Replaceable end wear-resistant device

Abstract

The invention relates to a replaceable end wear-resistant device which is installed on a lower tube plate of a circulating fluidized bed heat exchanger so as to provide wear-resistant allowance. Comprising a flitch plate, a plurality of first through holes and a plurality of second through holes are formed in the flitch plate, and the second through holes are used for achieving connection and fixation of the flitch plate and a tube plate; wear-resistant pipes with holes are arranged in the first through holes in a floating manner; a receding structure is arranged on the upper surface of the flitch plate so as to achieve coaxial butt joint of the wear-resisting pipe with the holes and the heat exchange pipe. And at least part of the end faces of the wear-resistant pipe with the holes and the heat exchange pipe are ground to be flat. By means of the end abrasion-resistant device, the pipe head can be effectively prevented from being abraded, and convenient replacement can still be achieved after long-term operation.

Description

Technical Field

[0001] The invention relates to the field of circulating fluidized beds, in particular to an end wear-resistant device suitable for a Geldart D type liquid-solid fluidized bed heat exchanger for preventing heat exchange tube wear. Background Art

[0002] A circulating fluidized bed heat exchanger is a type of heat exchanger that uses fluidized particles to flush the heat exchange tube wall to prevent scaling of the heat exchange tube wall. Currently, the circulating fluidized bed heat exchangers that have been industrialized are mainly vertical structures, and the fluid and the corresponding descaling particles are in a bottom-in-top-out mode (entering from the bottom of the heat exchange tube and exiting from the top). In this operating mode, particles will cause wear on the heat exchange tube head (referring to the lower inlet end of the heat exchange tube protruding from the tube sheet), and have become the main reason for the scrapping and failure of circulating fluidized bed heat exchangers.

[0003] To overcome this problem, patent DE3432864A1 (publication date March 20, 1986) discloses a wear-resistant solution, which prolongs the service life of the heat exchanger by extending the heat exchange tube head to reserve wear margin. However, it is well known that there are three methods for fixing heat exchange tubes and tube sheets, namely welding, expansion and welding and expansion. Welding and welding and expansion are only used for the case where the heat exchange tube head is short. Under the current conventional pipe spacing, the length of the tube head extending from the tube sheet will not exceed 5mm to ensure the operating space required for the welding process. However, since the patent uses an extended heat exchange tube head, there is no longer any operating space required for the welding process between the heat exchange tube and the tube sheet, so the heat exchange tube and the tube sheet can only be fixed by a pure expansion process. However, due to factors such as processing accuracy, equipment cost and operating pressure, the expansion process is more prone to leakage than the welding process, and is only applicable to relatively low pressure environments. In addition, this solution is still a one-time process. Once the tube head is worn, it means that the heat exchange equipment is scrapped.

[0004] Patent CN210198151 U (published on March 27, 2020) proposed a replaceable wear-resistant solution, which uses a wear-resistant inner tube with an outer diameter smaller than the inner diameter of the heat exchange tube. The inner tube is inserted into the heat exchange tube to provide a wear-resistant margin; when the inner tube is worn, the worn inner tube can be removed and a new inner tube can be reinserted to replace the wear-resistant margin. The inner tube of this solution is essentially equivalent to a replaceable end of the heat exchange tube, which can theoretically extend the service life of the heat exchange tube indefinitely. However, after the actual operation of this scheme, it has the following technical defects: first, the wall thickness of the inner tube is severely limited. When the wall thickness of the inner tube is large, an obvious inner diameter mutation zone will be formed at the interface between the inner tube and the heat exchange tube (the small inner diameter of the inner tube mutates to the large inner diameter of the heat exchange tube), and the solid-liquid mixed fluid will be greatly turbulent when flowing through the inner diameter mutation zone, thereby causing the local wear of this area to increase. At the same time, the aforementioned turbulence also causes some particulate matter (mainly dirt that has been worn off) to enter the gap between the inner tube and the heat exchange tube and scale again, which ultimately makes it impossible to pull the worn inner tube out of the heat exchange tube during maintenance; and when using thin-walled inner tubes, the wear resistance margin that can be provided by its too thin thickness is too small, and due to the use of the interpolation method, there is still an inner diameter mutation zone at the interface between the two, which ultimately leads to the need for frequent shutdowns and maintenance during equipment operation.

