A shell-and-tube graphite heat exchanger

Abstract

The utility model discloses a column pipe type graphite heat exchanger belongs to column pipe type heat exchanger technical field, including cylinder, and the both ends of cylinder are connected with the tube sheet respectively, and the outside of two tube sheets is connected with upper head and lower head respectively, and the upper head is opened with the pipe medium export, and the lower head is opened with the pipe medium import, the baffle is arranged staggeredly in the cylinder, and the bottom end outside of cylinder is opened with the shell medium export, and the top end outside is opened with the shell medium import, the array of a plurality of graphite heat exchange pipes is arranged between two tube sheets, and the both ends of graphite heat exchange pipe respectively penetrate two tube sheets and communicate upper head inner chamber and lower head inner chamber, and the carbon fiber is twisted outside graphite heat exchange pipe, and the carbon fiber is twisted staggeredly outside graphite heat exchange pipe. The utility model discloses a carbon fiber reinforcing layer is twisted staggeredly outside graphite heat exchange pipe, can effectively promote graphite heat exchange pipe strength, reduce splicing leakage, restrain high temperature thermal expansion, and improve overall structure reliability.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of shell and tube heat exchanger, especially relates to a shell and tube graphite heat exchanger. BACKGROUND

[0002] The shell and tube graphite heat exchanger is a kind of heat exchanger widely used in chemical industry and alcohol production and other fields, and is mainly used as cooler, condenser or heater.The shell and tube graphite heat exchanger is flowed by one medium in shell side in shell body, and another medium is flowed in graphite pipe by pipe side.Two kinds of medium carry out heat exchange between heat exchange pipe and shell side, and realize the transmission of heat energy.Moreover, graphite material has acid corrosion resistance and good heat conduction performance, so that the shell and tube graphite heat exchanger can bear higher service temperature and certain range of rapid cooling and rapid heating.

[0003] The heat exchange element of traditional shell and tube graphite heat exchanger is ordinary compression or impregnated graphite pipe, and the following structural defects exist:

[0004] Impregnated graphite single pipe length is limited: due to processing limitation, single graphite pipe is 1200mm at most, and overlength pipe needs to be bonded and spliced, which leads to the increase of sealing point and high leakage risk;

[0005] Thermal expansion and corrosion problem of compression graphite pipe: phenolic resin-based graphite pipe is significantly thermal expansion at >120 DEG C, easily causes pipe body stress rupture, and influences the reliability of heat exchanger.

[0006] Therefore, it is urgent to improve the strength and thermal stability and corrosion resistance of graphite pipe.

[0007] Therefore, a new shell and tube graphite heat exchanger is proposed. INVENTION CONTENTS

[0008] To solve the above technical problems, the utility model provides a kind of shell and tube graphite heat exchanger.

[0009] To realize the above purpose, the utility model provides a kind of shell and tube graphite heat exchanger, including: cylinder, the upper and lower ends of the cylinder are connected with tube sheet respectively, the outer sides of two tube sheets are connected with upper head and lower head respectively, the upper head is opened with pipe side medium outlet, and the lower head is opened with pipe side medium inlet;Baffle is arranged staggeredly in the cylinder, shell side medium outlet is opened in the outer side of the bottom end of the cylinder, and shell side medium inlet is opened in the outer side of top end;A plurality of graphite heat exchange pipes are arranged in array between two tube sheets, and the two ends of the graphite heat exchange pipe are respectively penetrated through two tube sheets and communicated with the inner cavity of the upper head and the inner cavity of the lower head;Carbon fiber is wound outside the graphite heat exchange pipe, and the carbon fiber is staggered wound outside the graphite heat exchange pipe.

[0010] Preferably, the carbon fiber is wound at an angle of 45°-90° outside the graphite heat exchange pipe, and the carbon fibers of adjacent two layers are cross-wound in X shape.

[0011] Preferably, the thickness of the carbon fiber wound outside the graphite heat exchange pipe is 0.2-0.5 mm.

[0012] Preferably, the overall outer diameter of the graphite heat exchange pipe after winding the carbon fiber matches that of a conventional tube-type graphite heat exchanger.

[0013] Preferably, the shell side medium inlet is arranged outside the anti-impact ring and communicates with the top of the cylinder through the anti-impact ring.

[0014] Preferably, the tube plate close to the upper head is a fixed tube plate, the upper end of the fixed tube plate abuts against the upper head, and the lower end of the fixed tube plate abuts against the cylinder, the cylinder and the upper head are connected by bolt fastening, so that the fixed tube plate is pressed to abut between the upper head and the cylinder, and first sealing gaskets are arranged between the abutting surfaces of the fixed tube plate and the upper head and between the abutting surfaces of the fixed tube plate and the cylinder.

