Vertical falling film heat exchanger with internal carrier gas

Abstract

The utility model discloses a vertical tube inner carrier gas's falling -film heat exchanger, including the shell body, the cavity of shell body is equipped with from top to bottom in proper order in proper order air pipe, falling liquid half pipe, guide liquid bottom plate and tube plate, and the top of shell body is equipped with the air inlet pipe, and the upper pipe mouth of air pipe is connected with the air inlet pipe, and the lower pipe mouth of air pipe is connected with the upper pipe mouth of falling liquid half pipe, and one side of shell body upper portion is equipped with the feed inlet pipe, and the feed inlet pipe is connected with the lower part of falling liquid half pipe, and the vertical installation of guide liquid bottom plate is equipped with a plurality of air branch pipe, and still be equipped with a plurality of guide flow hole on guide liquid bottom plate, and the lower of air branch pipe is provided with the same heat exchange pipe as air branch pipe number, and the upper pipe mouth of heat exchange pipe is connected with the film distributor. The compact structure of the application, convenient operation, high heat transfer efficiency, heat exchange pipe is not easy to scale, and a small amount of inert gas is introduced in heat exchange pipe as carrier gas, makes the boiling mechanism change, changes the boiling on the heating wall surface to the evaporation process on the gas, liquid phase interface.

Description

Technical Field

[0001] This utility model relates to the technical field of falling film evaporators, and more specifically, to a falling film heat exchanger with a vertical tube carrying gas. Background Technology

[0002] Falling film heat exchangers are widely used in pharmaceuticals, food processing, chemicals, environmental protection, and energy. A falling film heat exchanger adds a liquid film-forming device to a conventional heat exchanger, forming a falling film structure including a film distribution device and heat exchange tubes. The liquid enters the heat exchange tubes through the film distribution device, which acts as a flow guide. In other words, influenced by the structure of the film distribution device, the liquid flows along a specific streamline, quickly covering the inner wall of the heat exchange tubes to form a liquid film. This film is maintained and flows downwards along the heat exchange tubes, exchanging heat with the fluid outside the tubes during this flow. However, when processing special materials, such as heat-sensitive, high-viscosity, easily fouling, or easily foaming materials, traditional heat exchangers are prone to overheating, deterioration, and scaling on the heated wall surface, affecting the performance of the heat exchanger. Utility Model Content

[0003] In view of the above-mentioned technical problems in related technologies, this utility model provides a falling film heat exchanger with vertical tube internal carrier gas, which can solve the above problems.

[0004] To achieve the above-mentioned technical objectives, the technical solution of this utility model is implemented as follows: A falling film heat exchanger with vertical tube in-situ gas carrier includes an outer shell. Within the cavity of the outer shell, from top to bottom, are arranged a main vent pipe, a downcomer pipe, a liquid guide plate, and a tube sheet. An inlet pipe is located at the top of the outer shell. The upper inlet of the main vent pipe is connected to the inlet pipe, and the lower inlet of the main vent pipe is connected to the upper inlet of the downcomer pipe. A feed pipe is located on one side of the upper part of the outer shell, and the feed pipe is connected to the lower part of the downcomer pipe. Several vent branch pipes are vertically installed on the liquid guide plate. The liquid guiding base plate is also provided with several flow guiding holes, which are arranged around the venting branch pipe. The same number of heat exchange tubes as the venting branch pipe are arranged directly below the venting branch pipe. The heat exchange tubes are vertically installed below the tube sheet. The upper end of the heat exchange tube is connected to a film distributor. Several tangential liquid inlet windows are opened on the side wall of the film distributor. The tangential liquid inlet windows are located above the tube sheet. The upper end of the film distributor is arranged opposite to the lower end of the venting branch pipe. The bottom of the outer shell is provided with a gas-liquid outlet pipe.

[0005] Furthermore, an L-shaped baffle is provided at the outlet of the feed pipe.

[0006] Furthermore, the membrane distributor is perpendicular to the tube sheet, and a set of opposite ventilation branches are coaxially arranged with the membrane distributor.

[0007] Furthermore, a liquid level sensor is provided above both the liquid guiding base plate and the tube sheet.

