A fluoroplastic steel heat exchanger composite tube plate sealing structure
Patent Information
- Application Number
- CN202522272849.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-28
- Publication Date
- 2026-09-11
- Estimated Expiration
- 2035-10-28
AI Technical Summary
[0002]在化工、冶金、电力等行业中，换热器广泛应用于腐蚀性烟气的余热回收，管板密封结构是管壳式换热器的核心部件之一，其性能直接决定了设备的密封可靠性、使用寿命及适用范围，然而传统的常规的管孔多为直角台阶面或直孔，与之配合的密封套环定位精度有限，在装配过程中易发生偏斜，且在承受内部介质压力时，轴向力无法被有效地转化和吸收，容易导致密封界面松动，发生泄漏；其次氟塑钢等复合管材与钛合金、钢等金属管板的热膨胀系数存在显著差异，在工况温度波动时，两者之间产生的热应力会使连接部位发生松弛，导致密封失效泄漏；此外在腐蚀性烟气环境中，介质易从管板与氟塑钢换热管的间隙渗入，对管板本体及背部结构造成腐蚀，严重影响设备安全，因此，迫切需要一种便于装配、有效防腐且密封可靠的管板密封结构
[0012]相比于现有技术，本实用新型的有益效果在于：设置斜向扩口，与钛合金翻边法兰套的相应结构形成锥面配合，利用其自动对中导向特性，为钛合金翻边法兰套提供了稳定的定位基准，便于装配，斜面配合能有效将轴向力转化为压紧力，从而提升了密封界面的耐久性和抗压能力；选用90°的翻边钛合金翻边法兰套，使得复合板端部与压盖不产生接触，在钛合金翻边法兰套与复合板之间形成密封区域，通过压盖对翻边端面施加轴向压紧力，增强了密封可靠性；设有密封斜面，密封斜面能形成深厚的焊缝，便于焊接，且能够将介质压力分解到复合板本体上，避免了应力集中；
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Figure CN224744157U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of heat exchanger technology, and more specifically, relates to a fluoroplastic steel heat exchanger composite tube sheet sealing structure. Background Technology
[0002] In industries such as chemical, metallurgy, and power, heat exchangers are widely used for waste heat recovery from corrosive flue gas. The tube sheet sealing structure is one of the core components of shell-and-tube heat exchangers, and its performance directly determines the sealing reliability, service life, and applicability of the equipment. However, traditional conventional tube holes are mostly right-angled stepped surfaces or straight holes, which limits the positioning accuracy of the matching sealing rings. They are prone to misalignment during assembly, and when subjected to internal medium pressure, the axial force cannot be effectively converted and absorbed, easily leading to loosening of the sealing interface and leakage. Secondly, there is a significant difference in the coefficient of thermal expansion between composite tubes such as fluoroplastic steel and metal tube sheets such as titanium alloy and steel. When the operating temperature fluctuates, the thermal stress generated between the two can cause the connection to loosen, leading to seal failure and leakage. In addition, in corrosive flue gas environments, the medium can easily seep in through the gap between the tube sheet and the fluoroplastic steel heat exchange tubes, causing corrosion to the tube sheet body and the back structure, seriously affecting equipment safety. Therefore, there is an urgent need for a tube sheet sealing structure that is easy to assemble, effectively corrosion-resistant, and has reliable sealing. Utility Model Content
[0003] The technical problem to be solved by this utility model is to provide a fluoroplastic steel heat exchanger composite tube sheet sealing structure, which can meet the requirements of easy assembly, effective corrosion prevention and reliable sealing of heat exchangers.
[0004] This utility model discloses a composite tube sheet sealing structure for a fluoroplastic steel heat exchanger, comprising fluoroplastic steel heat exchange tubes, a composite plate, a gland, a sealing ring, and a titanium alloy flange sleeve. The gland is installed on one side of the composite plate. Both the composite plate and the gland have tube holes. The fluoroplastic steel heat exchange tubes pass through the tube holes of the composite plate and the gland in sequence and are connected to the composite plate and the gland. The composite plate has an oblique flared opening on the side facing the gland. The titanium alloy flange sleeve is installed inside the tube hole, fitted onto the outer wall of the fluoroplastic steel heat exchange tube, and fixedly connected to the fluoroplastic steel heat exchange tube. This is a titanium alloy flange method. The flange provides a stable positioning reference, facilitating assembly. The beveled fit effectively converts axial force into clamping force, thereby improving the durability and pressure resistance of the sealing interface. The sealing ring is installed between the gland and the fluoroplastic steel heat exchange tube, and is pressed against the titanium alloy flange sleeve. The flanged surface of the titanium alloy flange sleeve is respectively in contact with the surface of the beveled flared area of the composite plate and the sealing ring. The fluoroplastic steel heat exchange tube, the gland, and the titanium alloy flange sleeve together cause the sealing ring to deform under force to complete the radial seal.
