A distributor and falling film heat exchanger

Abstract

The utility model discloses a distributor and falling film heat exchanger, the distributor is fixedly connected with upper tube sheet, and the upper tube sheet forms the upper cavity in the upper portion, and a plurality of heat exchange pipes that are communicated with the upper cavity are arranged on the upper tube sheet. The distributor comprises a liquid distribution disc and a membrane distribution pipe corresponding to the heat exchange pipe, the liquid distribution disc is located above the upper tube sheet and separates the upper cavity into a first cavity and a second cavity distributed above and below, and a plurality of through holes are formed in the liquid distribution disc and communicated with the first cavity and the second cavity. The membrane distribution pipe and the heat exchange pipe correspond to each other, the membrane distribution pipe comprises an inner tube and an outer tube sleeved outside the inner tube, the two ends of the inner tube extend out of the outer tube, a channel is formed between the inner tube and the outer tube, the lower end of the outer tube abuts against the upper tube sheet and surrounds the heat exchange pipe, overflow holes are formed in the outer tube and communicated with the second cavity and the channel, the part of the inner tube extending out of the outer tube is inserted into the heat exchange pipe and a ring gap is formed between the inner tube and the heat exchange pipe. The double-layer liquid distribution structure of the membrane distribution pipe and the liquid distribution disc improves the uniformity of liquid distribution.

Description

Technical Field

[0001] This utility model relates to the field of heat exchange equipment technology, and in particular to a distributor and a falling film heat exchanger. Background Technology

[0002] Falling film heat exchangers are highly efficient heat exchange devices, belonging to the category of thin-film evaporators. The distributor is a crucial component of a falling film heat exchanger. A good distributor ensures that the liquid forms a stable and uniform liquid film across the entire tube wall. Uneven liquid distribution can lead to flow deviation or channeling, causing interruptions in the liquid film within the tubes or even evaporation, creating dry paths and resulting in scaling or buildup, ultimately reducing heat transfer efficiency. Therefore, the proper arrangement of the distributor significantly impacts the final heat exchange effect. Utility Model Content

[0003] To overcome the above-mentioned shortcomings, the purpose of this utility model is to provide a distributor and a falling film heat exchanger with a double-layer liquid distribution structure of the film distribution tube and the liquid distribution plate, which improves the uniformity of liquid distribution. The double-layer structure of the film distribution tube allows the liquid to enter the circumferential gap evenly and form a uniform liquid film.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is: a distributor, wherein the distributor is fixedly connected to an upper tube sheet, an upper cavity is formed above the upper tube sheet, and a plurality of heat exchange tubes communicating with the upper cavity are arranged on the upper tube sheet; the distributor includes: A liquid equalization plate is located above the upper tube sheet and divides the upper cavity into a first cavity and a second cavity distributed vertically. The liquid equalization plate has multiple through holes that connect the first cavity and the second cavity. A membrane tube, which corresponds one-to-one with the heat exchange tube, includes an inner tube and an outer tube sleeved outside the inner tube. Both ends of the inner tube extend out of the outer tube, and a channel is formed between the inner tube and the outer tube. The lower end of the outer tube abuts against the upper tube sheet and surrounds the heat exchange tube. An overflow hole is provided on the outer tube to conduct the second cavity and the channel. A component of the inner tube extending downward out of the outer tube is inserted into the heat exchange tube and forms a circumferential gap with the heat exchange tube.

[0005] The equalizing plate evenly distributes the liquid into the second chamber. The liquid in the second chamber then passes through the corresponding film distribution tubes of the heat exchanger, forming a two-stage film distribution system. Simultaneously, the film distribution tubes have a double-layer structure. Liquid in the second chamber enters the channel through the overflow hole and flows downwards into the circumferential gap, forming a liquid film on the inner wall of the heat exchange tube. This double-layer structure allows the liquid to enter the circumferential gap evenly, forming a uniform liquid film.

[0006] Furthermore, the inner tube includes an inner tube body and a flared portion located at the lower end of the inner tube body. The small circular surface of the flared portion is aligned with the inner tube body and has the same diameter, while the large circular surface of the flared portion abuts against the inner wall of the heat exchange tube. Because the flared portion abuts against the inner wall of the heat exchange tube, but is not completely sealed, liquid can still flow downwards between the flared portion and the inner wall of the heat exchange tube, ensuring better final liquid film formation.

[0007] Furthermore, the through holes are evenly distributed around the heat exchange tube in the vertical projection of the horizontal plane where the heat exchange tube is located. At this time, the liquid in the inlet pipe is evenly distributed into the second cavity by these through holes, while these through holes avoid the inner tube, preventing the liquid from directly entering the inner tube.

