A baffled shell and tube heat exchanger with longitudinal sealing structure

Abstract

The present invention discloses a baffle shell-and-tube heat exchanger with a longitudinal sealing structure, comprising a cylinder, a tube sheet, a heat exchange tube, and a baffle. A longitudinal sealing structure is provided at the matching portion between the baffle and the cylinder; the longitudinal sealing structure is a semicircular ring-shaped sealing sheet group, a groove matching the sealing sheet group is provided on the baffle, and the sealing sheet group is fixed to the baffle by bolts; the sealing sheet group includes two or more sealing sheets, sealing teeth are provided on the outside of the sealing sheets, a compensation seam is provided between adjacent sealing teeth, and adjacent sealing sheets are arranged in a staggered manner. The inner diameter of the sealing sheet is greater than the outer diameter of the tube bundle, the outer diameter of the sealing sheet is greater than the inner diameter of the cylinder, and the diameter of the circle where the root of the sealing teeth is located is smaller than the inner diameter of the cylinder. The present invention effectively ensures the positioning accuracy of the sealing sheet, greatly improves the sealing performance and the reliability of the seal, and improves the adaptability to the unevenness and out-of-roundness of the cylinder; at the same time, it also reduces the penetration resistance. In addition, the dead zone phenomenon is reduced, and the heat exchange efficiency is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of heat exchanger structures, and in particular to a baffle shell and tube heat exchanger with a longitudinal sealing structure. The heat exchanger is provided with a longitudinal sealing structure on the baffle, thereby improving the sealing performance between the baffle and the heat exchanger cylinder. Background Art

[0002] The shell side structure of traditional shell and tube heat exchangers is mostly single-bow type, with a long history of application and relatively accurate process calculation results.

[0003] In process calculation, the classic flow path analysis method is to divide the flow paths formed by the arched plate into five types, namely: A flow path - leakage flow path between the baffle tube hole and the tube; B flow path - cross-flow flow path; C flow path - bypass flow path between the outer periphery of the tube bundle and the inner wall of the shell-side cylinder; E flow path - leakage flow path between the baffle and the inner wall of the shell-side cylinder; F flow path - intermediate through-flow flow path at the tube-side partition (single-pass heat exchanger does not have this flow path). Its flow state is as follows Figure 1 As shown; among them, flow path B is the mainstream, which is beneficial to heat transfer, and its value should be as large as possible, generally required to be >0.6; for other flow path values, the usual principle of selection is the smaller the better; and for E flow path, the E value will cause deformation of the temperature profile, usually limited to E < 0.15.

[0004] However, during installation, it is necessary to ensure that the tube bundle containing the baffle can be smoothly installed into the cylinder, and the cylinder has a roundness deviation (the national standard requires that the circumferential deviation is not more than 10mm and the diameter deviation is not more than 0.5%), so there is always a gap between the baffle and the inner wall of the cylinder, and this value is difficult to guarantee. In the prior art, ZL 01217765.2 and ZL 201520098216.6 disclose two sealing methods, mainly using a rubber seal mounted on the outer edge of the baffle to achieve sealing, but it can only be used at a lower temperature, the installation reliability is not high, the installation is laborious, and it is easy to break; ZL 201721443804.4 uses plastic material components and metal baffles to cast and form, the process is cumbersome and complicated, it is difficult to implement in engineering, and the temperature resistance of plastic is also limited, and it cannot be replaced after damage. In summary, there is no universal and effective sealing structure in the heat exchanger of the prior art, which can better control the gap between the baffle and the cylinder, thereby improving the heat exchange efficiency. Summary of the invention

[0005] The object of the present invention is to provide a baffle shell and tube heat exchanger with a longitudinal sealing structure to solve the problem of large leakage flow path between the baffle and the inner wall of the shell cylinder in the prior art.

[0006] The present invention is realized through the following technical scheme: a baffle shell and tube heat exchanger with a longitudinal sealing structure, comprising a cylinder, a tube sheet, a heat exchange tube, and a baffle, wherein the tube sheet is fixedly connected to both ends of the cylinder, a heat exchange tube is arranged in the cylinder, the axes of the heat exchange tube are parallel, and both ends of the heat exchange tube are fixed between the two tube sheets, a baffle is arranged in the cylinder, the baffle has a liquid through notch for changing the flow direction of the fluid, each adjacent arched baffle is relatively arranged up and down with the liquid through notch, and a plurality of circular tube holes matched with the heat exchange tube are arranged on the baffle, and the heat exchange tube passes vertically through the circular tube hole, characterized in that: a longitudinal sealing structure is provided at the matching part of the baffle and the cylinder; the longitudinal sealing structure is a semicircular ring sealing plate group, a groove matched with the sealing plate group is provided on the baffle, and the sealing plate group is fixed to the baffle by bolts; the sealing plate group includes two or more sealing plates, sealing teeth are provided on the outside of the sealing plate, compensation seams are provided between adjacent sealing teeth, and adjacent sealing plates are staggered.