[0015] Preferably, the tube plate close to the lower head is a floating tube plate, the floating tube plate is sleeved on the bottom end of the cylinder, and one end of the floating tube plate close to the cylinder is sleeved with a floating pressure ring, a 0-shaped ring is arranged between the floating pressure ring and the floating tube plate, and the floating pressure ring is connected with the cylinder by bolt fastening.

[0016] Preferably, one end of the floating tube plate close to the lower head is fixedly connected with a split ring, a split ring pressure ring is arranged above the split ring, the split ring pressure ring is connected with the lower head by bolt fastening, and a second sealing gasket is arranged between the floating tube plate and the lower head.

[0017] Compared with the prior art, the utility model has the advantages and technical effects that:

[0018] By interlaced winding carbon fiber outside the graphite heat exchange pipe to form a mechanical constraint layer, the compression and bending strength of the pipe material is significantly improved, the sealing points and leakage risks caused by splicing are reduced, and the problems of insufficient strength of the traditional pipe material and thermal expansion rupture are solved; the baffle in the cylinder optimizes the disturbance of the medium to improve the heat exchange efficiency, the anti-impact ring reduces the impact and wear of the medium, the fixed tube plate and the floating tube plate are designed to enhance the sealing reliability and compensate the thermal stress, and the baffle arranged in the cylinder can guide the turbulent flow of the shell side medium, increase the contact area and disturbance intensity of the medium and the graphite pipe, and improve the heat exchange efficiency; the structure design of the cylinder, the tube plate and the head forms independent pipe side and shell side medium channels, ensures that the two kinds of media effectively exchange heat through the graphite heat exchange pipe, and enhances the overall structural reliability. BRIEF DESCRIPTION OF DRAWINGS

[0019] The accompanying drawings, which form a part of this patent, are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and serve to explain the principles of the application. In the drawings, where like reference numerals refer to identical or

[0020] Figure 1 Structure schematic view of the tube type graphite heat exchanger of the present application;

[0021] Figure 2 Structure schematic view of the graphite heat exchange tube and the carbon fiber wound thereon in the present application;

[0022] Figure 3 Winding schematic view of the carbon fiber in the present application;

[0023] Figure 4 is Figure 1 Enlarged view of A in the present application;

[0024] Figure 5 is Figure 1 Enlarged view of B in the present application.

[0025] In the drawing, 1, cylinder; 2, upper head; 3, lower head; 4, tube side medium outlet; 5, tube side medium inlet; 6, baffle; 7, shell side medium outlet; 8, shell side medium inlet; 9, graphite heat exchange tube; 10, carbon fiber; 11, anti-impact ring; 12, fixed tube sheet; 13, first sealing gasket; 14, floating tube sheet; 15, floating pressure ring; 16, 0-shaped ring; 17, split ring; 18, split ring pressure ring; 19, second sealing gasket. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0027] In order to make the above purposes, features and advantages of the present application more apparent, obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0028] The following professional terms will be used in the specific embodiments of the present application, which are described in advance here:

[0029] Tube side and tube side medium: the tube side refers to the flow path of fluid inside the graphite heat exchange tube (9), which is composed of the tube bundle passage between the upper head (2), the lower head (3) and the tube sheet. The heat exchange medium flowing in the tube side is the tube side medium.

[0030] Shell side and shell side medium: The shell side refers to the annular space flow path of the fluid outside the graphite heat exchange tube (9) and inside the shell (1), which consists of the shell (1), the baffle (6) and the space outside the tube sheet. The heat exchange medium flowing in the shell side is the shell side medium.

[0031] In a shell-and-tube heat exchanger, the shell side and the tube side are two independent fluid channels, each carrying different flow paths for the heat exchange medium.

[0032] Reference Figures 1 to 5 As shown, this embodiment provides a shell-and-tube graphite heat exchanger, including: a cylindrical body 1, tube sheets connected to the upper and lower ends of the cylindrical body 1 respectively, an upper end cap 2 and a lower end cap 3 connected to the outer sides of the two tube sheets respectively, a tube-side medium outlet 4 opened on the upper end cap 2, and a tube-side medium inlet 5 opened on the lower end cap 3; baffles 6 are staggered inside the cylindrical body 1, a shell-side medium outlet 7 is opened on the outer side of the bottom end of the cylindrical body 1, and a shell-side medium inlet 8 is opened on the outer side of the top end; a plurality of graphite heat exchange tubes 9 are arranged in an array between the two tube sheets, and the two ends of the graphite heat exchange tubes 9 respectively penetrate the two tube sheets and connect the inner cavity of the upper end cap 2 and the inner cavity of the lower end cap 3; carbon fiber 10 is wound around the outside of the graphite heat exchange tubes 9, and the carbon fiber 10 is staggered wound around the outside of the graphite heat exchange tubes 9.

