Winding pipe type heat exchanger

Abstract

A winding tube type heat exchanger is vertically arranged, a shell pass and a tube pass are arranged in the winding tube type heat exchanger, the tube pass is provided with a tube pass inlet for inputting a cold medium and a tube pass outlet for outputting the cold medium after heat exchange, the bottom of the shell pass is provided with a shell pass inlet for inputting a medium to be condensed, and the top of the shell pass is provided with a shell pass gas phase outlet for outputting non-condensable gas; a vertical flow guide cylinder is arranged in the shell side and located below the tube side and above an inlet of the shell side, a channel defined by the side peripheral wall of the flow guide cylinder allows a medium to be condensed to pass upwards, the side peripheral wall of the flow guide cylinder is opposite to the corresponding side wall of the shell side at intervals, and the edge of the lower end of the flow guide cylinder is connected with the corresponding side wall of the shell side. An annular cavity with the top open and the bottom closed is formed between the side peripheral wall of the guide cylinder and the corresponding shell pass side wall, and the shell pass side wall is provided with a shell pass liquid phase outlet allowing condensate in the annular cavity to be output. The annular cavity plays a role of a storage tank, and a storage tank does not need to be additionally arranged, so that downstream equipment is simplified.

Description

Technical Field

[0001] This utility model belongs to the field of heat exchanger technology, specifically relating to a wound tube heat exchanger. Background Technology

[0002] Conventional vacuum towers have low overhead gas temperatures, making heat recovery difficult. The overhead gas is directly cooled by air and / or water cooling. The condensed liquid phase enters a separate storage tank. The storage tank is equipped with non-condensable gas condensation and recovery systems and a vacuum pumping connection. Please refer to [link to details]. Figure 1 In existing technologies, the condensation at the top of the tower, the separation of non-condensable gases after condensation, and the vacuum system are cumbersome and have a large resistance drop, making it difficult to guarantee the vacuum level at the top of the vacuum tower or resulting in high energy consumption. Furthermore, due to these problems, the vacuum level of the vacuum tower is reduced, the operating temperature of the vacuum tower is too high, the feed to the vacuum tower needs to be directly heated by a heat source, and the heat source temperature is too high, leading to high energy consumption during vacuum tower operation.

[0003] Meanwhile, existing equipment for tower top air cooling, such as air-cooled and / or water-cooled condensers, storage tanks, pumps, and condensers above the storage tanks, is numerous, occupies a large area, and has high operating and maintenance costs. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a wound tube heat exchanger that can be used for the condensation of medium waiting for condensation of tower top gas, in order to reduce the number of downstream equipment.

[0005] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows: a wound tube heat exchanger, which is arranged vertically and has a shell side and a tube side inside. The tube side has a tube side inlet for inputting cold medium and a tube side outlet for outputting cold medium after heat exchange. The bottom of the shell side has a shell side inlet for inputting medium to be condensed, and the top of the shell side has a shell side gas phase outlet for outputting non-condensable gas.

[0006] Its features are:

[0007] A vertical guide tube is provided in the shell side, located below the tube side and above the shell side inlet. The channel defined by the side wall of the guide tube allows the medium to be condensed to pass upward. The side wall of the guide tube is spaced apart from the corresponding shell side wall, and the lower edge of the guide tube is engaged with the corresponding shell side wall, so that an annular chamber with an open top and closed bottom is formed between the side wall of the guide tube and the corresponding shell side wall. The shell side wall has a shell liquid phase outlet for the condensate in the annular chamber to be discharged.

[0008] After the medium to be condensed enters the shell side and exchanges heat with the cold medium in the tube side, the condensate flows into the annular chamber under its own gravity and is then discharged from the shell-side liquid phase outlet. The non-condensable gas flows upward and is discharged from the shell-side gas phase outlet. In this process, the annular chamber acts as a "storage tank," eliminating the need for a separate storage tank. There is also no need for additional equipment such as a condenser above the storage tank. Therefore, the design of this spiral-wound tube heat exchanger simplifies downstream equipment.

[0009] To prevent condensate from flowing directly down the channel, preferably, a cap is also included, located at the upper port of the guide tube to close the upper port;

[0010] The sidewall of the guide tube slopes upwards towards the center, forming a conical shape. Multiple windows are spaced circumferentially at intervals on the upper part of the sidewall for the medium to be condensed to pass through. The combination of the windows and the conical sidewall ensures the upward flow of the medium.

[0011] Preferably, the lower part of the sidewall of the guide tube is provided with multiple reflux holes spaced circumferentially. By designing the height, number, and diameter of the reflux holes, a portion of the condensate can be controlled to flow back to upstream equipment (such as a vacuum tower) to meet process requirements.

[0012] To further prevent condensate from flowing directly down the channel, preferably, it also includes multiple baffles spaced circumferentially around the periphery of the guide tube, with the upper edge of each baffle engaging with the edge of the upper port of the guide tube, the lower edge of each baffle extending into the annular cavity, and the inner side of each baffle blocking the window at intervals with its corresponding window, forming a gap between two adjacent baffles in the circumferential direction for the medium to be condensed to pass through.