[0007] Furthermore: the inner diameter of the sealing sheet is larger than the outer diameter of the tube bundle, the outer diameter of the sealing sheet is larger than the inner diameter of the cylinder, and the diameter of the circle where the roots of the sealing teeth are located is smaller than the inner diameter of the cylinder.

[0008] Furthermore: the center line of any sealing tooth corresponds to the center line of the compensation seam on the adjacent sealing sheet.

[0009] Furthermore: taking the outer diameter of the baffle as a reference, the difference between the outer diameter of the sealing sheet and the outer diameter of the baffle is greater than 4 times the gap value between the baffle and the cylinder.

[0010] The advantages of the present invention are:

[0011] 1. The sealing sheet is fixed by the groove and the baffle, which ensures the positioning accuracy of the sealing sheet and prevents it from falling off during the transportation and service of the heat exchanger, thus improving the maintenance cycle of the heat exchanger;

[0012] 2. Sealing is performed through the sealing sheet, which greatly improves the sealing performance and reliability. The bending deformation of the sealing sheet improves the adaptability to the unevenness (such as uniformly raised welds) and out-of-roundness of the cylinder; the contact with the cylinder is surface contact, and the sealing is reliable;

[0013] 3. The clamping ring plate ensures the flatness of the sealing sheet;

[0014] 4. When the sealing sheet contacts the inner wall of the cylinder, the solid part of each tooth will bend independently. After bending, multiple sealing sheets are overlapped and arranged in a fish scale-like distribution, which improves the sealing performance while reducing the penetration resistance and ensures the flatness of each tooth without wrinkles. The tooth-shaped part is elastically bent and close to the inner wall of the cylinder. Since the sealing sheet is installed in an offset manner, there is no gap along the axial direction of the tube bundle, which can completely eliminate the installation gap between the outer diameter of the baffle and the inner wall of the cylinder, making the E value close to 0;

[0015] 5. The sealing position of the sealing sheet is an inclined surface or an arc surface, which can further reduce the dead zone phenomenon generated at the root of the baffle when the fluid moves, thereby increasing the heat exchange efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the classification of fluid flow paths in the shell side of a baffle heat exchanger;

[0017] Figure 2 Schematic diagram of the relationship between the structure of the present invention and the position of the heat exchanger;

[0018] Figure 3 for Figure 2 Side view of

[0019] Figure 4 for Figure 3 A magnified view of point A;

[0020] Figure 5 It is a schematic diagram of the top view of the sealing piece;

[0021] Figure 6 It is a schematic diagram of the side structure of the sealing piece.

[0022] Explanation of the reference numerals: 1 is a cylinder, 2 is a baffle, 3 is a heat exchange tube, 4 is a sealing sheet, 41 is a sealing tooth, 42 is a compensation seam, 5 is a groove, 6 is a bolt, and 7 is a clamping ring plate. DETAILED DESCRIPTION

[0023] like Figure 1 -6 shows the structure of the present invention, which is a baffle shell and tube heat exchanger with a longitudinal sealing structure, including a cylinder 1, a tube sheet, a heat exchange tube 3, and a baffle 2. The tube sheet is fixedly connected to both ends of the cylinder. A heat exchange tube is arranged in the cylinder, the axes of the heat exchange tube are parallel, and both ends of the heat exchange tube are fixed between the two tube sheets. A baffle is arranged in the cylinder, and the baffle has a liquid-passing notch for changing the flow direction of the fluid. Each adjacent arched baffle is arranged vertically with the liquid-passing notch, and a plurality of circular tube holes compatible with the heat exchange tube are provided on the baffle, and the heat exchange tube passes vertically through the circular tube holes. In the present structure, a longitudinal sealing structure is provided at the matching part between the baffle and the cylinder; the longitudinal sealing structure is a semicircular ring-shaped (can be a large semicircular ring or a small semicircular ring) sealing sheet group, a groove 5 matching with the sealing sheet group is provided on the baffle, the sealing sheet group is fixed to the baffle by bolts 6, and a clamping ring plate 7 is also provided between the bolts and the sealing sheet group; the sealing sheet group includes two or more sealing sheets 4, sealing teeth 41 are provided on the outside of the sealing sheet, compensation seams 42 are provided between adjacent sealing teeth, adjacent sealing sheets are staggered, and the sealing teeth of adjacent sealing sheets match with the compensation seams.

