic cross-sectional view of a continuous firing furnace in which an exhaust gas treating unit according to another embodiment of the present invention is installed, and FIG. 5 is a side view of the continuous firing furnace.

The continuous calcination furnace provided with the exhaust gas treatment unit was fired while conveying the upper and lower workpieces W and W mounted on the two-stage setter by the conveying roller 2 at the same time. The tubular gas suction member 3 mentioned above is provided in one side part in the direction parallel to the conveyance direction of the to-be-baked object W. As shown in FIG. Then, the exhaust pipe passage 4 from the gas suction member 3 passes through the side wall 1c of the furnace body 1 to the outside, and in the middle of the exhaust pipe passage 4 (derived from the furnace body 1). The exhaust gas processing unit 5 mentioned above is provided in the part near a part. The gas suction member 3 may be provided in multiple numbers above and below the side of the furnace body 1, and in that case, the suction of the atmospheric gas containing binder volatiles becomes further more favorable. In addition, since the distance from the lead portion of the exhaust pipe passage 4 to the exhaust gas treatment unit 5 is also short in this continuous firing furnace, the heat insulating heater and the heat insulating material for covering the exhaust pipe passage 4 are omitted.

Since the other structure of the continuous kiln provided with this waste gas processing unit is the same as the continuous kiln provided with the waste gas processing unit of FIG. 2, 3 mentioned above, in FIG. 4, FIG. 5, the same code | symbol is attached | subjected to the same member, and description is abbreviate | omitted. I shall do it.

Like the continuous firing furnace in which the exhaust gas treatment unit of this embodiment is installed, the type of conveying and baking the top and bottom workpieces W and W at the same time, when the gas suction member 3 is installed in the upper part of the furnace 1, Although it is difficult to suck and discharge the atmosphere gas containing the binder volatiles generated from the fired matters W and W without leaving it, it is tubular in the side of the temperature raising intermediate region in the furnace 1 as in the continuous firing furnace of this embodiment. If the gas suction member 3 is installed in the direction parallel to the conveyance direction of the to-be-fired object W, the atmospheric gas containing the binder volatiles generated from the to-be-fired material W is formed by the to-be-fired material W and W. It is sucked in a wide range without being disturbed, and is sent to the exhaust gas processing unit 5 through the exhaust pipe passage 4. Since the binder volatiles are oxidized and decomposed (burned) when passing through the catalyst support 5a, and the treated exhaust gas is exhausted to the injector 4a, the binder volatiles do not solidify or generate odor. In addition, the state of oxidative decomposition is similar to the continuous firing furnace of FIGS. 1, 2, and 3 described above, and the exhaust gas temperature before treatment and the exhaust gas after treatment detected by the first temperature sensor 5c and the second temperature sensor 5d. By contrasting the temperature, if oxidative decomposition is insufficient, the heating temperature of the auxiliary heater 5b or the air introduction amount from the air inlet 5g may be increased to promote oxidative decomposition, thereby improving processing efficiency. You can.

In any of the continuous firing furnaces of the above-described embodiments, the gas suction member is provided in the upper part or the side part in the furnace, but in some cases, the gas suction member is provided in both the upper part and the side part of the furnace body to contain the binder volatiles. Inhalation of the atmospheric gas may be performed more reliably.

As described above, the continuous firing furnace provided with the exhaust gas treating unit of the present invention sucks the atmospheric gas containing the binder volatiles generated from the fired matter W from the gas intake member without leaving a wide range and discharges the gas. The binder volatiles are oxidatively decomposed (combusted) and exhausted by the catalyst when the air is sent to the unit and passed through the catalyst support of the unit, thereby eliminating contamination in the furnace to enable firing in a clean atmosphere and to solidify the binder volatiles. It is possible to solve problems such as generation of odors and dissipation from the furnace exit. In addition, the auxiliary heater, the first and second temperature sensors, the air inlet for adjusting the flow rate, and the like are installed in the exhaust gas treatment unit, so that the state of oxidative decomposition of the binder volatiles can be grasped, and the heating temperature and the air inlet of the auxiliary heater are provided. By controlling the amount of air introduced from the mixture, the oxidative decomposition of the binder volatiles is promoted, and the treatment efficiency can be improved.

Claims (6)

A tubular or elongated box-shaped gas suction member formed with a plurality of holes or slits for sucking gas containing binder volatiles generated from a to-be-applied product over its entire length is orthogonal to the conveying direction of the to-be-applied material at the top of the furnace body. In the direction or in the direction parallel to the conveying direction of the workpiece from the side in the furnace, and ventilated to support the catalyst for oxidatively decomposing the binder volatiles from the gas suction member to the exhaust pipe drawn out of the furnace. A continuous firing furnace in which an exhaust gas treatment unit is installed, comprising an exhaust gas treatment unit incorporating a catalyst support. The continuous firing furnace according to claim 1, wherein an auxiliary heater for heating the exhaust gas above the activation temperature of the catalyst is built in the gas inlet side than the catalyst support of the exhaust gas processing unit. The catalyst support of the exhaust gas treatment unit according to claim 2, wherein a first temperature sensor for controlling the temperature of the exhaust gas heated by the auxiliary heater is provided on the gas inlet side rather than the catalyst support of the exhaust gas treatment unit. And a second temperature sensor for monitoring the temperature of the discharged gas after the treatment is provided on the gas discharge side. 4. The continuous firing furnace according to claim 2 or 3, wherein an air inlet for controlling the flow rate is formed on the gas inlet side rather than the auxiliary heater of the exhaust gas treatment unit. The continuous firing furnace according to claim 2 or 3, wherein a filter is built in the auxiliary heater side rather than the catalyst support of the exhaust gas processing unit. The continuous firing furnace according to claim 4, wherein a filter is built in the auxiliary heater side rather than the catalyst support of the exhaust gas processing unit.

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