JP4476095B2 - Baking and drying furnace - Google Patents

Description

  The present invention relates to a baking / drying furnace, and more particularly to a baking / drying furnace having an enhanced cooling function so that the temperature in the furnace rapidly drops.

  In general, baking and drying furnaces are installed in many industrial product painting lines, including those related to automobiles, and the temperature in the furnace is usually 110 ° C. in order to bake and dry the uncured paint applied to the workpiece. It is comprised so that it may become -200 degreeC. Therefore, when any trouble occurs in the baking / drying furnace, it is necessary to quickly lower the high furnace temperature to a temperature at which an operator can enter the furnace (for example, around 40 ° C.).

Therefore, as shown in FIG. 4, conventionally, when the temperature in the baking / drying furnace 1 is lowered, the supply of gas to the gas burner 2 is stopped to stop the generation of heated air in the combustion chamber 3, and when the burner blower 4 is inhaled. The normal temperature air A1 around the baking / drying furnace 1 sent to the combustion chamber 3 after filtering is sent to the baking / drying furnace 1 by the hot air circulation fan 5 as it is without burning. Then, after the hot air A2 in the furnace is circulated to the combustion chamber 3 by the circulation fan 5, it is discharged out of the line (outside the factory) by the opening operation of the purge damper 6 as shown by the broken line arrow in FIG. The cooling method used was used.
Further, in combination with the above-described method, as shown in FIG. 5, the maintenance door 9 that closes the work loading / unloading ports 7 and 8 of the baking / drying furnace 1 is opened, and is indicated by a broken-line arrow in FIG. As described above, a cooling method in which the hot air A2 in the furnace is directly discharged outside the furnace may be used. In addition, the code | symbol W attached | subjected in FIG.4, 5 has shown the workpiece | work.

However, the above-described conventional baking drying furnace cooling method has the following problems. That is, in the former cooling method, as shown in FIG. 4, the baking / drying furnace 1, the combustion chamber 3, the hot air supply duct 10 and the hot air circulation duct 11 are provided with a heat insulating material 12 (in the drawing) in order to increase heat retention. In this case, it is covered with a hatched portion). Therefore, the normal temperature air A1 sucked by the burner blower 4 is heated by the radiant heat from the combustion chamber 3 and the air duct 10 before reaching the baking / drying furnace 1, so that the temperature inside the baking / drying furnace 1 is set. It was difficult to descend in a short time.
For this reason, for example, in a mountain furnace having extremely poor cooling efficiency, it may take about 7 hours to lower the temperature to a level at which an operator can enter the furnace. .

Further, in the latter cooling method, although the furnace temperature can be expected to drop quickly by using the former cooling method together, the air A1 flowing into the furnace as the hot air A2 is discharged is sucked by the burner blower 4. Unlike air A1, which is not filtered, there is a problem that a large amount of dust flows into the furnace together with air A1. And if the dust which flowed in the furnace adheres to the coating surface of the workpiece | work W before hardening, since coating quality will be greatly damaged, it will suffer a great damage.
By the way, Patent Document 1 proposes a heating device with a rapid cooling function that rapidly cools by passing a refrigerant through the device main body. However, such a device is large for automobiles in terms of cost and maintenance. There is a problem that it is not suitable for the baking and drying furnace.

Japanese Patent Laid-Open No. 09-189692

  Therefore, the present invention has been made to solve the above-mentioned problems of the prior art, and is a baking drying furnace capable of quickly lowering the furnace temperature without adhering dust to the workpiece coating surface. The purpose is to provide.

In order to achieve the above object, the invention described in claim 1 is a combustion chamber for generating heated air, and the heated air generated in the combustion chamber is sucked and sent to a baking and drying furnace to bake the workpiece coating surface. In a baking drying furnace provided with a circulation device for drying and circulating to the combustion chamber,
In the case of lowering the temperature in the baking / drying furnace, the combustion chamber stops generation of heated air and communicates with the upper part of the painting booth for painting the work, and is filtered into the painting booth. An air intake means capable of taking in the fed air is provided at least on the suction side of the circulation device or in the baking and drying furnace.

According to the present invention, in addition to the configuration of the invention described in claim 1, the combustion chamber feeds the air around the baking and drying furnace for generating heated air into the combustion chamber in a filtered state, and the baking In the case of lowering the temperature in the drying furnace, it is provided with a blowing means that operates together with the circulation device and feeds the filtered air into the baking drying furnace.

The present invention is characterized in that, in addition to the configuration of the invention described in claim 1 , the painting booth is supplied with air whose air volume is adjusted and regulated by a supply air conditioner for the painting booth.