[0005] Patent EP0496070A1 (published on July 29, 1992) provides another replaceable wear-resistant solution, which uses a thick orifice plate, and inserts the lower end of the heat exchange tube into the upper end of the thick orifice plate, and the upper end of the wear-resistant tube into the lower end of the thick orifice plate. However, it is obvious that in this solution, both the ends of the heat exchange tube and the wear-resistant tube are buried inside the thick orifice plate, so welding cannot be performed between the tube and the plate. Therefore, similar to patent DE3432864A1, it can only fix the tube and the plate through a pure expansion process, which limits the application scenarios of such heat exchangers.

[0006] Patent DE4007583A1 (publication date September 12, 1991) proposed another replaceable wear-resistant solution, which adds a flange plate and inserts the wear-resistant tube into several holes on the flange plate; in this solution, the heat exchange tube only protrudes slightly from the tube plate, so it is allowed to use a welding solution to achieve the connection and fixation of the heat exchange tube and the tube plate; in addition, when the wear-resistant tube is worn, the flange plate can be directly removed to achieve the overall replacement of the wear-resistant tube. Therefore, this solution is more advantageous than the previous solution. However, in this solution, the upper end of the wear-resistant tube is recessed in the upper surface of the flange plate, thereby forming a groove for accommodating a sealing ring; the sealing ring provides a good seal between the heat exchange tube and the wear-resistant tube. However, the material of the sealing ring (typically rubber, PTFE, perfluoroether, etc.) is very different from that of the heat exchange tube and wear-resistant tube. Even if the expensive perfluoroether sealing material is used, it will be quickly worn out before the heat exchange tube and wear-resistant tube during use, and form a defect depression at the connection between the heat exchange tube and the wear-resistant tube. The defect depression will promote the turbulence of the solid-liquid mixed flow, and then aggravate the local wear of the connection. At this time, the local wear is not only the wear of the wear-resistant tube, but also the wear of the heat exchange tube head. This obviously violates the original purpose of setting the wear-resistant tube to prevent the wear from affecting the heat exchange tube head. More importantly, in actual processes, it is difficult to ensure that the tube heads of the heat exchange tubes extending out of the tube sheet are absolutely flush, that is, there are certain differences in the lengths of the tube heads of the heat exchange tubes; and the wire diameters of the sealing rings used with the heat exchange tubes are usually only at the millimeter level; the aforementioned tube head length differences will cause obvious differences in the amount of compression of the sealing rings by the heat exchange tubes during assembly, and some heat exchange tubes may even be unable to squeeze the sealing rings, resulting in uneven sealing effects of the heat exchange tubes; and the heat exchange tube heads that fail to form a good seal may be worn before the sealing rings, causing the heat exchanger to fail and be scrapped.

[0007] More importantly, the applicant discovered that in the actual equipment manufacturing process, especially for large-scale heat exchange equipment, it is impossible to ensure that the lengths of the tube heads of all heat exchange tubes extending out of the tube sheet are the same, nor is it possible to ensure that the axes of all heat exchange tubes are strictly parallel; this results in the end faces of the tube heads of the heat exchange tubes not actually being located on the same plane. Summary of the invention

[0008] The present invention provides a replaceable end wear-resistant device, comprising a plate, on which a plurality of first through holes and a plurality of second through holes are opened; the second through holes are preferably bolt holes; and a plurality of wear-resistant tubes with holes are floatingly placed in the first through holes; the plate is fixedly connected to the tube sheet of the heat exchanger by screws / bolts / pins penetrating the second through holes.

[0009] Generally speaking, the number of perforated anti-wear tubes should be consistent with the number of heat exchange tubes. However, in some cases, the number of perforated anti-wear tubes can be less than the number of heat exchange tubes.