[0008] Furthermore, the outer tube is fixedly connected to the inner tube via a connecting plate at the upper end, and the overflow hole is located between the connecting plate and the upper tube plate.

[0009] Furthermore, the overflow holes are distributed in multiple rows along the vertical direction, with each row containing multiple overflow holes evenly distributed along the circumference of the outer tube. When the amount of liquid stored in the second cavity is large, it can quickly flow into the channel through the overflow holes in different rows.

[0010] Furthermore, the upper end of the heat exchange tube extends upward beyond the upper surface of the upper tube sheet and is located below the overflow hole.

[0011] Furthermore, the equalization tray is fixedly connected to the upper tube sheet via a support member. The support member includes a support tube located between the upper tube sheet and the equalization tray. A locking bolt passes through the support tube, through the equalization tray, and is threadedly connected to the upper tube sheet. The support tube supports the equalization tray, ensuring that the equalization tray and the upper tube sheet are spaced apart. The locking bolt is used to fix the equalization tray and the upper tube sheet; the nut of the locking bolt is pressed against the equalization tray, and the bolt passes through the support tube and is threadedly connected to the upper tube sheet. The equalization tray and the upper tube sheet are detachably connected via the support member.

[0012] Furthermore, the equalization plate includes a base plate and a side plate extending upward around the base plate, and the through hole is formed on the base plate.

[0013] This utility model also discloses a falling film heat exchanger, including a shell, in which the above-mentioned distributor is disposed, the upper tube sheet is fixedly connected to the shell, and an inlet pipe located in the first cavity is disposed on the shell. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the distributor in an embodiment of the present invention; Figure 2 for Figure 1 Enlarged view of point A in the middle; Figure 3 This is a schematic diagram of the membrane tube in an embodiment of the present invention; Figure 4 This is a schematic diagram of the liquid equalization plate in an embodiment of the present invention; Figure 5 This is a top view of the equalization plate in an embodiment of the present invention; Figure 6 This is a schematic diagram of the heat exchanger in an embodiment of this utility model.

[0015] In the picture: 100. Distributor; 200. Housing; 201. Inlet pipe; 1. Upper tube sheet; 2. Heat exchange tubes; 21. Circumferential clearance; 3. Equalizing tray; 31. Base plate; 311. Through hole; 32. Side plate; 4. Membrane tube; 41. Inner tube; 411. Inner tube body; 412. Flared end; 42. Outer tube; 421. Overflow hole; 43. Connecting plate; 44. Channel; 5. Support components; 51. Support tube; 52. Locking bolts; 6a, First cavity; 6b, Second cavity. Detailed Implementation

[0016] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the scope of protection of the present invention.

[0017] For ease of subsequent description, the terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and are not limited in number; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0018] One embodiment of the distributor 100 is used for distributing a membrane on the heat exchange tube 2, see attached drawing. Figure 1 As shown, the distributor 100 is fixedly connected to the upper tube sheet 1, and an upper cavity is formed above the upper tube sheet 1. A plurality of heat exchange tubes 2, which are in communication with the upper cavity, are provided on the upper tube sheet 1. The heat exchange tubes 2 are hollow tubes, and the heat exchange tubes 2 and the upper tube sheet 1 are welded and fixed.

[0019] See appendix Figure 1 As shown, the distributor 100 includes a liquid equalization plate 3 and a film distribution tube 4 located below the liquid equalization plate 3.

[0020] The liquid distribution plate 3 is located above the upper tube sheet 1 and divides the upper cavity into a first cavity 6a and a second cavity 6b, which are distributed vertically. The liquid distribution plate 3 has multiple through holes 311 that connect the first cavity 6a and the second cavity 6b. Liquid enters from the inlet pipe 201 in the first cavity 6a and flows into the second cavity 6b through the through holes 311 on the liquid distribution plate 3, where the liquid completes primary distribution.

[0021] See appendix Figure 2 As shown, the membrane tube 4 and the heat exchange tube 2 correspond one-to-one. The membrane tube 4 includes an inner tube 41 and an outer tube 42 sleeved outside the inner tube 41. The inner tube 41 and the outer tube 42 are fixedly connected, and a channel 44 is formed between the inner tube 41 and the outer tube 42. Both ends of the inner tube 41 extend out of the outer tube 42. The lower end of the outer tube 42 abuts against the upper tube sheet 1 and surrounds the heat exchange tube 2. An overflow hole 421 is provided on the outer tube 42 to conduct through the second cavity 6b and the channel 44. The part of the inner tube 41 extending downward out of the outer tube 42 is inserted into the heat exchange tube 2, forming a circumferential gap 21 between the inner tube 41 and the heat exchange tube 2. See Appendix Figure 2 The hollow arrow in the diagram indicates the direction of liquid flow. After the liquid accumulates in the second chamber 6b, it enters the channel 44 through the overflow hole 421. Under the action of gravity, the liquid in the channel 44 flows into the circumferential gap 21. The width of the circumferential gap 21 is small, which ensures that the liquid forms a liquid film on the inner wall of the heat exchange tube 2.

