Maintenance method and system for heat exchanger plates of plate heat exchanger

Abstract

Provided is a maintenance method and system for heat exchange plates of a plate heat exchanger, which can more efficiently inspect for the presence or absence of cracks in the heat exchange plates. [Solution] The plate-type heat exchanger includes multiple robot arms 30 that form a coating made of fluorescent liquid on one side of a heat exchange plate of a plate-type heat exchanger, a transport device 20 that transports the heat exchange plate 10 to the robot arms, and an inspection means 60 that irradiates the other side of the heat exchange plate 10 with ultraviolet light and determines that a through defect has occurred at a location where fluorescence is confirmed, and each robot arm 30 forms the coating with an amount of fluorescent liquid that is less than the total amount of fluorescent liquid required for the coating to be formed on the heat exchange plate 10, or forms the coating on an area that is smaller than the total area of ​​the heat exchange plate 10 on which the coating is to be formed.

Description

[Technical field]

[0001] The present invention relates to a maintenance method and system for the heat exchange plates of a plate heat exchanger, which can efficiently maintain the heat exchange plates of the plate heat exchanger. [Background technology]

[0002] Plate heat exchangers are periodically maintained. As part of the maintenance, an inspection is conducted to find the presence or absence of cracks in the heat exchange plates of the plate heat exchanger. Specifically, a fluorescent liquid is first applied to the entire surface of one side of the heat exchange plate. Next, ultraviolet light is irradiated from the other side, and if fluorescence is confirmed, it is determined that a penetrating crack has occurred in the fluorescent area (see, for example, Patent Document 1). Recently, the demand for maintenance of plate heat exchangers has been increasing. To meet this demand, a robot arm is used to reduce the time required for the application of the fluorescent liquid, but further efficiency is required. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-121989 A Summary of the Invention [Problem to be solved by the invention]

[0004] In view of the above circumstances, an object of the present invention is to provide a maintenance method and system for heat exchange plates of a plate heat exchanger, which can more efficiently inspect for the presence or absence of cracks in the heat exchange plates. [Means for solving the problem]

[0005] An embodiment for achieving the above object is a maintenance method for a heat exchange plate of a plate-type heat exchanger, comprising: a coating step of forming a coating made of a fluorescent liquid on one surface of a heat exchange plate of the plate-type heat exchanger; and an inspection step of irradiating the other surface of the heat exchange plate with ultraviolet light and determining that a through defect has occurred at a location where fluorescence is confirmed, wherein the coating step is characterized in that the coating is formed on the heat exchange plate in a plurality of stages, and in each stage, the coating is formed with an amount of fluorescent liquid that is less than the total amount of fluorescent liquid required for the coating to be formed on the heat exchange plate, or the coating is formed on an area that is smaller than the total area of ​​the heat exchange plate on which the coating is to be formed.

[0006] Another aspect for achieving the above object is a maintenance system for heat exchange plates of a plate type heat exchanger, comprising a plurality of robot arms for forming a coating made of a fluorescent liquid on one surface of a heat exchange plate of a plate type heat exchanger, a transport device for transporting the heat exchange plate to the robot arms and the heat exchange plate with the coating formed thereon to the next robot arm, and an inspection means for irradiating the other surface of the heat exchange plate with ultraviolet light and determining that a through defect has occurred at a location where fluorescence is confirmed, wherein each of the robot arms forms a coating with an amount of fluorescent liquid that is smaller than the total amount of fluorescent liquid required for the coating to be formed on the heat exchange plate, or forms a coating on an area that is smaller than the total area of ​​the heat exchange plate on which the coating is to be formed. Effect of the Invention

[0007] According to the present invention, there are provided a maintenance method and a maintenance system for heat exchange plates of a plate heat exchanger, which are capable of more efficiently inspecting the heat exchange plates for the presence or absence of cracks. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic configuration diagram of a maintenance system for heat exchange plates of a plate heat exchanger. [Diagram 2] FIG. 2 is a block diagram showing the functions of the maintenance system. [Diagram 3] FIG. [Figure 4] FIG. 13 is a diagram showing fluorescence and a penetrating defect portion captured in an image by a line sensor. [Diagram 5] FIG. 13 is a diagram showing application of fluorescent liquid by two robot arms. [Figure 6] 11A and 11B are diagrams for explaining the time required for a replenishing operation and a coating operation. [Figure 7] FIG. 13 shows a second robot arm having multiple brushes. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Fig. 1 is a schematic diagram of a maintenance system for a heat exchange plate of a plate heat exchanger. Fig. 2 is a block diagram showing the functions of the maintenance system. Fig. 3 is a plan view of a heat exchange plate. The maintenance method and maintenance system of the present invention are for detecting a through defect that occurs in a heat exchange plate of a plate heat exchanger. First, the heat exchange plate will be described with reference to Fig. 3.

