JP2008134014A - Drying furnace for coated object - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently reduce the amount of an odor gas and the like flowing out to the external from a drying chamber. <P>SOLUTION: Control units 95, 97 of this drying furnace 1 perform the control to increase hot air blowing amount by an inlet-side hot air force nozzle 51, and to adjust a gas jetting amount by an inlet-side air curtain device 79 according to the increase of the blowing amount, when a gas outflow rate at an inlet 7 side detected by an inlet-side temperature sensor 47 is increased, and to increase the hot water blowing amount by an outlet-side hot air force nozzle 53, and to adjust the gas jetting amount by an outlet-side air curtain device 81 according to the increase of the blowing amount, when the gas outflow rate at an outlet 9 side detected by an outlet-side temperature sensor 49 is increased. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a drying furnace for drying an object to be coated.

Conventionally, as shown in Patent Document 1 below, an object to be coated consisting of a painted vehicle body or the like carried into the furnace body by circulatingly supplying hot air to a tunnel-type furnace body having openings at both ends. In the drying furnace, the hot air pushing nozzle that blows hot air toward the inside from the vicinity of the inlet / outlet of the furnace body, and the odor gas (from components such as volatilized solvent) flowing out together with the hot air through the inlet / outlet of the furnace body A detector comprising a temperature sensor for detecting the amount of gas) and an automatic damper for adjusting the hot air supply amount of a supply duct for supplying hot air to the hot air pushing nozzle, and detected by the detector By adjusting the opening of the automatic damper according to the amount of odor gas, the amount of hot air blown from the hot air pushing nozzle is adjusted, thereby Be constantly suppressed is being carried out the amount of odor gases flowing out.
Reality 6-2727

  However, in the drying furnace disclosed in Patent Document 1, since the only means for suppressing the outflow of the odor gas is the hot air pushing nozzle, the pressure balance in the furnace is temporarily largely broken. When a relatively large amount of odor gas leaking to the outside of the furnace body is detected, the outflow of the odor gas may not be sufficiently suppressed. Of course, by increasing the number of hot air pushing nozzles or by increasing the capacity of the blower fan that supplies hot air to the nozzles, the upper limit value of the blowing amount of the hot air pushing nozzles is increased, and as described above. Although it may be possible to cope with a relatively large amount of outflow of gas, if the amount of hot air blowing is increased excessively, the cost of equipment such as the pushing nozzle and the blower fan will increase. As a result, there has been a problem of incurring unnecessary costs.

  The present invention has been made in view of the above circumstances, and in a drying furnace for drying an object to be coated, the amount of odorous gas or the like flowing out from the furnace to the outside is more efficiently suppressed at a low cost. For the purpose.

  In order to solve the above-mentioned problems, the present invention provides a drying method for drying an object carried in a drying chamber by supplying hot air to a drying chamber formed in a housing having an entrance at both ends. An inlet side and outlet side detection means for detecting the amount of gas flowing out together with the hot air through the door of the drying chamber, respectively, in the vicinity of the door of the drying chamber, Inlet-side and outlet-side hot air blowing means for blowing hot air toward the air, and a gas flow for sealing to block the flow of gas flowing out from the inside of the drying chamber to the outside of the inlet-side and outlet-side hot air blowing means Control the amount of hot air blown by the hot air blowing means and the amount of gas blown by the gas blowing means. The control means increases the amount of hot air blown by the inlet-side hot air blowing means when the amount of gas flow on the inlet side detected by the inlet-side detection means increases. When the control is performed to adjust the gas ejection amount by the inlet-side gas ejection means according to the increase in the spraying amount, while the outlet gas outflow amount detected by the outlet-side detection means increases, The control unit is configured to increase the amount of hot air sprayed by the outlet-side hot air spraying means and to adjust the amount of gas jetted by the outlet-side gas jetting means in accordance with the increase in the amount of spraying. (Claim 1).

  In the above configuration, “gas” refers to components such as odor gas which are undesirable when flowing out of the drying chamber, and examples include those in which the solvent in the paint applied to the object is volatilized. Can do.

  According to the present invention, in addition to the inlet side and the outlet side hot air blowing means for blowing hot air from the vicinity of the inlet / outlet of the drying chamber to the inside thereof, the inlet side for blocking the flow of gas flowing out from the hot air blowing means Since the outlet-side gas ejection means is provided, the hot air blowing means and the gas ejection means can suppress the outflow of gas through the inlet / outlet in a double manner. When the amount of gas flowing out through the door of the drying chamber increases, the amount of hot air blowing means on the side where the amount of outflow gas increases increases, and the gas blowing means on the same side accordingly. Therefore, the hot air blowing means and the gas blowing means are appropriately controlled in accordance with the increase / decrease of the gas outflow amount, and the gas outflow is more effectively suppressed. There is an advantage that. In addition, by coordinating both means in this way and efficiently suppressing the outflow of gas, it is possible to improve the environment around the drying furnace at a lower cost by increasing cost effectiveness.

