Paraxylene condenser

Abstract

The application provides a p-xylene condenser which provides a large-volume heat exchange shell, improves gas-liquid phase replacement space in a shell pass, and ensures purity of shell pass gas; meanwhile, gas phase medium and liquid phase medium at a tube pass outlet are collected in a split manner to ensure that they can be reused subsequently. The p-xylene condenser comprises a horizontal combined cylinder which comprises small cylinder bodies at two length direction ends and a large cylinder body at a middle part in the length direction, an upper part of the large cylinder body is a self-lower-to-upper conical frustum structure, a first tube box which is a tube pass inlet tube box and comprises an upper large-diameter inlet, a second tube box which is a tube pass outlet tube box and comprises an upper gas phase outlet and a lower liquid phase outlet, a gas outlet tank, a tube bundle, and two end tube plates.

Description

Technical Field

[0001] This invention relates to the technical field of paraxylene production equipment, specifically paraxylene condensers. Background Technology

[0002] In the production of para-xylene, multiple operations are required to finally extract the corresponding substance. During this process, the intermediate product gas-liquid mixture needs to be purified by heat exchange to reliably separate the gas and liquid in the gas-liquid mixture for subsequent operations.

[0003] Existing paraxylene condensers generally adopt a horizontal cylindrical tank structure, which exchanges heat between the high-temperature medium and the gas-liquid mixture in the shell side through heat exchange tubes. The gas after heat exchange is located in the upper space of the horizontal cylindrical tank and is then directly output to the corresponding gas storage device through the exhaust port. The high-temperature medium in the tube side becomes a low-temperature medium after heat exchange and is directly discharged.

[0004] In existing paraxylene condensers, the high-temperature medium used for tube-side heat exchange mixes with the gas-liquid mixture in the shell side, generating both gaseous and liquid phases. However, existing paraxylene condensers have only one tube-side outlet, making it impossible to reliably distinguish and collect the two phases. Consequently, the gaseous medium, which could otherwise be reused, cannot be directly reused. Furthermore, since the gas and liquid in the shell side are placed in the upper and lower layers of a horizontal cylindrical tank, a gas cavity needs to be reserved. This means the heat exchange tubes cannot completely fill the vertical space of the horizontal cylindrical tank, resulting in low heat exchange efficiency. Moreover, since the gas is discharged directly through the exhaust port without effective isolation between the gas and liquid, the discharged gas is easily mixed with liquid droplets, resulting in low purity of the gas obtained through the paraxylene condenser. In addition, the arrangement of the horizontal cylindrical tank leaves four corner positions at both ends of the shell-side cavity, which is not conducive to sufficient heat exchange. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a paraxylene condenser, which features a large-volume heat exchange shell, increasing the gas-liquid phase displacement space in the shell side and ensuring the purity of the shell-side gas; simultaneously, it separates and collects the gaseous and liquid phase media at the tube-side outlet, ensuring subsequent reuse.

[0006] p-xylene condenser, characterized in that it comprises: A horizontal combined cylindrical body includes small cylindrical bodies at both ends along the length direction and a large cylindrical body in the middle along the length direction. The upper part of the large cylindrical body is a truncated cone structure that tapers from bottom to top. The first tube box is a tube-side feed tube box, which includes an upper large-diameter feed inlet; The second tube box is a tube-side discharge tube box, which includes an upper gas phase outlet and a lower liquid phase outlet; Vent canister; Tubes; and the tube sheets at both ends; The smaller cylinders at both ends of the horizontal combined cylinder along its length are connected to the tube sheet and the corresponding connecting flanges of the two sets of tube boxes via fastening connectors. The high-temperature tube medium is introduced into the large-diameter inlet at the top of the first tube box. Tube bundles are arranged in the area of ​​the large cylinder corresponding to the tube sheet, and the two ends of each tube bundle are respectively inserted into the corresponding interfaces of the tube sheet. The top of the concave cone structure is connected to the bottom of the gas outlet tank via several upwardly protruding and spaced connecting pipes. The top of the gas outlet tank is provided with a large-diameter gas outlet.