[0010] 3 illustrates two types of heat exchange plates 10a and 10b having different shapes. The heat exchange plates 10a and 10b are collectively referred to as heat exchange plates 10. The heat exchange plate 10 is a plate-shaped member used in a plate-type heat exchanger in a plant that manufactures liquid products such as beverages (hereinafter, liquid products).

[0011] As shown in FIG. 3(a), the heat exchange plate 10a has liquid introduction parts 13a, 13b, 13c, and 13d at the four corners, which are flow paths for the liquid product and the liquid heat transfer medium, and includes a heat exchange part 11 formed between the liquid introduction parts 13a and 13b. The heat exchange plate 10a also has a groove part 12 surrounding the liquid introduction parts 13a and 13b and the heat exchange part 11. A gasket (not shown) is attached to the groove part 12. A plurality of heat exchange plates 10 are used in a stacked manner, and the gasket is provided to seal the gap between the adjacent heat exchange plates 10. As shown in FIG. 3(b), the heat exchange plate 10b differs from the heat exchange plate 10a in that it does not have the liquid introduction part 13a and the liquid introduction part 13b.

[0012] In a plate heat exchanger, adjacent heat exchange plates 10a are stacked with a gasket between them, with the front and back of the plates reversed, and a heat exchange plate 10b is attached to the outermost plate. Thus, even if the heat exchange plates 10 have the same shape, there are differences depending on whether or not they have a liquid introduction section.

[0013] The heat exchange section 11 of the heat exchange plate 10 is the region inside the groove section 12 for the gasket. The liquid product flowing on one side of the heat exchange plate 10 and the heat medium flowing on the other side are heat exchanged across the heat exchange section 11. There are no particular limitations on the shape of the heat exchange section 11, but the heat exchange section 11 of this embodiment has both ends in the vertical direction formed flat, and a plurality of irregularities that are rectangular in plan view are formed between them.

[0014] In the heat exchange plate 10, cracks penetrating in the thickness direction can occur in the heat exchange portion 11 due to various causes. Such cracks are called penetrating defects. The maintenance method and maintenance system are intended to detect such penetrating defects.

[0015] As shown in FIGS. 1 and 2, the maintenance system 1 includes a transfer device 20 that transfers a heat exchange plate 10, a robot arm 30, and a control device 40.

[0016] The conveying device 20 is a device that conveys the heat exchange plate 10. There are no particular limitations on the type of the conveying device 20 as long as it is a device that can convey the heat exchange plate 10 in the horizontal direction with one surface of the heat exchange plate 10 facing upward, and for example, a roller conveyor or a belt conveyor can be applied.

[0017] The transfer device 20 transfers the heat exchange plates 10 one by one from upstream to downstream. A first robot arm 31 and a second robot arm 32 are arranged in this order along the moving direction of the transfer device 20. The first robot arm 31 and the second robot arm 32 are also collectively referred to as the robot arm 30.

[0018] The robot arm 30 performs a coating operation (including an operation of simply bringing the brush 34 into contact) by grasping the brush 34, moving the brush to a container storing the fluorescent liquid 2 to adhere the fluorescent liquid to the brush 34, and moving the brush 34 in contact with one side of the heat exchange plate 10. The type and specific structure of the robot arm 30 are not particularly limited as long as it is capable of performing such an operation, but it is, for example, a six-axis robot arm equipped at its tip with a function for grasping the brush 34.

[0019] Further, a third robot arm 33 is disposed downstream of the second robot arm 32 and upstream of a line sensor 60 described later. The third robot arm 33 is a robot arm capable of lifting the heat exchange plate 10 that has been transported with one surface coated with the fluorescent liquid facing upward, inverting the heat exchange plate 10 so that the other surface not coated with the fluorescent liquid faces upward, and placing the heat exchange plate 10 on the transport device 20. The type and specific structure of the third robot arm 33 are not particularly limited as long as it is capable of such an operation. For example, it is a six-axis robot arm with a gripping hand 37 attached to the tip.

