JP2021173501A - Drying system for coating application line - Google Patents

Abstract

To improve deterioration in cooling efficiency of a cooling process in a coating application line and a heat loss of a drying furnace.SOLUTION: A drying system for a coating application line includes: a drying furnace; a cooling booth provided downstream of the drying furnace; an intermediate chamber provided between the drying furnace and the cooling booth; a first air shutter provided in an upstream end of the intermediate chamber; and a second air shutter provided in a downstream end of the intermediate chamber. The intermediate chamber or cooling booth includes an exhaust port for evacuating internal air from the intermediate chamber or cooling booth.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a coating line drying system.

Conventionally, a painting line for painting an automobile body or a part or the like is provided with a plurality of zones in which each processing step is performed along a transport line of an object to be painted. Then, after the coating step, a step of baking and drying the coating film formed on the object to be coated in a drying furnace and a step of cooling the object to be coated which has become hot in the baking and drying step are performed.

According to Patent Document 1, as a cooling step after the baking and drying step, the object to be coated is precooled by supplying outside air at room temperature in the precooling zone, and the object to be coated after precooling is cooled by air cooled by a cooler in the cooling zone. It is disclosed to do.

Japanese Patent No. 5274417

The cooling process disclosed in Patent Document 1 requires a pre-cooling zone and a cooling booth, requires a long time for the cooling process, and has a problem that the line length required for the cooling process becomes long. Therefore, it is conceivable to omit the pre-cooling zone and directly connect the cooling booth to the drying furnace to solve the above problem. However, if the drying furnace with a high temperature atmosphere and the cooling booth are directly connected, the temperature of the drying furnace becomes high. There is a problem that air flows in and the cooling efficiency is lowered, and low-temperature air flows into the drying furnace from the cooling booth, causing heat loss in the drying furnace.

The present disclosure has been made in view of the above-mentioned problems, and an object of the present disclosure is to improve the reduction of the cooling efficiency of the cooling process in the coating line and the heat loss of the drying furnace.

In order to achieve the above object, the drying system of the coating line according to the present disclosure is provided between the drying furnace, a cooling booth provided on the downstream side of the drying furnace, and the drying furnace and the cooling booth. The intermediate chamber, the first air shutter provided at the upstream end of the intermediate chamber, and the second air shutter provided at the downstream end of the intermediate chamber are provided, and the intermediate chamber or the cooling booth is the intermediate. It has an outlet for exhausting air in the room or in the cooling booth.
In the present specification, the "upstream side" means the upstream side in the transport direction of the object to be coated to be transported on the coating line, and the "downstream side" means the downstream side in the transport direction of the object to be coated. ..

According to the coating line drying system according to the present disclosure, since the intermediate chamber having the first air shutter and the second air shutter is provided, a decrease in cooling efficiency of the cooling process in the coating line and a heat loss of the drying furnace are suppressed. At the same time, it is possible to shorten the time required for the cooling process of the object to be coated after drying and shorten the line length of the cooling zone.

It is a system diagram of the drying system which concerns on one Embodiment. It is a system diagram of the drying system which concerns on one Embodiment. It is a system diagram of the drying system which concerns on one Embodiment. It is a system diagram of the drying system which concerns on one Embodiment. It is a system diagram of the drying system which concerns on one Embodiment. It is a system diagram of the drying system which concerns on one Embodiment. It is a system diagram of the drying system which concerns on one Embodiment. It is a system diagram of the drying system which concerns on one Embodiment. It is a system diagram of the drying system which concerns on one Embodiment. It is a schematic front view of the intermediate chamber of the drying system which concerns on one Embodiment. It is a schematic plan view of the intermediate chamber of the drying system which concerns on one Embodiment. It is a schematic front view of the intermediate chamber and the cooling booth of the drying system which concerns on one Embodiment. It is a schematic plan view of the intermediate chamber and the cooling booth of the drying system which concerns on one Embodiment.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in these embodiments or shown in the drawings are not intended to limit the scope of the present invention to this, and are merely explanatory examples. It's just that.
For example, expressions that represent relative or absolute arrangements such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric" or "coaxial" are exact. Not only does it represent such an arrangement, but it also represents a state of relative displacement with tolerances or angles and distances to the extent that the same function can be obtained.
For example, expressions such as "same", "equal", and "homogeneous" that indicate that things are in the same state not only represent exactly the same state, but also have tolerances or differences to the extent that the same function can be obtained. It shall also represent the existing state.
For example, an expression representing a shape such as a quadrangular shape or a cylindrical shape not only represents a shape such as a quadrangular shape or a cylindrical shape in a geometrically strict sense, but also an uneven portion or chamfering within a range in which the same effect can be obtained. The shape including the part and the like shall also be represented.
On the other hand, the expressions "equipped", "equipped", "equipped", "included", or "have" one component are not exclusive expressions that exclude the existence of other components.

1 to 9 are system diagrams schematically showing a drying system for a coating line according to some embodiments. The painting line performs a step of painting the object to be painted w on the upstream side, baking and drying the painted object w on the downstream side, and a cooling step of cooling the baked and dried object w to be painted. The drying system 10 described below is a system for baking and drying and cooling the object to be coated w painted on the upstream side.

