A tube heat exchanger tube cutting tool

Abstract

The application discloses a cutting tool in a tube of a tube heat exchanger and relates to the technical field of the tube heat exchanger.The cutting tool comprises a cutter head, a mounting rod and a driving rod.The cutter head comprises two identical cutter head rotating blocks, and the two cutter head rotating blocks are rotationally installed at one end of the mounting rod.A cutting blade is arranged on the side of the cutter head rotating block away from the other cutter head rotating block, the cutting blade is located at the end of the cutter head rotating block away from the mounting rod, and the cutting blade is arranged along the axis direction of the mounting rod.A butt joint protrusion is arranged on the side of the cutter head rotating block close to the other cutter head rotating block, and the butt joint protrusion is located at the end of the cutter head rotating block away from the mounting rod.The driving rod is slidably arranged along the axis of the mounting rod and penetrates through the mounting rod, a driving block is arranged at the end of the driving rod close to the cutter head rotating block, and the driving block is located between the two cutter head rotating blocks and between the butt joint protrusion and the mounting rod.The application can cut the damaged heat exchange tube, thereby eliminating the expansion force suffered by the heat exchange tube and enabling the heat exchange tube to be removed and replaced.

Description

Technical Field

[0001] This application relates to the technical field of tubular heat exchangers, and in particular to an in-tube cutting tool for tubular heat exchangers. Background Technology

[0002] Finned-tube heat exchangers are one of the earliest and most successful discoveries in improving tube heat exchangers, and this method remains the most widely used among all methods for enhancing heat transfer in tube heat exchange surfaces. It is widely used not only in single-finned-tube heat exchangers in power, chemical, petrochemical, air conditioning, and refrigeration engineering, but also in other applications. In finned-tube heat exchangers, fluids with higher heat transfer coefficients flow inside the tubes, while fluids with lower heat transfer coefficients flow outside. The tubes have numerous fins on the outside to mitigate the imbalance of thermal conductivity on both sides. Heat transfer between the hot and cold fluids occurs through conduction through the tube walls.

[0003] There are various ways to connect the fins and heat exchange tubes of a finned tube heat exchanger, such as expansion joint, welding, and brazing. The fins can be single fins or continuous fins. Among them, the finned tube heat exchanger with continuous fins (hereinafter referred to as the finned heat exchanger) is the most widely used in compact heat exchangers.

[0004] However, one difficulty in the application of finned heat exchangers is that when a single heat exchange tube breaks, the tube and fins are "expanded" together, and the adhesion at the expansion joint is extremely strong, making it difficult to pull out the broken tube. The only solution is to plug the tube. However, when a certain number of tubes are plugged, the performance of the heat exchanger cannot meet the requirements, which means that the heat exchanger must be replaced, greatly shortening its service life. Utility Model Content

[0005] This application proposes an internal cutting tool for tubular heat exchangers, which can cut the heat exchange tubes, thereby eliminating the expansion force of damaged heat exchange tubes, allowing the damaged heat exchange tubes to be replaced, thus making the heat exchanger repairable and extending its service life.

[0006] This application provides an in-tube cutting tool for tubular heat exchangers, employing the following technical solution: A tube-to-tube cutting tool for a tubular heat exchanger includes a cutting head, a mounting rod, and a drive rod. The cutting head includes two identical rotating blocks, both of which are rotatably mounted on one end of the mounting rod. A cutting blade is provided on the side of the rotating block away from the other rotating block, and the cutting blade is located at the end of the rotating block away from the mounting rod. The cutting blade is arranged along the axial direction of the mounting rod. The rotating blade block has an abutment protrusion on one side near the other rotating blade block, and the abutment protrusion is located at the end of the rotating blade block away from the mounting rod; the drive rod is slidably disposed along the axis of the mounting rod and passes through the mounting rod, and a drive block is disposed at the end of the drive rod near the rotating blade block, the drive block being located between the two rotating blade blocks and between the abutment protrusion and the mounting rod; the drive block lifts the end of the rotating blade block away from the mounting rod so that the cutting blade contacts the heat exchange tube wall.