[0022] In this embodiment, the equalizing plate 3 evenly disperses the liquid from the outlet pipe with a smaller outlet into the second chamber 6b. The liquid in the second chamber 6b then passes through the film distribution tube 4 corresponding to the heat exchanger to form a film. The equalizing plate 3 and the film distribution tube 4 form a two-stage film distribution. At the same time, the film distribution tube 4 has a double-layer structure. The liquid in the second chamber 6b enters the channel 44 from the overflow hole 421 and then flows downward from the channel 44 into the circumferential gap 21, forming a liquid film on the inner wall of the heat exchange tube 2. The double-layer structure allows the liquid to enter the circumferential gap 21 evenly, forming a uniform liquid film.

[0023] The inner tube 41 includes an inner tube body 411, which can be hollow or solid. For example, the tube body is hollow, which can meet the usage requirements while using less material.

[0024] To further ensure the film formation rate of the liquid film, please refer to the appendix. Figure 3As shown, the inner tube 41 also includes a flared portion 412 located at the lower end of the inner tube body 411. The small circular surface of the flared portion 412 is aligned with the inner tube body 411 and has the same diameter, while the large circular surface of the flared portion 412 abuts against the inner wall of the heat exchange tube 2. Because the flared portion 412 abuts against the inner wall of the heat exchange tube 2, but is not completely sealed, liquid can still flow downwards between the flared portion 412 and the inner wall of the heat exchange tube 2, ensuring better final liquid film formation.

[0025] In this embodiment, the membrane tube 4, the upper tube sheet 1, and the heat exchange tube 2 are all detachably connected. The outer tube 42 rests against the upper tube sheet 1 to ensure that the membrane tube 4 does not sag. At the same time, the inner tube 41 is inserted into the heat exchange tube 2, and the flared part 412 abuts against the inner wall of the heat exchange tube 2 to prevent the membrane tube 4 from shaking radially. At this time, the membrane tube 4 is easy to replace. When it is necessary to replace the membrane tube 4, simply pull the membrane tube 4 upward to remove the inner tube 41 from the heat exchange tube 2.

[0026] The inner diameter of the outer tube 42 is larger than the outer diameter of the heat exchange tube 2 to ensure that the outer tube 42 can surround the heat exchange tube 2. The outer diameter of the inner tube 41 is smaller than the outer diameter of the heat exchange tube 2 to ensure that the inner tube 41 can be inserted into the heat exchange tube 2.

[0027] See appendix Figure 5 As shown, the through holes 311 are evenly distributed around the heat exchange tube 2 in the vertical projection of the horizontal plane where the heat exchange tube 2 is located. At this time, the liquid in the inlet pipe 201 is evenly distributed into the second cavity 6b by these through holes 311, while these through holes 311 avoid the inner tube 41, preventing the liquid from directly entering the inner tube 41.

[0028] See appendix Figure 4 As shown, the liquid equalization tray 3 includes a base plate 31 and a side plate 32 extending upward around the base plate 31. The through hole 311 is formed on the base plate 31. The base plate 31 and the side plate 32 form a cavity, which can store excess liquid and prevent liquid from entering the lower second cavity 6b from the periphery of the side plate 32.

[0029] The outer tube 42 is fixedly connected to the inner tube 41 via the upper connecting plate 43, and the overflow hole 421 is located between the connecting plate 43 and the upper tube plate 1. The connecting plate 43 is annular and is welded and fixed to the outer tube 42 and the inner tube 41 respectively. The inner tube 41 and the outer tube 42 are connected by the connecting plate 43, so that the membrane tube 4 forms an integral structure.

[0030] In one embodiment, the overflow holes 421 are arranged in multiple rows along the vertical direction, and each row of overflow holes 421 has multiple holes evenly distributed around the circumference of the outer tube 42. With multiple rows of overflow holes 421 arranged vertically, when the amount of liquid stored in the second cavity 6b is large, it can quickly flow into the channel 44 through the overflow holes 421 in different rows.

[0031] See appendix Figure 2 As shown, the upper end of the heat exchange tube 2 extends upward beyond the upper surface of the upper tube sheet 1 and is located below the overflow hole 421. The heat exchange tube 2 does not exceed the overflow, but extends beyond the upper tube sheet 1, ensuring that when the outer tube 42 abuts against the upper tube sheet 1, it can cover the portion of the heat exchange tube 2 extending beyond the upper tube sheet 1.