[0008] Furthermore, the opening shape of the tangential liquid inlet window is an oblique rectangular groove, and the tangential liquid inlet windows are evenly distributed on the same horizontal plane.

[0009] Furthermore, an inert gas is introduced into the air intake pipe.

[0010] The beneficial effects of this invention are as follows: This invention features a compact structure, convenient operation, high heat transfer efficiency, and reduced scaling on the heat exchange tubes. Introducing a small amount of inert gas as a carrier gas into the heat exchange tubes alters the boiling mechanism, transforming boiling on the heated wall surface into an evaporation process at the gas-liquid interface. Due to the increased bubble agitation and circulation speed, the overall heat transfer coefficient can be increased by 30-60%, while simultaneously reducing superheat on the heated wall surface. This reduces and suppresses the possibility of material deterioration and scaling due to overheating on the heated wall surface. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] The present invention will now be described in further detail with reference to the accompanying drawings.

[0013] Figure 1 This is a schematic diagram of the structure of a falling film heat exchanger with a vertical tube carrying gas as described in an embodiment of this utility model; Figure 2 This is a partial schematic diagram of the liquid-guiding base plate from a top view according to an embodiment of the present invention; Figure 3 This is an axial cross-sectional view of the relative positions of a set of ventilation branch pipes and membrane distributors as described in an embodiment of this utility model.

[0014] In the picture: 1. Main vent pipe; 2. Downcomer half pipe; 3. Vent branch pipe; 4. Liquid guide bottom plate; 5. Membrane distributor; 6. Tube sheet; 7. Heat exchange tube; 8. Feed inlet pipe; 9. Baffle plate; 10. Air inlet pipe; 11. Flow guide hole; 12. Tangential liquid inlet window. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model are within the protection scope of the present utility model.

[0016] like Figure 1-3 As shown, this utility model discloses a falling film heat exchanger with vertical in-tube carrier gas, including an outer shell. Inside the cavity of the outer shell, from top to bottom, are arranged a main vent pipe 1, a downcomer half-pipe 2, a liquid guiding base plate 4, and a tube sheet 6. An air inlet pipe 10 is provided at the top of the outer shell. The upper port of the main vent pipe 1 is connected to the air inlet pipe 10, and the lower port of the main vent pipe 1 is connected to the upper port of the downcomer half-pipe 2. A feed pipe 8 is provided on one side of the upper part of the outer shell, and the feed pipe 8 is connected to the lower part of the downcomer half-pipe 2. Several vent branch pipes are vertically installed on the liquid guiding base plate 4. 3. The liquid guiding base plate 4 is also provided with a plurality of flow guiding holes 11. The flow guiding holes 11 are arranged around the venting branch pipe 3. The same number of heat exchange tubes 7 as the venting branch pipe 3 are arranged directly below the venting branch pipe 3. The heat exchange tubes 7 are vertically installed below the tube sheet 6. The upper port of the heat exchange tube 7 is connected to a film distributor 5. The side wall of the film distributor 5 is provided with a plurality of tangential liquid inlet windows 12. The tangential liquid inlet windows 12 are located above the tube sheet 6. The upper port of the film distributor 5 is arranged opposite to the lower port of the venting branch pipe 3. The bottom of the outer shell is provided with a gas-liquid outlet pipe.

[0017] In a specific embodiment of this application, liquid material enters the cavity of the outer shell through the feed pipe 8. An L-shaped baffle 9 is provided at the outlet of the feed pipe 8 to prevent the liquid material from entering the gas phase space in the venting manifold 1. The liquid material entering the cavity of the outer shell flows from the lower part of the downcomer 2 to the liquid guide plate 4, which liquid seals the guide hole 11 on the liquid guide plate 4. At the same time, the liquid material flowing into the liquid guide plate 4 flows from the guide hole 11 to the upper end of the tube sheet 6. The liquid material at the upper end of the tube sheet 6 enters the film distributor 5 through the tangential inlet window 12. The liquid material entering through the tangential inlet window 12 impacts the inner wall of the film distributor 5 along the tangential direction, forming a swirling flow on the inner wall of the film distributor 5. Under the combined action of centrifugal force and gravity, it is evenly attached to the inner wall of the film distributor and flows smoothly into the heat exchange tube 7.