  It is preferable that the control means performs control so as to decrease the ejection amount of the inlet-side or outlet-side gas ejection means in accordance with an increase in the amount of blowing of the inlet-side or outlet-side hot air blowing means. ).

  In this way, the amount of hot air spraying means is increased to sufficiently suppress the outflow of the gas, and the amount of gas jetting means is reduced accordingly, thereby reducing the energy consumption of the entire facility. There is an advantage that the outflow of the gas can be effectively suppressed while effectively avoiding the increase.

  However, depending on the shape of the drying chamber or the like, it is also assumed that the effect of suppressing the outflow gas as expected by the increase in the amount of spray of the hot air spraying means cannot be obtained. In such a case, the control means may control to increase the ejection amount of the inlet-side or outlet-side gas ejection means in response to an increase in the amount of the inlet-side or outlet-side hot air blowing means. Preferred (claim 3).

  In this way, in addition to the increase in the amount of hot air spraying means, in addition to the increase in the amount of gas jetting means, it is difficult to obtain the effect of suppressing the outflow gas by the hot air spraying means. There is an advantage that the outflow of the gas can be surely suppressed.

  Preferably, the inlet side and outlet side gas ejection means are configured to generate hot air as the sealing gas flow.

  In this case, for example, unlike the case where low temperature gas is used as the gas flow for the sealing, a part of the low temperature gas enters the drying chamber and the temperature in the drying chamber is lowered, and drying is performed accordingly. There is an advantage that it is possible to effectively prevent the drying capacity of the furnace from being lowered.

  When the object to be coated is a vehicle body, a hot air blowing means for in-vehicle body for blowing hot air inside the vehicle body is provided at a position closer to the inside of the drying chamber than the outlet-side hot air blowing means. Preferred (claim 5).

  In this way, the gas accumulated inside the vehicle body can be expelled before the vehicle body is carried out from the exit of the drying chamber, effectively preventing the gas in the drying chamber from being taken out together with the vehicle body. can do.

  As described above, according to the present invention, in a drying furnace for drying an object to be coated, the amount of odorous gas or the like flowing out from the inside of the furnace can be more efficiently suppressed at a low cost.

  FIG. 1 is a diagram showing a drying furnace 1 according to an embodiment of the present invention. The drying furnace 1 shown in this figure has a housing 3 extending in the horizontal direction, and a drying chamber 5 for drying a vehicle body B as a coated object to be coated is formed inside the housing 3. ing. In addition, the housing 3 is formed with an inlet 7 for carrying the vehicle body B into the internal drying chamber 5 on one end side (right side in the figure), and for carrying the vehicle body B out of the drying chamber 5. An outlet 9 is formed on the other end side (left side in the figure). Then, the vehicle body B carried into the drying chamber 5 from the inlet 7 is dried while being transported from the upstream to the downstream (from right to left in the drawing) in the drying chamber 5 by a transport means such as a conveyor (not shown). Then, it is carried out of the drying chamber 5 through the outlet 9.

  Inside the drying chamber 5, first to third hot air generators 11 to 13 for generating hot air for drying are provided in order from the upstream side along the conveying direction of the vehicle body B. These first to third hot air generators 11 to 13 are provided with a supply unit 15 disposed near the lower side of the drying chamber 5 and a suction unit disposed near the upper side of the drying chamber 5 so as to face the supply unit 15. The hot air blown from the supply unit 15 is sucked by the suction unit 17 and returned to the supply unit 15 again through a predetermined circulation path (details will be described later). Yes. That is, hot air is circulated and supplied from the first to third hot air generators 11 to 13 to the drying chamber 5, and the hot air generators 11 to 13 are conveyed through the drying chamber 5. The vehicle body B moving in order between the two is heated by hitting the hot air, so that the paint applied to the vehicle body B is dried.

  The first to third hot air generators 11 to 13 are each provided with a hot air circulator 19 that circulates hot air between the supply unit 15 and the suction unit 17. The hot air circulator 19 includes an air duct 21 that forms a circulation path between the supply unit 15 and the suction unit 17, and a heater 23, a blower fan 25, a filter 27, and an outside air remover that are respectively provided in the middle of the air duct 21. The hot air sucked from the suction part 17 is heated again to a predetermined temperature by the heater 23, and the heated hot air is pumped to the supply part 15 by the blower fan 25. It has become. At this time, outside air is taken in from the outside air taking-in portion 29 as necessary for air replenishment or temperature adjustment, and foreign matter contained in the hot air circulating through the air duct 21 is removed by the filter 27. It is like that.

