JP5421022B2 - Chemical liquid warming system and method for stopping the same - Google Patents

Description

  The present invention relates to a structure of a chemical conversion liquid heating system and a method for stopping the structure.

  In the painting line, in order to perform oil removal and undercoat treatment as pretreatment when painting a workpiece, the treatment areas are arranged on the line so as to be adjacent to each other. For example, in a painting line for performing electrodeposition coating on a workpiece, the workpiece is washed with hot water of about 30 ° C. to remove dust and the like, and then conveyed to a degreasing treatment area by a conveying device. In the degreasing area, degreasing is performed by spraying a degreasing liquid heated to about 50 ° C. on the workpiece. After being degreased, the workpiece is conveyed to the washing area, and the degreasing washing liquid is washed away by spraying the washing water, and is conveyed to the chemical conversion treatment area by the conveying device. In the chemical conversion treatment area, chemical conversion treatment of the workpiece surface is performed by spraying the chemical conversion liquid heated to 35 to 50 ° C. onto the workpiece. The workpiece that has undergone the chemical conversion treatment is conveyed by the conveying device to the water washing treatment apparatus after the chemical conversion treatment, and washed with sprayed flushing water. As described above, the workpiece pretreated by the steps of degreasing, chemical conversion treatment, and water washing is immersed in an electrodeposition tank for performing electrodeposition coating by the transfer device, and electrodeposition coating is performed.

  Since the chemical conversion liquid used in such pretreatment must always be kept at a temperature of about 35 to 50 ° C., the chemical conversion liquid in the chemical conversion tank is warm water heated to about 60 to 80 ° C. It is configured to be heated and maintained at about 35 ° C. to 50 ° C. by circulating through the flow path of the heat exchanger through which the gas flows. Hot water for heating is provided near the chemical conversion tank, and is supplied to the heat exchanger from a hot water tank whose temperature is maintained at 60 to 80 ° C. by steam introduced from outside (see, for example, Patent Document 1). ).

2004-238881

  By the way, the chemical conversion liquid contains metal ions such as zinc, nickel and iron in the phosphoric acid solution, and when heated, it is hydrolyzed and sludge such as iron phosphate and zinc phosphate is formed. Occur. In the heat exchanger with warm water, the chemical conversion liquid is heated to 35 to 50 ° C. by hot water of 50 to 80 ° C., and this heating causes the chemical conversion liquid in the heat exchanger to flow into the flow path. Sludge is generated. The generated sludge accumulates inside the flow path, causing problems such as increasing the resistance of the flow path or closing the flow paths of some heat exchangers.

  In particular, when the coating line is stopped and the chemical conversion liquid no longer circulates in the heat exchanger flow path, the chemical conversion liquid remaining in the heat exchanger is heated with 60 to 80 ° C. hot water remaining in the heat exchanger. Since it contacts for a long time through the wall of a heat exchanger, the temperature will rise to 60-70 degreeC which is the same temperature as the remaining warm water. The generation of sludge due to the hydrolysis of the chemical conversion liquid increases as the temperature of the chemical conversion liquid increases. Therefore, a large amount of sludge accumulates on the inner surface of the flow path of the chemical conversion liquid inside the heat exchanger while the coating line is stopped. There was a problem. Some painting lines operate for 24 hours, but many stop at night. For this reason, there has been a problem that a large amount of sludge is accumulated in the flow path of the chemical conversion liquid of the heat exchanger during the nighttime stoppage.

  As a coping method when sludge is accumulated on the inner surface of the flow path in this way, pickling for cleaning the inner surface of the flow path with an acid solution has been used conventionally. For example, when a large amount of chemical liquid sludge accumulates and the pressure loss of the pipe increases, a method of dissolving and cleaning the sludge by circulating a nitric acid solution through the chemical liquid flow path of the heat exchanger is common. It was.

  However, cleaning with an acid solution needs to be performed at a frequency of about once a week, and the wastewater treatment of the cleaning solution is necessary. Further, it is necessary to stop the coating line during cleaning. There was a problem that the production efficiency of the painting line would be lowered.

  Then, an object of this invention is to suppress generation | occurrence | production of the sludge inside a heat exchanger in the chemical conversion liquid heating system used for a coating line.