[0020] The operations of the first robot arm 31 to the third robot arm 33 are controlled by a control device 40. The application of the fluorescent liquid by the first robot arm 31 and the second robot arm 32 will be described later.

[0021] A heat exchange plate sensor 50 is disposed upstream of the first robot arm 31 in the vicinity of the transport device 20. The heat exchange plate sensor 50 is for identifying the type of the heat exchange plate 10. Specifically, a sensor that uses a laser to identify the position of the object for the heat exchange plate 10 that has reached a predetermined position in the transport device 20 can be mentioned. By detecting the presence or absence of a liquid introduction section using such a laser, it is possible to identify whether the object is the heat exchange plate 10a or the heat exchange plate 10b shown in FIG. 3. The sensor for identifying the type of the heat exchange plate 10 is not limited to a sensor that uses a laser to identify the position. For example, the heat exchange plate may be identified by imaging the heat exchange plate 10 and analyzing the obtained image, or a barcode reader that reads a code that identifies the type of the heat exchange plate, such as a barcode, attached to the heat exchange plate.

[0022] A line sensor 60 is disposed near the transport device 20, downstream of the third robot arm 33. The line sensor 60 is an imaging device that images the surface of the heat exchange plate 10. The line sensor 60 is capable of imaging an area wider than the width direction of the heat exchange plate 10, and forms an image of the other side of the heat exchange plate 10 (the side on which the fluorescent liquid is not applied) by imaging an area from the beginning to the end in the traveling direction of the heat exchange plate 10 transported by the transport device 20.

[0023] Although not shown, a black light is provided to irradiate ultraviolet light toward the imaging range of the line sensor 60. The ultraviolet light from the black light is irradiated while the line sensor 60 is imaging. If a through defect occurs in the heat exchange plate 10, fluorescent liquid will appear from one surface (the surface facing downward) through the through defect to the other surface, and fluorescence will be emitted by the ultraviolet light. Therefore, if a through defect occurs, the line sensor 60 will form an image of the surface of the heat exchange plate 10 that contains fluorescence.

[0024] It is preferable to irradiate light from multiple light sources toward the imaging range of the line sensor 60. For example, light is irradiated toward the imaging range from all four sides in a plan view. By providing multiple light sources like this, it is possible to reduce the shadow that may occur on the uneven heat exchanger 11. By reducing the shadow of the heat exchanger 11, the shadow can be eliminated from the image formed by the line sensor, making it easier to detect the through-hole defect by image processing, which will be described later.

[0025] The control device 40 includes a CPU and a memory, and reads and executes a program stored in the memory. By executing the program, the control device 40 selects a pattern for applying the fluorescent liquid according to the type of heat exchange plate 10, and causes the robot arm 30 to apply the fluorescent liquid. Each function of the control device 40 will be described with reference to FIG. 2.

[0026] The control device 40 includes a transport control unit 41, a heat exchange plate determination unit 42, a coating control unit 43, and a penetration defect determination unit 44.

[0027] The transfer control unit 41 controls the transfer device 20 to transfer the heat exchange plate 10. Specifically, the transfer and stopping are performed so that the heat exchange plate 10 is at a predetermined position relative to the heat exchange plate sensor 50, the robot arm 30, and the line sensor 60.

[0028] The heat exchange plate determination unit 42 determines the type of heat exchange plate 10 based on the information obtained from the heat exchange plate sensor 50. The control device 40 stores information about the shapes of all types of heat exchange plates 10 that are handled in advance. The heat exchange plate determination unit 42 then determines the type of heat exchange plate 10 being transported by comparing the information sent from the heat exchange plate sensor 50 with the information about the heat exchange plate 10.

[0029] The coating control unit 43 selects a coating pattern set according to the type of heat exchange plate 10, and causes the robot arm 30 to form a coating based on the selected pattern. The coating refers to the fluorescent liquid applied to the heat exchange plate 10. The coating pattern refers to the shape and arrangement of the coating applied to the heat exchange plate 10. The control device 40 stores the coating pattern in advance, and operates the robot arm 30 to form the pattern. The coating pattern will be described later. The coating control unit is an example of a coating formation control unit in the claims.