[0010] Theoretically, in order to prevent the wear of the heat exchange tube heads, a perforated anti-wear tube should be installed under the tube head of each heat exchange tube. However, the applicant was surprised to find in the process of experimental verification that after removing the perforated anti-wear tubes under some heat exchange tubes, the anti-wear effect of the heat exchange tubes can still be basically maintained, and the flow rate of the solid-liquid mixture inside the remaining heat exchange tubes can be gradually increased, thereby enhancing the efficiency of the particles in removing the scale inside the remaining heat exchange tubes, and at the same time it is beneficial to reduce the equipment cost. Specifically, the applicant found that in production practice, the equipped heat exchanger is not completely equivalent to the actual heat exchange demand, and usually the maximum load of the equipped heat exchanger will be greater than the heat exchange load required for operation (that is, only part of the heat exchange tubes are kept in a flowing state to meet the heat exchange demand). When the end wear-resistant device of the present invention is used (for example, to modify an existing heat exchanger), the number of perforated anti-wear tubes can be appropriately reduced based on long-term operating data, and the fluidization state of the solid-liquid mixed fluid can be adjusted so that only the perforated anti-wear tubes can extend into the particle fluidization zone, while the heat exchange tubes cannot extend into the particle fluidization zone; in this operating state, for heat exchange tubes that are not provided with perforated anti-wear tubes, the particles cannot reach their bottom openings and thus cannot cause wear to their tube heads (but this will also result in the inability to grind away scale on the inner wall of the tube, so that this part of the heat exchange tubes will gradually become clogged and lose their heat exchange function).

[0011] Therefore, the number of perforated anti-wear tubes provided in the present invention is determined according to the maximum heat exchange load required for operation, and ensures that the total heat exchange load of the heat exchange tubes provided with perforated anti-wear tubes is not lower than the maximum heat exchange load required for operation.

[0012] In the present invention, at least part of the heat exchange tube and the perforated anti-wear tube are end-surface-ground before assembly, so that when the end surfaces of the two are in contact, fluid sealing can be achieved spontaneously without the aid of additional sealing components.

[0013] The solution in which the perforated anti-wear tube is floatingly arranged in the first through hole allows the perforated anti-wear tube to be pushed during assembly to adjust the length of the tube extending out of the plate (hereinafter referred to as the assembly adjustment stage) to compensate for the defect of uneven tube heads of the heat exchange tubes (referring to the inconsistent lengths of the heat exchange tubes extending out of the tube sheet) caused by manufacturing factors, thereby ensuring that the assembled heat exchange tubes and the end faces of the perforated anti-wear tubes form a good contact seal.

[0014] It should be pointed out that the aforementioned floating setting is a temporary state. Specifically, only before assembly and during the assembly adjustment stage, the perforated anti-wear tube and the first through hole on the plate are in a floating setting state; and when the adjustment is completed, the perforated anti-wear tube and the plate can be fixed by means of spot welding (no sealing requirement, so spot welding is sufficient), and the spot welding can be performed on the lower surface of the plate.

[0015] Regarding the floating arrangement between the perforated anti-wear pipe and the plate, the present invention provides the following three specific solutions:

[0016] Solution 1 is threaded connection, that is, corresponding internal and external threads are respectively set on the inner wall of the first through hole and the outer wall of the perforated anti-wear tube to thread the two. When this solution is adopted, during the assembly and adjustment stage, the plate is first aligned and fitted with the tube sheet, and fixed with bolts, and then the perforated anti-wear tubes are rotated one by one to achieve the end face fit with the heat exchange tube; the threaded connection rotation resistance resists the weight of the perforated anti-wear tube itself to keep it in the adjusted position after the adjustment is completed. Of course, in order to keep the position of the perforated anti-wear tube constant, each perforated anti-wear tube can also be fixed to the plate by spot welding or expansion after being screwed into place.

[0017] The second scheme is sliding connection. In this scheme, the wear-resistant tube with holes is a smooth tube, and the inner diameter of the first through hole is equal to or slightly larger than the outer diameter of the wear-resistant tube with holes, so as to allow the wear-resistant tube with holes to slide in the first through hole. When this scheme is adopted, in the assembly and adjustment stage, the plate and the tube sheet are first aligned and fitted, and fixed with bolts, etc., and then the wear-resistant tubes with holes are inserted into the first through hole one by one, and pushed forward with force. When the heat exchange tube is encountered, it can be stopped. In the state of pushing, the wear-resistant tube with holes and the lower surface of the plate are spot welded, or the connection between the wear-resistant tube with holes and the plate is squeezed with a tube expander to expand the two, or welding and expansion are used at the same time; the spot welding and / or expansion can not only fix the position but also resist the weight of the wear-resistant tube with holes to maintain the correct position. After the spot welding and / or expansion is completed, the next wear-resistant tube with holes is inserted and fixed in turn.