[0013] The baffles prevent condensate from flowing down through the window, and the gaps between adjacent baffles ensure the flow of the medium to be condensed.

[0014] Preferably, the baffle is inclined from bottom to top toward the center of the guide tube, and the upper edge of the baffle is engaged with the edge of the upper port of the guide tube through an annular retaining ring.

[0015] Preferably, the upper surface of the cap is an arc-shaped surface that is higher in the center and lower at the edges. The arc-shaped surface can prevent condensate from accumulating on the cap and promote the downward flow of condensate into the annular cavity.

[0016] In the above embodiments, preferably, the bottom of the shell side is open to form the shell side inlet.

[0017] Compared with existing technologies, the advantages of this invention are as follows: By setting a guide tube inside the shell side and below the tube side, an annular chamber with a shell-side liquid phase outlet is formed between the guide tube and the shell side wall. This allows the medium to be condensed to pass through the internal channel of the guide tube and exchange heat with the cold medium in the tube side, resulting in condensation. The condensate then flows into the annular chamber under its own gravity and exits from the shell-side liquid phase outlet. Non-condensable gases flow upwards and exit from the shell-side gas phase outlet. In this process, the annular chamber acts as a "storage tank," eliminating the need for a separate storage tank. Furthermore, there is no need for additional equipment such as a condenser above the storage tank. Therefore, the design of this spiral tube heat exchanger simplifies subsequent equipment. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a vacuum tower top condenser reflux system in the prior art;

[0019] Figure 2 This is a schematic diagram of the structure of the vacuum tower top condenser reflux system according to an embodiment of the present invention;

[0020] Figure 3 This is a longitudinal sectional view of the wound tube heat exchanger according to an embodiment of the present utility model;

[0021] Figure 4 This is a longitudinal sectional view of the baffle, the cover, and the shell-side sidewall in an embodiment of the present invention;

[0022] Figure 5 for Figure 4 Top view;

[0023] Figure 6 This is a longitudinal sectional view of the flow guide tube, the cap, and the shell-side sidewall in an embodiment of the present invention;

[0024] Figure 7 for Figure 6 Top view;

[0025] Figure 8 This is a longitudinal sectional view of the baffle, guide tube, cap, and shell-side sidewall in an embodiment of the present invention.

[0026] Figure 9 for Figure 8 Top view. Detailed Implementation

[0027] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0028] like Figures 2 to 9 The image shows a preferred embodiment of a wound-rotor heat exchanger according to this utility model. This wound-rotor heat exchanger can be used for the condensation of overhead gas in a vacuum tower. This embodiment is described in conjunction with a vacuum tower, and the details are as follows:

[0029] The upper part of the vacuum tower 1 has a vertically extending space 11, the bottom of which is open to allow the upper and lower spaces of the vacuum tower 1 to communicate. The lower part of the vacuum tower 1 is a prior art technology used for the separation of light components in the raw materials, and the separated vacuum tower top gas can enter the upper space 11 of the vacuum tower 1 through the opening.

[0030] The wound tube heat exchanger 2 is vertically arranged and has a tube side 21 and a shell side 22. There are two tube sides 21, namely a first tube side 211 and a second tube side 212. The inlet 211a of the first tube side is used for raw material input, and the outlet 211b of the first tube side is connected to the vacuum tower 1 through a pipeline. The inlet 212a of the second tube side is used for external cold source input, and the outlet 212b of the second tube side is used for cold source output after heat exchange. In this embodiment, the shell side of the wound tube heat exchanger 2 is integrally designed with the body of the vacuum tower 1. Specifically, the heat exchange tubes forming the tube side 21 are vertically arranged in the space 11 and form the shell side 22 between the tubes and the inner wall of the space 11. At this time, the bottom of the space 11 is open as the shell side inlet 22a for the input of vacuum tower top gas, and the top of the space 11 has a shell side gas phase outlet 22c for the output of non-condensable gas. The shell side gas phase outlet 22c is connected to the vacuum pump. Meanwhile, the space 11 is equipped with a vertical guide tube 23, a cap 24 covering the upper port of the guide tube 23 to close the upper port, and multiple baffles 25 spaced circumferentially around the guide tube 23. Figure 3 As shown, the guide tube 23 is located below the tube side 21. The side wall of the guide tube 23 slopes upwards towards the center of the space 11 and is generally conical. Multiple windows 231 for the passage of vacuum tower overhead gas are spaced circumferentially on the upper part of the side wall of the guide tube 23. The side wall of the guide tube 23 is spaced opposite to the side wall of the corresponding space 11. The lower edge of the guide tube 23 is joined to the side wall of the corresponding space 11, forming an annular chamber 220 with an open top and closed bottom between the side wall of the guide tube 23 and the side wall of the corresponding space 11. This annular chamber 220 is used to receive the condensate after the vacuum tower overhead gas is condensed. The side wall of the space 11 has a shell-side liquid phase outlet 22b for the condensate to exit from the annular chamber 220. Figure 6 , 7 As shown, the lower part of the side wall of the guide tube 23 is provided with multiple reflux holes 232 spaced circumferentially to allow the condensate in the annular chamber 220 to flow back into the vacuum tower 1. The height, number, and diameter of the reflux holes 232 can be designed according to the required condensate reflux ratio. The reflux ratio at the top of the tower can be adjusted by controlling the liquid level in the annular chamber 220. The upper surface of the cover 24 is arc-shaped, with a higher center and lower edges.