[0024] Preferably, the inner diameter of the sealing sheet is larger than the outer diameter of the tube bundle (circle defined by the heat exchange tube), the outer diameter of the sealing sheet is larger than the inner diameter of the cylinder, and the diameter of the circle where the roots of the sealing teeth (i.e. the lower part of the compensation seam) are located is smaller than the inner diameter of the cylinder.

[0025] Preferably, the center line of any sealing tooth corresponds to the center line of the compensation seam on the adjacent sealing sheet, so that the overall sealing is more reliable.

[0026] Preferably: based on the outer diameter of the baffle, the difference between the outer diameter of the sealing sheet and the outer diameter of the baffle is greater than 4 times the gap between the baffle and the cylinder; after a large number of experiments, when the size ratio reaches the above value, the effect is best.

[0027] Preferably, the sealing teeth are 3mm to 5mm wide, the gap is 2mm to 3mm wide, the tooth root diameter is 2mm to 4mm smaller than the baffle outer diameter, and the sealing sheet is 0.2mm to 0.4mm thick; the tooth shape is processed by wire cutting or water jet machining with high precision.

[0028] It should be noted that the drawings in the specification show the connection relationship between the various components, but for the sake of clarity, the proportions or positions in the drawings may be slightly different from the actual ones. Figure 5-6 There are no gaps between the sealing sheets, and there may be multiple sealing sheets.

[0029] The working principle and process of the present invention are as follows: In the structure of the present invention, the main improvement lies in the sealing sheet structure. The sealing sheet is a metal sheet with good elasticity; based on the outer diameter of the baffle, the outer diameter of the sealing sheet is larger than the gap value of 4 times the outer diameter of the baffle, and the inner diameter of the sealing sheet should be slightly larger than the limited circular diameter of the tube bundle. After the two sealing sheets are displaced (the solid part of the sheet should completely cover the gap), they are connected together (non-toothed part) by gluing or resistance welding, and then bolt holes are processed on the sealing sheet to form a sealing sheet group. One or more groups of sealing sheet groups and sealing clamping ring plates are connected to the baffles with clamping bolts and clamping nuts. When all baffles on the tube bundle are equipped with such a sealing sheet group, the tube bundle can be penetrated. At this time, the sealing sheet meets the inner wall of the cylinder, and the solid part of each tooth will bend independently, which reduces the penetration resistance and ensures the flatness of each tooth without wrinkles; the toothed part is elastically bent and close to the inner wall of the cylinder. Since the sealing sheets are installed in groups with staggered positions, there is no gap along the axial direction of the tube bundle, which can completely eliminate the installation gap between the outer diameter of the baffle and the inner wall of the cylinder, making the E value close to 0. In addition, when the sealing sheet and the cylinder are sealed by the elasticity of the bending, the sealing position is an inclined surface, which can further reduce the dead zone phenomenon at the root of the baffle when the fluid moves, and increase the heat exchange efficiency.

Claims

1. A baffled shell and tube heat exchanger with a longitudinal sealing structure, comprising a cylinder, a tube sheet, a heat exchange tube, and a baffle, wherein the tube sheet is fixedly connected to both ends of the cylinder, a heat exchange tube is arranged in the cylinder, the axes of the heat exchange tube are parallel, and both ends of the heat exchange tube are fixed between the two tube sheets, a baffle is arranged in the cylinder, a liquid-passing notch is provided on the baffle for changing the flow direction of the fluid, each adjacent arcuate baffle is arranged vertically with the liquid-passing notch, and a plurality of circular tube holes adapted to the heat exchange tube are provided on the baffle, and the heat exchange tube passes vertically through the circular tube holes, characterized in that: A longitudinal sealing structure is provided at the matching part of the baffle and the cylinder; the longitudinal sealing structure is a semicircular ring-shaped sealing sheet group, a groove matching the sealing sheet group is provided on the baffle, and the sealing sheet group is fixed to the baffle by bolts; the sealing sheet group includes two or more sealing sheets, sealing teeth are provided on the outside of the sealing sheets, compensation seams are provided between adjacent sealing teeth, and adjacent sealing sheets are arranged alternately; the inner diameter of the sealing sheet is larger than the outer diameter of the tube bundle, the outer diameter of the sealing sheet is larger than the inner diameter of the cylinder, and the diameter of the circle where the roots of the sealing teeth are located is smaller than the inner diameter of the cylinder; the center line of any sealing tooth corresponds to the center line of the compensation seam on the adjacent sealing sheet; taking the outer diameter of the baffle as a reference, the difference between the outer diameter of the sealing sheet and the outer diameter of the baffle is larger than 4 times the value of the gap between the baffle and the cylinder.

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