[0018] Solution three is an elastic connection. In this solution, the wear-resistant tube with holes is still a plain tube, but a protrusion is provided on the outer side wall of the upper section thereof. It also includes a top plate and a spring. The top plate is provided with a plurality of third through holes corresponding to the first through holes, and a plurality of fourth through holes. The fourth through holes are used to fix the top plate to the plate and / or tube sheet. When this solution is adopted, during the assembly and adjustment stage, the plate and the tube sheet are first aligned, attached and fixed, and then the spring is sleeved on the pipe section of the wear-resistant tube with holes located below the protrusion. Then the pipe section of the wear-resistant tube with holes located below the protrusion is inserted from top to bottom into the third through hole on the top plate. Then the pipe section of the wear-resistant tube with holes located above the protrusion is inserted from bottom to top into the first through hole on the plate. Then the top plate is adjusted so that the wear-resistant tube with holes and the end surface of the heat exchange tube are correspondingly attached, and the spring is compressed, and then the top plate is fixed. At this time, the compressed spring pushes the protrusion upward, thereby promoting the wear-resistant tube with holes to maintain good contact and sealing with the heat exchange tube. In this solution, there is no need to rotate or push the wear-resistant tubes with holes one by one, nor is there any need to weld the wear-resistant tubes with holes to the mounting plate.

[0019] The side wall of the perforated anti-wear pipe is provided with a through hole, and after assembly, the through hole is located below the pasting plate and / or the top plate to directly contact the solid-liquid mixed flow.

[0020] Preferably, a clearance structure is provided on the upper surface of the plate, and the clearance structure has sufficient depth and width to accommodate the tube head of the heat exchange tube and the annular weld between the tube head and the tube sheet, so that even if the tube head of the heat exchange tube is not aligned and the annular weld is fluctuating, the plate and the tube sheet can achieve good positioning and fit. The clearance structure is important in the present invention to ensure a good fit and seal between the heat exchange tube and the perforated anti-wear tube. If the clearance structure is not provided, the good fit between the plate and the tube sheet cannot be guaranteed, which will make the adjustment process difficult on the one hand, and on the other hand, it cannot ensure that the heat exchange tube and the perforated anti-wear tube are coaxially docked, which may lead to poor sealing between the two and cause serious local wear.

[0021] For better understanding, three specific yielding structures are listed in the present invention. The first yielding structure is as follows: Figure 2 As shown, the said giving way structure can be an integral groove located on the upper surface of the said plate, and the said groove has a ring edge around it which abuts against the lower surface of the tube sheet; the second giving way structure is as shown Figure 3 As shown, the said giving way structure can be a chamfer-like structure located on the circumference of each anti-wear pipe with holes; the third kind of giving way structure can be a plurality of discrete protrusions arranged on the upper surface of the said plate, through which the said discrete protrusions abut against the lower surface of the said tube sheet, and the said plate is positioned parallel to the said tube. It should be pointed out that, without violating the function of the giving way groove in the present invention, those skilled in the art may also make simple deformations on the giving way groove structure form listed in the present invention, for example, setting the above two or three giving way structures on the upper surface of the said plate at the same time.

[0022] Compared with the prior art, the present invention can at least achieve the following beneficial effects: using an easily replaceable perforated anti-wear tube to provide a wear-resistant margin and prevent wear of the tube head; the perforated anti-wear tube is directly in contact with the end face of the heat exchange tube, and no external sealing ring is required, so it is easy to install and has no material transition zone (sealing ring area), so local wear will not form at the tube head; the perforated anti-wear tube is floatingly arranged in the first through hole on the plate during assembly, so it can effectively adapt to the uneven tube heads caused by manufacturing defects and ensure a uniform sealing effect; a yield structure is provided on the upper surface of the plate, which is conducive to quickly positioning and fitting the plate and the tube sheet, and is conducive to the coaxial docking of the heat exchange tube and the perforated anti-wear tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a real shot of the heat exchange tube, tube sheet and the weld between them;

[0024] Figure 2Make way for the overall groove structure;

[0025] Figure 3 Make way for chamfer-like structures;

[0026] Figure 4 It is a longitudinal section diagram without giving way structure;

[0027] Figure 5 It is the main view without giving way structure;

[0028] Figure 6 This is an illustration of an elastic connection.