  A recovery port 31 communicating with the internal drying chamber 5 is provided in the vicinity of the central portion of the housing 3 in the longitudinal direction, and a part of the hot air accumulated in the drying chamber 5 is recovered from the recovery port 31 to The air is discharged to the outside through an air duct 35 or the like extending to the outside. However, since the hot air collected in the drying chamber 5 contains an odor gas component obtained by volatilization of the solvent in the paint, it is necessary to exhaust the odor gas component after removing the odor gas component. Therefore, an exhaust treatment device 33 is provided on the downstream side of the air duct 35, and the hot air collected from the collection port 31 is purified by the exhaust treatment device 33 and then discharged to the outside. A filter 37 is provided in the middle of the air duct 35, and hot air from which foreign matter has been removed is sent to the exhaust treatment device 33 for processing.

  The exhaust treatment device 33 includes a catalyst furnace 39 for removing odorous gas components contained in the hot air, a deodorizing fan 45 for pumping the deodorized hot air, and first and second heat exchangers 41 and 43. The hot air recovered from the recovery port 31 is heated to some extent by the first heat exchanger 41 and then sent to the catalyst furnace 39 where the hot air is purified (recovery). A part of the hot air is directly sent to the catalyst furnace 39 and used for combustion in the furnace). The hot air purified in the catalyst furnace 39 is cooled by the first and second heat exchangers 41 and 43 and then discharged to the outside through the deodorizing fan 45.

  Inside the drying chamber 5, there are an inlet side and an outlet side that are arranged in the vicinity of the entrances 7 and 9 and on the outer sides of the installation portions of the first to third hot air generators 11 to 13, respectively. Hot air pushing nozzles 51 and 53 (corresponding to the inlet side and outlet side hot air blowing means according to the present invention) are provided. These hot air pushing nozzles 51, 53 have a plurality of nozzles arranged circumferentially along the inner wall of the housing 3, and the inside of the drying chamber 5 (the central portion in the longitudinal direction of the drying chamber 5) from the nozzles. It is configured to blow hot air toward the side. In this way, hot air is always blown from the hot air pushing nozzles 51 and 53, so that the odor gas in the drying chamber 5 passes through the installation portion of the hot air pushing nozzles 51 and 53 and flows out from the entrances 7 and 9 to the outside. Is to be prevented.

  A position closer to the inside of the drying chamber 5 than the outlet-side hot air pushing nozzle 53, that is, a position offset by a predetermined distance from the installation portion of the outlet-side hot air pushing nozzle 53 upstream in the conveying direction of the vehicle body B (right side in the figure). Is provided with a hot air blowing nozzle 55 (corresponding to the hot air blowing means for the inside of the vehicle body according to the present invention) for blowing hot air into the inside of the vehicle body B approaching the outlet 9 side in the drying chamber 5 as shown in the figure. It has been. The hot air jet nozzle 55 has a plurality of nozzles provided along the inner wall of the housing 3 in the same manner as the hot air push nozzles 51 and 53, and the hot air blown from the nozzles is supplied to the inside of the vehicle body B. The odor gas accumulated inside the vehicle body B is driven out of the vehicle body B by being blown onto the vehicle body B. Then, the odor gas is expelled to the outside of the vehicle body B before the vehicle body B is carried out from the outlet 9 in this way, so that the odor gas is prevented from being taken out of the drying chamber 5 together with the vehicle body B. It has become.

  Air ducts 65 a to 65 c that branch off from a hot air supply air duct 63 provided outside the drying chamber 5 are connected to the inlet side and outlet side hot air pushing nozzles 51 and 53 and the hot air jet nozzle 55, respectively. The hot air supplied through the air ducts 65a to 65c is blown into the drying chamber 5 from the nozzles 51, 53, and 55. A hot air supply device 57 for generating and supplying hot air is provided on the upstream side of the air duct 63 for supplying hot air. The hot air supply device 57 includes an outside air intake portion 59 in which a filter for removing foreign matter is incorporated, a blower fan 61 for pumping air taken in from the outside air intake portion 59, and the exhaust treatment device 33. The second heat exchanger 43 is shared, and the air (hot air) heated by the second heat exchanger 43 is transferred to the hot air pushing nozzles 51 and 53 and the hot air jet nozzle 55 through the air duct 63 and the like. It is configured to supply. That is, the hot air supply device 57 generates hot air using the exhaust heat collected by the exhaust treatment device 33 (second heat exchanger 43), and supplies the hot air to the nozzles 51, 53, and 55. It is configured to.