[0033] By forming a mechanical constraint layer by interlacing carbon fiber 10 around the graphite heat exchange tube 9, the compressive and bending strength of the tube is significantly improved, reducing the risk of sealing points and leakage caused by splicing. At the same time, it suppresses thermal expansion at high temperatures (>120℃), solving the problems of insufficient strength and thermal expansion rupture of traditional tubes. In conjunction with the baffle 6 inside the shell 1 to optimize medium disturbance and improve heat exchange efficiency, the anti-impact ring 11 reduces medium impact wear, and the design of fixed tube sheet 12 and floating tube sheet 14 enhances sealing reliability and compensates for thermal stress. The interlaced baffle 6 inside the shell 1 can guide the turbulent flow of the shell-side medium, increase the contact area and disturbance intensity between the medium and the graphite tube, and improve heat exchange efficiency. The structural design of the shell 1, tube sheet and end cap forms independent tube-side and shell-side medium channels, ensuring that the two media can effectively exchange heat through the graphite heat exchange tube 9, and enhancing the overall structural reliability.

[0034] Further optimization of the scheme: the carbon fiber 10 is wound around the graphite heat exchange tube 9 at an angle of 45°-90°, and the carbon fiber 10 of adjacent two layers is wound in an X-shape.

[0035] The 45°-90° cross-winding provides effective support for carbon fiber 10 in the circumferential, axial, and shear directions. Compared to single-angle winding, it improves the balance of the tube's tensile, compressive, and shear strength, especially enhancing the graphite tube's resistance to torsion under complex working conditions. This avoids cracking caused by stress concentration in one direction, such as circumferential stress caused by thermal expansion or shear stress caused by media impact. The X-shaped cross-winding layer restricts the thermal expansion of the graphite tube in all directions through mesh-like mechanical constraints. Compared to traditional unidirectional winding, it can more evenly offset the circumferential and axial stress imbalance caused by thermal expansion of the tube body at high temperatures (>120℃), significantly reducing the risk of thermal stress cracking. Moreover, the dense interlayer structure formed by cross-winding is like a "three-dimensional maze," which can effectively prevent corrosive media such as acids and alkalis from penetrating into the graphite matrix along the fiber gaps, significantly improving corrosion resistance.

[0036] The scheme was further optimized so that the thickness of the carbon fiber 10 wrapped around the graphite heat exchange tube 9 was 0.2-0.5mm.

[0037] The structure with a carbon fiber 10 winding thickness of 0.2-0.5mm achieves multiple technical advantages through precise control of the reinforcement layer thickness: This thickness range can effectively stack carbon fiber 10 to form a continuous and dense mechanical constraint layer, thereby improving the strength of a single tube, while avoiding insufficient constraint due to excessive thinness or increased material cost and processing difficulty due to excessive thickness, thus achieving a balance between mechanical performance and economy; the thin winding layer has minimal impact on the heat conduction of the graphite tube, ensuring that the heat exchange efficiency is not significantly affected under high-temperature conditions.

[0038] The design was further optimized so that the overall outer diameter of the graphite heat exchange tube 9 after being wrapped with carbon fiber 10 is matched with that of the traditional shell and tube type graphite heat exchanger.

[0039] The graphite heat exchange tube 9, after being wound with carbon fiber 10, has an overall outer diameter that matches that of a traditional shell-and-tube graphite heat exchanger. This standardized outer diameter design achieves seamless compatibility with traditional equipment. Because its outer diameter is exactly the same as that of a traditional graphite tube, no modifications are needed to the core structure of the heat exchanger, such as the inner diameter of the shell 1, the tube sheet hole spacing, or the baffle 6 spacing. It can directly replace the original heat exchange elements, significantly reducing the technical threshold and modification costs for equipment upgrades. This is particularly suitable for technological iteration scenarios involving existing, outdated equipment in the industry, avoiding systemic replacement costs due to structural incompatibility. Simultaneously, the standardized outer diameter ensures a perfect fit between the new heat exchange tube and existing tube sheet holes, sealing components, and connecting parts. No special tooling or customized processes are required during installation, allowing for rapid assembly and significantly reducing downtime for modifications. In later maintenance, a single damaged carbon fiber 10-reinforced tube can be independently disassembled and replaced without disassembling the entire heat exchanger, reducing maintenance complexity and improving production continuity. This design breaks down the contradiction between technological upgrades and equipment compatibility, enabling carbon fiber 10-reinforced technology to be widely applied to various operating conditions using traditional shell-and-tube graphite heat exchangers. This promotes the large-scale popularization of new technologies while avoiding additional material, manpower, and downtime losses caused by structural modifications, achieving a "low-cost, high-efficiency" technological upgrade and significantly improving the economy and feasibility of enterprise equipment upgrades.