[0007] Its further features are: The connecting pipes are arranged in a straight line at equal intervals, and all connecting pipes have the same diameter. The gas outlet is arranged horizontally, and the length of the gas outlet covers all connecting pipes, which can effectively prevent gas turbulence caused by a large amount of gas gushing out. The space of the concave truncated cone structure corresponds to the position below all the connecting pipes, where a wire mesh demister is installed to ensure the purity of the gas. The horizontal combined cylinder is provided with shell-side feed inlets on both sides of the middle region of the tube bundle area in the height direction. The shell-side feed inlets are arranged close to the first tube box. The horizontal combined cylinder is provided with shell-side liquid phase outlets on both sides of the middle region of the tube bundle area in the height direction. The shell-side liquid phase outlets are arranged close to the second tube box. This ensures that the shell-side gas-liquid mixture in the horizontal combined cylinder is kept at a relatively high level. The second tube box is equipped with vertically arranged baffles. The baffles are arranged behind the tube sheet and are fixedly installed in the middle and upper regions of the second tube box. The baffles guide the tube-side medium flowing out of the tube bundle downwards. In this way, the baffles can prevent the tube-side medium after heat exchange from directly scouring the end cap of the second tube box and reduce the flow rate of the tube-side medium after heat exchange. After the baffles are guided, the heavy components flow out from the lower liquid phase outlet and the light components flow out from the upper gas phase outlet. This separates the heat exchange medium in the shell side into gas and liquid phases. The gas phase medium can be reused directly, while the liquid phase medium needs to be reheated to form a gas phase medium before it can be used. The horizontal combined cylinder is a structure that gradually slopes upward from one end of the second tube box to one end of the first tube box, with an inclination of 1° to 2° relative to the horizontal plane. When the horizontal combined cylinder is arranged at an incline, an expansion joint is installed on the small cylinder of the horizontal combined cylinder corresponding to the second pipe box side. A low saddle and a high saddle are respectively set at both ends of the bottom length direction of the large cylinder. The high saddle is arranged close to the first pipe box, and the low saddle is arranged close to the second pipe box. The setting of the expansion joint allows the inclination of the horizontal combined cylinder to be quickly adjusted, making assembly simple and quick. When the horizontal combined cylinder is arranged at an incline, the top of the concave cone structure is an inclined surface. By adjusting the upward convex distance of the connecting pipe, the exhaust tank is arranged horizontally to ensure stable and reliable exhaust. The horizontal combined cylinder is equipped with several level gauges and thermometers. Due to the large heat exchange volume in the shell side, the multiple sets of level gauges and thermometers ensure that the medium level and temperature in the shell side meet the process requirements after heat exchange. By adjusting the input flow rate of the shell side medium, the shell side medium level and temperature can be adjusted, while the input flow rate of the tube side medium remains constant.

[0008] With this invention, the high-temperature tube-side medium enters the first tube box through the upper large-diameter inlet, and then exchanges heat with the shell-side medium located in the horizontal combined cylinder through the annular tube bundle. Since the horizontal combined cylinder includes small cylinders at both ends of the length direction and a large cylinder in the middle of the length direction, and the upper region of the large cylinder is a concave truncated cone structure from bottom to top, the gas chamber is set on the upper layer of the concave truncated cone structure. Thus, the tube bundle can be arranged in the height space of the large cylinder corresponding to the tube sheet, which improves the gas-liquid phase replacement space of the shell side. Moreover, since the gas chamber and the shell-side heat exchange space are reliably separated, the purity of the shell-side gas is ensured. In addition, after the tube-side medium enters the second tube box through the tube bundle, it is diverted according to the state of the tube-side medium. The liquid flows out from the lower liquid phase outlet and the gas flows out from the upper gas phase outlet. At the same time, the gas phase medium and liquid phase medium at the tube-side outlet are diverted and collected to ensure that they can be reused later. Attached Figure Description

[0009] Figure 1 This is a simplified schematic diagram of the main view structure of the present invention; Figure 2 This is a simplified schematic diagram of the left view structure of the present invention; The names corresponding to the serial numbers in the diagram are as follows: Horizontal combined cylinder 10, shell-side feed inlet 101, shell-side liquid phase outlet 102, small cylinder 11, large cylinder 12, tapering conical structure 13, expansion joint 14, low saddle 15, high saddle 16, first tube box 20, upper large-diameter feed inlet 21, second tube box 30, upper gas phase outlet 31, lower liquid phase outlet 32, guide plate 33, gas outlet tank 40, large-diameter gas outlet 41, tube bundle 50, tube sheet 60, fastening connector 70, connecting pipe 80, wire mesh demister 90, manhole 100. Detailed Implementation

[0010] paraxylene condenser, see Figure 1 and Figure 2 It includes a horizontal combined cylinder 10, a first tube box 20, a second tube box 30, an exhaust tank 40, a tube bundle 50, and tube sheets 60 at both ends; The horizontal combined cylinder 10 includes small cylinders 11 at both ends in the length direction and a large cylinder 12 in the middle in the length direction. The upper part of the large cylinder 12 is a truncated cone structure 13 that tapers from bottom to top. The first tube box 20 is a tube-side feed tube box, which includes an upper large-diameter feed port 21; The second tube box 30 is a tube-side discharge tube box, which includes an upper gas phase outlet 31 and a lower liquid phase outlet 32. The small cylinders 11 at both ends of the horizontal combined cylinder 10 are connected to the tube plate 60 and the corresponding connecting flanges of the first tube box 20 and the second tube box 30 through fastening connectors 70. The high-temperature tube medium is introduced into the upper large-diameter inlet 21 of the first tube box 20. The tube bundles 50 are arranged in the middle of the large cylinder 12 corresponding to the surface area of ​​the tube plate 60. The two ends of each tube bundle 50 are respectively inserted into the corresponding interface of the tube plate 60. The top of the conical structure 13 is connected to the bottom of the gas outlet tank 40 through several upwardly protruding and spaced connecting pipes 80. The top of the gas outlet tank 40 is provided with a large-diameter gas outlet 41.