[0030] The through defect determination unit 44 determines the presence or absence of a through defect based on the image obtained by the line sensor 60. For example, as shown in FIG. 4, a fluorescent portion 6 that fluoresces is detected by known image processing of an image 70 obtained by the line sensor 60. If a fluorescent portion 6 is detected, it is determined that a through defect 15 has occurred in the fluorescent portion 6. The result of this determination may be displayed on the monitor 61 (see FIG. 1), for example, as an image 70 in which the fluorescent portion 6 is enlarged or marked. The presence or absence of a through defect may also be determined by irradiating ultraviolet light in a dark room and visually observing the fluorescence.

[0031] The application of the fluorescent liquid will be described in detail with reference to FIG. 5. Two robot arms, a first robot arm 31 and a second robot arm 32, share the task of applying the fluorescent liquid to one heat exchange plate 10. Each robot arm forms a coating with an amount of fluorescent liquid smaller than the total amount of fluorescent liquid required for the coating formed on the heat exchange plate 10, or forms a coating on an area smaller than the total area of ​​the heat exchange plate 10 on which the coating is formed. The coating formed on the heat exchange plate 10 refers to a coating formed on the entire area of ​​the heat exchange plate 10 where a through defect may occur. In the heat exchange plate 10 shown in FIG. 3, a coating is formed on the groove portion 12 on one side and the entire heat exchange portion 11 located inside the groove portion 12.

[0032] First, the first robot arm 31 on the upstream side forms a first coating 3 made of fluorescent liquid at multiple locations spaced apart on one surface of the heat exchange plate 10. In the example shown in the figure, a rectangular coating is formed at multiple locations spaced apart. In the case of the heat exchange plate 10a, since there are liquid introduction portions 13a-13d, the pattern is such that the first coating 3 is not formed in those portions. In the case of the heat exchange plate 10b, since there are no liquid introduction portions 13a-13b, the pattern is such that the first coating 3 is formed in those portions.

[0033] The second robot arm 32 on the downstream side moves the brush 34 to extend the first coating 3, thereby forming a second coating 4 that covers the entire one side. Furthermore, the second robot arm 32 applies fluorescent liquid to the grooves 12 to form a third coating 5. In the case of the heat exchange plate 10a, since the liquid introduction portions 13a-13d are present, a pattern is adopted in which the second coating 4 is not formed in those portions. In the case of the heat exchange plate 10b, since the liquid introduction portions 13a-13d are not present, a pattern is adopted in which the second coating 4 is formed in those portions.

[0034] When the fluorescent liquid cannot be applied to form a coating in one operation, the application control unit 43 causes the first robot arm 31 and the second robot arm 32 to move the brush 34 to the container to apply the fluorescent liquid.

[0035] In this manner, the first robot arm 31 forms a rough coating on one side of the heat exchange plate 10, while the second robot arm 32 forms a coating evenly over the entire one side of the heat exchange plate 10 and in the grooves 12.

[0036] The time-saving effect of dividing the roles is explained in Fig. 6. The horizontal direction in Fig. 6 indicates the time required for various operations of the robot arm.

[0037] First, as shown in FIG. 6(a), when forming a coating with one robot arm, first, a brush is dipped into the fluorescent liquid in a container to adhere the fluorescent liquid to the brush. This operation is called a replenishing operation. Then, the brush is moved while in contact with one side of the heat exchange plate to form a coating on the heat exchange plate. This operation is called a coating operation. If the coating cannot be formed on the heat exchange plate in one coating operation, the replenishing operation and the coating operation are appropriately repeated. In the example of FIG. 6(a), these operations are repeated four times to form a coating on one heat exchange plate 10.

[0038] FIG. 6(b) shows the case where two robot arms 30 are used as described above. The first robot arm 31 uses a smaller area and a smaller amount of fluorescent liquid than the coating formed on the entire heat exchange plate 10, so that, for example, the refilling operation is completed in one go. The second robot arm 32 spreads the first coating 3 already formed on the heat exchange plate 10, so that the coating operation can be performed without the need for refilling. Therefore, the second coating 4 can be formed in a considerably short time. Then, the refilling operation is performed by utilizing the time saved, and the third coating 5 is formed in the groove portion 12. In this way, it is preferable to form the coating so that the operation time by the first robot arm 31 and the operation time by the second robot arm 32 are approximately the same.

[0039] As shown in Fig. 6(b), the first robot arm 31 can reduce the time required for the coating operation because the area to be coated is small. Also, because the amount of fluorescent liquid required is small, the number of refilling operations can be reduced, resulting in a time-saving effect. With the second robot arm 32, the coating operation is to spread the already formed first coating 3, so refilling operations are not necessary, and the time required for the work can be shortened accordingly.