[0040] In a further optimized design, the shell-side medium inlet 8 is located outside the anti-impact ring 11 and is connected to the top of the cylinder 1 through the anti-impact ring 11.

[0041] The shock-absorbing ring 11 has a buffering and guiding function, preventing the shell-side medium from directly impacting the tube bundle at high speed, thereby significantly reducing the risk of wear, vibration and structural damage to the tube bundle caused by medium impact, and extending the service life of the heat exchanger. The specific structure of the shock-absorbing ring 11 is existing technology and will not be described in detail here.

[0042] In a further optimized design, the tube sheet near the upper end cap 2 is a fixed tube sheet 12. The upper end of the fixed tube sheet 12 abuts against the upper end cap 2, and the lower end abuts against the cylinder 1. The cylinder 1 and the upper end cap 2 are fastened together by bolts, so that the fixed tube sheet 12 is compressed and abuts against the upper end cap 2 and the cylinder 1. A first sealing gasket 13 is provided between the abutting surfaces of the fixed tube sheet 12 and the upper end cap 2, and between the abutting surfaces of the fixed tube sheet 12 and the cylinder 1.

[0043] The fixed tube sheet 12 is bolted together to form a rigid connection system between the upper end cap 2, the tube sheet, and the shell 1, ensuring physical isolation between the inner cavity of the upper end cap 2 and the inner cavity of the shell 1, thus preventing the mixing of the two media. The first sealing gasket 13 is respectively set on the contact surface between the fixed tube sheet 12, the upper end cap 2, and the shell 1, using the elasticity of the material to compensate for the micro gaps at the interface, enhancing the sealing reliability under high pressure and high temperature conditions, and significantly reducing the risk of media leakage. At the same time, the fixed tube sheet 12 forms a rigid support for the upper end of the graphite heat exchange tube 9, reducing the displacement and vibration of the tube bundle under the impact of the media, improving the overall structural stability of the heat exchanger, and the bolt connection method facilitates equipment installation and disassembly, providing convenience for later maintenance, replacement of gaskets or tube bundles.

[0044] The scheme is further optimized so that the tube sheet near the lower end cap 3 is a floating tube sheet 14. The top of the floating tube sheet 14 is sleeved on the bottom of the cylinder 1. A floating flange 15 is sleeved on one end of the floating tube sheet 14 near the cylinder 1. An O-ring 16 abuts between the floating flange 15 and the floating tube sheet 14. The floating flange 15 and the cylinder 1 are fastened together by bolts.

[0045] The floating tube sheet 14 can freely adapt to the thermal expansion deformation caused by the temperature difference between the graphite heat exchange tubes 9 and the shell 1, avoiding tube sheet cracking or tube bundle leakage caused by thermal stress concentration, and is especially suitable for working conditions with large temperature differences. The combination of the floating flange 15 and the O-ring 16 allows the tube sheet to move axially while maintaining the clamping force of the sealing surface through bolt adjustment, ensuring the sealing reliability of the shell-side medium in dynamic environments and reducing the risk of leakage. This structure also provides a retractable support end for the tube bundle, reducing tube bundle vibration caused by medium impact, improving the overall stability of the heat exchanger, and the tube bundle can be inspected or cleaned by disassembling the floating flange 15, which significantly improves the convenience of equipment maintenance.

[0046] In a further optimized design, a split ring 17 is fixedly connected to one end of the floating tube sheet 14 near the lower end cap 3. A split ring flange 18 is abutted above the split ring 17. The split ring flange 18 is bolted to the lower end cap 3. A second sealing gasket 19 is provided between the floating tube sheet 14 and the lower end cap 3.

