Film distribution device for falling film evaporator

Abstract

The utility model belongs to the technical field of falling-film evaporators, and particularly relates to a film distribution device for a falling-film evaporator, which comprises a tube plate, a connecting tube embedded at the bottom of the tube plate, a heat exchange tube connected to the bottom end of the connecting tube and positioned below the tube plate, and liquid inlets uniformly formed in the upper part of the connecting tube at intervals along the circumferential direction. Liquid blocking plates used for blocking the liquid inlet are evenly arranged on the upper portion in the connecting pipe at intervals in the circumferential direction, a driving mechanism used for driving the liquid blocking plates to ascend and descend is arranged on the pipe plate, a hollow column is connected into the connecting pipe through a spiral flow guide plate, a hollow connecting rod capable of ascending and descending is slidably connected into the hollow column, and a rotary disperser is rotatably arranged on the lower portion of the hollow connecting rod. The liquid inlet amount can be adjusted by adjusting the height of the liquid blocking plate so as to adapt to changes of different working conditions, accurate control over the liquid film distribution amount in the heat exchange pipe can be achieved, and therefore the adaptability and the overall performance of the device can be improved, and the product quality and the operation stability of the device can be improved.

Description

Technical Field

[0001] This utility model belongs to the technical field of falling film evaporators, and in particular relates to a film-laying device for falling film evaporators. Background Technology

[0002] Falling film evaporators are commonly used industrial evaporation equipment, widely applied in industries such as chemical, food, and pharmaceutical. Their working principle involves the liquid flowing along the inner wall of the heating tube to form a thin film, evaporating the solvent through heat exchange. This design improves heat transfer efficiency and reduces the risk of overheating, decomposition, or deterioration of materials.

[0003] The liquid distribution device (also known as a distributor or liquid distributor) is an important component of a falling film evaporator. Its function is to evenly distribute the liquid on the inner wall of the heating tubes before it enters the evaporator, forming a stable liquid film. This ensures that the liquid is in full contact with the heating surface during evaporation, improving evaporation efficiency and product quality.

[0004] A search revealed a Chinese patent with publication number CN207012582U, which describes a film distribution device for a falling film evaporator. The device includes a distribution head, a riser pipe, a spacer pipe, and a distribution disc. The spacer pipe and the distribution disc are connected by a nut, which facilitates disassembly and ensures the horizontality of the distribution disc installation. The distribution head has several small holes along the tangential direction, which, together with the dovetail structure at the bottom of the riser pipe, achieves uniform distribution of the liquid film.

[0005] While the aforementioned patents can achieve a uniform liquid film distribution, they do not allow for adjustment of the inlet liquid flow rate, making it impossible to adjust the flow rate according to actual operating conditions, resulting in unstable heat transfer efficiency. In contrast, the inlet liquid flow rate of a falling film evaporator's heat exchange tubes needs to be adjusted according to specific process requirements, as the flow rate directly affects the evaporator's heat transfer efficiency, product quality, and equipment operational stability. If the inlet liquid flow rate remains constant, it cannot adapt to changes in operating conditions, potentially leading to equipment instability. Furthermore, the amount of liquid film distributed inside the heat exchange tubes cannot be precisely controlled, thus affecting the equipment's adaptability and overall performance. Utility Model Content

[0006] The purpose of this invention is to provide a membrane cloth device for a falling film evaporator with adjustable liquid inlet to adapt to different operating conditions in order to solve the above problems.

[0007] This utility model achieves the above-mentioned objective through the following technical solution: A film-laying device for a falling film evaporator includes a tube sheet, a connecting pipe embedded in the bottom of the tube sheet, a heat exchange tube connected to the bottom end of the connecting pipe located below the tube sheet, liquid inlets evenly spaced along the circumference at the upper part of the connecting pipe, the lower diameter of the connecting pipe being larger than the upper diameter, forming a cone shape with a smaller upper diameter and a larger lower diameter, liquid-blocking plates evenly spaced along the circumference at the upper part of the connecting pipe for sealing the liquid inlets, a driving mechanism for driving the liquid-blocking plates to rise and fall on the tube sheet, and a hollow column connected to the connecting pipe through a spiral guide plate, the hollow column being located at the liquid-blocking plate. Inside the hollow column, there are multiple spiral guide plates distributed circumferentially. A hollow connecting rod that can be raised and lowered is slidably connected inside the hollow column. A rotary disperser is rotatably installed at the lower part of the hollow connecting rod. The rotary disperser is located in the conical area at the lower part of the connecting pipe. The spiral guide plates guide the liquid downward to the rotary disperser. Under the impact of the liquid, the rotary disperser is pushed to rotate and divide the liquid, so that the liquid is evenly distributed on the inner wall of the heat exchange tube. A guide frame located above the liquid blocking plate is connected to the upper part of the connecting pipe. A pull rope is connected to the top of the liquid blocking plate. The pull rope passes around the guide frame and is connected to the top of the hollow connecting rod.