  The chemical conversion liquid heating system of the present invention includes a chemical conversion tank for storing a chemical conversion liquid for performing chemical conversion treatment on a workpiece surface, a hot water tank for storing hot water heated by a heating source, and one flow path connected to the chemical conversion tank. And a heat exchanger for exchanging heat between the chemical liquid flowing in each flow path and the hot water, the other flow path being connected to the hot water tank, and storing the replacement water A replacement water tank, a replacement water supply channel that connects one or both of the replacement water tank and the heat exchanger, a valve that opens and closes the replacement water supply channel, and a control that opens and closes the valve And the controller, when stopping the chemical conversion liquid heating system, opens the valve, supplies replacement water into one or both flow paths in the heat exchanger, and heat exchanger And a stop means for replacing the fluid inside with replacement water.

  In the chemical conversion liquid heating system of the present invention, the replacement water is also suitable as tap water, industrial water or flush water for washing a workpiece after chemical conversion treatment, ion exchange water, or RO water filtered by a reverse osmosis membrane. It is.

  The method for stopping the chemical conversion liquid heating system according to the present invention includes a chemical conversion tank for storing a chemical conversion liquid for performing chemical conversion treatment on a workpiece surface, a hot water tank for storing hot water heated by a heating source, and one of the flow paths thereof. A heat exchanger that is connected to the tank, the other flow path is connected to the hot water tank, and exchanges heat between the chemical liquid flowing in each flow path and the hot water, a replacement water tank that stores replacement water, and replacement water A method for stopping a chemical conversion liquid heating system comprising: a replacement water supply flow path that connects one or both of the tank and the heat exchanger; and a valve that opens and closes the replacement water supply flow path, When shutting down the chemical liquid warming system, open the valve, supply replacement water into one or both flow paths in the heat exchanger, and replace the fluid in the heat exchanger with replacement water. It is characterized by.

  The present invention has an effect that generation of sludge inside a heat exchanger can be suppressed in a chemical conversion liquid heating system used for a coating line.

It is explanatory drawing which shows the structure of the coating line in which the chemical conversion liquid heating system in embodiment of this invention is used. It is a systematic diagram which shows the structure of the chemical conversion liquid heating system in embodiment of this invention. It is a flowchart showing operation | movement of the chemical conversion liquid heating system in embodiment of this invention. It is a systematic diagram which shows the structure of the chemical conversion liquid heating system in other embodiment of this invention. It is a systematic diagram which shows the structure of the chemical conversion liquid heating system in other embodiment of this invention. It is a systematic diagram which shows the structure of the chemical conversion liquid heating system in other embodiment of this invention. It is a systematic diagram which shows the structure of the chemical conversion liquid heating system in other embodiment of this invention. It is a systematic diagram which shows the structure of the chemical conversion liquid heating system in other embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the chemical conversion liquid heating system 100 is used in a surface treatment area 501 of a coating system 500. The surface treatment area 501 includes a rail 510 for transporting the workpiece 600, a degreasing tank 502 for storing a solution for degreasing and cleaning, a washing tank 505 for storing washing water after degreasing and cleaning, and a surface for storing a solution for surface adjustment. The adjustment tank 507, the chemical conversion tank 11 which stores the chemical conversion liquid for chemical conversion treatment, and the chemical conversion system washing tank 61 which stores the flush water after chemical conversion treatment are provided. The degreasing tank 502 and the chemical conversion tank 11 are connected to heat exchangers 503 and 10 connected to the hot water tanks 504 and 21, respectively, so that the solution for degreasing and the chemical conversion liquid are heated to a predetermined temperature. ing. Each tank is provided with a spray nozzle 506 for spraying the solution stored in each tank toward the workpiece 600, and an enclosure 511 is provided in the spray area so that each solution does not scatter to the outside. . The workpiece 600 that has been pretreated in the surface treatment area 501 is conveyed to the painting area.

  As shown in FIG. 2, the chemical conversion liquid heating system 100 includes a chemical conversion tank 11 that stores a chemical conversion liquid, a hot water tank 21 that stores hot water, a heat exchanger 10 that performs heat exchange between the chemical conversion liquid and hot water, A replacement water tank 41 for storing replacement water, a chemical conversion liquid circulation system 110, a hot water circulation system 120, and a replacement water supply system 130 are provided.