[0007] By adopting the above technical solution, during use, the cutter head and mounting rod are inserted into the heat exchange tube. The drive rod slides on the mounting rod towards the cutter head, and the drive block moves towards the direction of the rotating block of the cutter head. After the drive block abuts against the abutting protrusion, it lifts the end of the two rotating blocks of the cutter head away from the mounting rod, causing the end of the rotating blocks away from the mounting rod to rotate towards the heat exchange tube wall, so that the cutting blade contacts the tube wall. Then, the entire cutter is rotated to cut the inner wall of the heat exchange tube, which increases the inner diameter of the heat exchange tube at the cut, thins the heat exchange tube wall, reduces its load-bearing cross-sectional size, and releases the radial pressure, thereby eliminating the tension force. This makes it easier to remove and replace the damaged heat exchange tube, thus making the heat exchanger repairable and extending its service life.

[0008] Preferably, the side of the abutting protrusion near the mounting rod is configured as a connecting slope.

[0009] By adopting the above technical solution, a connecting slope is set on the side of the abutment protrusion near the mounting rod. The connecting slope more effectively converts the axial linear motion of the drive block into a radial pushing force on the rotating block of the cutter head, which is equivalent to providing a ramp, making the force transmission smoother.

[0010] Preferably, the cutting head rotating block has an installation groove on the side away from the other cutting head rotating block, the cutting blade is installed in the installation groove, the side of the cutting blade away from the bottom of the installation groove protrudes from the installation groove, and the side of the cutting blade away from the bottom of the installation groove is serrated.

[0011] By adopting the above technical solution, the mounting groove provides fixed support for the cutting blade, preventing the blade from shifting or shaking during the cutting process and ensuring cutting accuracy; the blade protrudes from the mounting groove to ensure that the blade can fully contact the pipe wall; the cutting blade adopts a serrated design, which enhances the cutting effect and improves cutting efficiency.

[0012] Preferably, it also includes a tensioning spring, wherein a spring groove is provided on the side of the cutter head rotating block away from the mounting rod, and the two ends of the tensioning spring are respectively placed in the spring grooves of the two cutter head rotating blocks, and the two ends of the tensioning spring are respectively fixed to the two cutter head rotating blocks.

[0013] By adopting the above technical solution, when the cutting head rotating blocks open, the spring is stretched and stores energy; when it needs to close, the spring releases the stored elastic potential energy, contracts itself, and resets the two cutting head rotating blocks.

[0014] Preferably, a positioning block is provided at the end of the drive rod away from the drive block, and the positioning block abuts against the end of the mounting rod away from the cutter head rotating block to limit the distance the drive rod slides toward the cutter head rotating block.

[0015] By adopting the above technical solution, a positioning block is set at the end of the drive rod, the size of which is larger than the channel of the mounting rod. When the drive rod slides to the predetermined position, the positioning block will abut against the end of the mounting rod, thereby limiting the maximum sliding distance of the drive rod through physical obstruction.

[0016] Preferably, when the positioning block abuts against the end of the mounting rod away from the blade rotating block, the blade rotating block is inclined relative to the axis of the mounting rod, and the diameter of the maximum cutting surface formed by the end of the cutting blade away from the mounting rod is smaller than the outer diameter of the heat exchange tube.

[0017] By adopting the above technical solution, the stroke limit of the driving block by the positioning block is made so that the final opening angle of the cutting head rotating block is limited to a specific value. At this time, the diameter of the circular cutting surface formed by the outer edge of the cutting blade is designed to be smaller than the outer diameter of the heat exchange tube. In this way, the blade can cut through the tube wall, but its cutting range will not exceed the heat exchange tube itself, thereby protecting the fins that are tightly attached to the outside of the heat exchange tube.

