A leak testing device for a shell-and-tube heat exchanger

Abstract

The application relates to the technical field of heat exchanger detection, in particular to a column-tube heat exchanger leak detection device, which comprises a semi-open detection cabin body, an air inlet pipeline, a sealing cover plate, a moving frame, a collection plate and a fluorescent dyeing assembly, the air inlet pipeline is rotationally connected to one side of the top of the semi-open detection cabin body, the moving frame is slidingly connected to the inside of the semi-open detection cabin body, and the collection plate is screwedly connected to the outside of the moving frame. The column-tube heat exchanger leak detection device is sensitive to trace leakage by integrating the fluorescent dyeing assembly and the optical sensor, replaces the traditional manual observation of soap bubbles or the pressure gauge mode, and significantly improves the automation degree and reliability of detection. The coating spray head driven by the stepping motor can be accurately moved along the transverse support, cooperates with the square array collection plate, can perform full-coverage scanning on the column tube, the optical sensor can immediately lock the leakage point position once leakage occurs, and the positioning difficulty problem is solved.

Description

Technical Field

[0001] This application relates to the field of heat exchanger testing technology, and in particular to a leak testing device for shell and tube heat exchangers. Background Technology

[0002] Shell-and-tube heat exchangers are the most widely used type of heat exchanger in chemical and alcohol production. They mainly consist of a shell, tube sheet, heat exchange tubes, end caps, and baffles. The required materials can be ordinary carbon steel, copper, or stainless steel. During heat exchange, one fluid enters through the connecting pipe of the end cap, flows in the tube, and exits through the outlet pipe at the other end of the end cap; this is called the tube side. The other fluid enters through the connecting pipe on the shell and exits through another connecting pipe on the shell; this is called the shell side. If a shell-and-tube heat exchanger leaks, it is necessary to identify which tube(s) in the heat exchanger has a crack that is causing the medium leakage.

[0003] Chinese utility model patent CN204202821U discloses a leak testing device for a shell-and-tube heat exchanger. The device includes a shell composed of a long cylinder and a short cylinder connected by a central connecting flange. The long cylinder has a small-end connecting flange at its outer end, and the short cylinder has a large-end connecting flange at its outer end. The large-end connecting flange is connected to the large-end tube sheet of the heat exchanger, while the small-end connecting flange houses the small-end tube sheet. A loose flange is connected to the outer end of the small-end connecting flange, and a blind flange is located in the middle of the loose flange, connecting to the small-end tube sheet. The long cylinder wall is fitted with a toothed joint with a ball valve, and graphite gaskets are used at each flange connection to form a sealing structure. This device can test all heat exchange tubes for leaks in one operation, saving time and effort.

[0004] Regarding the aforementioned technologies, the inventors believe that the following technical shortcomings exist that require improvement: Traditional leak testing methods, such as hydrostatic testing and soap bubble testing, generally suffer from inherent defects such as low sensitivity, difficulty in localization, and insufficient automation. Although some advanced leak detection technologies possess high sensitivity, their operation is complex, time-consuming, and the equipment cost is high, making them difficult to widely apply in industrial settings. Utility Model Content

[0005] This application provides a leak testing device for shell-and-tube heat exchangers to address the following technical problems: Traditional leak testing methods, such as hydrostatic testing and soap bubble testing, generally suffer from inherent defects such as low sensitivity, difficulty in locating leaks, and insufficient automation. Although some advanced leak detection technologies possess high sensitivity, their operation is complex, time-consuming, and the equipment cost is high, making them difficult to widely apply in industrial settings.

[0006] This application provides a leak testing device for a shell-and-tube heat exchanger, employing the following technical solution:

[0007] A leak testing device for a shell-and-tube heat exchanger includes a semi-open testing chamber, an air inlet pipe, a sealing cover, a movable frame, a collection plate, and a fluorescent staining assembly. The air inlet pipe is rotatably connected to the top side of the semi-open testing chamber, the movable frame is slidably connected to the inside of the semi-open testing chamber, the collection plate is threaded to the outside of the movable frame, the sealing cover is rotatably connected to the side of the semi-open testing chamber near the movable frame, and the fluorescent staining assembly is installed inside the semi-open testing chamber.