[0040] The second robot arm 32 forms two types of coatings, the second coating 4 and the third coating 5. In such a case, the second robot arm 32 may have a brush suitable for each coating. FIG. 7 shows an example of the second robot arm 32 having multiple brushes. The second robot arm 32 has a first brush 35 and a second brush 36 at its tip. The first brush 35 is wider than the second brush 36.

[0041] Since the second coating 4 is formed by extending the scattered first coating 3 in the horizontal direction, the application control unit 43 controls the second robot arm 32 to form the second coating 4 using the wide first brush 35. On the other hand, since the third coating 5 is formed by applying the fluorescent liquid to the grooves 12, the application control unit 43 controls the second robot arm 32 to form the third coating 5 using the relatively narrow and long second brush 36. Either the second coating 4 or the third coating 5 may be formed first.

[0042] By providing the second robot arm with a plurality of types of first brushes 35 and second brushes 36 suitable for the shape of the object to be coated in this way, it is possible to more reliably form a coating on one side of the heat exchange plate 10 without omission. In addition, since there is no need for a robot arm having the first brush 35 and a robot arm having the second brush 36, there is an effect of reducing costs. In addition, it is also possible to form the second coating 4 with the first brush 35 on one robot arm, and then replace the first brush 35 with the second brush 36 to form the third coating 5, but this method requires time for replacement. However, since the second robot arm 32 is provided with the first brush 35 and the second brush 36, the time required for such replacement can be eliminated, and the time required for forming the coating can be shortened.

[0043] The maintenance system 1 configured and controlled as described above transports the heat exchange plate 10 using the transport device 20, and forms a coating made of fluorescent liquid on one surface of the heat exchange plate 10. This coating is formed by multiple robot arms 30, two in this embodiment, which share the role of forming the coating. That is, the first robot arm 31 on the upstream side forms the first coating 3 by applying the fluorescent liquid so that it is scattered at multiple points. Next, the second robot arm 32 on the downstream side extends the first coating 3 to form the second coating 4 that covers the entire one surface, and also forms the third coating 5 in the grooves 12.

[0044] The first coating 3 is smaller than the total amount of fluorescent liquid required for the entire one side of the heat exchange plate 10, and is smaller than the area to be coated on that side. Therefore, the time required to form the first coating 3 is shorter than the time required to form a coating on the entire one side. In addition, because the amount of fluorescent liquid to be applied is small, the number of operations that the first robot arm 31 needs to carry the brush 34 to the fluorescent liquid container can be reduced, and the time required for application can be shortened accordingly.

[0045] On the other hand, since the second coating 4 is formed by simply extending the first coating 3, the second robot arm 32 does not need to carry the fluorescent liquid to the fluorescent liquid container, and the time required for application can be shortened accordingly. Even if additional fluorescent liquid is required to form the second coating 4, only a small amount is required because the first coating 3 is already present, and the time required for the second robot arm 32 to form the second coating 4 can be shortened. In addition, the third coating 5 is also less than the total amount of fluorescent liquid required for the entire one side of the heat exchange plate 10 and is smaller than the area to be coated on the one side. Since the amount of fluorescent liquid to be applied is thus small, the number of times that the second robot arm 32 needs to carry the brush 34 to the fluorescent liquid container can be reduced, and the time required for application can be shortened accordingly.

[0046] In this way, the maintenance system 1 is formed by dividing the roles among multiple robot arms 30, thereby shortening the time required to apply the fluorescent liquid and form a coating, thereby enabling efficient detection of penetrating defects in the heat exchange plate 10.

[0047] Although an embodiment of the present invention has been described, it goes without saying that the present invention is not limited to the above-described embodiment, and additions, omissions, substitutions, and other modifications of the configuration are possible without departing from the spirit of the present invention.

[0048] The following describes examples of coating formation patterns. [Variation 1] The first robot arm 31 forms the first coating 3 and also forms part of the third coating 5 made of fluorescent liquid in the grooves 12, while the second robot arm 32 extends the first coating 3 to form the second coating 4 covering the entire one side and also forms the remaining part of the third coating 5. In other words, the first robot arm 31 and the second robot arm 32 share the work of forming the third coating 5 in the grooves 12. For example, as shown in FIG. 6(c), the work of forming the third coating 5 is shared between the robot arms 30 so that the working time of each robot arm 30 is approximately the same.