[0029] In the figure: 1 is a tube sheet, 2 is a heat exchange tube, 3 is a plate, 4 is a perforated anti-wear tube, 5 is a weld, 6 is a protrusion, 7 is a spring, and 8 is a top plate. Specific implementation plan

[0030] Example 1

[0031] This embodiment provides a replaceable end wear-resistant device with a threaded floating connection, which is detachably mounted on the bottom of the lower tube sheet 1 of the circulating fluidized bed heat exchanger to provide a wear-resistant margin for the heat exchange tube. Specifically, the end wear-resistant device includes a plate 3, which is provided with a plurality of first through holes and a plurality of second through holes; and also includes a plurality of perforated wear-resistant tubes 4 threadedly connected to the first through holes; the plate 3 is connected to the tube sheet 1 of the heat exchanger by screws / bolts / pins penetrating the second through holes.

[0032] The heat exchange tube 2 and the perforated anti-wear tube 4 are both end-surface ground before assembly, so that fluid sealing can be achieved spontaneously when the end surfaces of the two are in contact.

[0033] The side wall of the perforated anti-wear pipe 4 is provided with a through hole, and after assembly, the through hole is located below the pasting plate 3 to directly contact the solid-liquid mixed flow.

[0034] The upper surface of the plate 3 is provided with an integral groove giving way structure, which has sufficient depth and width to accommodate the tube head of the heat exchange tube 2 and the annular weld between the tube head and the tube sheet 1.

[0035] In the assembly and adjustment stage, the plate 3 is first aligned and fitted with the tube sheet 1, and fixed with bolts or the like. Then the perforated anti-wear tubes 4 are rotated one by one to achieve fitting with the end surface of the heat exchange tube 2; after being screwed into place, they are fixed to the plate 3 by spot welding. Then the next perforated anti-wear tube 4 is screwed in and fixed.

[0036] Example 2

[0037] This embodiment provides a replaceable end wear-resistant device with sliding connection. The difference from embodiment 1 is that in this embodiment, the wear-resistant tube 4 with holes is a smooth tube, and the inner diameter of the first through hole is equal to or slightly larger than the outer diameter of the wear-resistant tube 4 with holes, so as to allow the wear-resistant tube 4 with holes to slide in the first through hole. In the assembly and adjustment stage, the plate 3 is first aligned and fitted with the tube sheet 1, and fixed with bolts, etc., and then the wear-resistant tubes 4 with holes are inserted into the first through hole one by one, and pushed forward with force. When the heat exchange tube 2 is encountered, it can be stopped. The wear-resistant tube 4 with holes and the lower surface of the plate 3 are spot welded and fixed in the pushed state. After the spot welding is completed, the next wear-resistant tube 4 with holes is inserted and fixed in sequence.

[0038] Example 3

[0039] The present embodiment provides a replaceable end wear-resistant device with an elastic connection. The difference from Embodiments 1 and 2 is that in the present embodiment, the perforated anti-wear tube 4 is still a plain tube, but a protrusion 6 is provided on the outer side wall of its upper section; it also includes a top plate 8 and a spring 7; the top plate 8 is provided with a plurality of third through holes corresponding to the first through holes, and also with a plurality of fourth through holes, and the fourth through holes are used to fix the top plate 8 to the pasting plate 3 or the tube plate 1. During the assembly and adjustment stage, the plate 3 is first aligned and fixed with the tube sheet 1, and then the spring 7 is sleeved on the pipe section of the perforated anti-wear tube 4 located below the protrusion 6, and then the pipe section of the perforated anti-wear tube 4 located below the protrusion 6 is inserted from top to bottom into the third through hole on the top plate 8; then the pipe section of the perforated anti-wear tube 4 located above the protrusion 6 is inserted from bottom to top into the first through hole on the plate 3; then the top plate 8 is adjusted to make the perforated anti-wear tube 4 and the end surface of the heat exchange tube 2 correspondingly fit, and the spring 7 is compressed, and then the top plate 8 is fixed. At this time, the compressed spring 7 pushes the protrusion 6 upward, thereby causing the perforated anti-wear tube 4 to maintain good contact and sealing with the heat exchange tube 2.

