Directional parallel sand blasting device suitable for inner surface of whole heat exchange tube of shell-and-tube heat exchanger

Abstract

The invention relates to a directional parallel sand blasting device suitable for the inner surface of a whole heat exchange tube of a shell-and-tube heat exchanger. The directional parallel sand blasting device comprises a nut, a long positioning device, a short positioning device and an elastic positioning device, the elastic positioning device is inserted into a tube hole formed after the heat exchange tube and the tube plate are welded, and a protruding shoulder of the elastic positioning device is tightly attached to the welding position of the heat exchange tube and the tube plate. The plane where the shoulder of the elastic positioning device is located is perpendicular to the pipe length direction of the heat exchange pipe so as to guide the sand blasting direction after the sand blasting gun is inserted to be parallel to the pipe length direction. According to the device, sand grains can be sprayed in parallel in the pipe length direction, the situation that the sand grains diverge in the spraying process, and consequently pipe wall treatment is uneven is avoided, the treatment efficiency and uniformity are improved, and energy consumption is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of pipeline inner wall treatment equipment, and specifically to a directional parallel sandblasting device suitable for the inner surface of the heat exchange tube of a shell and tube heat exchanger. The device is particularly suitable for cleaning, rust removal and coating pretreatment of the inner wall of a long straight tubular workpiece (such as a heat exchange tube), and can realize directional parallel spraying of sand particles along the length of the tube. Background Art

[0002] During the manufacturing and maintenance of shell-and-tube heat exchangers, the cleanliness and roughness of the inner surface of the heat exchange tubes directly impact heat transfer efficiency and coating adhesion. Sand particles from traditional sandblasting guns tend to disperse during blasting, resulting in energy dispersion, low processing efficiency, and difficulty accurately covering narrow or long tubular workpieces. While existing technologies have improved concentration by shrinking the nozzle or increasing air pressure, the following issues remain:

[0003] 1. Sand flow diffusion leads to uneven pipe wall treatment;

[0004] 2. High air pressure increases energy consumption and abrasive loss;

[0005] 3. It is difficult to achieve full-section synchronous processing of the inner wall of a complex pipeline.

[0006] In the prior art, for example, patent document (CN116276679A) discloses an automatic centered fixed sandblasting gun, which is fixed in the center by an elastic sleeve, but does not solve the problem of directional parallel injection of sand particles, and the sand flow is still divergent; patent document (CN118204917A) designs an automatic sandblasting device for oil pipe couplings, which relies on a rotating mechanism to achieve uniformity, but is not suitable for directional processing of long straight pipes, and has a complex structure, making it difficult to adapt to the dense heat exchange tube layout of the heat exchanger.

[0007] Therefore, there is an urgent need for a device that can direct and guide sand particles to be ejected in parallel. Summary of the Invention

[0008] The purpose of the present invention is to provide a directional parallel sandblasting device suitable for the inner surface of the heat exchange tube of a shell and tube heat exchanger. It is used to solve the problem that when sandblasting the shell and tube heat exchanger, the welding position of the heat exchange tube and the tube sheet is uneven, resulting in the sandblasting gun being inserted into the tube hole for sandblasting. The device can realize the parallel spraying of sand particles along the length of the tube, avoiding the divergence of sand particles during the spraying process, resulting in uneven treatment of the tube wall.

[0009] To achieve the above-mentioned purpose, the technical solution of the present invention is: a device for directional parallel sandblasting of the inner surface of the heat exchange tube of a shell and tube heat exchanger, comprising a nut, a long positioning device, a short positioning device and an elastic positioning device; the elastic positioning device is inserted into the tube hole after the heat exchange tube is welded to the tube sheet, and the boss of the elastic positioning device is in close contact with the welding position of the heat exchange tube and the tube sheet; the plane where the boss of the elastic positioning device is located is perpendicular to the long direction of the heat exchange tube, so as to guide the sandblasting direction after the sandblasting gun is inserted to be parallel to the long direction of the tube.

[0010] Furthermore, the long positioning device and the short positioning device are assembled in the elastic positioning device.

[0011] Furthermore, the short positioning device is sleeved on the upper screw of the long positioning device, and the nut is screwed into the screw and drives the long positioning device and the short positioning device to push the elastic positioning device through the tightening force, so that the elastic positioning device expands outward and fits tightly against the inner wall of the heat exchange tube.