[0049] [Variation 2] The first robot arm 31 forms a coating made of fluorescent liquid on a portion of one surface, and the second robot arm 32 forms a coating made of fluorescent liquid on the other portion of the one surface. That is, in the above-described embodiment, the second robot arm 32 forms the already-existing first coating 3, and therefore no replenishing operation is required, but this is not limited thereto, and the second robot arm 32 may perform the replenishing operation to form a coating on the heat exchange plate 10. In this case, it is preferable that the first robot arm 31 forms a coating on a portion of one surface of one heat exchange plate 10, and the second robot arm 32 forms a coating on the remaining portion of the one surface.

[0050] [Variation 3] The robot arm 30 has a brush 34, and forms a coating by dipping the brush 34 in the fluorescent liquid in the container and then moving the brush 34 over one side of the heat exchange plate 10. At this time, the brush 34 may be dipped into the fluorescent liquid in the container once for each heat exchange plate 10, and a coating may be formed by the brush 34. In other words, a coating is formed in an area on one side of the heat exchange plate 10 that is handled by the robot arm 30 by performing a refilling operation only once.

[0051] For example, in the above embodiment, the fluorescent liquid is applied with a brush to form the coating, but the method is not limited to this. For example, the coating may be formed by spraying the fluorescent liquid onto the heat exchange plate 10 from a position spaced a certain distance from the heat exchange plate 10 using a spray or injection nozzle.

[0052] Also, the fluorescent liquid is stored in a container, and the brush is dipped in the fluorescent liquid to adhere to the fluorescent liquid, but the present invention is not limited to such an embodiment. For example, a brush, a tank storing the fluorescent liquid, and a tube or pump for sending the fluorescent liquid from the tank to the brush are provided on the robot arm. The fluorescent liquid is then sent from the tank to the brush, so that the brush is impregnated with the fluorescent liquid, and a coating is formed on the heat exchange plate 10 by the brush. With such a configuration, a refilling operation is not required, and therefore further time saving can be achieved.

[0053] Further, although the coating formation is shared by two robot arms 30, the present invention is not limited to such a method, and the coating formation may be shared by three or more robot arms.

[0054] Furthermore, the film formation by the two robot arms 30 is not limited to the above-mentioned division of labor. For example, one surface to which the fluorescent liquid is applied may be divided into areas equal to the number of robot arms, and each robot arm may form a film in each of the divided areas. [Explanation of symbols]

[0055] REFERENCE SIGNS LIST 1...maintenance system, 2...fluorescent liquid, 3...first coating, 4...second coating, 5...third coating, 6...fluorescent portion, 10, 10a, 10b...heat exchange plate, 11...heat exchange portion, 12...groove portion, 15...penetration defect portion, 20...transport device, 30...robot arm, 31...first robot arm, 32...second robot arm, 33...third robot arm, 34...brush, 35...first brush, 36...second brush, 37...gripping hand, 40...control device, 50...heat exchange plate sensor, 60...line sensor, 61...monitor, 70...image

Claims

1. A coating process for forming a coating made of a fluorescent liquid on one surface of a heat exchange plate of a plate-type heat exchanger; and an inspection step of irradiating the other surface of the heat exchange plate with ultraviolet light and determining that a penetration defect has occurred at a location where fluorescence is confirmed. The coating forming step is performed by forming the coating on the heat exchange plate in two steps, In the first step, a first coating made of a fluorescent liquid is formed at intervals at a plurality of locations on the one surface. 、 In a second step, the first coating is extended to form a second coating that covers the entire one surface. A maintenance method for a heat exchange plate of a plate heat exchanger.

2. A coating process for forming a coating made of a fluorescent liquid on one surface of a heat exchange plate of a plate-type heat exchanger; and an inspection step of irradiating the other surface of the heat exchange plate with ultraviolet light and determining that a penetration defect has occurred at a location where fluorescence is confirmed. The heat exchange plate has a groove in which a gasket is attached, The coating forming step is performed by forming the coating on the heat exchange plate in two steps, In the first step, a first coating made of a fluorescent liquid is formed at intervals at a plurality of locations on the one surface. 、 In a second step, the first coating is extended to form a second coating that covers the entire one surface. At the same time, a third coating made of a fluorescent liquid is formed in the groove portion. A maintenance method for a heat exchange plate of a plate heat exchanger.