1 to 9 are system diagrams showing drying systems 10 (10A, 10B, 10C, 10D, 10E, 10F, 10G, 10H, 10I) according to each of several embodiments. As shown in FIG. 1, a transport line 26 or 28 is provided for transporting the object to be coated w in the direction indicated by the arrow a from the coating process (not shown) performed on the upstream side. The object to be coated w is hung on a hanger on the transport line 26, or is transported in the direction of arrow a by a conveyor provided on the floor surface on the transport line 28. A drying furnace 12 and a cooling booth 14 provided on the downstream side of the drying furnace 12 are provided in order along the transfer line 26 or 28. An intermediate chamber 16 is provided between the drying furnace 12 and the cooling booth 14, a first air shutter 18 is provided at the upstream end of the intermediate chamber 16, and a second air shutter 20 is provided at the downstream end of the intermediate chamber 16. There is. The intermediate chamber 16 or the cooling booth 14 has a discharge port 22 or 24 for discharging the internal air of the intermediate chamber 16 or the cooling booth 14.

In the drying furnace 12, the object to be coated w that has completed the coating process is baked and dried. The first air shutter 18 and the second air shutter 20 form an air film so as to cross the transport lines 26 and 28 to shut off heat. For example, it is composed of an air outlet formed in the vertical direction on one side surface of both side surfaces of the intermediate chamber 16 and an air suction port formed in the vertical direction on the other side surface. An air flow is ejected from the air outlet toward the air suction port, and the air flow is sucked into the air suction port to form an air film on the cross section of the intermediate chamber 16 orthogonal to the transport direction. The air film blocks the flow of air and heat.
The transport lines 26 and 28 are omitted in FIG. 2 and below.

According to the above embodiment, since the intermediate chamber 16 is provided as a buffer zone between the drying furnace 12 and the cooling booth 14, and the air shutters 18 and 20 are provided at the inlet and the outlet of the intermediate chamber 16, respectively, the inside of the drying furnace 12 is provided. It is possible to prevent the high temperature air from entering the cooling booth 14. Further, by accompanying the high temperature air leaking from the drying furnace 12 to the intermediate chamber 16 or the air leaking from the intermediate chamber 16 to the cooling booth 14 with the air discharged from the discharge port 22 or 24, the cooling booth 14 It is possible to suppress the temperature rise of the cooling booth 14 due to the intrusion of air into the inside. As a result, it is possible to suppress a decrease in cooling efficiency in the cooling booth 14 and a heat loss in the drying furnace 12. Further, unlike Patent Document 1, it is not necessary to provide a pre-cooling zone between the drying furnace 12 and the cooling booth 14, so that the time of the cooling step can be shortened and the line length of the cooling zone can be shortened.

In the embodiment shown in FIGS. 10 and 11, the first air shutter 18 and the second air shutter 20 are respectively arranged on both side surfaces of the intermediate chamber 16 so as to face each other, and have an air outlet portion 54 having an air outlet. An air suction unit 56 having an air suction port is provided.
In one embodiment, as shown in FIGS. 1 to 9, an air shutter 30 is also provided at the outlet of the cooling booth 14 to block the flow of air and hot air between the cooling booth 14 and the booth for performing the next step. ing.

In one embodiment, as shown in FIGS. 1 to 9, a heat pump device 40 is provided, and the heat pump device 40 supplies a heat source for heating the high-temperature air supplied to the drying furnace 12 and a cooling booth 14. Since a cold heat source for cooling the low temperature air is supplied, the thermal efficiency of the drying system 10 can be improved as compared with other heat source supply methods.

The drying system 10 (10A, 10C, 10E, 10G, 10H) shown in FIGS. 1, 3, 5, 7, and 8 is an embodiment in which the discharge port 22 is provided in the intermediate chamber 16, and FIG. The drying system 10 (10B, 10D, 10F, 10G, 10H, 10I) shown in FIGS. 4 and 6, 7, 8, and 9 is an embodiment in which the cooling booth 14 is provided with the discharge port 24. ..

In one embodiment, the heat pump device 40 is composed of a first heat pump device 40 (40A) using _{CO 2 as a refrigerant.} The first heat pump device 40 (40A) using CO ₂ as a refrigerant can generate high temperature air of 100 to 120 ° C. from the outside air temperature, for example, when taking in outside air oa by setting _{CO 2 in a supercritical state.} In the embodiment including the first heat pump device 40 (40A) as in the drying system 10 (10A, 10B) shown in FIGS. 1 and 2, the high temperature air generated by the first heat pump device 40 (40A) is used in a drying furnace. The supply line 42 for supplying to 12 is provided with an auxiliary burner 44. As a result, the high temperature air of 100 to 120 ° C. generated by the first heat pump device 40 (40A) can be further heated to 180 to 200 ° C. by the auxiliary burner 44 and supplied to the drying furnace 12. Therefore, it can be applied to baking and drying of metal objects to be coated such as automobile bodies, which require a high temperature atmosphere of 180 to 200 ° C. in the baking and drying step.

In one embodiment, the heat pump device 40 is a second heat pump using a refrigerant capable of circulating heating by changing the phase at a temperature below the critical temperature, such as the drying system 10 (10C, 10D) shown in FIGS. 3 and 4. It is composed of a device 40 (40B). In this embodiment, for example, a so-called green refrigerant is used as the refrigerant. In the present specification, the green refrigerant refers to a natural refrigerant (mainly hydrocarbon-based such as propylene, propane, butane, etc.), an HFO-based refrigerant having an ODP of 0 and a low GWP. As used herein, low GWP means, for example, GWP ≦ 20. The second heat pump device 40 (40B) using such a refrigerant can circulate and generate high-temperature air at 80 to 85 ° C. as high-temperature air to be supplied to the drying furnace 12, and thus, for example, a resin-made object to be coated. It can be applied to baking and drying.