[0018] Preferably, it also includes a hydraulic rod, which is connected to the end of the drive rod away from the positioning block, and the hydraulic rod drives the drive rod to slide along the axis of the mounting rod.

[0019] By adopting the above technical solution, the hydraulic rod provides a powerful, controllable and remotely operable power source for the sliding of the drive rod. The hydraulic rod can generate huge thrust to ensure that the cutting blade has enough pressure to press against the tube wall and make effective cuts, while facilitating operation by the operator outside the heat exchanger.

[0020] Preferably, the mounting rod has a connecting groove at one end near the rotating cutter head, and the rotating cutter head is installed in the connecting groove; the rotating cutter head is provided with a connecting pin at one end near the mounting rod, the connecting pin is perpendicular to the axis of the mounting rod, the connecting pin first passes through one side wall of the connecting groove, then through the rotating cutter head, and then out through the other side wall of the connecting groove, so that the rotating cutter head is rotatably installed at the end of the mounting rod.

[0021] By adopting the above technical solution, the connecting pin vertically passes through the mounting rod and the cutting head rotating block, forming a classic hinge structure, which allows the cutting head rotating block to rotate stably around the pin.

[0022] In summary, this application includes at least one of the following beneficial technical effects: 1. In use, insert the cutter head and mounting rod into the heat exchange tube. The drive rod slides on the mounting rod towards the cutter head, and the drive block moves towards the direction of the rotating block of the cutter head. After the drive block abuts against the abutting protrusion, it lifts the end of the two rotating blocks away from the mounting rod, causing the end of the rotating blocks away from the mounting rod to rotate towards the heat exchange tube wall, so that the cutting blade contacts the tube wall. Then, the entire cutter rotates to cut the inner wall of the heat exchange tube, which increases the inner diameter of the heat exchange tube at the cut, thins the heat exchange tube wall, reduces its load-bearing cross-sectional size, and releases the radial pressure, thereby eliminating the tension force. This makes it easier to remove and replace the damaged heat exchange tube, thus making the heat exchanger repairable and extending its service life. 2. A spring groove is provided on the side of the cutter head rotating block away from the mounting rod, and a tensioning spring is provided on the side of the cutter head rotating block away from the mounting rod. The two ends of the tensioning spring are respectively placed in the spring grooves of the two cutter head rotating blocks, and the two ends of the tensioning spring are respectively fixed to the two cutter head rotating blocks. When the cutter head rotating blocks open, the spring is stretched and stores energy; when it needs to close, the spring releases the stored elastic potential energy, contracts itself, and resets the two cutter head rotating blocks. 3. A positioning block is set at the end of the drive rod, the size of which is larger than the channel of the mounting rod. When the drive rod slides to the predetermined position, the positioning block will abut against the end of the mounting rod, limiting the maximum sliding distance of the drive rod through physical blocking. By limiting the stroke of the drive block by the positioning block, the final opening angle of the cutter head rotating block is limited to a specific value. At this time, the diameter of the circular cutting surface formed by the outer edge of the cutting blade is designed to be slightly smaller than the outer diameter of the heat exchange tube. In this way, the blade can cut through the tube wall, but its cutting range will not exceed the heat exchange tube itself, thereby protecting the fins that are tightly attached to the outside of the heat exchange tube. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application; Figure 2 This is an exploded view of an embodiment of this application; Figure 3 yes Figure 2 Enlarged view of the rotating block section of the cutting head; Figure 4 This is a cross-sectional view of the cutter head before use in the embodiments of this application; Figure 5 This is a cross-sectional view of the cutter head in use in the embodiments of this application.

[0024] Reference numerals: 1. Cutter head; 101. Cutter head rotating block; 2. Mounting rod; 3. Drive rod; 4. Hydraulic rod; 5. Drive block; 6. Connecting groove; 7. Connecting pin; 8. Mounting groove; 9. Cutting blade; 10. Abutment protrusion; 11. Accommodation space; 12. Connecting inclined surface; 13. Tensioning spring; 14. Spring groove; 15. Positioning block. Detailed Implementation

[0025] The following is in conjunction with the appendix Figure 1 -Appendix Figure 5 This application will be described in further detail.