  The chemical conversion liquid circulation system 110 is connected to the chemical conversion tank 11, a chemical conversion liquid circulation pump 12 that circulates the chemical conversion liquid in the heat exchanger 10, a chemical conversion tank outlet electric valve 13 that opens and closes the chemical conversion liquid circulation channel, and a chemical conversion tank. 11 and the chemical conversion liquid inlet pipe 14 connecting the chemical conversion liquid side flow path 10a of the heat exchanger 10 and the chemical conversion liquid outlet pipe 15 connected to the outlet side of the chemical conversion liquid flow path 10a of the heat exchanger 10. And a manual valve 16 attached to the chemical conversion liquid outlet pipe 15 and a chemical conversion liquid return pipe 17 for guiding the chemical conversion liquid from the manual valve 16 to the upper part of the chemical conversion tank 11. Further, a temperature sensor 18 for measuring the temperature of the stored chemical conversion solution is attached to the chemical conversion tank 11.

  The hot water circulation system 120 is connected to the hot water tank 21, and hot water circulating pump 22 that circulates the hot water in the heat exchanger 10, and hot water that connects the hot water tank 21 and the inlet side of the hot water side channel 10 b of the heat exchanger 10. An inlet pipe 23, a hot water outlet pipe 24 connected to the outlet side of the hot water side channel 10 b of the heat exchanger 10, and a hot water return pipe 25 connected to the hot water outlet pipe 24 to guide the hot water to the upper part of the hot water tank 21. It has. Further, a steam pipe 26 for introducing heating steam is connected to the hot water tank 21, and a steam flow rate adjusting valve 27 for adjusting the steam flow rate is attached to the steam pipe 26. A distribution pipe 28 for distributing the steam introduced from the steam pipe 26 is attached inside the hot water tank 21. Moreover, the temperature sensor 29 for measuring the temperature of the hot water stored in the hot water tank 21 is attached.

  The replacement water supply system 130 includes a replacement water tank 41 for storing replacement water such as tap water, industrial water, ion exchange water, RO water filtered by a reverse osmosis membrane, a replacement water tank 41 and a chemical conversion tank outlet motor operated valve 13. A replacement water supply pipe 46 connected to the downstream chemical conversion liquid inlet pipe 14, a replacement water supply pump 43 that supplies replacement water to the chemical conversion liquid circulation system 110, and a replacement water supply pipe on the outlet side of the replacement water supply pump 43. A replacement water supply electromagnetic valve 44 attached to 46 and a check valve 45 are provided. An upper portion of the replacement water tank 41 is connected to a water supply source such as a water supply, a replacement water supply pipe 48 for supplying replacement water to the replacement water tank 41 is provided, and a water supply electromagnetic valve 47 is attached to the replacement water supply pipe 48. ing. A water level meter 42 for measuring the water level of the replacement water tank 41 is attached to the upper part of the replacement water tank 41.

  Moreover, the chemical conversion liquid heating system 100 of this embodiment is connected with the chemical conversion liquid circulation system 110, and the pickling system 200 which circulates a pickling liquid to the chemical conversion liquid circulation system 110 is provided. The pickling system 200 includes a pickling tank 31 that stores the pickling liquid, a pickling liquid circulation pump 32 that circulates the pickling liquid, and a pickling liquid supply that connects the pickling tank 31 and the chemical conversion liquid outlet pipe 15. A pipe 33, a pickling liquid discharge pipe 37 connecting the chemical conversion liquid inlet pipe 14 and the pickling tank 31, and a pickling liquid supply pipe 33 are connected to the tap water, industrial water, ion exchange water, and reverse osmosis membrane. A water supply pipe 38 for introducing water supply such as filtered RO water and manual valves 34, 35, 36, 39 are provided. When the pressure loss of the chemical conversion liquid side flow path 10a of the heat exchanger 10 becomes large due to the sludge, the coating system 500 shown in FIG. 1 is stopped, and the chemical conversion tank outlet electric valve 13 of the chemical conversion liquid circulation system 110 is manually operated. The valve 16 is closed, the manual valves 34 and 35 are opened, and the pickling liquid circulation pump 32 is activated to circulate the pickling liquid between the pickling tank 31 and the chemical conversion liquid side channel 10 a of the heat exchanger 10. The sludge is washed. When the cleaning of the sludge is completed, the manual valves 34 and 35 are closed, the manual valves 36 and 39 are opened, and water is supplied to the chemical conversion liquid side channel 10a of the heat exchanger 10 to discharge the pickling liquid.