In one embodiment, for example, as in the drying system 10 (10E, 10F) shown in FIGS. 5 and 6, the heat pump device 40 is equal to or lower than the critical temperature of the first heat pump device 40 (40A) using _{CO 2 as a refrigerant.} The second heat pump device 40 (40B), which uses a refrigerant (for example, a green refrigerant) capable of circulating and heating by changing the phase at the temperature of the above, is included. The first heat pump device 40 (40A) and the second heat pump device 40 (40B) are configured to operate so as to be switchable according to the type of the object to be coated w. Thereby, the range of the object to be coated that can be baked and dried can be expanded by properly using the heat pump device suitable for the object to be coated w according to the type of the object to be coated w. Further, energy saving can be achieved by using a heat pump device suitable for the object to be coated w.

In one embodiment, as shown in FIGS. 1 to 9, the exhaust gas discharged from the discharge port 22 of the intermediate chamber 16 or the discharge port 24 of the cooling booth 14 is discharged through the circulation line 48 to the first heat pump device 40 (40A). ) Or the inlet side of the second heat pump device 40 (40B). As a result, the retained heat of the exhaust gas discharged from the exhaust port 22 or 24 can be effectively used. Since the COP of the first heat pump device 40 (40A) decreases when the supply temperature of the air serving as the cooling medium is high, the first heat pump device 40 (40A) is supplied to the supply line 42 on the outlet side of the first heat pump device 40 (40A).

Further, in order to reheat the heated air supplied to the drying furnace 12, a circulation line 46 is provided, and the outlet side of the first heat pump device 40 (40A) or the second heat pump device 40 ( It is supplied to the entrance side of 40B). Further, an exhaust line 47 is provided as needed, and the air is exhausted from the drying furnace 12 to the outside of the system via the exhaust line 47.

In one embodiment, as shown in FIGS. 1 to 9, outside air oa is supplied to the first heat pump device 40 (40A) or the second heat pump device 40 (40B) as air to be supplied to the drying furnace 12. .. Further, between the heat exchanger 41, the circulation line 43 connected between the cooling booth 14 and the heat exchanger 41, and the first heat pump device 40 (40A) or the second heat pump device 40 (40B) and the heat exchanger 41. A connected circulation line 45 is provided. In the heat exchanger 41, the cooling medium (for example, cooling water) flowing through the circulation line 45 cooled by the heat pump device cools the cooling air flowing through the circulation line 43 to, for example, 12 to 15 ° C. and supplies the cooling air to the cooling booth 14. ..

In the embodiment shown in FIGS. 5 to 9, the circulation line 45 is branched into a circulation line 45 connected to the first heat pump device 40 (40A) and the second heat pump device 40 (40B), respectively. The numerical values of the temperatures of the respective parts shown in FIGS. 1 to 9 show an example.

In one embodiment, as shown in FIGS. 1-9, the discharge port 22 or 24 is provided on the upper surface of the intermediate chamber 16 or the cooling booth 14. In rooms such as the drying furnace 12 and the intermediate room 16, the hottest air is stored in the upper layer due to the difference in density due to the temperature difference. Therefore, the maximum temperature air leaking from the drying furnace 12 to the intermediate chamber 16 leaks from the upper layer region of the drying furnace 12 to the upper layer region of the intermediate chamber 16. Since the discharge port 22 or 24 is provided on the upper surface of the intermediate chamber 16 or the cooling booth 14, the maximum temperature air leaking from the drying furnace 12 to the intermediate chamber 16 or the maximum temperature air leaking from the intermediate chamber 16 to the cooling booth 14 Can be preferentially discharged to the outside from the discharge port 22 or 24.

In one embodiment, as shown in FIGS. 1 to 9, the intermediate chamber 16 or the cooling booth 14 has an intermediate temperature between the high temperature air of the drying furnace 12 and the low temperature air of the cooling booth 14 (hereinafter, simply “intermediate”). It has a suction port 50 or 52 for sucking air having a temperature (also referred to as “temperature”), and the suction port 50 or 52 is provided at a position lower than the discharge port 22 or 24. The air at an intermediate temperature is, for example, outside air oa at room temperature. By providing the suction port 50 or 52, an intermediate temperature rising flow flowing from the suction port 50 or 52 to the discharge port 22 or 24 can be formed inside the intermediate chamber 16 or the cooling booth 14. Therefore, the air leaking from the drying furnace 12 to the intermediate chamber 16 or the intermediate chamber 16 to the cooling booth 14 can be discharged from the discharge port 22 or 24 along with this ascending current. Therefore, it is possible to suppress the temperature rise of the cooling booth 14 due to the intrusion of air from the intermediate chamber 16 into the cooling booth 14.