  A blower fan 67 for pumping hot air and an electric flow control valve 69 for adjusting the flow rate of hot air are provided in the middle of the air duct 65a communicating with the inlet-side hot air pushing nozzle 51. Similarly, a blower fan 71 and a flow rate adjusting valve 73 are also provided in the middle of the air duct 65 b that communicates with the outlet-side hot air pushing nozzle 53. Then, the amount of hot air supplied to the inlet-side and outlet-side hot air pushing nozzles 51, 53 is adjusted by controlling the opening degree of the flow rate adjusting valves 69, 73 by control units 95, 97, which will be described later. In response to this, the amount of hot air blown into the drying chamber 5 from the hot air pushing nozzles 51 and 53 is increased or decreased.

  Between the inlet 7 of the drying chamber 5 and the inlet-side hot air pushing nozzle 51 and between the outlet 9 on the opposite side and the outlet-side hot air pushing nozzle 53, hot air is blown in the vertical direction to generate a seal flow. The inlet side and outlet side air curtain devices 79 and 81 (corresponding to the inlet side and outlet side gas ejection means according to the present invention) are respectively provided. These air curtain devices 79 and 81 have a supply unit 83 and a suction unit 85 that are arranged to face each other in the vertical direction in the drying chamber 5, and hot air blown from the upper supply unit 83 is sucked downward. The air is sucked by the section 85 and returned to the supply section 83 again through the hot air circulator 87 provided outside the drying chamber 5. The hot air circulator 87 includes an air duct 89 that forms a hot air circulation path between the supply unit 83 and the suction unit 85, and a blower fan 91 and a filter 93 that are respectively provided in the middle of the air duct 89. The hot air sucked from the suction part 85 and removed by the filter 93 is pressure-fed to the supply part 83 by the blower fan 91.

  The hot air circulators 87 and 87 for the inlet-side and outlet-side air curtain devices 79 and 81 have air ducts 76 extending from the air ducts 65a and 65b for supplying hot air to the hot-air pushing nozzles 51 and 53, respectively. , 78 is supplied with hot air, and this hot air is circulated between the supply part 83 and the suction part 85 via the hot air circulator 87. In the middle of the air ducts 76 and 78, electric flow rate adjusting valves 75 and 77 for adjusting the flow rate of hot air supplied to the hot air circulators 87 and 87 through these pipes are provided. The opening amounts of the flow rate control valves 75 and 77 are controlled by control units 95 and 97, which will be described later, thereby adjusting the amount of hot air supplied to the inlet side and outlet side air curtain devices 79 and 81. Accordingly, the amount of hot air ejected by the air curtain devices 79 and 81 is increased or decreased.

  Outside the inlet side and outlet side air curtain devices 79 and 81 and at positions corresponding to the inlet 7 and outlet 9 of the drying chamber 5 are inlet side and outlet side temperature sensors 47 and 49 (such as thermocouples). Corresponding to such inlet side and outlet side detection means) are provided. Each of these temperature sensors 47 and 49 is provided as a sensor for detecting the amount of odorous gas flowing out through the entrances 7 and 9 of the drying chamber 5. That is, since the odor gas flows out together with the hot air supplied into the drying chamber 5 from the hot air generators 11 to 13 and the like, as shown in FIG. The amount of outflow of the odor gas increases. Therefore, it is possible to determine how much odor gas is flowing out by measuring the temperatures of the entrances 7 and 9 using the inlet side and outlet side temperature sensors 47 and 49.

  The temperature values detected by the inlet-side and outlet-side temperature sensors 47, 49 are input to the inlet-side and outlet-side control units 95, 97 (corresponding to the control means according to the present invention) provided outside the drying chamber 5. Each is output. And these control units 95 and 97, according to the detected temperature values of the temperature sensors 47 and 49, flow rate control valves 69 and 73 for the inlet side and outlet side hot air pushing nozzles 51 and 53, and The amount of hot air blown by the hot air pushing nozzles 51 and 53 and the air curtain are controlled by appropriately operating the opening degree of the flow rate adjusting valves 75 and 77 for the inlet and outlet air curtain devices 79 and 81. The amount of hot air ejected by the devices 79 and 81 is increased or decreased. That is, the inlet side and outlet side control units 95 and 97 perform the hot air pushing nozzle 51 by feedback control based on the detected temperatures of the temperature sensors 47 and 49 (that is, the amount of odor gas flowing out from the inlets and outlets 7 and 9). 53 and air curtain devices 79 and 81 are operated to increase or decrease the amount of odorous gas flowing out from the entrances 7 and 9 of the drying chamber 5 within a certain range. Yes.