3. A plurality of robot arms for forming a coating of a fluorescent liquid on one surface of a heat exchange plate of a plate-type heat exchanger; a conveying device that conveys the heat exchange plate to the robot arm and conveys the heat exchange plate on which the coating has been formed to the next robot arm; and an inspection means for irradiating the other surface of the heat exchange plate with ultraviolet light and determining that a penetration defect has occurred at a location where fluorescence is confirmed, The plurality of robot arms are two robot arms, a first robot arm and a second robot arm, the first robot arm forms a first coating made of a fluorescent liquid at a plurality of locations on the one surface at intervals; A second robot arm extends the first coating to form a second coating that covers the entire one side. A maintenance system for heat exchange plates of a plate heat exchanger.

4. A plurality of robot arms for forming a coating of a fluorescent liquid on one surface of a heat exchange plate of a plate-type heat exchanger; a conveying device that conveys the heat exchange plate to the robot arm and conveys the heat exchange plate on which the coating has been formed to the next robot arm; and an inspection means for irradiating the other surface of the heat exchange plate with ultraviolet light and determining that a penetration defect has occurred at a location where fluorescence is confirmed, The heat exchange plate has a groove in which a gasket is attached, The plurality of robot arms are two robot arms, a first robot arm and a second robot arm, the first robot arm forms a first coating made of a fluorescent liquid at a plurality of locations on the one surface at intervals; The second robot arm extends the first coating to form a second coating that covers the entire one surface, and forms a third coating made of a fluorescent liquid in the groove. A maintenance system for heat exchange plates of a plate heat exchanger.

5. A plurality of robot arms for forming a coating of a fluorescent liquid on one surface of a heat exchange plate of a plate type heat exchanger; a conveying device that conveys the heat exchange plate to the robot arm and conveys the heat exchange plate on which the coating has been formed to the next robot arm; and an inspection means for irradiating the other surface of the heat exchange plate with ultraviolet light and determining that a penetration defect has occurred at a location where fluorescence is confirmed, The heat exchange plate has a groove in which a gasket is attached, The plurality of robot arms are two robot arms, a first robot arm and a second robot arm, a first robot arm forming a first coating made of a fluorescent liquid at intervals in a plurality of locations on the one surface and forming a part of a third coating made of a fluorescent liquid in the groove portion; The second robot arm extends the first coating to form a second coating that covers the entire one side and forms a remainder of the third coating. A maintenance system for heat exchange plates of a plate heat exchanger.

6. The maintenance system for heat exchange plates of a plate heat exchanger according to claim 4, The heat exchange plate has the groove in which the gasket is attached, The second robot arm is A brush for forming the second coating and a brush for forming the third coating are provided, The fluorescent liquid is applied with the brush to form the second coating and the third coating. A maintenance system for heat exchange plates of a plate heat exchanger.

7. The maintenance system for the heat exchanger plates of the plate heat exchanger according to any one of claims 3 to 6, A heat exchange plate determination unit that determines the type of the heat exchange plate having a plurality of different shapes; a coating formation control unit that selects a coating pattern set according to the type of the heat exchange plate and causes the robot arm to form a coating based on the pattern. A maintenance system for heat exchange plates of a plate heat exchanger.

8. The maintenance system for the heat exchanger plates of the plate heat exchanger according to any one of claims 3 to 5, A container for storing a fluorescent liquid is provided, the robot arm has a brush, and after dipping the brush in the fluorescent liquid in the container, moves the brush over one surface of the heat exchange plate to form the coating; Furthermore, the brush is dipped into the fluorescent liquid in the container once for each heat exchange plate, and the coating is formed by the brush. A maintenance system for heat exchange plates of a plate heat exchanger.

9. The maintenance system for the heat exchanger plates of the plate heat exchanger according to any one of claims 3 to 5, the robot arm includes a brush, a container for storing a fluorescent liquid, and a liquid delivery means for delivering the fluorescent liquid from the container to the brush; The fluorescent liquid is delivered from the container to the brush to impregnate the brush with the fluorescent liquid, and the coating is formed by moving the brush over one surface of the heat exchange plate. A maintenance system for heat exchange plates of a plate heat exchanger.

10. The maintenance system for the heat exchanger plates of the plate heat exchanger according to any one of claims 3 to 6, The inspection means includes: a line sensor that forms an image on the other surface of the heat exchange plate; and a through-hole defect determination unit that determines that the through-hole defect occurs at a location where the fluorescence reflected in the image is confirmed by image processing. A maintenance system for heat exchange plates of a plate heat exchanger.

Images