[0008] Preferably, the rotary disperser includes a rotating shaft rotatably connected to the lower part of the hollow connecting rod, the bottom end of the rotating shaft extending out of the hollow connecting rod and connected to a rotating disk, the rotating disk being located in the conical region below the connecting pipe, and fan blades being circumferentially spaced at the top of the rotating disk.

[0009] Preferably, the rotating disk is connected with guide rods at uniform intervals along the circumference, and the guide rods are used to guide the liquid to the inner wall of the heat exchange tube.

[0010] Preferably, the drive mechanism includes an electric push rod installed on the outer wall of the tube sheet. A lifting plate located on the upper side of the tube sheet is connected to the telescopic rod of the electric push rod. A lifting rod is connected to the lifting plate. The bottom end of the lifting rod passes through the guide wire frame and is connected to a ring frame. The liquid blocking plate is fixedly connected to the ring frame.

[0011] Preferably, a spring connects the hollow connecting rod to the ring frame.

[0012] Preferably, each spiral guide plate is connected to a baffle at its top, the baffle is in contact with the outer wall of the hollow column and the inner wall of the connecting pipe, and each baffle is located between two adjacent liquid inlets.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] 1. The liquid inlet flow rate can be adjusted by changing the height of the liquid blocking plate to adapt to different operating conditions, thereby achieving precise control over the amount of liquid film inside the heat exchange tube, which can improve the adaptability and overall performance of the device, and thus improve product quality and equipment operation stability.

[0015] 2. The spiral guide plate directs the liquid downwards to the rotary disperser. The impact of the liquid drives the rotary disperser to rotate and distribute the liquid, ensuring that the liquid is evenly distributed on the inner wall of the heat exchange tube. When the liquid flow rate increases, the rotary disperser moves downwards, increasing the gap between it and the conical inner wall at the bottom of the connecting pipe. When the liquid flow rate decreases, the rotary disperser moves upwards, decreasing the gap between it and the conical inner wall at the bottom of the connecting pipe. This ensures that regardless of whether the liquid flow rate increases or decreases, the liquid can adhere evenly and effectively to the heat exchange tube wall, improving the uniformity of the film distribution and thus increasing the heat transfer efficiency. Attached Figure Description

[0016] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0017] Figure 2 This is a three-dimensional structural diagram of the drive mechanism of this utility model.

[0018] Figure 3 This is a partial three-dimensional structural diagram of the present invention. Figure 1 .

[0019] Figure 4 This is a partial three-dimensional structural diagram of the present invention. Figure 2 .

[0020] Figure 5 This is a schematic diagram showing the connection between the hollow column, spiral guide plate, and baffle of this utility model.

[0021] Figure 6 This is a three-dimensional structural diagram of the rotary disperser of this utility model.

[0022] Figure 7 This is a cross-sectional view of the rotating disk of this utility model.

[0023] The labels in the attached diagram are as follows: 1-Tube sheet, 2-Connecting pipe, 21-Liquid inlet, 3-Heat exchange tube, 4-Liquid blocking plate, 51-Electric push rod, 52-Lifting plate, 53-Guide sleeve, 54-Slide rod, 55-Lifting rod, 56-Ring frame, 6-Hollow column, 7-Spiral guide plate, 8-Hollow connecting rod, 9-Rotating disperser, 91-Shaft, 92-Rotating disk, 93-Fan blade, 10-Wire guide frame, 11-Pull rope, 12-Draining rod, 13-Spring, 14-Baffle. Detailed Implementation