  Chemical conversion liquid circulation pump 12, warm water circulation pump 22, replacement water supply pump 43, pickling liquid circulation pump 32, chemical conversion tank outlet electric valve 13, replacement water supply electromagnetic valve 44, water supply electromagnetic valve 47 and steam The flow rate adjustment valve 27 is connected to the control unit 50 and is configured to be driven by a command from the control unit 50. Further, the temperature sensor 18, the water level gauge 42, and the temperature sensor 29 are connected to the control unit 50, and the signal is input to the control unit 50. The control unit 50 is a computer that includes a CPU that performs computation and signal processing and a memory that stores a control program and control data. The control unit 50 is connected to a start / stop button 51 for starting and stopping the chemical conversion tank heating system 100. The start / stop button 51 may be used to start and stop the entire painting line. When the start / stop button 51 is pressed, the chemical liquid warming system 100 starts, and when the start / stop button 51 is pressed during operation, the chemical liquid warming system 100 stops and then stops.

  A normal operation of the chemical conversion liquid heating system 100 configured as described above will be described. When the coating system 500 shown in FIG. 1 starts operation, the chemical conversion liquid stored in the chemical conversion tank 11 is transferred from the lower part of the chemical conversion tank 11 to the chemical conversion liquid side of the heat exchanger 10 from the chemical conversion liquid inlet pipe 14 by the chemical conversion liquid circulation pump 12. After entering the flow path 10 a and exchanging heat with warm water in the heat exchanger 10 and increasing its temperature, the chemical conversion liquid outlet pipe 15 passes through the manual valve 16 and the chemical conversion liquid return pipe 17 to the upper part of the chemical conversion tank 11. Return. One warm water enters the warm water side channel 10b from the warm water tank 21 through the warm water inlet pipe 23 of the heat exchanger 10, and after the heat exchange with the chemical liquid in the heat exchanger 10 decreases its temperature, the warm water outlet It returns to the upper part of the hot water tank 21 from the pipe 24 through the hot water return pipe 25. The temperature of the hot water in the hot water tank 21 is detected by the temperature sensor 29, and the control unit 50 adjusts the opening of the steam flow rate control valve 27 according to the temperature of the hot water, and the temperature of the hot water is maintained at 60 to 80 ° C. Adjust as follows. Moreover, the control part 50 acquires the temperature of a chemical conversion liquid with the temperature sensor 18, changes the flow volume of the hot water circulation pump 22 according to the temperature of a chemical conversion liquid, and controls it so that the temperature of a chemical conversion liquid may be 35-50 degreeC. . Further, the control unit 50 may adjust the temperature of the chemical conversion liquid by turning on / off the hot water circulation pump 22.

  Next, the operation | movement at the time of the stop of the chemical conversion liquid heating system 100 of this embodiment is demonstrated. As shown in step S101 of FIG. 3, the control unit 50 acquires the signal of the start / stop button 51, and determines whether or not the start / stop button 51 has been pressed, as shown in step S102 of FIG. When it is determined that the start / stop button 51 has been pressed during operation, a stop operation is started as shown in step S103 of FIG. The control unit 50 stops the chemical conversion liquid circulation pump 12 as shown in Step S104 of FIG. 3, and then closes the chemical conversion tank outlet electric valve 13 as shown in Step S105 of FIG. Then, the controller 50 opens the replacement water supply electromagnetic valve 44 as shown in Step S106 of FIG. 3 and starts the replacement water supply pump 43 as shown in Step S107 of FIG. Then, the replacement water in the replacement water tank 41 flows from the replacement water tank 41 through the replacement water supply pipe 46 into the chemical liquid inlet pipe 14 on the downstream side of the chemical conversion tank outlet electric valve 13. The replacement water flows from the chemical conversion liquid inlet pipe 14 while extruding the chemical conversion liquid staying inside toward the chemical conversion liquid flow path 10 a of the heat exchanger 10. Then, the replacement water flows into the chemical conversion tank 11 from the chemical conversion liquid outlet pipe 15 through the chemical conversion liquid return pipe 17. When a predetermined amount of replacement water such as three times the capacity from the inflow point of the replacement water in the conversion liquid inlet pipe 14 to the outlet of the conversion liquid side channel 10a of the heat exchanger 10 is introduced into the conversion liquid circulation system, the heat exchanger The chemical conversion liquid staying inside the chemical conversion liquid side channel 10a can be replaced with replacement water. Further, when a predetermined amount of replacement water such as three times the capacity from the inflow point of the replacement water in the conversion liquid inlet pipe 14 to the conversion liquid return pipe 17 is introduced into the conversion liquid circulation system, the conversion liquid side of the heat exchanger 10 The chemical conversion liquid remaining in the flow path 10a, the chemical conversion liquid inlet pipe 14, the chemical conversion liquid outlet pipe 15 and the chemical conversion liquid return pipe 17 can be replaced with replacement water. Since the replacement water is tap water, industrial water, ion exchange water, RO water filtered by a reverse osmosis membrane, etc. and does not contain phosphoric acid or various metal components, the conversion liquid side channel 10a of the heat exchanger 10 is replaced with replacement water. When the chemical conversion liquid heating system 100 is stopped, it is possible to suppress the generation of sludge on the inner surface of the chemical conversion liquid side flow path 10a of the heat exchanger 10.