10 and 12 are schematic side views of the intermediate chamber 16 or the cooling booth 14 according to each embodiment, and FIGS. 11 and 13 are schematic side views of the intermediate chamber 16 or the cooling booth 14 according to these embodiments. It is a plan view.
In one embodiment, as shown in FIG. 10, when the height of the suction port 50 formed in the intermediate chamber 16 is H, the height h0 of the opening of the suction port 50 is from the vicinity of the floor surface. It is provided up to a height of 0.7H. By arranging the suction port 50 in the above range including the central height of the intermediate chamber 16 in this way, an intermediate temperature rising flow from the suction port 50 to the discharge port 22 can be formed. As a result, the maximum temperature air leaking from the upper layer region of the drying furnace 12 to the upper layer region of the intermediate chamber 16 can be effectively discharged from the discharge port 22 along with this rising flow.

In one embodiment, as shown in FIG. 10, the opening of the suction port 50 has a slit-like shape extending along the height direction. As a result, the suction air can be supplied to the intermediate chamber 16 at a uniform flow rate in the height direction, and the slit-shaped shape makes it possible to secure a flow velocity capable of forming the upward flow at the time of suction.
Further, in one embodiment, as shown in FIG. 11, the suction port 50 includes suction ports 50 (50a, 50b) provided on both side walls of the intermediate chamber 16. As a result, the intake air can be uniformly supplied in the width direction of the intermediate chamber 16.

In one embodiment, as shown in FIG. 11, in the intermediate chamber 16, when the discharge port 22 is provided near the upper surface of the upstream region Au of the intermediate chamber 16 and the width of the intermediate chamber 16 is W, In the width direction of the intermediate chamber 16, the width w0 of the discharge port 22 has a width of 0.3 to 0.8 W at the central portion in the width direction. Here, the upstream region Au refers to the upstream region from the intermediate line of the longitudinal dimension of the intermediate chamber 16.
As a result, the high-temperature air of the drying furnace 12 that has entered the intermediate chamber 16 is accompanied by the air discharged from the discharge port 22 on the upstream side of the intermediate chamber 16, so that the high-temperature air flows to the downstream side of the intermediate chamber 16. Can be suppressed.

In one embodiment, as shown in FIG. 11, the discharge port 22 has a slit-like shape extending in the width direction of the intermediate chamber 16. As a result, it is possible to discharge at a uniform flow rate in the width direction of the intermediate chamber 16, and because of the slit-shaped shape, it is possible to secure a flow velocity at which the above-mentioned upward flow can be formed at the time of discharge.
Further, in one embodiment, the discharge port 22 is open toward the upstream side. As a result, the maximum temperature air leaking from the upper layer region of the drying furnace 12 to the upper layer region of the intermediate chamber 16 can be discharged.

In one embodiment, the discharge port 22 is arranged in a region downstream of the virtual straight line L connecting the downstream end of the air blowing portion 54 of the first air shutter 18 and the downstream end of the air suction portion 56. As a result, it is possible to avoid interference between the air film formed by the air blowing portion 54 and the air suction portion 56 and the air flow formed by the air discharged from the discharge port 22.

In one embodiment, as shown in FIGS. 10 and 12, in the intermediate chamber 16 or the cooling booth 14, the suction port 50 or 52 is provided on the downstream side of the discharge port 22 or 24. As a result, a flow of intake air toward the upstream side can be formed from the intake port 50 or 52 to the discharge port 22 or 24. Since this air flow is a countercurrent flow in the opposite direction to the high temperature air leaking from the drying furnace 12 to the intermediate chamber 16 or the air leaking from the intermediate chamber 16 to the cooling booth 14, these air leaks can be suppressed.

In one embodiment, as shown in FIGS. 10 and 12, when the intermediate chamber 16 or the cooling booth 14 is divided into an upstream region and a downstream region, the discharge port 22 or 24 is arranged in the upstream region. The suction port 50 or 52 is arranged in the downstream region. Thereby, the countercurrent can be formed between the discharge port 22 or 24 and the suction port 50 or 52.

In one embodiment, as shown in FIGS. 11 and 13, the suction ports 50 or 52 are suction ports 50 (50a, 50b) and 52 (52a, 52b) provided on both sides of the intermediate chamber 16 or the cooling booth 14. )including. As a result, the air sucked from the suction port 50 or 52 can be uniformly dispersed in the cross-sectional direction (direction orthogonal to the transport direction a) of the intermediate chamber 16 or the cooling booth 14.

In one embodiment, the individual cross-sectional areas of the suction ports 50 (50a, 50b) or 52 (52a, 52b) provided on both sides of the intermediate chamber 16 or the cooling booth 14 are one of the cross-sectional areas of the discharge ports 22 or 24. Make it larger than / 2. As a result, the amount of air sucked from the suction port 50 or 52 is made larger than the amount of air discharged from the discharge port 22 or 24. As a result, it is possible to prevent the inside of the intermediate chamber 16 or the cooling booth 14 from becoming negative pressure due to the resistance of the intake air when passing through the suction port. Therefore, it is possible to suppress the formation of a suction air flow provided on both side surfaces of the cooling booth 14 and connecting the two suction ports 52 (52a, 52b).

In one embodiment, as shown in FIG. 12, in the cooling booth 14, the suction port 52 is provided in the lower part of the inlet side region of the cooling booth 14. As a result, the relatively high temperature air leaking from the intermediate chamber 16 to the cooling booth 14 can be discharged from the discharge port 24 along with the ascending flow from the suction port 52 to the discharge port 24. Therefore, it is possible to prevent the high-temperature air leaking from the intermediate chamber 16 into the cooling booth 14 from entering the area downstream of the inlet side region of the cooling booth 14.