[0005] As a further improvement of this utility model, the titanium alloy flange sleeve includes a sleeve body. The flanged surface of the titanium alloy flange sleeve is a sealing plane of the sleeve body at 90° on the obliquely flared side. The two ends of the sealing plane are respectively attached to the composite plate and the gland, so that the end of the composite plate does not come into contact with the gland, forming a sealing area between the titanium alloy flange sleeve and the composite plate. The gland applies axial clamping force to the flanged end face, which enhances the sealing reliability.
[0006] As a further improvement of this utility model, the flanged surface of the titanium alloy flange sleeve is set as a sealing slope that matches the oblique flare, extending along the oblique flare direction of the sleeve body. This can form a deep weld, which is convenient for welding and decomposes the medium pressure onto the composite plate body, thus avoiding stress concentration.
[0007] As a further improvement of this utility model, the top of the sealing bevel does not extend beyond the end face of the composite plate, so that the gland is in contact with the surface of the composite plate and the clamping force of the gland can be directly transmitted through the complete end face, avoiding abnormal distribution of clamping force or gland tilting caused by excessive height of the titanium alloy flange sleeve.
[0008] As a further improvement of this utility model, the titanium alloy flange sleeve and the outer wall of the fluoroplastic steel heat exchange tube are interference fit, which prevents the medium from leaking from the gap between the fluoroplastic steel heat exchange tube and the titanium alloy flange sleeve. It also ensures that the titanium alloy flange sleeve remains synchronized with the fluoroplastic steel heat exchange tube when subjected to vibration and temperature changes, and will not loosen or shift, thereby maintaining the long-term stability of the entire sealing system.
[0009] As a further improvement of this utility model, the pressure cap is provided with a sealing groove, and the sealing ring is a fluororubber O-ring. The sealing ring is installed in the sealing groove, which increases the corrosion resistance of the sealing ring. The elastic deformation of the sealing ring can automatically compensate for the gap changes caused by manufacturing errors, vibration and thermal expansion and contraction, thereby improving the adaptability and reliability of the seal.
[0010] As a further improvement of this utility model, the sealing groove is designed as a conical groove, and the groove wall is a conical surface that expands from the bottom of the groove to the opening of the groove. This guides the sealing ring to generate more significant radial expansion while undergoing axial compression, thereby filling the gap between the fluoroplastic steel heat exchange tube and the gland more tightly and forming a more effective seal.
[0011] As a further improvement of this utility model, the thickness ratio of the base layer to the composite layer is 20:3, which facilitates welding, forms a deep and strong weld, and preserves the corrosion resistance of the composite layer to the maximum extent, thus ensuring the overall structural rigidity and stability of the tube sheet.
[0012] Compared with existing technologies, the advantages of this utility model are as follows: The inclined flare forms a conical fit with the corresponding structure of the titanium alloy flange sleeve, utilizing its automatic centering and guiding characteristics to provide a stable positioning reference for the titanium alloy flange sleeve, facilitating assembly. The inclined fit effectively converts axial force into clamping force, thereby improving the durability and pressure resistance of the sealing interface. The use of a 90° flanged titanium alloy flange sleeve ensures that the end of the composite plate does not contact the gland, forming a sealing area between the titanium alloy flange sleeve and the composite plate. The gland applies axial clamping force to the flanged end face, enhancing sealing reliability. The inclined sealing surface forms a deep weld, facilitating welding and distributing the medium pressure to the composite plate body, avoiding stress concentration. The top of the sealing bevel does not extend beyond the end face of the composite plate, allowing the clamping force of the gland to be directly transmitted through the complete end face. This avoids abnormal distribution of clamping force or gland tilting due to excessive height of the titanium alloy flange sleeve. The titanium alloy flange sleeve and the outer wall of the fluoroplastic steel heat exchange tube are interference-fitted to prevent media leakage from the gap between the fluoroplastic steel heat exchange tube and the titanium alloy flange sleeve. The elastic deformation of the sealing ring can automatically compensate for gap changes caused by manufacturing errors, vibration, and thermal expansion and contraction, improving the adaptability and reliability of the seal. The sealing groove is designed as a conical groove, guiding the sealing ring to generate more significant radial expansion while undergoing axial compression, thereby more tightly filling the gap between the fluoroplastic steel heat exchange tube and the gland, forming a more effective seal. Attached Figure Description
[0013] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the orthographic section of the present invention; Figure 3 This is a schematic diagram of the cross-sectional structure of the composite plate of this utility model; Figure 4 This is a schematic diagram of the sealing groove structure of this utility model; Figure 5 This is a schematic diagram of the titanium alloy flange sleeve structure of this utility model; Figure 6 This is a schematic diagram of the front section structure of Embodiment 2 of this utility model; Figure 7 This is a schematic diagram of the titanium alloy flange sleeve structure according to Embodiment 2 of this utility model.