  Specifically, the inlet side and outlet side control units 95 and 97 control the hot air pushing nozzles 51 and 53, for example, based on the relationship shown by the solid line in FIG. According to this figure, the inlet-side hot air pushing nozzle 51 increases the amount of hot air sprayed as the temperature detected by the inlet-side temperature sensor 47 increases, that is, as the amount of odor gas flowing out from the inlet 7 increases. Controlled. Similarly, the outlet-side hot air pushing nozzle 53 is also controlled to increase the amount of hot air sprayed as the detected temperature of the outlet-side temperature sensor 49 increases, that is, as the amount of odor gas flowing out from the outlet 9 increases. The As the amount of odor gas flowing out from the inlet 7 or the outlet 9 increases, a larger amount of hot air is blown from the inlet-side hot air pushing nozzle 51 or the outlet-side hot air pushing nozzle 53 toward the inside of the drying chamber 5. Thus, the outflow of the odor gas from the entrances 7 and 9 is effectively suppressed.

  On the contrary, according to FIG. 3, when the temperature in the vicinity of the entrances 7 and 9 is low (when the amount of odor gas flowing out from the entrances 7 and 9 is small), the air volume of the hot air pushing nozzles 51 and 53 is Will be reduced. This prevents the hot air pushing nozzles 51 and 53 from being operated unnecessarily at a high output even though the amount of outflow gas is small, and the energy consumption of the entire facility is suppressed. In FIG. 3, an upper limit value and a lower limit value are provided for the air volume of the hot air pushing nozzles 51, 53, and in the region where the temperature near the inlet / outlet 7, 9 is too high or too low, the temperature further changes from there. Also, the air volume of the hot air pushing nozzles 51 and 53 is kept constant.

  On the other hand, in conjunction with the increase / decrease of the air flow of the hot air pushing nozzles 51, 53 as described above, the air flow of the inlet side and outlet side air curtain devices 79, 81 is increased / decreased as indicated by the broken line in FIG. That is, the air volume of each air curtain device 79, 81 is controlled so as to decrease when the air volume of the hot air pushing nozzles 51, 53 increases and to increase when the air volume of the hot air pushing nozzles 51, 53 decreases. In the configuration of the present embodiment shown in FIG. 1, hot air is supplied to the air curtain devices 79 and 81 through air ducts 76 and 78 branched from the air ducts 65a and 65b for the hot air pushing nozzles 51 and 53, respectively. Since the blower fans 67 and 71 shared with the hot air pushing nozzles 51 and 53 are used as the air blowing source, if the amount of hot air supplied to the hot air pushing nozzles 51 and 53 is increased, the air curtain is correspondingly increased. While the amount of hot air supplied to the devices 79 and 81 decreases, the amount of hot air supplied to the hot air pushing nozzles 51 and 53 decreases, so that the amount of hot air supplied to the air curtain devices 79 and 81 increases accordingly. is there. For the same reason, by operating the flow control valves 75 and 77 for the air curtain devices 79 and 81 to increase or decrease the air volume of the air curtain devices 79 and 81, the hot air pushing nozzle 51. , 53 can be reduced or increased. Accordingly, by operating both the flow rate adjusting valves 69 and 73 for the hot air pushing nozzles 51 and 53 and the flow rate adjusting valves 75 and 77 for the air curtain devices 79 and 81, these hot air pushing nozzles 51 and 53 are operated. In addition, the air volume of the air curtain devices 79 and 81 can be increased or decreased within a wide range.

  By the way, according to the configuration as described above, even if the air volume of the hot air pushing nozzles 51 and 53 is increased in accordance with the increase of the outflow gas from the entrances 7 and 9, the air volume of the air curtain devices 79 and 81 is correspondingly increased. Will decrease. However, when the odor gas outflow suppression effect due to the increase in the air volume of the hot air pushing nozzles 51, 53 is sufficiently exerted, even if the air volume of the air curtain devices 79, 81 is reduced, these hot air pushing nozzles 51, 53 53 and the air curtain devices 79 and 81 can maintain the odor gas outflow suppressing effect at a necessary level. In particular, as in the present embodiment, when the drying chamber 5 is composed of a substantially linear space, the outflow suppression effect is efficiently exhibited by increasing the air volume of the hot air pushing nozzles 51 and 53. Therefore, even if it is the above structures, the quantity of the odor gas which flows out from the entrances 7 and 9 is fully suppressed. And according to the said structure, since it can supply a required amount of hot air to both the said hot air pushing nozzles 51 and 53 and the air curtain apparatuses 79 and 81 only by providing the said ventilation fans 67 and 71 one each, The advantage that the outflow of the odor gas can be sufficiently suppressed while effectively avoiding an increase in the overall energy consumption is obtained.