In one embodiment, as shown in FIG. 12, in the cooling booth 14, the discharge port 24 is provided in the upper part of the inlet side region of the cooling booth 14 (for example, the upper surface of the cooling booth 14 as shown in FIG. 12). .. As a result, the relatively high temperature air leaking from the intermediate chamber 16 to the cooling booth 14 is accompanied by the ascending flow from the suction port 52 to the discharge port 24 provided in the inlet side region of the cooling booth 14, and is discharged. It can be discharged from 24.

In the embodiment shown in FIG. 12, as described above, in the cooling booth 14, a suction port 52 for sucking air in the intermediate chamber 16 having an intermediate temperature is provided in the lower part of the inlet side region of the cooling booth 14. Further, the discharge port 24 is provided in the upper part of the inlet side region of the cooling booth 14. In the present embodiment, further, at the downstream end of the inlet side region of the cooling booth 14, air that protrudes from the bottom surface or the upper surface of the cooling booth 14 and goes from the region downstream of the inlet side region to the inlet side region of the cooling booth 14. A protrusion 60 or 62 for obstructing the flow is provided.

According to this embodiment, the discharge port 24 provided in the upper part of the inlet side region and the suction port 52 provided in the lower part of the inlet side region can form an ascending flow of air introduced from the outside. As a result, the air that has entered the cooling booth 14 from the intermediate chamber 16 can be discharged to the outside along with the ascending flow. Therefore, it is possible to suppress the temperature rise of the cooling booth 14 due to the intrusion of air in the intermediate chamber 16. Further, the protrusions 60 and 62 can prevent the cooling air in the cooling booth 14 from approaching the suction port 52 and the discharge port 24, thereby suppressing the temperature rise of the cooling air in the cooling booth 14.

The protrusions 60 and 62 may have a certain height with respect to the bottom surface or the upper surface of the cooling booth 14. If there is a certain height, it is possible to prevent the cooling air formed on the bottom surface or the upper surface of the cooling booth 14 from reaching the suction port 52 or the discharge port 24 in the shortest distance.

In one embodiment, as shown in FIGS. 10 to 13, the first air shutter 18 and the second air shutter 20 are an upper air shutter 18a or 20a provided in the upper region of the intermediate chamber 16 and a lower portion of the intermediate chamber 16. It is composed of a lower air shutter 18b or 20b provided in the region. These air shutters have at least one ejection portion and one or more suction portions to circulate, and form an air film between the opposing air shutters. In the upper air shutter 18a or 20a, the air outlet of the air blowing portion 54 is directed to the upstream side, forms a convex air film toward the upstream side, and is sucked into the air suction portion 56. In the lower air shutter 18b or 20b, the air outlet of the air outlet 54 is directed to the downstream side, forms a convex air film toward the downstream side, and is sucked into the air suction portion 56. In the figure, the arrow b indicates the direction of the air blown from the air blowing portion 54 of the upper air shutter 18a or 20a, and the arrow c indicates the direction of the air blown from the air blowing portion 54 of the lower air shutter 18b or 20b.

As a result, it is possible to suppress leakage of high-temperature air from the upper region of the drying furnace 12 to the upper region of the intermediate chamber 16, and it is possible to suppress leakage of cooling air from the lower region of the cooling booth 14 to the intermediate chamber 16.

In one embodiment, the intermediate chamber 16 or the cooling booth 14 is configured to supply outside air oa to the suction port 50 or 52. Thereby, the air of the intermediate temperature can be supplied from the suction port 50 or 52 to the intermediate chamber 16 or the cooling booth 14 by utilizing the outside air oa.

In one embodiment, as shown in FIG. 7, the discharge duct 64 or 66 is connected to the discharge port 22 or 24 of the intermediate chamber 16 or the cooling booth 14. A damper 68 or 70 is provided on the inlet side of the discharge duct 64 or 66. Further, a temperature sensor 72 or 74 for detecting the internal temperature of the intermediate chamber 16 or the cooling booth 14 is provided. The controller 76 controls the opening degree of the damper 68 or 70 according to the detection signal of the temperature sensor 72 or 76. According to this embodiment, the controller 76 controls the opening degree of the damper 68 or 78 according to the detected value of the temperature sensor 72 or 74, so that the temperature of the intermediate chamber 16 or the cooling booth 14 can be controlled.

In the exemplary embodiment shown in FIG. 7, the temperature sensor 72 or 74 is provided in the intermediate chamber 16 or the cooling booth 14, but is connected to the discharge duct 64 or 66 connected to the intermediate chamber 16 or the cooling booth 14. Alternatively, it may be provided at the inlet of these ducts in the vicinity thereof.

In one embodiment, as shown in FIG. 7, a fan 78 is provided in the discharge duct 64 or 66, and the fan 78 sucks the outside air oa from the suction port 50 or 52 into the intermediate chamber 16 or the cooling booth 14 and discharges the outside air oa. Power is obtained to exhaust air from the duct 64 or 66.

In one embodiment, as shown in FIG. 7, a suction duct 80 or 82 is connected to the suction port 50 or 52, and a damper 84 or 86 is provided in the suction duct 80 or 82. By controlling the opening degree of the damper 68 or 70 with the controller 76, the suction amount of the air sucked into the intermediate chamber 16 or the cooling booth 14 can be controlled. Further, by switching the opening and closing of the dampers 68, 70, 84 and 86 by the controller 76, the intake and exhaust of the outside air oa to the intermediate chamber 16 or the cooling booth 14 can be switched.