[0047] The combination of the split ring 17 and the split ring flange 18 forms a rigid limit on the lower end of the floating tube sheet 14, preventing excessive axial displacement under shell-side medium pressure or thermal expansion, ensuring the relative position stability of the floating tube sheet 14 and the cylinder 1. At the same time, by tightening the split ring flange 18 with bolts, the second sealing gasket 19 can be further tightened, enhancing the sealing reliability at the connection between the lower head 3 and the floating tube sheet 14 and reducing the risk of shell-side medium leakage. This structure adopts a split design, which facilitates quick disassembly of the split ring flange 18 and the split ring 17 during maintenance. The floating tube sheet 14 or the lower end of the tube bundle can be maintained, cleaned or replaced without completely disassembling the connection between the cylinder 1 and the lower head 3, significantly improving the convenience and efficiency of equipment maintenance, and is especially suitable for high-corrosion or high-impurity operating conditions that require frequent maintenance.

[0048] Any aspects of this utility model that are not detailed herein are conventional technical means known to those skilled in the art.

[0049] In the description of this utility model, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0050] The embodiments described above are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Various modifications and improvements made to the technical solutions of the present utility model by those skilled in the art without departing from the spirit of the present utility model should fall within the protection scope defined by the claims of the present utility model.

Claims

1. A shell-and-tube graphite heat exchanger, characterized in that, include: A cylindrical body (1) is connected to tube sheets at its upper and lower ends. An upper end cap (2) and a lower end cap (3) are connected to the outer sides of the two tube sheets respectively. A tube-side medium outlet (4) is opened on the upper end cap (2), and a tube-side medium inlet (5) is opened on the lower end cap (3). Baffles (6) are staggered inside the cylindrical body (1). A shell-side medium outlet (7) is opened on the outer side of the bottom end of the cylindrical body (1), and a shell-side medium inlet (8) is opened on the outer side of the top end. A plurality of graphite heat exchange tubes (9) are arranged in an array between the two tube sheets. The two ends of the graphite heat exchange tubes (9) pass through the two tube sheets respectively and connect the inner cavity of the upper end cap (2) and the inner cavity of the lower end cap (3). Carbon fiber (10) is wound around the outside of the graphite heat exchange tubes (9). The carbon fiber (10) is staggered and wound around the outside of the graphite heat exchange tubes (9).

2. The shell-and-tube graphite heat exchanger according to claim 1, characterized in that: The carbon fiber (10) is wound around the graphite heat exchange tube (9) at an angle of 45°-90°, and the carbon fibers (10) of adjacent two layers are intertwined in an X-shape.

3. The shell-and-tube graphite heat exchanger according to claim 1, characterized in that: The carbon fiber (10) is wound around the graphite heat exchange tube (9) with a thickness of 0.2-0.5 mm.

4. The shell-and-tube graphite heat exchanger according to claim 1, characterized in that: The overall outer diameter of the graphite heat exchange tube (9) after being wound with the carbon fiber (10) is matched with that of a conventional shell-and-tube graphite heat exchanger.

5. The shell-and-tube graphite heat exchanger according to claim 1, characterized in that: The shell-side medium inlet (8) is located outside the anti-impact ring (11) and is connected to the top of the cylinder (1) through the anti-impact ring (11).

6. The shell-and-tube graphite heat exchanger according to claim 1, characterized in that: The tube sheet near the upper end cap (2) is a fixed tube sheet (12). The upper end of the fixed tube sheet (12) abuts against the upper end cap (2) and the lower end abuts against the cylinder (1). The cylinder (1) and the upper end cap (2) are fastened together by bolts, so that the fixed tube sheet (12) is squeezed and abuts against the upper end cap (2) and the cylinder (1). A first sealing gasket (13) is provided between the abutting surfaces of the fixed tube sheet (12) and the upper end cap (2) and between the abutting surfaces of the fixed tube sheet (12) and the cylinder (1).

7. The shell-and-tube graphite heat exchanger according to claim 1, characterized in that: The tube sheet near the lower end cap (3) is a floating tube sheet (14). The top of the floating tube sheet (14) is fitted onto the bottom of the cylinder (1). A floating flange (15) is fitted onto one end of the floating tube sheet (14) near the cylinder (1). An O-ring (16) abuts between the floating flange (15) and the floating tube sheet (14). The floating flange (15) is fastened to the cylinder (1) by bolts.

8. The shell-and-tube graphite heat exchanger according to claim 7, characterized in that: A split ring (17) is fixedly connected to one end of the floating tube plate (14) near the lower end cap (3). A split ring flange (18) abuts above the split ring (17). The split ring flange (18) is bolted to the lower end cap (3). A second sealing gasket (19) is provided between the floating tube plate (14) and the lower end cap (3).

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