[0026] This application discloses an internal cutting tool for a tubular heat exchanger.

[0027] refer to Figure 1 and Figure 2 A tube-to-tube cutting tool for a tubular heat exchanger includes a cutting head 1, a mounting rod 2, a drive rod 3, and a hydraulic rod 4. The cutting head 1 is mounted on one end of the mounting rod 2 for cutting the heat exchange tubes. The drive rod 3 is arranged along the axis of the mounting rod 2 and its two ends pass through both ends of the mounting rod 2. A drive block 5 is inserted and fitted onto the end of the drive rod 3 near the cutting head 1. The drive block 5 is used to open or retract the cutting head 1. The piston rod of the hydraulic rod 4 is bolted to the end of the drive rod 3 away from the drive block 5, thereby driving the drive rod 3 to slide towards or away from the cutting head 1.

[0028] Figure 2 and Figure 3 The cutter head 1 includes two identical cutter head rotating blocks 101. The mounting rod 2 is a cylindrical rod. A connecting groove 6 is provided at one end of the mounting rod 2 near the cutter head rotating block 101. A connecting pin 7 is inserted into one end of the cutter head rotating block 101 near the mounting rod 2. The axis of the connecting pin 7 is perpendicular to the axis of the mounting rod 2. When installing the cutter head rotating block 101, the connecting pin 7 first passes through one side of the groove wall of the connecting groove 6, then through the cutter head rotating block 101, and then out through the other side of the groove wall of the connecting groove 6. One end of the cutter head rotating block 101 is then rotated and installed on one end of the mounting rod 2.

[0029] A mounting groove 8 is provided on the side of the cutting head rotating block 101 away from the other cutting head rotating block 101. The length direction of the mounting groove 8 is perpendicular to the axis of the mounting rod 2. A cutting blade 9 is embedded in the mounting groove 8. The side of the cutting blade 9 away from the bottom of the mounting groove 8 protrudes from the mounting groove 8. The side of the cutting blade 9 away from the bottom of the mounting groove 8, that is, the side of the cutting blade 9 used for cutting, is set with a serrated structure.

[0030] Two rotating blade blocks 101 are symmetrically arranged around the axis of the mounting rod 2. An abutment protrusion 10 is integrally formed on the side of the rotating blade block 101 closest to the other rotating blade block 101. The abutment protrusion 10 is located at the end of the rotating blade block 101 away from the mounting rod 2. Both rotating blade blocks 101 have an abutment protrusion 10 integrally formed. The part between the two rotating blade blocks 101 without the abutment protrusion 10 forms a receiving space 11. The driving block 5 is located in the receiving space 11 between the two rotating blade blocks 101, that is, the driving block 5 is located between the two rotating blade blocks 101 and between the abutment protrusion 10 and the mounting rod 2.

[0031] In use, the cutter head 1 and mounting rod 2 are inserted into the heat exchange tube. The hydraulic rod 4 drives the drive rod 3 to slide on the mounting rod 2 toward the cutter head 1, and the drive block 5 moves toward the direction of the cutter head rotating block 101. After the drive block 5 abuts against the abutting protrusion 10, it lifts the ends of the two cutter head rotating blocks 101 away from the mounting rod 2, causing the ends of the cutter head rotating blocks 101 away from the mounting rod 2 to rotate toward the heat exchange tube wall, so that the cutting blade 9 contacts the tube wall. Then the entire cutter is rotated to cut the inner wall of the heat exchange tube, which increases the inner diameter of the heat exchange tube at the cut, thins the heat exchange tube wall, reduces its load-bearing cross-sectional size, and releases the radial pressure, thereby eliminating the tension force.