[0012] Furthermore, the magnitude of the expansion force between the elastic positioning device and the weld is achieved by adjusting the pre-tightening force of the nut.

[0013] Furthermore, a boss is provided at the upper end of the elastic positioning device, and the boss is pressed between the weld and the nut to provide positioning for the sandblasting gun.

[0014] Furthermore, the elastic positioning device is an open ring structure, the lower part of which is provided with at least three open grooves along the circumferential direction, and the upper part of the open grooves is provided with three fins, which have a taper larger at the top and smaller at the bottom, and are used to fit with the inner wall of the heat exchange tube.

[0015] Furthermore, the long positioning device is a hollow structure with a gravel circulation area inside; the upper portion of the long positioning device is provided with an external thread, and the lower portion is a conical structure.

[0016] Furthermore, the taper of the conical structure is consistent with the taper of the inner wall of the elastic positioning device.

[0017] Furthermore, the outer surface of the short positioning device is a conical surface, and a through hole is opened in the center of the short positioning device. The diameter of the through hole is 0.5 to 1 mm larger than the diameter of the upper screw of the long positioning device.

[0018] Furthermore, the taper of the conical surface of the short positioning device is consistent with the taper of the inner wall of the elastic positioning device.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention provides a sandblasting device that can control the parallel injection of sand particles along the length of the pipe. The device can realize the parallel injection of sand particles along the length of the pipe, avoid the divergence of sand particles during the injection process, and cause uneven treatment of the pipe wall, thereby improving treatment efficiency and uniformity and reducing energy consumption.

[0021] (1) The directional accuracy is significantly improved: through the boss positioning and taper coordination of the elastic positioning device, the angle between the sandblasting direction and the tube length direction can be controlled, which improves the uniformity of the roughness of the inner wall of the heat exchange tube.

[0022] (2) Improved processing efficiency: The directional parallel injection of sand particles concentrates the energy, shortens the single-tube processing time, and can be adapted to multiple parallel heat exchange tubes at the same time, thereby improving batch processing efficiency.

[0023] (3) Reduced energy consumption and loss: The processing requirements can be met at low air pressure, which reduces energy consumption and abrasive loss rate.

[0024] (4) Strong adaptability: By adjusting the nut pre-tightening force, it can adapt to heat exchange tubes of different specifications. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the structure of the directional parallel sandblasting device for the inner surface of the heat exchange tube of the shell and tube heat exchanger of the present invention;

[0026] Figure 2 is a schematic diagram of an elastic positioning device;

[0027] In the figure: 1-tube sheet; 2-nut; 3-long positioning device; 4-short positioning device; 5-elastic positioning device; 6-heat exchange tube. DETAILED DESCRIPTION

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0029] like Figure 1 As shown, an embodiment of the present invention provides a directional parallel sandblasting device suitable for the inner surface of the heat exchange tube of a shell and tube heat exchanger, including a tube plate 1, a nut 2, a long positioning device 3, a short positioning device 4, an elastic positioning device 5, and a heat exchange tube 6.

[0030] like Figure 1 As shown, the elastic positioning device 5 is inserted into the tube hole after the heat exchange tube 6 is welded to the tube sheet 1, and the convex shoulder of the elastic positioning device 5 is in close contact with the weld. The long positioning device 3 and the short positioning device 4 are installed in the elastic positioning device 5, and the short positioning device 4 is sleeved on the upper screw of the positioning device 3. The nut 2 is screwed into the screw. By tightening the nut 2, the long positioning device 3 and the short positioning device 4 push the elastic positioning device 5 to expand outward, and the diameter becomes larger, so that the elastic positioning device 5 is in close contact with the inner wall of the heat exchange tube 6, playing a positioning role, so that the plane where the convex shoulder of the elastic positioning device is located is perpendicular to the long direction of the heat exchange tube, which is conducive to the sandblasting direction being parallel to the long direction of the tube after the sandblasting gun is inserted.