According to the present invention, in addition to the configuration of the invention described in claim 1 or 2 , the baking / drying furnace includes an exhaust unit that allows the air that has been fed into the baking / drying furnace to be discharged to the outside. Features.

According to the present invention, when the temperature in the baking / drying furnace is lowered, the combustion chamber stops generating heated air, and the suction side of the circulation device or the air in the space different from the baking / drying furnace is used for the baking / drying furnace. That is, air outside the furnace is sent in a state of being filtered by the air intake means. Since this filtered air is sent directly to the baking and drying furnace in a short time without passing through the combustion chamber, an increase in temperature due to radiant heat is suppressed.

  As a result, the interior of the high-temperature baking / drying furnace is cooled by clean air sent from the air intake means and at a temperature that is not so different from room temperature, so even if the work carry-in / out port of the baking / drying furnace is completely closed, The temperature in the drying furnace can be quickly lowered. In addition, there is no fear of dust adhering to the workpiece coating surface before curing, and the coating quality is not impaired.

According to the present invention, when the temperature in the baking and drying furnace is lowered, the air filtered by the blowing means is sent into the combustion chamber without being burned and heated by radiant heat, but is filtered by the air intake means. The temperature rise is extremely small because of mixing with the air outside the furnace. As a result, the air at substantially room temperature is increased and supplied to the baking / drying furnace, so that the inside of the baking / drying furnace can be cooled in a shorter time.

According to the present invention, the air intake means again filters air having a relatively low solvent concentration among the air once filtered before being sent into the coating booth, and then sends it to the baking and drying furnace. As a result, the presence of dust, which is a concern when air outside the furnace is fed into the baking / drying furnace, can be reduced to the utmost limit, and it is possible to prevent dust from adhering to the workpiece coating surface before curing. it can.

According to the present invention, the air supplied from the air supply air conditioner for the painting booth is supplied to the painting booth. As a result, by using the air volume and pressure supplied from the supply air conditioner for the painting booth, the hot air in the baking and drying furnace can be discharged out of the furnace more quickly, so that the temperature in the baking and drying furnace can be further increased. It can be lowered quickly.

According to the present invention, the air whose temperature has been increased by being sent to the baking / drying furnace is discharged outdoors by the exhaust means. Thereby, since the hot air in the baking / drying furnace is smoothly discharged to the outside, the temperature drop in the baking / drying furnace can be promoted.

  By filtering the air around the baking / drying furnace and then sending it directly to the baking / drying furnace in a short time, there is no need to worry about dust and the temperature inside the baking / drying furnace can be lowered quickly even when the baking / drying furnace is closed. A stoving and drying furnace capable of achieving this has been realized.

(Reference example)
Hereinafter, reference examples of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram for explaining a baking / drying furnace according to a reference example . In addition, the same code | symbol is attached | subjected and demonstrated about the structural member similar to the past.

  As shown in FIG. 1, the main baking and drying furnace 1 is applied to a coating line for many industrial products including those related to automobiles, and includes a combustion chamber 3 that generates heated air, and a combustion chamber 3. The generated heated air is sucked and sent to the baking / drying furnace 1 to bake and dry the workpiece coating surface, and the hot-air circulating fan 5 as a circulation device that circulates in the combustion chamber 3. A hot air supply duct 10 for sending heated air into the furnace, and a hot air circulation duct 11 for connecting the baking / drying furnace 1 and the combustion chamber 3 to send hot air in the furnace into the combustion chamber 3. It is prepared for. Further, the combustion chamber 1, the baking / drying furnace 3, the hot-air supply duct 10, and the hot-air circulation duct 11 are covered with a heat insulating material (not shown) (see FIG. 4), so that the heat retaining power is enhanced.

  In the combustion chamber 3, a gas supply pipe 13 for supplying combustion gas for generating heated air, and air in a space different from the baking / drying furnace 1, for example, room temperature air A <b> 1 around the baking / drying furnace are not shown. Is connected to a burner blower 4 supplied in a filtered state. Further, the combustion chamber 3 is provided with a gas burner 2 for heating the air A1 sent from the burner blower 4 and the hot air A2 sent from the baking / drying furnace 1 by burning the combustion gas. The gas burner 2 is configured to stop the generation of heated air when the temperature in the baking / drying furnace 1 is lowered, and the air from the burner blower 4 even when the supply of combustion gas is stopped. The supply of A1 is not stopped.

  The hot air circulation fan 5 can be operated together with the burner blower 4 or can be operated alone, and the suction side thereof communicates with the combustion chamber 3 via the connecting duct 14 and the exhaust side. Is communicated with the inside of the baking / drying furnace 1 through the hot air supply duct 10. The hot air supply duct 10 is provided with a branching outdoor exhaust duct 16 with a purge damper 15 that can discharge heated air of a set temperature or higher passing through the duct to the outside.