[0032] refer to Figure 2 and Figure 3 Furthermore, the side of the abutment protrusion 10 near the mounting rod 2 is set as a connecting slope 12. The side of the abutment protrusion 10 near the other cutting head rotating block 101 is connected to the side of the cutting head rotating block 101 near the other cutting head rotating block 101 through the connecting slope 12. The connecting slope 12 more effectively converts the axial linear motion of the drive block 5 into a radial pushing force on the cutting head rotating block 101, which is equivalent to providing a ramp, making the force transmission smoother.

[0033] It also includes a tensioning spring 13. A spring groove 14 is provided on the side of the cutter head rotating block 101 away from the mounting rod 2. The two ends of the tensioning spring 13 are respectively placed in the spring groove 14 of the two cutter head rotating blocks 101, and the two ends of the tensioning spring 13 are respectively fixed to the two cutter head rotating blocks 101 by screws. When the cutter head rotating blocks 101 open, the spring is stretched and stores energy. When it needs to close, the spring releases the stored elastic potential energy, contracts itself, and resets the two cutter head rotating blocks 101.

[0034] refer to Figure 4 and Figure 5Furthermore, a positioning block 15 is integrally formed at the end of the drive rod 3 away from the drive block 5. The piston rod of the hydraulic rod 4 is bolted to the positioning block 15. When the drive rod 3 slides toward the cutter head rotating block 101 to a certain position, the positioning block 15 can abut against the end of the mounting rod 2 away from the cutter head rotating block 101, thereby limiting the maximum sliding distance of the drive rod 3 through physical obstruction.

[0035] refer to Figure 5 When the positioning block 15 abuts against the end of the mounting rod 2 away from the blade rotating block 101, the driving block 5 lifts up the two blade rotating blocks 101. The blade rotating blocks 101 are inclined relative to the axis of the mounting rod 2. The diameter of the circular cutting surface formed by the end of the cutting blade 9 away from the mounting rod 2, i.e. the diameter of the maximum cutting surface, is slightly smaller than the outer diameter of the heat exchange tube. In this way, the blade can cut through the tube wall, but its cutting range will not exceed the heat exchange tube itself, thereby protecting the fins that are tightly attached to the outside of the heat exchange tube.

[0036] The implementation principle of this application embodiment is as follows: When using this cutter, the operator inserts the cutter head 1 and the mounting rod 2 into the heat exchange tube. The hydraulic rod 4 drives the drive rod 3 to slide on the mounting rod 2 towards the cutter head 1. The drive block 5 moves towards the direction close to the cutter head rotating block 101. The drive block 5 contacts the connecting inclined surface 12 and slowly lifts the cutter head rotating block 101. Then, the positioning block 15 abuts against the mounting rod 2. At this time, the drive block 5 lifts the two cutter head rotating blocks 101 away from the mounting rod 2 to the highest position, so that the cutting blade 9 contacts the tube wall. Then, the entire cutter is rotated, so that the cutter head rotating block 101 rotates around the axis of the heat exchange tube. The serrations on the cutting blade 9 cut the heat exchange tube wall. At this time, the rotating block 101 of the cutter head is inclined relative to the axis of the mounting rod 2, so that the cutting depth of the sawtooth cutting end of the cutting blade 9 on the heat exchange tube wall gradually increases. The diameter of the largest circular cutting surface formed by the end of the cutting blade 9 away from the mounting rod 2 is slightly smaller than the outer diameter of the heat exchange tube. On the one hand, this increases the inner diameter of the heat exchange tube at the cutting point, thins the heat exchange tube wall, reduces its load-bearing cross-sectional size, and releases the radial pressure, thereby eliminating the tension force and making it easier to remove and replace the damaged heat exchange tube. This makes the heat exchanger more repairable and extends its service life. On the other hand, the blade can cut through the tube wall, but its cutting range will not exceed the heat exchange tube itself, thus protecting the fins that are tightly attached to the outside of the heat exchange tube.