  FIG. 4 is a flowchart showing the contents of the air volume control of the hot air pushing nozzles 51 and 53 and the air curtain devices 79 and 81 performed by the control means including the inlet side and outlet side control units 95 and 97. When this control flow starts, the control units 95 and 97 first execute control for taking in the measured temperature T, which is a detected value of the temperature at the inlets 7 and 9, from the inlet side and outlet side temperature sensors 47 and 49. (Step S1).

  Next, the control units 95 and 97 determine whether or not the measured temperature T is equal to the target temperature Ta shown in FIG. 2 (step S3). The target temperature Ta is appropriately set according to the target value Qa of the flow rate Q of the odor gas flowing out from the entrances 7 and 9 (the target outflow amount of odor gas determined from the viewpoint of maintenance of the facility environment). If the measured temperature T is equal to the target temperature Ta (YES in step S3), the process returns as it is, and the air volumes of the hot air pushing nozzles 51 and 53 and the air curtain devices 79 and 81 are maintained as they are.

  On the other hand, if it is determined NO in step S3 and it is confirmed that the measured temperature T is not equal to the target temperature Ta, the process proceeds to the next step S5, and whether the measured temperature T is higher than the target temperature Ta ( Whether T> Ta) or not. The control units 95 and 97 determine YES here and confirm that T> Ta, that is, a larger amount of odor gas than the target flow rate Qa flows out from the inlet / outlet ports 7 and 9. When the measured temperature T (> Ta) is applied to the graph of FIG. 3, the set value of the air volume Q1 of the hot air pushing nozzles 51, 53 is set to the normal air volume Q1a (T = Ta). The air volume of the hot air pushing nozzles 51 and 53 at a certain time is increased (step S7), and the set value of the air volume Q2 of the air curtain devices 79 and 81 is set to the normal air volume Q2a (T = Ta). Control for decreasing the air volume of the curtain devices 79 and 81 is executed (step S9).

  Next, the control units 95 and 97 adjust the hot air pushing nozzles 51 and 53 to match the actual air volumes of the hot air pushing nozzles 51 and 53 and the air curtain devices 79 and 81 with the set air flow calculated in the steps S7 and S9. Control for operating the flow control valves 69 and 73 for 53 and the flow control valves 75 and 77 for the air curtain devices 79 and 81 is executed (step S15). For example, by operating the flow rate adjusting valves 69 and 73 for the hot air pushing nozzles 51 and 53 in the opening direction and operating the flow rate adjusting valves 75 and 77 for the air curtain devices 79 and 81 in the closing direction, the hot air pushing nozzles While increasing the air volume of 51 and 53 by a predetermined amount, the air volume of the air curtain devices 79 and 81 is decreased accordingly. As a result, the amount of odorous gas flowing out from the entrances 7 and 9 is suppressed again to the target value Qa, for example, and the external environment of the drying chamber 5 is well maintained.

  On the other hand, when it is determined NO in Step S5 and it is confirmed that T <Ta, that is, when it is confirmed that the amount of outflow of odor gas from the inlets 7 and 9 is smaller than the target flow rate Qa. In contrast to steps S7 and S9, the set value of the air volume Q1 of the hot air pushing nozzles 51 and 53 is decreased with respect to the normal air volume Q1a (step S11), and the air volume Q2 of the air curtain devices 79 and 81 is reduced. Is set to increase the set value for the normal air volume Q2a (step S13). Then, the process proceeds to step S15, and control is performed to match the actual air volumes of the hot air pushing nozzles 51 and 53 and the air curtain devices 79 and 81 with the set values calculated in steps S11 and S13. As a result, the amount of odorous gas flowing out from the entrances 7 and 9 is increased and returned to the target value Qa.

  In the above flowchart, the control operations by the inlet side and outlet side control units 95 and 97 have been described together. However, since these control units 95 and 97 are independent of each other, different control operations are performed simultaneously. There is also. For example, when the detected value of the inlet side temperature sensor 47 is lower than the target temperature Ta and the detected value of the outlet side temperature sensor 49 is higher than the target temperature Ta, the inlet side control unit 95 performs the inlet side hot air pushing nozzle. On the contrary, the outlet side control unit 97 increases the air volume of the outlet-side hot air pushing nozzle 53 and reduces the air volume of the inlet-side air curtain device 79. Control for reducing the air volume of the air curtain device 81 is executed.