[0031] The number of baffles 25 is the same as the number of windows 231. The upper edge of each baffle 25 is engaged with the edge of the upper port of the guide tube 23, and the lower edge of each baffle 25 extends into the annular chamber 220. The inner side of each baffle 25 is spaced apart from its corresponding window 231, thus blocking the window 231. A gap 251 is formed between two adjacent baffles 25 in the circumferential direction to allow the vacuum tower top gas to pass through. In this embodiment, the baffles 25 are arranged parallel to the side circumferential wall of the guide tube 23, and the upper edge of the baffle 25 is engaged with the edge of the upper port of the guide tube 23 through an annular retaining ring 252. The cross-section of the annular retaining ring 252 is an upwardly arched arc. Please refer to [link to details] for further information. Figure 4 , 5 8, 9.

[0032] In this embodiment, the wound tube heat exchanger replaces the original top condenser (air-cooled + water-cooled), storage tank, reflux pump, and distillate pump, reducing equipment investment and significantly improving energy efficiency. Furthermore, the wound tube heat exchanger's higher installation height allows the condensate to be transported by its own height and gravity, eliminating the need for a pump. Simultaneously, the vacuum pump in this embodiment can operate directly on the vacuum tower body, reducing space and resistance losses associated with the original system's pipe heat exchangers and storage tanks, greatly lowering vacuum pump energy consumption, and further enhancing the tower's vacuum level for better separation.

[0033] In the specification and claims of this utility model, terms indicating direction, such as "upper," "lower," "side," "top," and "bottom," are used to describe various exemplary structural parts and elements of this utility model. However, the use of these terms is merely for the purpose of explanation and is based on the exemplary orientations shown in the accompanying drawings. Since the embodiments disclosed in this utility model can be arranged in different orientations, these terms indicating direction are for illustrative purposes only and should not be regarded as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

[0034] The term "vertical" is also used in the specification and claims of this utility model, meaning basically along the up and down direction, and is not limited to just the vertical direction, but can also be slightly deviated from the vertical direction.

Claims

1. A spiral wound heat exchanger vertically arranged and having a shell side (22) and a tube side (21) inside, the tube side (21) having a tube side inlet for input of cold medium and a tube side outlet for output of heat-exchanged cold medium, the shell side (22) having a shell side inlet (22a) at the bottom for input of medium to be condensed, and a shell side gas phase outlet (22c) at the top for output of non-condensed gas; characterized in that: a vertical draft tube (23) is arranged in the shell side (22) below the tube side (21) and above the shell side inlet (22a), the draft tube (23) having a side wall defining a passage for the medium to be condensed to pass upwardly, the side wall of the draft tube (23) being spaced from the corresponding side wall of the shell side (22), the lower end edge of the draft tube (23) being joined to the corresponding side wall of the shell side (22) so that an annular chamber (220) is formed between the side wall of the draft tube (23) and the corresponding side wall of the shell side (22), the annular chamber (220) being open at the top and closed at the bottom, the side wall of the shell side (22) having a shell side liquid phase outlet (22b) for output of condensed liquid from the annular chamber (220).

2. The spiral wound heat exchanger of claim 1, wherein: a cover (24) is further arranged at the upper end of the draft tube (23) to close the upper end; the side wall of the draft tube (23) is tapered from the bottom to the top towards the center, and the upper portion of the side wall of the draft tube (23) is circumferentially spaced and has a plurality of windows (231) for the medium to be condensed to pass through.

3. The spiral wound heat exchanger of claim 2, wherein: the lower portion of the side wall of the draft tube (23) is circumferentially spaced and has a plurality of backflow holes (232).

4. The spiral wound heat exchanger of claim 2, wherein: a plurality of baffles (25) are further circumferentially spaced and arranged at the periphery of the draft tube (23), the upper edge of each baffle (25) is joined to the edge of the upper end of the draft tube (23), the lower edge of each baffle (25) extends into the annular chamber (220), the inner side of each baffle (25) is spaced from and covers the corresponding window (231), and the gap (251) for the medium to be condensed to pass through is formed between circumferentially adjacent two baffles (25).

5. The spiral wound heat exchanger of claim 4, wherein: the baffles (25) are tapered from the bottom to the top towards the center of the draft tube (23), and the upper edge of each baffle (25) is joined to the edge of the upper end of the draft tube (23) by means of an annular baffle ring (252).

6. The spiral wound heat exchanger of claim 2, wherein: the upper surface of the cover (24) is arc-shaped and has a central high portion and edge low portions.

7. The spiral wound heat exchanger according to any one of claims 1 to 6, characterized in that: the bottom of the shell side (22) is open to form the shell side inlet (22a).

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