  When the replacement water is allowed to flow into the heat exchanger 10, the level of the replacement water tank 41 gradually decreases. As shown in step S108 of FIG. 3, the control unit 50 acquires the replacement water tank level from the water level gauge 42, and determines whether or not the level has become the L level as shown in step S109 of FIG. When the level of the replacement water tank 41 becomes the L level, the replacement water supply pump 43 is stopped as shown in step S110 of FIG. 3, and the replacement water supply electromagnetic valve 44 is closed as shown in step S111 of FIG. And And the control part 50 opens the water supply electromagnetic valve 47, and starts water supply to the replacement water tank 41, as shown to step S112 of FIG. As shown in step S113 of FIG. 3, the control unit 50 acquires the level of the replacement water tank 41 by the water level gauge 42, and determines whether the level has increased to the H level as shown in step S114 of FIG. to decide. When the level of the replacement water tank 41 rises to the H level, the water supply electromagnetic valve 47 is closed as shown in step S115 of FIG. 3, and the stop operation is ended as shown in step S116 of FIG.

  The H level and the L level of the replacement water tank 41 are the high water level and the low water level of the replacement water tank 41, respectively, and the capacity of the replacement water tank 41 between the H level and the L level is the predetermined replacement water described above. It is decided to become the amount of. If the capacity of the replacement water tank 41 is not so large, the replacement water is allowed to flow out until the replacement water tank reaches L level, and then the replacement water supply pump 43 is stopped and the water supply electromagnetic valve 47 is opened to replace the replacement water. After raising the level of the tank 41 to the H level, the replacement water supply pump 43 may be activated again to inject the replacement water into the chemical conversion liquid circulation system 110.

  In the present embodiment, substitution water is allowed to flow into the chemical liquid circulation system 110 and the chemical liquid remaining in the chemical liquid side channel 10a of the heat exchanger 10 is converted into tap water, industrial water, ion exchange water, and reverse osmosis membrane. The inner surface of the chemical conversion liquid side channel 10a of the heat exchanger 10 while the chemical conversion liquid heating system 100 is stopped by replacing with filtered water such as RO water that does not contain various metal components. It is possible to suppress the generation of sludge.

  In the present embodiment, it has been described that the stop operation is started by the start / stop button 51. However, the start / stop button 51 is not provided, and the stop operation may be started by another switch. The stop operation of the chemical conversion liquid heating system 100 may be started in conjunction with a switch such as a stop button on the panel being turned on.

  With reference to FIG. 4, another embodiment of the present invention will be described. Parts similar to those of the embodiment described above with reference to FIGS. 1 to 3 are denoted by the same reference numerals and description thereof is omitted. The replacement water supply system 131 of this embodiment arranges the replacement water tank 41 at a position higher than the chemical conversion tank 11 and the heat exchanger 10, and the replacement water is transferred from the replacement water tank 41 to the chemical conversion liquid inlet pipe 14 due to the water head difference. The replacement water supply pump 43 is not arranged. When the start / stop button 51 is pushed and the stop operation of the chemical conversion liquid heating system 100 is started, the control unit 50 opens the replacement water supply electromagnetic valve 44 and replaces the chemical conversion liquid side channel 10a of the heat exchanger 10 with the replacement water. To do. In the present embodiment, as in the above-described embodiment, it is possible to suppress the generation of sludge on the inner surface of the chemical conversion liquid flow path 10a of the heat exchanger 10 while the chemical conversion liquid heating system 100 is stopped. There is an effect that you can.