[0014] Explanation of the labels in the diagram: 1. Fluoroplastic steel heat exchange tube; 2. Composite plate; 21. Base layer; 22. Composite layer; 23. Beveled flare; 3. Gland; 31. Sealing groove; 4. Sealing ring; 5. Titanium alloy flange sleeve; 51. Sleeve body; 52. Sealing plane; 53. Sealing bevel; A. Flue gas side; B. Air side. Detailed Implementation
[0015] Specific Implementation Example 1: Please refer to Figures 1-5 This utility model relates to a sealing structure for a fluoroplastic steel heat exchanger composite tube sheet, including a fluoroplastic steel heat exchange tube 1, a composite plate 2, a carbon steel gland 3, a fluororubber sealing ring 4, and a titanium alloy flange sleeve 5. The composite plate 2 is composed of a carbon steel base layer 21 providing strength and a corrosion-resistant titanium alloy composite layer 22. The composite layer 22 is made of titanium alloy. The side closer to the composite layer 22 is designated as the flue gas side A, and the side closer to the base layer 21 is designated as the air side B. Both the composite plate 2 and the gland 3 have tube holes. Pipe 1 passes through the pipe holes of composite plate 2 and gland 3 in sequence. Sealing ring 4 is installed between gland 3 and fluoroplastic steel heat exchange tube 1. On the flue gas side, titanium alloy flange sleeve 5 is installed in the pipe hole and fitted onto the outer wall of fluoroplastic steel heat exchange tube 1 and fixedly connected to fluoroplastic steel heat exchange tube 1. The titanium alloy flange sleeve 5 and the outer wall of fluoroplastic steel heat exchange tube 1 are interference fit, which provides a stable positioning reference for the titanium alloy flange sleeve and facilitates assembly. The bevel fit can effectively convert axial force into clamping force, thereby improving the durability and pressure resistance of the sealing interface.
[0016] In a further embodiment, such as Figure 2 and Figure 5 As shown, the titanium alloy flange sleeve 5 is a flanged titanium alloy flange sleeve. The titanium alloy flange sleeve 5 includes a sleeve body 51. The sleeve body 51 has a 90° sealing plane 52 on the obliquely flared side 23. The two ends of the sealing plane 52 are respectively attached to the composite plate 2 and the gland 3, so that the end of the composite plate 2 does not come into contact with the gland 3, forming a sealing area between the titanium alloy flange sleeve and the composite plate. The gland applies axial clamping force to the flange end face, which enhances the sealing reliability.
[0017] In a further embodiment, such as Figure 2 and Figure 4 As shown, the pressure cap 3 is provided with a sealing groove 31, and the sealing ring 4 is a fluororubber O-ring. The sealing ring 4 is installed in the sealing groove 31. The sealing groove 31 is a conical groove with a conical surface that expands from the bottom to the opening. This can guide the sealing ring 4 to produce more optimized radial deformation, providing a larger accommodating space for the sealing ring 4. When the pressure cap 3 presses the composite plate 2, it makes the pressure cap 3 and the fluoroplastic steel heat exchange tube 1 form a tighter sealing contact, thereby significantly improving the reliability and service life of the seal.
[0018] The thickness ratio of the base layer 21 to the composite layer 22 is 20:3, the thickness of the base layer 21 is set to 8mm, and the thickness of the composite layer 22 is set to 1.2mm, to ensure the overall structural rigidity and stability of the tube sheet.
[0019] After installation, the sealing plane 52 is in close contact with the base layer 21 of the composite plate 2, and the two are welded together by a weld seam, forming the first sealing barrier against corrosive flue gas. The gland 3 is fixed to the composite plate 2 by bolts, and the sealing ring 4 is set in the sealing groove of the gland 3. When the bolts are tightened, the gland 3 presses the sealing ring 4, causing it to undergo elastic deformation and tightly fill the gap between the fluoroplastic steel heat exchange tube 1 and the gland 3, forming the second independent elastic seal.