  As described above, according to the above embodiment, in the drying furnace 1 for drying the vehicle body B as an object to be coated, the inlet side and the outlet for blowing hot air from the vicinity of the entrances 7 and 9 of the drying chamber 5 toward the inside thereof. In addition to the side hot air pushing nozzles 51 and 53, the inlet side and outlet side air curtain devices 79 and 81 for blocking the flow of odor gas flowing out from the hot air pushing nozzles are provided. And the air curtain devices 79 and 81 can double the outflow of the odor gas through the entrances 7 and 9. Since the hot air pushing nozzles 51 and 53 and the air curtain devices 79 and 81 are used as described above, the odor gas can be efficiently suppressed by interlocking these devices. Unlike the case where only the hot air pushing nozzles 51 and 53 are used (when the air curtain devices 79 and 81 are not present), the outflow of the odor gas can be suppressed efficiently and reliably. Moreover, according to the above configuration, since the outflow of the odor gas can be sufficiently suppressed without increasing the amount of hot air blown by the hot air pushing nozzles 51 and 53 in the normal time, mainly for drying the vehicle body B. The flow of hot air circulated and supplied from the first to third hot air generators 11 to 13 into the drying chamber 5 is not greatly disturbed by the hot air blown from the hot air pushing nozzles 51 and 53. For this reason, troubles in the drying process of the vehicle body B are effectively avoided, and there is an advantage that the vehicle body B can be efficiently dried while suppressing the outflow of the odor gas.

  Moreover, in the said embodiment, the outflow amount of the odor gas from the inlet 7 or the outlet 9 is determined in advance based on the determination based on the detection values of the inlet side and outlet side temperature sensors 47 and 49 (Qa in FIG. 2). When it is confirmed that the amount of air is larger than that of the hot air pushing nozzle (51 or 53) on the side where the amount of outflow gas has increased, the pressure balance in the drying chamber 5 is increased, for example. Even when the outflow amount of the odor gas is increased due to collapse or the like, the outflow amount of the odor gas can be suppressed again and the external environment of the drying chamber 5 can be favorably maintained.

  In particular, in the above-described embodiment, as indicated by the broken line in FIG. 3, the air curtain device 79 corresponds to the increase in the air volume of the hot-air pushing nozzles 51, 53 as described above and the outflow of odor gas. , 81 are controlled to reduce the air volume, there is an advantage that the outflow of the odor gas can be effectively suppressed while effectively avoiding an increase in energy consumption of the entire equipment. That is, in the case where the effect of suppressing the outflow of the odor gas is sufficiently enhanced by increasing the air volume of the hot air pushing nozzles 51 and 53, even if the air volume of the air curtain devices 79 and 81 is decreased as described above, Since the outflow of the odor gas is sufficiently suppressed by the action of both the hot air pushing nozzles 51 and 53 and the air curtain devices 79 and 81, the odor can be efficiently produced with less energy consumption by performing the above control. The advantage that gas outflow can be suppressed is obtained.

  However, depending on the shape of the drying chamber 5 and the like, even if the air volume of the hot air pushing nozzles 51 and 53 is increased, the odor gas outflow suppressing effect may not be sufficiently obtained. For example, when the shape of the drying chamber 5 is bent in the vicinity of the entrances 7 and 9 or is curved as a whole, the flow of hot air blown from the hot air pushing nozzles 51 and 53 is efficiently flown in the drying chamber 5. Odor gas that is not transmitted to the inside and flows out of the entrances 7 and 9 may not be sufficiently suppressed. In such a case, for example, as indicated by a broken line in FIG. 5, it is preferable to increase the air volume of the air curtain devices 79 and 81 in the same manner as the air volume of the hot air pushing nozzles 51 and 53 increases. In this way, the outflow of the odor gas can be surely suppressed even under a situation where the effect of suppressing the outflow of odor gas by the hot air pushing nozzles 51 and 53 is difficult to obtain.

  Further, as in the above-described embodiment, in the drying chamber 5, hot air is blown into the interior of the vehicle body B at a position offset by a predetermined distance upstream from the installation portion of the outlet-side hot air pushing nozzle 53 in the conveyance direction of the vehicle body B. When the hot air jet nozzle 55 for spraying is provided, the gas accumulated in the vehicle body B can be expelled before the vehicle body B is carried out from the outlet of the drying chamber 5, and the odor in the drying chamber 5 is There is an advantage that the gas can be effectively prevented from being taken out together with the vehicle body B.