[0008] In one feasible technical solution of this application, the fluorescent dyeing assembly includes a transverse support, an in-chamber sliding frame, a stepper motor, a drive shaft, a transmission gear, a paint nozzle, and a material delivery hose. The transverse support is fixedly connected to the inner side of the semi-open detection chamber and is disposed above the movable frame. The in-chamber sliding frame is slidably sleeved on the outer side of the transverse support. The stepper motor is threadedly connected to one side of the in-chamber sliding frame, and the output end of the stepper motor is fixedly connected to one end of the drive shaft via a coupling. The transmission gear is fixedly connected to the outer side of the drive shaft. The paint nozzle is fixedly connected to the outer side of the in-chamber sliding frame, and the material delivery hose is fixedly connected to the outer side of the inlet end of the paint nozzle.

[0009] In one feasible technical solution of this application, the semi-open detection chamber is further provided with several sets of equally spaced optical sensors on the side near the acquisition plate.

[0010] In one feasible technical solution of this application, the connection between the movable frame and the semi-open detection chamber is further provided with movable slide rails and sliders of mutually adapted size.

[0011] In one feasible technical solution of this application, a limiting groove is also provided on the top of the movable frame, and the width of the limiting groove is greater than the outer diameter of the air intake pipe.

[0012] In one feasible technical solution of this application, the paint nozzles are provided in two sets, and the two sets of paint nozzles are staggered inside the semi-open detection chamber, and the outer surface of the paint nozzles does not contact the surface of the acquisition plate in the moving state.

[0013] In one feasible technical solution of this application, the transverse support is further provided with a rack seat that meshes with the external teeth of the transmission gear.

[0014] In one feasible technical solution of this application, the acquisition board is provided in four sets, and the four sets of acquisition boards are arranged in a square array inside the semi-open detection chamber.

[0015] In summary, this application includes at least one of the following beneficial technical effects:

[0016] This device integrates fluorescent staining components and optical sensors to achieve a sensitive response to minute leaks, replacing the traditional method of manually observing soap bubbles or pressure gauges, significantly improving the automation and reliability of detection. The paint nozzle, driven by a stepper motor, can move precisely along the transverse support. Combined with a square array of acquisition plates, it can perform full coverage and point-by-point scanning of the tube array. Once a leak occurs, the optical sensor can immediately pinpoint the leak location, fundamentally solving the problems of difficult and time-consuming location issues associated with traditional methods. Furthermore, the device employs a semi-open chamber and movable frame design, facilitating the clamping and detection of heat exchangers. Its overall structure is compact, the equipment cost is controllable, and the operation process is simplified, overcoming the drawbacks of some high-sensitivity leak detection technologies that are expensive, complex to operate, and difficult to promote in industrial settings. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of the shell-and-tube heat exchanger leak testing device according to an embodiment of this application.

[0019] Figure 2 This is a distribution diagram of the acquisition board in the embodiments of this application.

[0020] Figure 3 This is a distribution diagram of the optical sensors in the embodiments of this application.

[0021] Figure 4 This is a cross-sectional view of the semi-open detection chamber in an embodiment of this application.

[0022] Figure 5 This is an exploded view of the fluorescent staining component in an embodiment of this application.

[0023] Explanation of reference numerals in the attached figures:

[0024] 1. Semi-open detection chamber; 2. Air inlet pipe; 3. Sealing cover; 4. Moving frame; 5. Data acquisition plate;

[0025] 6. Fluorescent dyeing assembly; 61. Horizontal support; 62. In-chamber sliding frame; 63. Stepper motor; 64. Drive shaft; 65. Transmission gear; 66. Paint nozzle; 67. Material delivery hose;

[0026] 7. Optical sensor; 8. Sliding rail; 9. Slider; 10. Limiting groove; 11. Rack and pinion seat. Detailed Implementation

[0027] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0028] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0029] The following is in conjunction with the appendix Figure 1-5 This application will be described in further detail.