[0018] In a specific embodiment of this application, inert gas enters the main vent pipe 10 through the inlet pipe 10, and then enters the downcomer pipe 2 through the main vent pipe 1. The inert gas in the downcomer pipe 2 is guided to flow through the vent branch pipe 3. The lower port of the vent branch pipe 3 is aligned with the upper port of the film distributor 5. Therefore, the gas discharged through the vent branch pipe 3 then enters the heat exchange tube 7 directly through the film distributor 5, flowing in the same direction as the liquid phase material. The simultaneous entry of inert gas and liquid phase material into the tube changes the boiling mechanism of the liquid phase material. As the bubble nuclei disappear on the heated wall surface, the boiling process changes to an evaporation process at the gas-liquid interface.

[0019] In one specific embodiment of this application, a liquid level sensor is provided above the liquid guiding base plate 4 to prevent the liquid phase material on the liquid guiding base plate 4 from submerging the venting branch pipe 3, and a liquid level sensor is provided above the tube sheet 6 to prevent the liquid phase material on the tube sheet 6 from submerging the film distributor 5.

[0020] In a specific embodiment of this application, such as Figure 2-3 As shown, a set of ventilation branch pipes 3 and the membrane applicator 5 are coaxially arranged. Preferably, the inner diameter of the ventilation branch pipe 3 is smaller than the inner diameter of the membrane applicator 5. Each ventilation branch pipe 3 is surrounded by six guide holes 11, and the inner diameter of the annulus formed by the guide holes 11 is larger than the outer diameter of the membrane applicator 5.

[0021] In one specific embodiment of this application, the opening shape of the tangential liquid inlet window 12 is an oblique rectangular groove, and the tangential liquid inlet windows 12 are evenly distributed on the same horizontal plane.

[0022] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A falling film heat exchanger with a vertical tube carrying gas, characterized in that, The device includes an outer shell. Inside the cavity of the outer shell, from top to bottom, are arranged a main vent pipe (1), a downcomer pipe (2), a liquid guide plate (4), and a tube sheet (6). An air inlet pipe (10) is located at the top of the outer shell. The upper opening of the main vent pipe (1) is connected to the air inlet pipe (10), and the lower opening of the main vent pipe (1) is connected to the upper opening of the downcomer pipe (2). A feed pipe (8) is located on one side of the upper part of the outer shell and is connected to the lower part of the downcomer pipe (2). Several vent branch pipes (3) are vertically installed on the liquid guide plate (4), and several... A flow guide hole (11) is provided around the ventilation branch pipe (3). The ventilation branch pipe (3) is provided with the same number of heat exchange tubes (7) as the ventilation branch pipe (3) directly below it. The heat exchange tubes (7) are vertically installed below the tube sheet (6). The upper port of the heat exchange tube (7) is connected to a film distributor (5). Several tangential liquid inlet windows (12) are opened on the side wall of the film distributor (5). The tangential liquid inlet windows (12) are located above the tube sheet (6). The upper port of the film distributor (5) is opposite to the lower port of the ventilation branch pipe (3). The bottom of the outer shell is provided with a gas-liquid outlet pipe.

2. A falling film heat exchanger with a vertical tube carrying gas according to claim 1, characterized in that, An L-shaped baffle (9) is provided at the outlet of the feed pipe (8).

3. A falling film heat exchanger with a vertical tube carrying gas according to claim 1, characterized in that, The membrane distributor (5) is perpendicular to the tube sheet (6), and a set of ventilation branch pipes (3) and the membrane distributor (5) are coaxially arranged.

4. A falling film heat exchanger with a vertical tube carrying gas according to claim 1, characterized in that, Liquid level sensors are provided above both the liquid guiding base plate (4) and the tube sheet (6).

5. A falling film heat exchanger with a vertical tube carrying gas according to claim 1, characterized in that, The opening shape of the tangential liquid inlet window (12) is an oblique rectangular groove, and the tangential liquid inlet windows (12) are evenly distributed on the same horizontal plane.

6. A falling film heat exchanger with a vertical tube carrying gas according to claim 1, characterized in that, Inert gas is introduced into the air inlet pipe (10).

Images