[0031] like Figure 2As shown, the elastic positioning device 5 has a shoulder at its top end, which presses between the weld and the nut to provide positioning for the sandblasting gun. The elastic positioning device 5 is an open ring with three circumferential slots at its bottom. The three fins above the slots are used to align with the interior of the heat exchange tube and have a certain taper, with a larger top and a smaller bottom.

[0032] The long positioning device 3 is a hollow structure with a gravel circulation area inside. The upper part is threaded and covered with a nut, and the lower part has a larger diameter and a conical structure with the same taper as the elastic positioning device.

[0033] The outer surface of the short positioning device 4 is a conical surface, the taper of which is consistent with that of the elastic positioning device, and the center is a hole with a diameter slightly larger than the thread diameter of the long positioning device.

[0034] The magnitude of the expansion force between the elastic positioning device 5 and the weld can be achieved by adjusting the pre-tightening force of the nut.

[0035] The present invention effectively solves the core problem of sandblasting the inner surface of the heat exchange tube of a shell and tube heat exchanger through precise positioning and directional guidance, and has significant economic benefits and application value.

Claims

1. A directional parallel sandblasting device suitable for the inner surface of the heat exchange tube of a shell and tube heat exchanger, characterized in that: It includes a nut, a long positioning device, a short positioning device and an elastic positioning device; the elastic positioning device is inserted into the tube hole after the heat exchange tube is welded to the tube sheet, and the boss of the elastic positioning device is tightly attached to the welding position of the heat exchange tube and the tube sheet; the plane where the boss of the elastic positioning device is located is perpendicular to the long direction of the heat exchange tube, so as to guide the sandblasting direction of the sandblasting gun after insertion to be parallel to the long direction of the tube.

2. The directional parallel sandblasting device for the inner surface of the heat exchange tube of the shell and tube heat exchanger according to claim 1 is characterized in that: The long positioning device and the short positioning device are assembled in the elastic positioning device.

3. The directional parallel sandblasting device for the inner surface of the heat exchange tube of the shell and tube heat exchanger according to claim 2 is characterized in that: The short positioning device is sleeved on the upper screw of the long positioning device, and the nut is screwed into the screw and drives the long positioning device and the short positioning device to push the elastic positioning device through the tightening force, so that the elastic positioning device expands outward and fits tightly against the inner wall of the heat exchange tube.

4. The directional parallel sandblasting device for the inner surface of the heat exchange tube of the shell and tube heat exchanger according to claim 1 is characterized in that: The magnitude of the expansion force between the elastic positioning device and the weld is achieved by adjusting the pre-tightening force of the nut.

5. The directional parallel sandblasting device for the inner surface of the heat exchange tube of the shell and tube heat exchanger according to claim 1 is characterized in that: The upper end of the elastic positioning device is provided with a convex shoulder, which is pressed between the weld and the nut to provide positioning for the sandblasting gun.

6. The directional parallel sandblasting device for the inner surface of the heat exchange tube of the shell and tube heat exchanger according to claim 4 is characterized in that: The elastic positioning device is an open ring structure, with at least three open grooves opened in the circumferential direction at the lower part, and three fins are provided on the upper part of the open grooves. The fins have a taper with a larger upper part and a smaller lower part, and are used to fit the inner wall of the heat exchange tube.

7. The directional parallel sandblasting device for the inner surface of the heat exchange tube of a shell and tube heat exchanger according to claim 1 is characterized in that: The long positioning device is a hollow structure with a gravel circulation area inside. The upper part of the long positioning device is provided with an external thread, and the lower part is a conical structure.

8. The directional parallel sandblasting device for the inner surface of the heat exchange tube of a shell and tube heat exchanger according to claim 7 is characterized in that: The taper of the conical structure is consistent with the taper of the inner wall of the elastic positioning device.

9. The directional parallel sandblasting device for the inner surface of the heat exchange tube of a shell and tube heat exchanger according to claim 1 is characterized in that: The outer surface of the short positioning device is a conical surface. A through hole is opened in the center of the short positioning device. The diameter of the through hole is 0.5 to 1 mm larger than the diameter of the upper screw of the long positioning device.

10. The directional parallel sandblasting device for the inner surface of the heat exchange tube of the shell and tube heat exchanger according to claim 9, characterized in that: The taper of the conical surface of the short positioning device is consistent with the taper of the inner wall of the elastic positioning device.

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