  When the purge damper 15 is in the state of being baked and dried, at least one of the outlet temperature of the combustion chamber 3, the suction side temperature of the hot air circulation fan 5, and the exhaust side temperature is set to a preset temperature ( For example, when the temperature is higher than 110 to 200 ° C., the opening is controlled to discharge the heated air to the outside to prevent overheating of the baking / drying furnace 1, and the others are closed to prevent the heating air from being discharged to the outside. Yes. Furthermore, it is preferable that the purge damper 15 is normally controlled to be opened in a state where the temperature of the baking / drying furnace 1 is lowered, but the invention is not limited to this.

The baking / drying furnace 1 uses the heated air generated in the combustion chamber 3 and the radiant heat in the furnace to bake and dry the coating before hardening of the workpiece W transferred from the coating booth 17 (shown in FIG. 2). A folding door-like maintenance door 9 for closing the inside of the furnace is provided at the work loading / unloading exits 7 and 8 so as to be openable and closable (see FIG. 5). This maintenance door 9 is set so that the inside of the furnace can be closed at all times regardless of whether the baking is performed or the temperature of the baking drying furnace is lowered, in addition to performing maintenance work inside the furnace. The air A1 that has not been filtered is prevented from entering the furnace.
In addition, an outlet 18 of the hot air supply duct 10 is provided at the lower part of the left and right side walls of the baking and drying furnace 1, and an inlet 19 of the hot air circulation duct 11 communicating with the combustion chamber 3 is provided at the upper part of the left and right side walls. Is provided.

  Thereby, the hot air circulation fan 5 sucks the heated air generated in the combustion chamber 3 in a normal operation state, and sends it to the baking / drying furnace 1 to bake and dry the painted surface of the workpiece W. It is possible to circulate in the combustion chamber 3. In the state where the temperature in the baking / drying furnace 1 is lowered, the air A1 in the combustion chamber 3 is sucked and sent to the baking / drying furnace 1 to lower the temperature in the furnace and then circulated in the combustion chamber 3. It is possible.

Further, a suction duct of the hot air circulation fan 5, for example, a connection duct 14 connecting the combustion chamber 3 and the hot air circulation fan 5, is provided in the pipe line when the temperature in the baking / drying furnace 1 is lowered. When the open / close damper 20 is opened, air in a space different from that of the baking / drying furnace 1, for example, air A1 around the baking / drying furnace 1 is filtered by a filter 21 integrally provided to remove dust. A cylindrical air intake duct 22 is provided as an air intake means that can be taken in.
The air intake duct 22 is not only provided on the suction side of the hot air circulation fan 5, but is integrated with, for example, an air supply fan as a blower that can supply air directly into the baking / drying furnace 1. It is possible to provide.

According to the baking / drying furnace 1 having such a configuration, when the temperature in the baking / drying furnace 1 is lowered, the combustion chamber 3 stops the generation of heated air, and the suction side of the hot air circulation fan 5 or the baking / drying furnace 1 includes Air in a space different from that of the baking / drying furnace 1, for example, air A <b> 1 around the baking / drying furnace 1 is sent in a state of being filtered by the air intake duct 22 . Since the filtered air A1 is sent directly to the baking / drying furnace 1 in a short time without passing through the combustion chamber 3, the temperature rise due to radiant heat is suppressed. As a result, the inside of the high-temperature baking / drying furnace 1 is cooled by the air A1 having a temperature that is clean and sent from the air intake duct 22 and is not so different from the normal temperature. Even in the closed state, the temperature in the baking / drying furnace 1 can be quickly lowered. In addition, there is no concern that dust will adhere to the workpiece coating surface before curing, and the coating quality will not be impaired.

Further, when the temperature in the baking / drying furnace 1 is lowered, the air A1 filtered by the burner blower 4 is sent into the combustion chamber 3 without being burned and heated by radiant heat, but is filtered by the air intake duct 22 . The temperature rise is extremely small because of mixing with the air A1. As a result, the amount of air A1 at substantially normal temperature is increased and supplied to the baking / drying furnace 1, so that the inside of the baking / drying furnace 1 can be cooled in a shorter time.
The hot air A2 in the baking / drying furnace 1 is discharged to the outside from the exhaust duct 16 when the purge damper 15 is opened. Thereby, since hot air A2 is discharged | emitted smoothly outdoors, the temperature fall in the baking drying furnace 1 can be accelerated | stimulated.

Example 1
Next, Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 2 is a configuration diagram for explaining the baking / drying furnace according to the first embodiment.