[0032] The equalization tray 3 and the upper tube sheet 1 are detachably connected to facilitate the replacement and cleaning of the equalization tray 3. See Appendix. Figure 1 As shown, the equalization tray 3 is fixedly connected to the upper tube sheet 1 via a support member 5. The support member 5 includes a support tube 51 located between the upper tube sheet 1 and the equalization tray 3. A locking bolt 52 passes through the support tube 51, passes through the equalization tray 3, and is threadedly connected to the upper tube sheet 1. The support tube 51 supports the equalization tray 3, ensuring that the equalization tray 3 and the upper tube sheet 1 are spaced apart. The locking bolt 52 is used to fix the equalization tray 3 and the upper tube sheet 1. The nut of the locking bolt 52 is pressed onto the equalization tray 3, and the bolt passes through the support tube 51 and is threadedly connected to the upper tube sheet 1.

[0033] There are multiple support components 5. When it is necessary to remove the liquid equalization plate 3, simply rotate the locking bolt 52 to separate the locking bolt 52 from the upper tube plate 1.

[0034] See appendix Figure 6 As shown, this embodiment also discloses a falling film heat exchanger, including a shell 200, in which the aforementioned distributor 100 is disposed. The upper tube sheet 1 is fixedly connected to the shell 200, and an inlet pipe 201 located in the first cavity 6a is disposed on the shell 200. External liquid enters the first cavity 6a through the inlet pipe 201, is evenly dispersed after being separated by a distribution plate, and enters the lower cavity. When the liquid in the lower cavity accumulates to a certain height, it enters the channel 44 of the film-distributing tube 4 through the overflow pipe, and then enters the annular gap from the channel 44, forming a liquid film on the inner wall of the heat exchange tube 2. The heat exchange tube 2 has a heat exchange medium on its outside, and the liquid film exchanges heat with the heat exchange medium during the flow process.

[0035] The above embodiments are only for illustrating the technical concept and features of this utility model. Their purpose is to enable those skilled in the art to understand the content of this utility model and implement it. They cannot be used to limit the protection scope of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be covered within the protection scope of this utility model.

Claims

1. A distributor, wherein the distributor is fixedly connected to an upper tube sheet, an upper cavity is formed above the upper tube sheet, and a plurality of heat exchange tubes communicating with the upper cavity are arranged on the upper tube sheet, characterized in that: The distributor includes: A liquid equalization plate is located above the upper tube sheet and divides the upper cavity into a first cavity and a second cavity distributed vertically. The liquid equalization plate has multiple through holes that connect the first cavity and the second cavity. A membrane tube, which corresponds one-to-one with the heat exchange tube, includes an inner tube and an outer tube sleeved outside the inner tube. Both ends of the inner tube extend out of the outer tube, and a channel is formed between the inner tube and the outer tube. The lower end of the outer tube abuts against the upper tube sheet and surrounds the heat exchange tube. An overflow hole is provided on the outer tube to conduct the second cavity and the channel. A component of the inner tube extending downward out of the outer tube is inserted into the heat exchange tube and forms a circumferential gap with the heat exchange tube.

2. The distributor according to claim 1, characterized in that: The inner tube includes an inner tube body and a flared portion located at the lower end of the inner tube body. The small circular surface of the flared portion is connected to the inner tube body and has the same diameter. The large circular surface of the flared portion abuts against the inner wall of the heat exchange tube.

3. The distributor according to claim 1, characterized in that: The through holes are evenly distributed around the heat exchange tube in the vertical projection of the horizontal plane where the heat exchange tube is located.

4. The distributor according to claim 1, characterized in that: The outer tube is fixedly connected to the inner tube via a connecting plate at the upper end, and the overflow hole is located between the connecting plate and the upper tube plate.

5. The distributor according to claim 1, characterized in that: The overflow holes are distributed in multiple rows along the vertical direction, and each row of overflow holes has multiple holes evenly distributed along the circumference of the outer pipe.

6. The distributor according to claim 1, characterized in that: The upper end of the heat exchange tube extends upward beyond the upper surface of the upper tube sheet and is located below the overflow hole.

7. The distributor according to any one of claims 1-6, characterized in that: The equalization plate is fixedly connected to the upper tube sheet via a support member. The support member includes a support tube located between the upper tube sheet and the equalization plate. A locking bolt passes through the support tube and is threadedly connected to the upper tube sheet.

8. The distributor according to claim 1, characterized in that: The equalization tray includes a base plate and a side plate extending upward around the base plate, and the through hole is formed on the base plate.

9. A falling film heat exchanger, characterized in that: The device includes a housing, in which a distributor according to any one of claims 1-8 is disposed, the upper tube sheet is fixedly connected to the housing, and an inlet pipe located in the first cavity is disposed on the housing.

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