[0020] Specific Implementation Example 2: Please refer to Figures 6-7 The difference between Example 2 and Example 1 is that the flanged part of the titanium alloy flange sleeve 5 is processed into a sealing bevel 53 that matches the inclined flare 23. The sealing bevel 53 is formed by the sleeve body 51 extending along the direction of the inclined flare 23. The sealing bevel 53 and the inclined flare 23 have the same inclination angle, and the end face of the sealing bevel 53 is close to the surface of the inclined flare 23, which can form a deep weld, which is convenient for welding and can decompose the medium pressure to the composite plate 2 body, avoiding stress concentration.
[0021] In a further embodiment, such as Figure 6 As shown, the top of the sealing slope 53 does not extend beyond the end face of the composite plate 2, so that the gland 3 contacts and connects with the surface of the composite plate 2, avoiding abnormal distribution of the clamping force or causing the gland 3 to tilt due to the excessive height of the titanium alloy flange sleeve 5.
Claims
1. A sealing structure for a fluoroplastic-steel heat exchanger composite tube sheet, characterized in that: The system includes a fluoroplastic steel heat exchange tube (1), a composite plate (2), a gland (3), a sealing ring (4), and a titanium alloy flange sleeve (5). The gland (3) is installed on one side of the composite plate (2). Both the composite plate (2) and the gland (3) have pipe holes. The fluoroplastic steel heat exchange tube (1) passes through the pipe holes of the composite plate (2) and the gland (3) in sequence and is connected to the composite plate (2) and the gland (3). The composite plate (2) has an oblique flared opening (23) on the side facing the gland (3). The titanium alloy flange sleeve (5) is installed inside the pipe hole and fitted onto the outer wall of the fluoroplastic steel heat exchange tube (1) and is fixedly connected to the fluoroplastic steel heat exchange tube (1). The sealing ring (4) is installed between the gland (3) and the fluoroplastic steel heat exchange tube (1) and is squeezed toward the titanium alloy flange sleeve (5). The flanged surface of the titanium alloy flange sleeve (5) is respectively attached to the surface of the oblique flared opening (23) area of the composite plate (2) and the sealing ring (4).
2. The sealing structure of a fluoroplastic steel heat exchanger composite tube sheet according to claim 1, characterized in that: The titanium alloy flange sleeve (5) includes a sleeve body (51). The flanged surface of the titanium alloy flange sleeve (5) is a sealing plane (52) of the sleeve body (51) at 90° on the obliquely flared (23) side. The two ends of the sealing plane (52) are respectively attached to the composite plate (2) and the gland (3).
3. The sealing structure of a fluoroplastic steel heat exchanger composite tube sheet according to claim 1, characterized in that: The outer wall of the titanium alloy flange sleeve (5) and the fluoroplastic steel heat exchange tube (1) are interference fit.
4. The sealing structure of a fluoroplastic steel heat exchanger composite tube sheet according to claim 1, characterized in that: The pressure cap (3) is provided with a sealing groove (31), and the sealing ring (4) is a fluororubber O-ring, and the sealing ring (4) is installed in the sealing groove (31).
5. The sealing structure of a fluoroplastic steel heat exchanger composite tube sheet according to claim 4, characterized in that: The sealing groove (31) is designed as a conical groove, and the groove wall is a conical surface that expands from the bottom of the groove to the opening of the groove.
6. The sealing structure of a fluoroplastic steel heat exchanger composite tube sheet according to claim 1, characterized in that: The composite panel (2) is composed of a base layer (21) that provides strength and a corrosion-resistant composite layer (22). The base layer (21) is made of carbon steel and the composite layer (22) is made of titanium alloy.
7. The sealing structure of a fluoroplastic steel heat exchanger composite tube sheet according to claim 1, characterized in that: The flanged surface of the titanium alloy flange sleeve (5) is a sealing slope (53) that matches the oblique flare (23) and extends along the oblique flare (23) direction of the sleeve body (51).
8. The sealing structure of a fluoroplastic steel heat exchanger composite tube sheet according to claim 7, characterized in that: The top of the sealing bevel (53) does not extend beyond the end face of the composite plate (2).
9. The sealing structure of a fluoroplastic steel heat exchanger composite tube sheet according to claim 6, characterized in that: The thickness ratio of the base layer (21) to the composite layer (22) is 20:3.