  Another embodiment of the present invention will be described with reference to FIG. Parts similar to those of the embodiment described above with reference to FIGS. 1 to 3 are denoted by the same reference numerals and description thereof is omitted. The replacement water supply system 140 of this embodiment includes a replacement water supply pipe 46 a for the chemical conversion liquid circulation system 110 in which the replacement water supply pipe 46 is connected to the chemical conversion liquid inlet pipe 14 at the outlet of the replacement water supply pump 43, and a hot water inlet. The replacement water supply pipe 46b for the hot water circulation system 120 connected to the pipe 23 is branched, and the replacement water supply electromagnetic valves 44a and 44b and check valves 45a and 45b are provided in the replacement water supply pipes 46a and 46b, respectively. Is. When the start / stop button 51 is pressed and the stop operation of the chemical conversion liquid heating system 100 is started, the control unit 50 opens the replacement water supply electromagnetic valves 44a and 44b to supply the replacement water to the chemical conversion liquid side flow of the heat exchanger 10. As in the above-described embodiment, the chemical liquid in the chemical liquid side channel 10a of the heat exchanger 10 and the hot water in the hot water side channel 10b are replaced with replacement water. .

  In the present embodiment, the control unit 50 opens only the replacement water supply electromagnetic valve 44b connected to the hot water circulation system 120 when the start / stop button 51 is pressed and the chemical conversion liquid heating system 100 is stopped. As described above, the replacement water is allowed to flow into the hot water side flow path 10b of the heat exchanger 10, and the hot water in the hot water side flow path 10b of the heat exchanger 10 may be replaced with the replacement water as in the embodiment described above. . In this case, the heat exchanger 10 is cooled by substituting warm water of about 70 to 80 ° C. staying in the heat exchanger 10 with room temperature replacement water, and the chemical conversion liquid side channel 10a of the heat exchanger 10 is cooled. Even when the chemical conversion liquid remains, the chemical conversion liquid inside the heat exchanger 10 is prevented from rising and hydrolyzing the chemical conversion liquid while the chemical conversion liquid heating system 100 is stopped, and the generation of sludge is suppressed. There is an effect that it can be suppressed.

  Another embodiment of the present invention will be described with reference to FIG. Parts similar to those of the embodiment described above with reference to FIGS. 1 to 3 are denoted by the same reference numerals and description thereof is omitted. As shown in FIG. 6, the replacement water supply system 132 of the present embodiment is provided with a heat exchanger outlet motor-operated valve 19 between the chemical conversion liquid outlet pipe 15 and the chemical conversion liquid return pipe 17 of the heat exchanger 10. A replacement water return pipe 49 extending from the outlet pipe 15 to the chemical conversion water washing tank 61 is provided, and the replacement water return pipe 49 is provided with a replacement water return electric valve 49a. When the start / stop button 51 is pushed and the stop operation of the chemical conversion liquid heating system 100 is started, the control unit 50 closes the chemical conversion tank outlet motor-operated valve 13 and the heat exchanger outlet motor-operated valve 19 and replaces the replacement water supply solenoid valve. 44 and the replacement water return electric valve 49 a are opened to allow replacement water to flow into the chemical conversion liquid side flow path 10 a of the heat exchanger 10, and the conversion liquid or replacement water discharged from the heat exchanger 10 is discharged from the replacement water return pipe 49. Return to the replacement water tank 41. Then, the replacement water supply pump 43 is operated for a predetermined time, and when a predetermined amount of replacement water is injected into the chemical conversion liquid circulation system 110, the operation of the replacement water supply pump 43 is stopped. In this way, the chemical liquid remaining inside the chemical liquid side channel 10 a, the chemical liquid inlet pipe 14, and the chemical liquid outlet pipe 15 of the heat exchanger 10 is pushed out by the replacement water from the replacement water return pipe 49. It flows into the replacement water tank 41. The replacement water tank 41 is very large compared to the capacities of the chemical conversion liquid side flow path 10a, the chemical conversion liquid inlet pipe 14, and the chemical conversion liquid outlet pipe 15 of the heat exchanger 10, so that the components of the chemical conversion liquid even when the chemical conversion liquid flows in. The concentration increases only slightly. And even if the density | concentration of a chemical conversion liquid component rises, the density | concentration will be low, and even if the chemical conversion liquid heating system 100 is heated during a stop, sludge will hardly be generated. In the present embodiment, since the replacement water circulates, the tank level of the replacement water tank 41 does not change. Therefore, it is not necessary to raise the level of the replacement water tank 41 after the replacement water supply pump 43 is stopped. In addition to the effect of the embodiment described above with reference to FIG. 5, this embodiment has an effect that the amount of water used can be further reduced because the replacement water is circulated. In this embodiment, as the number of replacements increases, the concentration of the chemical component in the replacement water increases. Therefore, after the replacement is performed a predetermined number of times, the replacement water tank 41 is blown and the water supply electromagnetic valve 47 is opened for replacement. Refill the water tank 41 with replacement water.