[0011] In a specific embodiment, four connecting pipes 80 are arranged in a straight line at equal intervals, and all connecting pipes 80 have the same diameter. The gas outlet tank 40 is arranged horizontally, and the length of the gas outlet tank 40 covers all connecting pipes 80, which can effectively prevent gas turbulence caused by a large amount of gas gushing out. The gas outlet tank 40 can collect gas, buffer the gaseous medium generated by heat exchange in the shell side, and also increase the gas phase space in the shell side.

[0012] In a specific embodiment, a wire mesh demister 90 is provided in the space of the concave truncated cone structure 13 corresponding to the position below all the connecting pipes 80 to ensure the purity of the gas. For ease of maintenance, a manhole 100 is also provided on the outer periphery of the concave truncated cone structure 13 corresponding to the area of ​​the wire mesh demister 90. The manhole 100 is used for the installation and replacement of the wire mesh demister 90.

[0013] In specific implementation, the horizontal combined cylinder 10 is provided with shell-side feed inlets 101 on both sides of the middle region of the tube bundle area in the height direction. The shell-side feed inlets 101 are arranged close to the first tube box 20. The horizontal combined cylinder 10 is provided with shell-side liquid phase outlets 102 on both sides of the middle region of the tube bundle area in the height direction. The shell-side liquid phase outlets 102 are arranged close to the second tube box 30, which makes the shell-side gas-liquid mixture in the horizontal combined cylinder 10 maintain a relatively high level.

[0014] In a specific embodiment, a vertically arranged guide plate 33 is provided inside the second tube box 30. The guide plate 33 is arranged behind the tube sheet 60 installed at the corresponding position in the second tube box 30. The guide plate 33 is fixedly installed in the middle and upper regions of the second tube box 30. The guide plate 33 guides the tube-side medium flowing out of the tube bundle 50 downwards. Thus, the guide plate 33 can prevent the tube-side medium after heat exchange from directly scouring the end cap of the second tube box 30 and can reduce the flow rate of the tube-side medium after heat exchange. After the flow is guided, the heavy components flow out from the lower liquid phase outlet 32, and the light components flow out from the upper gas phase outlet 31. This separates the heat exchange medium in the shell side into a gas phase and a liquid phase. The gas phase medium can be reused directly, while the liquid phase medium needs to be reheated to form a gas phase medium before it can be reused.

[0015] Preferably, in order to ensure that the shell-side medium is fully heat exchanged, the horizontal combined cylinder 10 is configured to gradually slope upward from one end of the second tube box 30 to one end of the first tube box 20, with an inclination of 1° to 2° relative to the horizontal plane. When the horizontal combined cylinder 10 is arranged at an angle, an expansion joint 14 is installed on the small cylinder 11 of the horizontal combined cylinder 10 corresponding to the side of the second pipe box 30. A low saddle 15 and a high saddle 16 are respectively set at both ends of the bottom length direction of the large cylinder 12. The high saddle 16 is arranged close to the first pipe box 20, and the low saddle 15 is arranged close to the second pipe box 30. The setting of the expansion joint 14 allows the inclination of the horizontal combined cylinder 10 to be quickly adjusted, making assembly simple and quick.

[0016] In practical implementation, the conical truncated structure 13 effectively increases the shell volume. The inclined arrangement of the horizontal combined cylinder 10 increases the flow velocity of the tube-side medium under the action of gravity. The symmetrical use of the two conical truncated structures 13 can effectively reduce the axial stress caused by the sudden change in equipment diameter. The use of the expansion joint 14 reduces the thermal stress caused by different operating temperatures and linear expansion coefficients of different materials between the tube side and the shell side, making the deformation of the tube sheet and heat exchange tubes coordinated. Furthermore, the shell-side inlet is on the first tube box side, and the equipment is inclined downwards towards the second tube box side, which allows the liquid phase to quickly pass through the support plate to reach the right shell side under the action of gravity.