[0037] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A tube-to-tube cutting tool for a tubular heat exchanger, characterized in that, The device includes a cutter head (1), a mounting rod (2), and a drive rod (3). The cutter head (1) includes two identical cutter head rotating blocks (101), both of which are rotatably mounted on one end of the mounting rod (2). A cutting blade (9) is provided on the side of the cutter head rotating block (101) away from the other cutter head rotating block (101). The cutting blade (9) is located at the end of the cutter head rotating block (101) away from the mounting rod (2) and is arranged along the axial direction of the mounting rod (2). The blade rotating block (101) has an abutment protrusion (10) on one side near the other blade rotating block (101). The abutment protrusion (10) is located at the end of the blade rotating block (101) away from the mounting rod (2). The drive rod (3) is slidably disposed along the axis of the mounting rod (2) and passes through the mounting rod (2). The drive rod (3) has a drive block (5) at the end near the blade rotating block (101). The drive block (5) is located between the two blade rotating blocks (101) and between the abutment protrusion (10) and the mounting rod (2). The drive block (5) lifts the end of the blade rotating block (101) away from the mounting rod (2) so that the cutting blade (9) contacts the heat exchange tube wall.

2. The tube-to-tube cutting tool for a tubular heat exchanger according to claim 1, characterized in that, The side of the abutting protrusion (10) near the mounting rod (2) is configured as a connecting slope (12).

3. The tube-to-tube cutting tool for a tubular heat exchanger according to claim 1, characterized in that, The cutting head rotating block (101) has an installation groove (8) on the side away from the other cutting head rotating block (101). The cutting blade (9) is installed in the installation groove (8). The side of the cutting blade (9) away from the bottom of the installation groove (8) protrudes from the installation groove (8). The side of the cutting blade (9) away from the bottom of the installation groove (8) is serrated.

4. The tube-to-tube cutting tool for a tubular heat exchanger according to claim 1, characterized in that, It also includes a tensioning spring (13). The blade rotating block (101) has a spring groove (14) on the side away from the mounting rod (2). The two ends of the tensioning spring (13) are respectively placed in the spring grooves (14) of the two blade rotating blocks (101), and the two ends of the tensioning spring (13) are respectively fixed to the two blade rotating blocks (101).

5. The tube-to-tube cutting tool for a tubular heat exchanger according to claim 1, characterized in that, A positioning block (15) is provided at the end of the drive rod (3) away from the drive block (5). The positioning block (15) abuts against the end of the mounting rod (2) away from the cutter head rotating block (101) to limit the distance that the drive rod (3) slides toward the cutter head rotating block (101).

6. The tube-to-tube cutting tool for a tubular heat exchanger according to claim 5, characterized in that, When the positioning block (15) abuts against the end of the mounting rod (2) away from the blade rotating block (101), the blade rotating block (101) is inclined relative to the axis of the mounting rod (2), and the diameter of the largest cutting surface formed by the end of the cutting blade (9) away from the mounting rod (2) is smaller than the outer diameter of the heat exchange tube.

7. The tube-to-tube cutting tool for a tubular heat exchanger according to claim 5, characterized in that, It also includes a hydraulic rod (4), which is connected to the end of the drive rod (3) away from the positioning block (15), and the hydraulic rod (4) drives the drive rod (3) to slide along the axis of the mounting rod (2).

8. The tube-to-tube cutting tool for a tubular heat exchanger according to claim 1, characterized in that, The mounting rod (2) has a connecting groove (6) at one end near the cutting head rotating block (101), and the cutting head rotating block (101) is installed in the connecting groove (6). The cutting head rotating block (101) is provided with a connecting pin (7) at one end near the mounting rod (2). The connecting pin (7) is perpendicular to the axis of the mounting rod (2). The connecting pin (7) first passes through one side of the connecting groove (6), then through the cutting head rotating block (101), and then out of the other side of the connecting groove (6), so that the cutting head rotating block (101) is rotated and installed at the end of the mounting rod (2).

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