  Another embodiment of the present invention will be described with reference to FIG. Parts similar to those of the embodiment described above with reference to FIGS. 1 to 3 are denoted by the same reference numerals and description thereof is omitted. The replacement water supply system 150 of the present embodiment is configured such that instead of the replacement water stored in the replacement water tank 41, the chemical conversion liquid side of the heat exchanger 10 is converted into the conversion water flush water stored in the chemical conversion water washing tank 61 of the chemical conversion treatment system. The flow path 10a is configured to be replaced, and the other configuration is the same as that of the embodiment described with reference to FIGS. The water stored in the chemical conversion chemical rinsing tank 61 is sprayed onto the workpiece 600 from the spray nozzle 506 shown in FIG. 1 by the rinsing water pump 68, and the workpiece 600 is washed with water and then returned to the chemical conversion rinsing tank 61. However, since the concentration of the chemical conversion liquid component is very low, sludge is hardly generated even when the temperature rises. In addition to the effects of the embodiment described above, this embodiment does not need to supply tap water, industrial water, ion exchange water, RO water filtered by a reverse osmosis membrane or the like as replacement water, and reduces the amount of water used. There is an effect that can be made.

  Another embodiment of the present invention will be described with reference to FIG. Parts similar to those of the embodiment described above with reference to FIG. As shown in FIG. 8, the replacement water supply system 151 of the present embodiment is provided with a heat exchanger outlet motor-operated valve 19 between the chemical conversion liquid outlet pipe 15 and the chemical conversion liquid return pipe 17 of the heat exchanger 10. A flush water return pipe 69 extending from the outlet pipe 15 to the chemical conversion water washing tank 61 is provided, and the flush water return pipe 69 is provided with a flush return electric valve 62. When the start / stop button 51 is pushed and the stop operation of the chemical conversion liquid heating system 100 is started, the control unit 50 closes the chemical conversion tank outlet motor-operated valve 13 and the heat exchanger outlet motor-operated valve 19 and replaces the replacement water supply solenoid valve. 44 and the flush return electric valve 62 are opened to allow flush water to flow into the chemical liquid side channel 10 a of the heat exchanger 10, and the chemical liquid or flush water discharged from the heat exchanger 10 is formed from the flush water return pipe 69. Return to the system washing tank 61. Then, the replacement water supply pump 43 is operated for a predetermined time, and when a predetermined amount of washing water is injected into the chemical conversion liquid circulation system 110, the operation of the replacement water supply pump 43 is stopped. In this way, the chemical liquid remaining in the chemical liquid side channel 10a, the chemical liquid inlet pipe 14 and the chemical liquid outlet pipe 15 of the heat exchanger 10 is pushed out by the flush water and from the flush water return pipe 69. It flows into the chemical conversion water washing tank 61. The chemical conversion water washing tank 61 is very large in comparison with the capacity of the chemical conversion liquid side flow path 10a, the chemical conversion liquid inlet pipe 14 and the chemical conversion liquid outlet pipe 15 of the heat exchanger 10, so that the concentration of the chemical conversion liquid flows even if it flows. It only rises slightly. And even if the density | concentration of a chemical conversion liquid component rises, the density | concentration will be low, and even if the chemical conversion liquid heating system 100 is heated during a stop, sludge will hardly be generated. In this embodiment, since the flush water circulates, the tank level of the chemical conversion water washing tank 61 does not change, so there is no water supply system, and it is necessary to raise the level of the chemical conversion water washing tank 61 after stopping the replacement water supply pump. There is no. In addition to the effects of the embodiment described above with reference to FIG. 7, this embodiment circulates flush water, so that the amount of water used can be further reduced, and a water level gauge, a water supply solenoid valve, and the like are not required. With this, the system can be simplified.