In one embodiment, as shown in FIG. 7, the branch line 48a in which the circulation line 48 is connected to the outlet side of the first heat pump device 40 (40A) and the circulation line 48 are on the inlet side of the second heat pump device 40 (40B). Dampers 88 and 90 are provided on the branch lines 48b connected to the dampers 88 and 90, respectively. Thereby, the flow rate of the exhaust gas sent to the branch lines 48a and 48b can be adjusted. Further, by switching the opening and closing of the dampers 68, 70, 84, 86, 88 and 90, the intermediate chamber 16 or the intermediate chamber 16 or Along with switching the intake and exhaust of the outside air oa to the cooling booth 14, it is possible to switch to the first heat pump device 40 (40A) or the second heat pump device 40 (40B).

In the drying system 10 (10H) shown in FIG. 8, the circulation duct 92 is connected to the discharge duct 66 connected to the discharge port 24 of the cooling booth 14 and the suction duct 80 connected to the suction port 50 of the intermediate chamber 16. Is provided. The exhaust gas exhausted from the discharge port 24 in the cooling booth 14 is supplied to the intermediate chamber 16 via the circulation duct 92 including the discharge duct 66 and the suction duct 80. As a result, it is possible to form a closed system that eliminates the suction of the outside air oa into the intermediate chamber 16, so that it is possible to suppress the air containing the volatile components volatilized from the object to be coated w from being released to the outside. Further, since the air discharged from the cooling booth 14 can be used as the intake air to the intermediate chamber 16, the temperature of the intake air can be stabilized while the temperature of the outside air oa fluctuates depending on the season.

As shown in FIG. 9, in the drying system 10 (10I), the discharge duct 66 connected to the discharge port 24 of the cooling booth 14 and the suction duct 82 connected to the suction port 52 of the cooling booth 14 are connected. A circulation duct 94 is provided. The exhaust gas exhausted from the discharge port 24 in the cooling booth 14 is supplied to the cooling booth 14 via the circulation duct 94 including the discharge duct 66 and the suction duct 82. As a result, it is possible to form a closed system that eliminates the suction of the outside air oa into the cooling booth 14, so that the suction air having a stable temperature can be supplied to the cooling booth 14 regardless of the temperature of the outside air oa.

The contents described in each of the above embodiments are grasped as follows, for example.

1) The coating line drying system (10 (10A-10I)) according to one aspect includes a drying furnace (12), a cooling booth (14) provided on the downstream side of the drying furnace, the drying furnace, and the above. An intermediate chamber (16) provided between the cooling booth, a first air shutter (18) provided at the upstream end of the intermediate chamber, and a second air shutter (18) provided at the downstream end of the intermediate chamber ( 20), and the intermediate chamber or the cooling booth has outlets (22, 24) for exhausting air in the intermediate chamber or the cooling booth.

According to such a configuration, the above intermediate chamber is provided as a buffer zone between the drying furnace and the cooling booth, and air shutters are provided at the inlet and outlet of the intermediate chamber, respectively, so that the high temperature air in the drying furnace is directly cooled. You can prevent it from entering the booth. Further, even if an air leak occurs from the drying furnace to the intermediate chamber and further from the intermediate chamber to the cooling booth, by accompanying the leaked air with the air discharged from the discharge port, the high temperature air into the cooling booth can be discharged. It is possible to suppress the temperature rise of the cooling booth due to intrusion. As a result, it is possible to suppress a decrease in cooling efficiency in the cooling booth and heat loss in the drying furnace. Further, unlike Patent Document 1, it is not necessary to provide a pre-cooling zone between the drying furnace and the cooling booth, so that the time of the cooling step can be shortened and the line length of the cooling zone can be shortened.

2) The coating line drying system (10) according to one aspect is the coating line drying system according to 1), and the discharge port (22 or 24) is the intermediate chamber (16) or the cooling booth. It is provided on the upper surface of (14).

According to such a configuration, the highest temperature air that has entered from the upper layer region of the drying furnace due to the density difference caused by the temperature difference can be preferentially discharged from the discharge port in the intermediate chamber or the cooling booth.

3) The coating line drying system (10) according to another aspect is the coating line drying system according to 1) or 2), and the intermediate chamber (16) or the cooling booth (14) is the above. It has a suction port (50 or 52) for sucking air (oa) having a temperature intermediate between the high temperature air of the drying furnace and the low temperature air of the cooling booth, and the suction port is the discharge port (22, It is provided at a lower position than 24).

According to such a configuration, air at an intermediate temperature is sucked from the suction port to form an ascending flow from the suction port to the discharge port, so that the air leaks from the upper layer of the drying furnace to the intermediate chamber and further to the cooling booth. The hottest air that has come can be discharged from the discharge port along with the upward flow. As a result, it is possible to suppress the temperature rise of the cooling booth due to the intrusion of high temperature air into the cooling booth.

4) The coating line drying system (10) according to still another aspect is the coating line drying system according to 3), and the intermediate chamber (16) has the height of the intermediate chamber set to H. When, the suction port (50) is provided at a height of 0.7H from the floor surface.

According to such a configuration, by arranging the suction port in the above range including the central height of the intermediate chamber, an ascending flow from the suction port to the discharge port can be formed. As a result, the maximum temperature air leaking from the upper layer region of the drying furnace to the intermediate chamber and further to the cooling booth can be discharged from the discharge port along with the ascending current.