[0030] This application discloses a leak testing device for a shell-and-tube heat exchanger. (Refer to...) Figures 1 to 5 The tube-and-shell heat exchanger leak test device includes a semi-open test chamber 1, an air inlet pipe 2, a sealing cover 3, a moving frame 4, a collection plate 5, and a fluorescent staining assembly 6. The air inlet pipe 2 is rotatably connected to the top side of the semi-open test chamber 1, the moving frame 4 is slidably connected to the inside of the semi-open test chamber 1, the collection plate 5 is threadedly connected to the outside of the moving frame 4, the sealing cover 3 is rotatably connected to the side of the semi-open test chamber 1 near the moving frame 4, and the fluorescent staining assembly 6 is installed inside the semi-open test chamber 1.

[0031] The fluorescent staining assembly 6 includes a transverse support 61, an in-chamber sliding frame 62, a stepper motor 63, a drive shaft 64, a transmission gear 65, a paint nozzle 66, and a material delivery hose 67. The transverse support 61 is fixedly connected to the inside of the semi-open detection chamber 1 and is positioned above the movable frame 4. The in-chamber sliding frame 62 is slidably sleeved on the outside of the transverse support 61. The stepper motor 63 is threadedly connected to one side of the in-chamber sliding frame 62, and the output end of the stepper motor 63 is fixedly connected to one end of the drive shaft 64 via a coupling. The transmission gear 65 is fixedly connected to the outside of the drive shaft 64. The paint nozzle 66 is fixedly connected to the outside of the in-chamber sliding frame 62, and the material delivery hose 67 is fixedly connected to the outside of the inlet end of the paint nozzle 66.

[0032] At the start of the test, guided by the sliding rails 8 and sliders 9, the moving frame 4 smoothly moves the four sets of collection plates 5 arranged in a square array on its outer side within the chamber. Simultaneously, the fluorescent dyeing assembly 6 is activated, its stepper motor 63 engaging with the rack and pinion seat 11 via the drive transmission gear 65, driving the sliding frame 62 within the chamber to move laterally along the transverse support 61. Two sets of staggered paint nozzles 66, fixed to the sliding frame, deliver fluorescent dye through the conveying hoses 67, providing a full-coverage, non-contact, uniform spray onto the surface of the collection plates 5 or heat exchanger tubes passing below.

[0033] Several sets of equally spaced optical sensors 7 are also installed on the side of the semi-open detection chamber 1 near the acquisition plate 5.

[0034] If a leak is found in the tube being tested, under internal pressure, the leaking medium will carry fluorescent dye and be specifically captured by the acquisition plate 5 directly above it, or a visible fluorescent trace will form nearby.

[0035] The connection between the movable frame 4 and the semi-open detection chamber 1 is also equipped with movable slide rails 8 and sliders 9 of mutually compatible sizes.

[0036] The top of the movable frame 4 is also provided with a limiting groove 10, the width of which is greater than the outer diameter of the air intake pipe 2.

[0037] There are two sets of paint nozzles 66, and the two sets of paint nozzles 66 are staggered inside the semi-open detection chamber 1, and the outer surface of the paint nozzles 66 does not contact the surface of the collection plate 5 in the moving state.

[0038] Optical sensors 7, pre-arranged at equal intervals inside the semi-open detection chamber 1, monitor the scanning area in real time. Once a specific fluorescent signal generated by the leak point is detected, the system immediately combines the real-time coordinates of the moving frame 4 and the paint spray nozzle 66 to achieve precise location of the leak point.

[0039] The transverse support 61 also has a rack seat 11 that meshes with the external teeth of the transmission gear 65.

[0040] There are four sets of acquisition plates 5, and the four sets of acquisition plates 5 are arranged in a square array inside the semi-open detection chamber 1.

[0041] The usage process of the shell-and-tube heat exchanger leak testing device in this application embodiment is roughly as follows:

[0042] Rotate to open the sealing cover 3, place the shell-and-tube heat exchanger to be tested on the moving frame 4, and use the limiting groove 10 on its top for initial positioning to ensure smooth connection of the air inlet pipe 2; close the sealing cover 3 to ensure the airtightness of the semi-open testing chamber 1. Start the device, and the moving frame 4 slides smoothly in the chamber through the moving slide rail 8 and the slider 9, driving the four sets of collection plates 5 arranged in a square array on its outer side to scan the surface of the heat exchanger. Simultaneously, the fluorescent dyeing component 6 starts working. The stepper motor 63 starts, driving the transmission gear 65 to rotate through the drive shaft 64, which meshes with the rack seat 11 fixed inside the transverse support 61, thereby driving the sliding frame 62 inside the chamber to move laterally along the transverse support 61. The two sets of staggered paint nozzles 66 fixed on the sliding frame 62 inside the chamber receive fluorescent dye through the conveying hose 67 and spray it evenly and non-contactly onto the collection plates 5 or the surface of the heat exchanger tubes that move below. If a leak is detected, the leaking medium containing fluorescent dye will be captured by the acquisition plate 5 or traced nearby. Several sets of optical sensors 7, arranged inside the semi-open detection chamber 1 and close to the acquisition plate 5, will monitor and identify the fluorescent signal in real time. Based on the sensor signals and the real-time position information of the moving frame 4 and the spraying components, the system can accurately determine the specific location of the leak. The entire process integrates clamping, scanning, spraying, detection, and positioning, with a high degree of automation and accurate positioning, making it suitable for the rapid and highly sensitive leak testing needs in industrial settings.

[0043] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A leak testing device for a shell-and-tube heat exchanger, characterized in that, The device includes a semi-open detection chamber (1), an air inlet pipe (2), a sealing cover (3), a moving frame (4), a collection plate (5), and a fluorescent staining assembly (6). The air inlet pipe (2) is rotatably connected to the top side of the semi-open detection chamber (1). The moving frame (4) is slidably connected to the inside of the semi-open detection chamber (1). The collection plate (5) is threadedly connected to the outside of the moving frame (4). The sealing cover (3) is rotatably connected to the side of the semi-open detection chamber (1) near the moving frame (4). The fluorescent staining assembly (6) is installed inside the semi-open detection chamber (1).

2. The leak testing device for a shell-and-tube heat exchanger according to claim 1, characterized in that, The fluorescent staining assembly (6) includes a transverse support (61), an in-chamber sliding frame (62), a stepper motor (63), a drive shaft (64), a transmission gear (65), a paint nozzle (66), and a material delivery hose (67). The transverse support (61) is fixedly connected to the inner side of the semi-open detection chamber (1) and is positioned above the movable frame (4). The in-chamber sliding frame (62) is slidably sleeved on the outer side of the transverse support (61). The stepper motor (63) is threadedly connected to one side of the in-chamber sliding frame (62), and the output end of the stepper motor (63) is fixedly connected to one end of the drive shaft (64) via a coupling. The transmission gear (65) is fixedly connected to the outer side of the drive shaft (64). The paint nozzle (66) is fixedly connected to the outer side of the in-chamber sliding frame (62), and the material delivery hose (67) is fixedly connected to the outer side of the feed end of the paint nozzle (66).

3. The leak testing device for a shell-and-tube heat exchanger according to claim 1, characterized in that, The semi-open detection chamber (1) is also provided with several sets of equally spaced optical sensors (7) on the side near the acquisition plate (5).

4. The leak testing device for a shell-and-tube heat exchanger according to claim 1, characterized in that, The connection between the movable frame (4) and the semi-open detection chamber (1) is also provided with movable slide rails (8) and sliders (9) of mutually compatible sizes.

5. The leak testing device for a shell-and-tube heat exchanger according to claim 1, characterized in that, The top of the movable frame (4) is also provided with a limiting groove (10), the width of which is greater than the outer diameter of the air intake pipe (2).

6. The leak testing device for a shell-and-tube heat exchanger according to claim 2, characterized in that, The paint nozzles (66) are provided in two sets, and the two sets of paint nozzles (66) are staggered inside the semi-open detection chamber (1), and the outer surface of the paint nozzles (66) does not contact the surface of the collection plate (5) in the moving state.

7. The leak testing device for a shell-and-tube heat exchanger according to claim 2, characterized in that, The transverse support (61) is also provided with a rack seat (11) that meshes with the external teeth of the transmission gear (65).

8. The leak testing device for a shell-and-tube heat exchanger according to claim 1, characterized in that, The acquisition board (5) is provided in four sets, and the four sets of acquisition boards (5) are arranged in a square array inside the semi-open detection chamber (1).

Images