  DESCRIPTION OF SYMBOLS 10,503 Heat exchanger, 10a Chemical conversion side flow path, 10b Hot water side flow path, 11 Chemical conversion tank, 12 Chemical conversion liquid circulation pump, 13 Chemical conversion tank outlet electric valve, 14 Chemical conversion liquid inlet pipe, 15 Chemical conversion liquid outlet pipe, 16 , 34, 35, 36, 39 Manual valve, 17 conversion liquid return pipe, 18 temperature sensor, 19 heat exchanger outlet motor operated valve, 21,504 hot water tank, 22 hot water circulation pump, 23 hot water inlet pipe, 24 hot water outlet pipe, 25 Hot water return pipe, 26 Steam pipe, 27 Steam flow control valve, 28 minute pipe, 29 Temperature sensor, 31 Pickling tank, 32 Pickling liquid circulation pump, 33 Pickling liquid supply pipe, 37 Pickling liquid discharge pipe, 38 Water supply pipe, 41 Replacement water tank, 42 Water level gauge, 43 Replacement water supply pump, 44, 44a, 44b Replacement water supply solenoid valve, 45, 45a, 45b Check valve, 46, 46a, 46b Replacement water supply pipe 47 Water supply solenoid valve, 48 Replacement water supply pipe, 49 Replacement water return pipe, 49a Replacement water return transmission valve, 50 Control unit, 51 Start / stop button, 61 Chemical water washing tank, 62 Water washing return electric valve, 68 Water washing pump, 69 Flushing water return pipe, 100 Chemical conversion liquid heating system, 110 Chemical conversion liquid circulation system, 120 Hot water circulation system, 130 Replacement water supply system, 200 Pickling system, 500 Coating system, 501 Surface treatment area, 502 Degreasing tank, 506 Spray Nozzle, 507 Surface adjustment tank, 510 rail, 600 workpiece.

Claims (3)

A chemical conversion tank for storing a chemical conversion liquid for chemical conversion treatment of the workpiece surface;
A hot water tank for storing hot water heated by a heating source;
One of the flow paths is connected to the chemical conversion tank, the other flow path is connected to the hot water tank, and a heat exchanger that exchanges heat between the chemical conversion liquid flowing in each flow path and the hot water is provided. A temperature system,
A replacement water tank for storing replacement water;
A replacement water supply flow path that connects the flow path of either or both of the replacement water tank and the heat exchanger;
A valve for opening and closing the replacement water supply flow path;
A control unit for opening and closing the valve,
The control unit
When the chemical liquid heating system is stopped, the valve is opened, replacement water is supplied to one or both flow paths in the heat exchanger, and the fluid in the heat exchanger is replaced with replacement water. Providing means,
Chemical solution warming system characterized by The chemical conversion liquid heating system according to claim 1,
The replacement water is tap water, industrial water, or flush water for washing the workpiece after chemical conversion treatment, ion exchange water, RO water filtered by a reverse osmosis membrane,
Chemical solution warming system characterized by A chemical conversion tank for storing a chemical conversion liquid for chemical conversion treatment of the workpiece surface;
A hot water tank for storing hot water heated by a heating source;
One of the flow paths is connected to the chemical conversion tank, the other flow path is connected to the hot water tank, and a heat exchanger that exchanges heat between the chemical conversion liquid flowing in each flow path and the hot water,
A replacement water tank for storing replacement water;
A replacement water supply flow path that connects the flow path of either or both of the replacement water tank and the heat exchanger;
A valve for opening and closing a replacement water supply flow path, and a method for stopping a chemical conversion liquid heating system comprising:
When shutting down the chemical liquid warming system, open the valve, supply replacement water into one or both flow paths in the heat exchanger, and replace the fluid in the heat exchanger with replacement water. ,
A method for stopping a chemical conversion liquid heating system characterized by

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