5) The coating line drying system (10) according to still another aspect is the coating line drying system according to 2) or 3), and the cooling booth (14) is an inlet side region of the cooling booth. It has the suction port (52) provided in the lower part of the.

According to such a configuration, the air having a temperature relatively higher than the cooling air of the cooling booth and entering the cooling booth from the intermediate chamber is discharged from the suction port provided in the lower part of the inlet side region of the cooling booth. It can be discharged from the discharge port along with the upward flow toward. As a result, it is possible to suppress the ingress of high-temperature air into the wake side of the cooling booth on the inlet side region.

6) The coating line drying system (10) according to still another aspect is the coating line drying system according to any one of 1) to 5), and in the intermediate chamber (16), the discharge port ( 22) is provided on the upper surface of the intermediate chamber on the upstream side, and has a width of 0.3 W or more and 0.8 W or less in the central portion in the width direction when the width of the intermediate chamber is W.

According to such a configuration, the high temperature air of the drying furnace that has entered the intermediate chamber is accompanied by the air discharged from the discharge port on the upstream side of the intermediate chamber, so that the high temperature air flows to the downstream side of the intermediate chamber. Can be suppressed.

7) The coating line drying system (10) according to still another aspect is the coating line drying system according to any one of 1) to 6), and in the cooling booth (14), the discharge port ( 24) is provided in the upper part of the inlet side region of the cooling booth.

According to such a configuration, air having a relatively high temperature in the intermediate chamber that has entered the upper region of the cooling booth from the intermediate chamber can be discharged along with the air discharged from the discharge port.

8) The coating line drying system (10) according to still another aspect is the coating line drying system according to 7), and the cooling booth (14) is connected to the high temperature air of the drying furnace (12). A suction port (52) for sucking air (oa) having a temperature intermediate with the low temperature air of the cooling booth is provided in the lower part of the inlet side region of the cooling booth, and is a downstream end of the inlet side region. The cooling booth is provided with protruding portions (60, 62) for projecting from the bottom surface or the upper surface of the cooling booth and obstructing the flow of cold air from the region downstream of the inlet side region of the cooling booth toward the inlet side region.

According to such a configuration, the discharge port provided at the upper part of the inlet side area of the cooling booth and the suction port provided at the lower part of the inlet side area form an intermediate temperature rising flow introduced from the outside. By doing so, the air that has entered from the intermediate chamber can be discharged to the outside along with the rising flow. As a result, the outflow of the invading air to the downstream side can be suppressed, and the temperature rise of the cooling booth due to the intrusion of the air in the intermediate chamber can be suppressed. In addition, the protrusion also has the effect of suppressing the cooling air in the cooling booth from approaching the suction port and the discharge port, whereby the temperature rise of the cooling air in the cooling booth can be suppressed.

9) The coating line drying system (10) according to still another aspect is the coating line drying system according to 1) or 2), and the intermediate chamber (16) or the cooling booth (14) is It has a suction port (50 or 52) for sucking air (oa) having a temperature intermediate between the high temperature air of the drying furnace and the low temperature air of the cooling booth, and the suction port is larger than the discharge port. It is installed on the downstream side.

According to such a configuration, in the intermediate chamber or the cooling booth, the flow of the intake air from the suction port to the discharge port toward the upstream side can be formed. Since this air flow is countercurrent to the air flow formed by the air leakage from the drying furnace to the intermediate chamber or the air leakage from the intermediate chamber to the cooling booth, the air leakage can be suppressed.

10) The coating line drying system (10) according to still another aspect is the coating line drying system according to any one of 1) to 9), and is connected to the discharge port (22, 24). A discharge duct (64, 66), a damper (68, 70) provided on the inlet side of the discharge duct, and a temperature sensor (72, 74) for detecting the internal temperature of the intermediate chamber or the cooling booth. A controller (76) for controlling the opening degree of the damper according to the detection signal of the temperature sensor.

According to such a configuration, the temperature of the intermediate chamber or the cooling booth can be controlled by controlling the opening degree of the damper according to the detection value of the temperature sensor by the controller.

11) The coating line drying system (10) according to still another aspect is the coating line drying system according to any one of 1) to 10), and is the intermediate chamber (16) or the cooling booth (14). ) Has a suction port (50 or 52) for sucking air having a temperature intermediate between the high temperature air of the drying (12) furnace and the low temperature air of the cooling booth, and the intermediate chamber or the cooling booth. The outside air (oa) is supplied to the suction port of the above.

According to such a configuration, the cost can be reduced by using the outside air as the air sucked from the suction port.

12) The coating line drying system (10) according to still another aspect is the coating line drying system according to any one of 1) to 11), and the high temperature air supplied to the drying furnace (12). A heat pump device (40 (40A, 40B)) for cooling the low-temperature air supplied to the cooling booth (14) is provided.

According to such a configuration, since the heat pump device is provided, the thermal efficiency can be improved as compared with other heat source supply methods.

13) The coating line drying system (10) according to still another aspect is the coating line drying system according to 12), and the heat pump device (40) is a first heat pump device using _{CO 2 as a refrigerant.} It is composed of (40 (40A)), and includes a flow path (42) for supplying air heated by the heat pump device to the drying furnace, and an auxiliary burner (44) provided in the flow path.