[0040] Comparative Example 1

[0041] The solution disclosed in patent DE3432864A1 is adopted to directly extend the tube head of the heat exchange tube 2. The length of the tube head of the heat exchange tube 2 is the same as the length of the perforated anti-wear tube 4 in the above embodiment, and the side wall of the tube head is provided with the same through hole.

[0042] Comparative Example 2

[0043] The inner tube solution disclosed in patent CN210198151 U is adopted. A wear-resistant inner tube is inserted into the heat exchange tube 2, and the wall thickness of the wear-resistant inner tube is (0.5mm); the exposed length is the same as the length of the aforementioned perforated anti-wear tube 4.

[0044] Comparative Example 3

[0045] The thick hole plate scheme disclosed in patent EP0496070A1 is adopted. A thick hole plate is set below the tube plate, and the lower end of the heat exchange tube 2 is inserted into the upper end of the aforementioned thick hole plate, and the upper end of the wear-resistant tube is inserted into the lower end of the aforementioned thick hole plate. The length of the wear-resistant tube is the same as that of the aforementioned perforated wear-resistant tube 4.

[0046] Comparative Example 4

[0047] The flange plate scheme disclosed in patent DE4007583A1 is adopted. A flange plate is set under the tube plate, and the wear-resistant tubes are inserted into several holes on the flange plate and welded and fixed; the heat exchange tube only slightly protrudes from the tube plate, and the upper end of the wear-resistant tube is recessed in the upper surface of the flange plate, and a perfluoroether sealing ring is placed in the recess to achieve a sealed connection between the wear-resistant tube and the heat exchange tube.

[0048] Experimental process and results

[0049] Existing circulating heat exchangers usually use stainless steel heat exchange tubes, which generally need tens of thousands of hours of wear and tear to fail. It is unrealistic to conduct comparative experiments over such a long period of time. Therefore, in order to evaluate the advantages and disadvantages of the above-mentioned embodiments and comparative examples, the present invention creatively uses two sets of devices to perform assembly experiments and wear experiments respectively.

[0050] The two devices use the following common parameters:

[0051] Heat exchanger height: 2 meters; number of heat exchange tubes: 19; heat exchange tube spacing: 33mm, tube head length: 5mm (except for comparative examples 1 and 3); heat exchange tube inner diameter 20mm; number of perforated anti-wear tubes: 19; perforated anti-wear tube inner diameter 20mm; circulating particles: 3mm (diameter) brass balls; fluid type: sewage; operating temperature: 35℃; operating pressure: 0.2mpa;

[0052] The differences between the two devices are as follows:

[0053] In the device used in the assembly experiment, the heat exchange tubes, tube sheets, perforated anti-wear tubes, plates and top plates are all made of 304 stainless steel, and the tubes and corresponding plates are connected by welding and / or expansion joints as specified in the aforementioned embodiments or comparative examples.

[0054] In the device used in the wear experiment, the materials of the heat exchange tubes, tube sheets, perforated anti-wear tubes, stickers, and top plates are all ABS resin, wherein the connection and fixation between the tubes and the corresponding plates adopts the welding and / or expansion connection specified in the aforementioned embodiments or comparative examples, but all steps involving welding and / or expansion connection are replaced by bonding, and bonding specifically refers to bonding using AB glue to simulate the welding process.

[0055] The experimental results are shown in the following table:

[0056]

[0057] It can be seen from comparative experiments that in the wear experiment, embodiments 1-3 can reach a wear time of more than 140 hours before the wear-resistant tube is worn out and then the heat exchange tube is damaged. At the same time, the wear-resistant tube structures of embodiments 1-3 are easy to replace and there is no defect of being unable to be pulled out; although comparative documents 1, 3, and 4 can also reach a wear time of more than 130 hours, since comparative example 1 directly uses an extended heat exchange tube head and cannot replace a new wear-resistant part, once the tube head is worn, the entire equipment will be scrapped; due to design defects, comparative example 3 requires that the heat exchange tube and the wear-resistant tube must be plugged into the thick plate, so only the expansion process can be used, and the use scenario is limited; comparative example 4 naturally has the defect of uneven squeezing of the heat exchange tube heads on the sealing ring, and the local heat exchange tube inlet is quickly worn due to poor sealing; comparative example 2 has the worst wear-resistant effect due to the thin wall thickness of the wear-resistant tube plug-in part, and the wear-resistant tube is difficult to pull out when replaced.