  As shown in FIG. 2, in the main baking / drying furnace 1, the air intake duct 22 communicates with the upper part of the painting booth 17 that paints the workpiece W via the painting booth air intake duct 23. At the same time, by opening the opening / closing damper 24 provided in the duct of the painting booth air intake duct 23, the air A3 sent to the painting booth 17 in a filtered state can be taken in. Yes. Further, the air A3 supplied to the painting booth 17 can be adjusted and regulated by a painting booth air supply air conditioner 25 (shown in FIG. 3).

  According to the baking and drying furnace 1 having such a configuration, the air intake duct 22 filters again the air A3 having a relatively low solvent concentration among the air A3 that has been filtered once before being fed into the coating booth 17, and then baking and drying. Feed into furnace 1. As a result, in addition to the effects of the reference example, the presence of dust that is a concern when the air A3 outside the furnace is fed into the baking and drying furnace 1 can be reduced to the utmost limit. Can be prevented in advance.

(Example 2)
It will now be described with reference to the accompanying drawings for Example 2 of the present invention. FIG. 3 is a configuration diagram for explaining a baking / drying furnace according to the second embodiment.

  As shown in FIG. 3, in the baking / drying furnace 1, the air intake duct 22 is provided integrally with an air supply fan 26 as a blower that can directly supply air into the baking / drying furnace 1. The exhaust side communicates with the inside of the baking / drying furnace 1. In addition, the suction side of the air supply fan 26 communicates with the interior of the painting booth 17 via the filtration filter 21 and the painting booth air intake duct 23. The opening / closing damper 24 provided in the painting booth air intake duct 23 is opened to adjust the air volume A4 adjusted and regulated by the painting booth air supply air conditioner 25 by the booth air conditioning supply fan 27. After being sucked in, it is filtered when it is sent into the painting booth 17 through the booth air-conditioning air supply duct 28, and the air A3 in the painting booth 17 that has been filtered and sent in can be taken in. .

According to the baking / drying furnace 1 having such a configuration, the air A4 supplied from the coating booth supply air conditioner 25 is supplied to the baking / drying furnace 1 through the coating booth 17. Thereby, in addition to the effect of a reference example and Example 1 , hot air A2 in the baking drying furnace 1 is made quicker by using the air A4 adjusted and regulated by the air supply air conditioner 25 for the painting booth. Since it can discharge | emit out of a furnace, the temperature in the baking drying furnace 1 can be dropped more rapidly.

As a result, it is possible to provide a baking / drying furnace capable of rapidly lowering the furnace temperature without causing dust to adhere to the workpiece coating surface. For this reason, accident recovery time when trouble occurs in the baking and drying furnace can be shortened, and the influence on productivity can be minimized. In addition, the influence on the coating quality of the workpiece W when cooling the furnace is also minimized. Furthermore, since an existing baking / drying furnace can be easily applied without significantly changing the structure, a low-cost baking / drying system can be realized.
The main baking / drying furnace is not only applied to a large-sized baking / drying furnace for automobiles, but can also be applied to a small baking / drying furnace.

It is a block diagram for demonstrating the baking drying furnace which concerns on a reference example . 1 is a configuration diagram for explaining a baking / drying furnace according to Embodiment 1. FIG. 5 is a configuration diagram for explaining a baking / drying furnace according to Embodiment 2. FIG. It is a block diagram for demonstrating the conventional baking drying furnace. It is the schematic diagram which showed the workpiece conveyance path | route in the conventional baking drying furnace.

1 Baking and drying furnace 3 Combustion chamber 4 Burner blower (air blowing means)
5 Hot air circulation fan (circulation device)
16 Outdoor exhaust duct (exhaust means)
17 Painting booth 22 Air intake duct (Air intake means)
25 Air supply air conditioner for painting booth A1 Room temperature air around baking drying furnace A2 Hot air in furnace A3 Air in painting booth A4 Air W adjusted and regulated by air supply air conditioner for painting booth

Claims (3)

A combustion chamber that generates heated air, and a circulation device that sucks the heated air generated in the combustion chamber, sends the heated air to a baking and drying furnace, bakes and dries the workpiece coating surface, and circulates it in the combustion chamber. In the baking and drying furnace,
In the case of lowering the temperature in the baking / drying furnace, the combustion chamber stops generation of heated air and communicates with the upper part of the painting booth for painting the work, and is filtered into the painting booth. Baking and drying furnace characterized in that air intake means capable of taking in the fed air is provided at least on the suction side of the circulation device or in the baking and drying furnace. 2. The baking / drying furnace according to claim 1 , wherein the painting booth is supplied with air whose air volume is adjusted and regulated by a supply air conditioner for the painting booth. The baking and drying oven, baking drying furnace according to claim 1 or 2, characterized in that it comprises an exhaust means to be discharged is fed to the drying oven with該焼temperature elevated air outdoors.

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