According to such a configuration, since high temperature air of 180 ° C. or higher can be generated, it can be applied to a drying furnace for baking and drying an object to be coated which requires a high temperature in the baking and drying step.

14) The coating line drying system (10) according to still another aspect is the coating line drying system according to 12) or 13), and the heat pump device (40) uses CO ₂ as a refrigerant. The first heat pump device (40 (40A)) and the second heat pump device (40 (40A)) including a first heat pump device and a second heat pump device (40 (40B)) using a refrigerant whose phase can change at a temperature below the critical temperature as a refrigerant. It is configured to be switchable from the heat pump device.

According to such a configuration, the range of applicable objects to be coated can be expanded and energy saving can be achieved by properly using a heat pump device suitable for the object to be coated according to the type of the object to be coated.

10 (10A, 10B, 10, 10D, 10E, 10F, 10G, 10H, 10I) Drying system 12 Drying furnace 14 Cooling booth 16 Intermediate room 18 1st air shutter 18a Upper air shutter 18b Lower air shutter 20 2nd air shutter 20a Upper air shutter 20b Lower air shutter 22, 24 Outlet 26, 28 Convey line 30 Air shutter 40 (40A) 1st heat pump device 40 (40B) 2nd heat pump device 41 Heat exchanger 42 Supply line 43, 45, 46, 48 Circulation line 48a, 48b Branch line
44 Auxiliary burner 47 Exhaust line 50 (50a, 50b), 52 (52a, 52b) Intake port 54 Air outlet 56 Air intake 58 Virtual square 60, 62 Projection 64, 66 Exhaust duct 68, 70, 84, 86, 88, 90 Damper 72, 74 Temperature sensor 76 Controller 78 Fan 80, 82 Intake duct 92, 94 Circulation duct Au Upstream area L Virtual straight line a Conveyance direction b, c Air ejection direction oa Outside air w Painted object

Claims (14)

With a drying oven
A cooling booth provided on the downstream side of the drying furnace and
An intermediate chamber provided between the drying furnace and the cooling booth,
A first air shutter provided at the upstream end of the intermediate chamber and
A second air shutter provided at the downstream end of the intermediate chamber and
With
The intermediate chamber or the cooling booth is a drying system for a coating line having an outlet for exhausting air in the intermediate chamber or the cooling booth. The drying system for a coating line according to claim 1, wherein the discharge port is provided on the intermediate chamber or the upper surface of the cooling booth. The intermediate chamber or the cooling booth has a suction port for sucking air having a temperature intermediate between the high temperature air of the drying furnace and the low temperature air of the cooling booth.
The coating line drying system according to claim 1 or 2, wherein the suction port is provided at a position lower than the discharge port. The drying system for a coating line according to claim 3, wherein the intermediate chamber is provided with an opening of the suction port up to a height of 0.7H from the floor surface when the height of the intermediate chamber is H. The coating line drying system according to claim 2 or 3, wherein the cooling booth has the suction port provided in the lower part of the inlet side region of the cooling booth. In the intermediate chamber, the discharge port is provided on the upper surface on the upstream side of the intermediate chamber, and when the width of the intermediate chamber is W, the width is 0.3 W or more and 0.8 W or less in the central portion in the width direction. The coating line drying system according to any one of claims 1 to 5. The coating line drying system according to any one of claims 1 to 6, wherein in the cooling booth, the discharge port is provided in the upper part of an inlet side region of the cooling booth. The cooling booth has a suction port for sucking air having a temperature intermediate between the high temperature air of the drying furnace and the low temperature air of the cooling booth at the lower part of the inlet side region of the cooling booth.
At the downstream end of the inlet side region, a protruding portion that protrudes from the bottom surface or the upper surface of the cooling booth and obstructs the flow of cold air from the region downstream of the inlet side region to the inlet side region of the cooling booth. The coating line drying system according to claim 7. The intermediate chamber or the cooling booth has a suction port for sucking air having a temperature intermediate between the high temperature air of the drying furnace and the low temperature air of the cooling booth.
The coating line drying system according to claim 1 or 2, wherein the suction port is provided on the downstream side of the discharge port. The discharge duct connected to the discharge port and
A damper provided on the inlet side of the discharge duct and
A temperature sensor for detecting the internal temperature of the intermediate chamber or the cooling booth, and
A controller for controlling the opening degree of the damper according to the detection signal of the temperature sensor, and
The coating line drying system according to any one of claims 1 to 9. The intermediate chamber or the cooling booth has a suction port for sucking air having a temperature intermediate between the high temperature air of the drying furnace and the low temperature air of the cooling booth.
The drying system for a coating line according to any one of claims 1 to 10, wherein outside air is supplied to the suction port of the intermediate chamber or the cooling booth. The drying system for a coating line according to any one of claims 1 to 11, further comprising a heat pump device for heating the high-temperature air supplied to the drying furnace and cooling the low-temperature air supplied to the cooling booth. .. The heat pump device is composed of a first heat pump device using _{CO 2 as a refrigerant.}
A flow path for supplying the air heated by the heat pump device to the drying furnace, and
An auxiliary burner provided in the flow path and
12. The coating line drying system according to claim 12. The heat pump device includes a _{first heat pump device using CO 2} as a refrigerant and a second heat pump device using a refrigerant whose phase can change at a temperature below the critical temperature as a refrigerant.
The coating line drying system according to claim 12 or 13, wherein the first heat pump device and the second heat pump device can be switched.

Images