[0058] The above are only examples of preferred embodiments of the present invention, which should not be understood as limiting all feasible technical solutions of the present invention. The protection scope of the present invention shall be based on the content defined in the claims.

Claims

1. A replaceable end wear-resistant device, comprising a plate (3) on which a plurality of first through holes and a plurality of second through holes are formed; characterized in that: It also includes a plurality of perforated anti-wear tubes (4) floatingly placed in the first through hole; the plate (3) is fixedly connected to the tube sheet (1) of the heat exchanger via a fixing member passing through the second through hole; a clearance structure is provided on the upper surface of the plate (3), the clearance structure having sufficient depth and width to accommodate the tube head of the heat exchange tube (2) and the annular weld between the tube head and the tube sheet (1), the clearance structure allowing the plate (3) and the tube sheet (1) to be well positioned and fitted, thereby enabling the perforated anti-wear tube (4) and the heat exchange tube (2) to be coaxially docked; at least part of the perforated anti-wear tube (4) and the heat exchange tube (2) are end-surface ground before assembly, so that fluid sealing can be spontaneously achieved when the end faces of the two are in contact.

2. The replaceable end wear-resistant device according to claim 1, characterized in that: The number of the perforated anti-wear tubes (4) is determined based on the maximum heat exchange load required for operation, and ensures that the total heat exchange load of the heat exchange tubes (2) provided with the perforated anti-wear tubes (4) is not less than the maximum heat exchange load required for operation.

3. The replaceable end wear-resistant device according to claim 1, characterized in that: Only before assembly and during the assembly adjustment stage, the perforated anti-wear pipe (4) and the first through hole on the mounting plate (3) are in a floating setting state.

4. The replaceable end wear-resistant device according to claim 3, characterized in that: The floating setting state means that the perforated anti-wear pipe (4) and the heat exchange pipe (3) are connected by threads; corresponding internal and external threads are arranged on the inner wall of the first through hole and the outer wall of the perforated anti-wear pipe (4).

5. The replaceable end wear-resistant device according to claim 3, characterized in that: The floating setting state refers to the perforated anti-wear pipe (4) and the heat exchange pipe (3) being connected by sliding; the perforated anti-wear pipe (4) is a smooth pipe, and the inner diameter of the first through hole is equal to or slightly larger than the outer diameter of the perforated anti-wear pipe (4) to allow the perforated anti-wear pipe (4) to slide in the first through hole.

6. The replaceable end wear-resistant device according to claim 3, characterized in that: The floating setting state refers to the elastic connection between the perforated anti-wear tube (4) and the heat exchange tube (3); the perforated anti-wear tube (4) is a smooth tube, and a protrusion (6) is provided on the outer side wall of the upper section thereof; it also includes a top plate (8) and a spring (7); the top plate (8) is provided with a plurality of third through holes corresponding to the first through holes, and is also provided with a plurality of fourth through holes, and the fourth through holes are used to fix the top plate (8) to the mounting plate (3) and / or the tube plate (1).

7. The replaceable end wear-resistant device according to any one of claims 4 to 6, characterized in that: The side wall of the perforated anti-wear pipe (4) is provided with a through hole, and after assembly, the through hole is located below the supporting plate (3) and / or the top plate (8) to directly contact the solid-liquid mixed flow.

8. The replaceable end wear-resistant device according to claim 7, characterized in that: The giving way structure is an integral groove located on the upper surface of the plate (3), and the groove has a ring edge around it that abuts against the lower surface of the tube sheet (1); or, the giving way structure is a chamfer-like structure located on the circumference of each perforated anti-wear tube (4); or, the giving way structure is a plurality of discrete protrusions arranged on the upper surface of the plate (3), and the plate (3) abuts against the lower surface of the tube sheet (1) through the discrete protrusions, so that the plate (3) is parallel to the tube sheet (1); or, the giving way structure is a combination of at least two of the aforementioned three structures.

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