  In the above embodiment, the same hot air as the hot air blown from the hot air pushing nozzles 51 and 53 is used as the air blown from the air curtain devices 79 and 81, but is blown from the air curtain devices 79 and 81. Since air does not directly flow into the area inside the hot air pushing nozzles 51 and 53 inside the drying chamber 5 (area where the vehicle body B is subjected to drying processing), the air is room temperature air (low temperature gas). ) May be used. However, particularly when the air curtain devices 79 and 81 and the hot air pushing nozzles 51 and 53 are provided close to each other, a part of the low-temperature gas ejected from the air curtain devices 79 and 81 is in the region. There is a possibility that the drying ability of the drying furnace 1 is reduced due to the intrusion. Therefore, in such a case, it is preferable to use hot air as the air ejected from the air curtain devices 79 and 81 as in the above embodiment. In this way, it is possible to effectively avoid a decrease in drying capability due to the intrusion of a low-temperature gas as described above.

  Moreover, in the said embodiment, the quantity of the odor gas which flows out outside from the entrances 7 and 9 of the drying chamber 5 is measured by detecting the temperature of the entrances 7 and 9 using the temperature sensors 47 and 49 which consist of thermocouples etc. However, you may make it measure the outflow amount of the said odor gas using the sensor which can measure the component density | concentration of odor gas. However, the embodiment using the temperature sensors 47 and 49 can measure the outflow amount of odor gas at a lower cost.

It is a figure which shows the structure of the drying furnace concerning one Embodiment of this invention. It is a figure which shows the relationship between the temperature of the entrance / exit part of a drying chamber, and the outflow amount of odor gas. It is a figure which shows the relationship between the temperature of the inlet / outlet part of a drying chamber, and the air volume of a hot air pushing nozzle, and the relationship between the temperature of the inlet / outlet part of a drying chamber, and the air volume of an air curtain apparatus. It is a flowchart which shows the content of the air volume control of a hot air pushing nozzle and an air curtain apparatus. It is a figure for demonstrating other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drying furnace 3 Housing 5 Drying chamber 7 Inlet 9 Outlet 47 Inlet side temperature sensor (inlet side detection means)
49 Outlet temperature sensor (exit side detection means)
51 Inlet side hot air pushing nozzle (inlet side hot air spraying means)
53 Outlet side hot air pushing nozzle (outlet side hot air blowing means)
55 Hot-air jet nozzle (hot-air spraying means for interior of vehicle body)
79 Inlet side air curtain device (inlet side gas ejection means)
81 Outlet side air curtain device (outlet side gas ejection means)
95 Inlet side control unit (control means)
97 Outlet side control unit (control means)
B body

Claims (5)

A drying furnace for drying an object carried into the drying chamber by supplying hot air to a drying chamber formed inside a housing having an inlet and outlet at both ends,
An inlet side and an outlet side detection means for detecting the amount of gas flowing out together with the hot air through the entrance of the drying chamber;
An inlet side and an outlet side hot air spraying means provided near the entrance of the drying chamber, respectively, for blowing hot air toward the inside of the drying chamber;
An inlet-side and outlet-side gas jetting means for generating a gas flow for sealing for blocking the flow of gas flowing out from the inside of the drying chamber to the outside of the inlet-side and outlet-side hot air blowing means;
Control means for controlling the amount of hot air blown by the hot air blowing means and the amount of gas blown by the gas blowing means,
The control means increases the amount of hot air blown by the inlet-side hot air blowing means when the amount of gas flow on the inlet side detected by the inlet-side detecting means increases, and increases the amount of blowing. In response to the control to adjust the amount of gas jetted by the inlet side gas jetting means, the outlet side hot air blowing means increases the amount of outlet gas outflow detected by the outlet side detecting means. The coating target is configured to increase the amount of hot air sprayed and to perform control for adjusting the amount of gas ejected by the outlet side gas ejecting means in accordance with the increase in the amount of sprayed air. Drying furnace for things. In the drying furnace of the to-be-coated object according to claim 1,
The said control means is controlled so that the injection amount of the said inlet side or outlet side gas blowing means may be decreased according to the increase in the amount of blowing of the said inlet side or outlet side hot-air spraying means. Drying furnace for things. In the drying furnace of the to-be-coated object according to claim 1,
The control means controls to increase the ejection amount of the inlet-side or outlet-side gas ejection means in accordance with an increase in the amount of spray of the inlet-side or outlet-side hot air blowing means. Drying furnace for things. In the drying furnace of the to-be-coated object of any one of Claims 1-3,
The coating object drying furnace, wherein the inlet side and outlet side gas jetting means are configured to generate hot air as the sealing gas flow. In the drying furnace of the coated object according to any one of claims 1 to 4,
The object to be coated is a vehicle body,
A drying oven for an object to be coated, characterized in that hot air blowing means for in-vehicle body for blowing hot air into the inside of the vehicle body is provided at a position closer to the inside of the drying chamber than the outlet-side hot air blowing means.

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