[0017] When the horizontal combined cylinder 10 is arranged at an incline, the top of the concave cone structure 13 is an inclined surface. By adjusting the upward convex distance of the connecting pipe 80, the exhaust tank 40 is arranged horizontally to ensure stable and reliable exhaust. The horizontal combined cylinder 10 is equipped with several level gauges and thermometers. Due to the large heat exchange in the shell side, the setting of multiple level gauges and thermometers ensures that the medium level and temperature in the shell side meet the process requirements after heat exchange by monitoring the medium level and temperature in the tube side. By adjusting the medium input in the shell side, the liquid level and temperature of the medium in the shell side can be adjusted, while the input of the medium in the tube side remains constant.

[0018] The workflow is as follows: The high-temperature tube-side medium enters the first tube box through the upper large-diameter inlet, and then exchanges heat with the shell-side medium located in the horizontal combined cylinder through the annular tube bundle. Since the horizontal combined cylinder includes small cylinders at both ends of the length direction and a large cylinder in the middle of the length direction, and the upper part of the large cylinder is a concave truncated cone structure from bottom to top, the gas chamber is set on the upper layer of the concave truncated cone structure. Thus, the tube bundle can be arranged in the height space of the large cylinder corresponding to the tube sheet, which improves the gas-liquid phase replacement space of the shell side. Moreover, since the gas chamber and the shell-side heat exchange space are reliably separated, the purity of the shell-side gas is ensured. In addition, after the tube-side medium enters the second tube box through the tube bundle, it is diverted according to the state of the tube-side medium. The liquid flows out from the lower liquid phase outlet and the gas flows out from the upper gas phase outlet. At the same time, the gas phase medium and liquid phase medium at the tube-side outlet are diverted and collected to ensure that they can be reused later.

[0019] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0020] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A p-xylene condenser, characterized in that, It includes: A horizontal combined cylindrical body includes small cylindrical bodies at both ends along the length direction and a large cylindrical body in the middle along the length direction. The upper part of the large cylindrical body is a truncated cone structure that tapers from bottom to top. The first tube box is a tube-side feed tube box, which includes an upper large-diameter feed inlet; The second tube box is a tube-side discharge tube box, which includes an upper gas phase outlet and a lower liquid phase outlet; Vent canister; Tubes; and the tube sheets at both ends; The smaller cylinders at both ends of the horizontal combined cylinder along its length are connected to the tube sheet and the corresponding connecting flanges of the two sets of tube boxes via fastening connectors. The high-temperature tube medium is introduced into the large-diameter inlet at the top of the first tube box. Tube bundles are arranged in the area of ​​the large cylinder corresponding to the tube sheet, and the two ends of each tube bundle are respectively inserted into the corresponding interfaces of the tube sheet. The top of the concave cone structure is connected to the bottom of the gas outlet tank via several upwardly protruding and spaced connecting pipes. The top of the gas outlet tank is provided with a large-diameter gas outlet.

2. The p-xylene condenser according to claim 1, characterized in that: The connecting pipes are arranged in a straight line at equal intervals, and all connecting pipes have the same diameter. The gas outlet is arranged horizontally, and the length of the gas outlet covers all connecting pipes.

3. The para-xylene condenser according to claim 1 or 2, characterized in that: A wire mesh demister is installed in the space corresponding to the lower position of all the connecting pipes of the constricted truncated cone structure.

4. The para-xylene condenser according to claim 1, characterized in that: The horizontal combined cylinder has shell-side feed inlets on both sides of the middle region in the height direction corresponding to the tube bundle region, and the shell-side feed inlets are arranged close to the first tube box. The horizontal combined cylinder also has shell-side liquid phase discharge outlets on both sides of the middle region in the height direction corresponding to the tube bundle region, and the shell-side liquid phase discharge outlets are arranged close to the second tube box.

5. The p-xylene condenser according to claim 1, characterized in that: The second tube box is equipped with vertically arranged guide plates, which are located behind the tube sheet and are fixedly installed in the middle and upper regions of the second tube box.

6. The para-xylene condenser according to claim 1, characterized in that: The horizontal combined cylinder has a structure that gradually slopes upwards from one end of the second pipe box to one end of the first pipe box.

7. The para-xylene condenser according to claim 6, characterized in that: When the horizontal combined cylinder is arranged at an incline, an expansion joint is installed on the smaller cylinder corresponding to the second pipe box side. A low saddle and a high saddle are respectively provided at both ends of the bottom length direction of the larger cylinder. The high saddle is arranged close to the first pipe box, and the low saddle is arranged close to the second pipe box.

8. The para-xylene condenser according to claim 6, characterized in that: When the horizontal combined cylinder is arranged at an incline, the top of the concave truncated cone structure is an inclined surface, and the gas outlet tank is arranged horizontally by adjusting the upward convex distance of the connecting pipe.

9. The paraxylene condenser according to claim 1, characterized in that: The horizontal combined cylinder is equipped with several level gauges and thermometers.

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