[0024] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0025] Please see Figures 1-7A film-forming device for a falling film evaporator includes a tube sheet 1. A connecting pipe 2 is embedded in the bottom of the tube sheet 1. A heat exchange tube 3 located below the tube sheet 1 is connected to the bottom end of the connecting pipe 2. Five liquid inlets 21 are evenly spaced along the circumference on the upper part of the connecting pipe 2. The diameter of the lower part of the connecting pipe 2 is larger than that of the upper part, forming a cone shape with a smaller top and a larger bottom. Five liquid blocking plates 4 are slidably arranged evenly spaced along the circumference on the upper part of the connecting pipe 2. The five liquid blocking plates 4 correspond one-to-one with the five liquid inlets 21 and are used to block the corresponding liquid inlets 21. The tube sheet 1 is provided with a driving mechanism for driving the liquid blocking plates 4 to rise and fall. The driving mechanism includes two electric push rods 51 installed on the outer wall of the tube sheet 1. Guide sleeves 53 are connected circumferentially spaced along the outer wall of the tube sheet 1. The guide sleeves 53 slide within the guide sleeves 53. A sliding rod 54 is connected to the top of the sliding rod 54, and a lifting plate 52 is connected between the top ends of the sliding rod 54. The telescopic rod of the electric push rod 51 is connected to the lifting plate 52. A lifting rod 55 is connected to the lifting plate 52, and a ring frame 56 is connected to the bottom end of the lifting rod 55. A liquid blocking plate 4 is fixedly connected to the ring frame 56. A hollow column 6 is connected to the connecting pipe 2 through a spiral guide plate 7. The hollow column 6 is located inside the liquid blocking plate 4 and below the ring frame 56. There are four spiral guide plates 7, which are distributed around the circumference of the hollow column 6. A hollow connecting rod 8 that can be raised and lowered is slidably connected inside the hollow column 6. A rotary disperser 9 is rotatably installed at the bottom of the hollow connecting rod 8. The spiral guide plates 7 guide the liquid downward to the rotary disperser 9. Under the impact of the liquid, the rotary disperser 9 is pushed to rotate and disperse the liquid. The rotating disperser 9 includes a rotating shaft 91 rotatably connected to the lower part of a hollow connecting rod 8. The bottom end of the rotating shaft 91 extends out of the hollow connecting rod 8 and is connected to a rotating disk 92. The rotating disk 92 is located in the conical region at the lower part of the connecting pipe 2. Fan blades 93 are circumferentially spaced on the top of the rotating disk 92. The top of the rotating disk 92 is a curved surface with a high center and a low outer edge to guide the liquid to be thrown onto the inner wall of the heat exchange tube 3 in a parabolic trajectory, thereby making the liquid uniformly distributed on the inner wall of the heat exchange tube 3. Guide rods 12 are evenly spaced circumferentially on the rotating disk 92 to guide the liquid to the inner wall of the heat exchange tube 3. The rotating shaft 91, rotating disk 92, fan blades 93 and guide rods 12 are all made of high temperature resistant plastic. The lightweight plastic rotary disperser 9 ensures smooth rotation under the impact of water flow. A guide frame 10, located above the liquid-blocking plate 4, is connected to the upper part of the connecting pipe 2. A lifting rod 55 passes through the guide frame 10. A pull rope 11 is connected to the top of the liquid-blocking plate 4, passing around the guide frame 10 and connecting to the top of the hollow connecting rod 8. A spring 13 connects the hollow connecting rod 8 and the ring frame 56. A baffle 14 is connected to the top of each spiral guide plate 7, contacting the outer wall of the hollow column 6 and the inner wall of the connecting pipe 2. Each baffle 14 is located between two adjacent liquid inlets 21, blocking the liquid and ensuring it falls precisely and concentratedly onto the spiral guide plate 7, increasing the impact force of the liquid on the fan blades 93.Ensure smoother rotation of the rotary diffuser 9.

[0026] Initially, the liquid blocking plate 4 blocks the liquid inlet 21, and the spring 13 is in a compressed state. The extension rod of the electric push rod 51 is extended to push the lifting plate 52 to move the lifting rod 55 upward. The upward movement of the lifting rod 55, through the ring frame 56, causes the liquid blocking plate 4 to move upward, releasing the blockage of the liquid inlet 21. The liquid in the tube sheet 1 then enters the connecting pipe 2 through the liquid inlet 21. The liquid then falls onto the spiral guide plate 7, which guides the liquid downward to the rotary disperser 9. Under the impact of the liquid, the fan blade 93 rotates, which in turn drives the rotating disk 92 to rotate. The rotating disk 92 then drives the guide rod 12 to rotate. When the rotating disk 92 rotates, under the action of centrifugal force, the liquid is evenly thrown onto the inner wall of the heat exchange tube 3. The guide rod 12 guides the liquid to the inner wall of the heat exchange tube 3, so that the liquid is evenly distributed on the inner wall of the heat exchange tube 3. The liquid inlet flow rate can be adjusted by changing the height of the liquid blocking plate 4 to adapt to different operating conditions, achieving precise control over the amount of liquid film distributed inside the heat exchange tube 3. This improves the adaptability and overall performance of the device, thereby enhancing product quality and equipment operational stability. When the liquid blocking plate 4 moves upward with the ring frame 56, the pull rope 11 is released, and the spring 13 returns to its original position and extends, pushing the hollow connecting rod 8 downward in the opposite direction. This ensures that when the liquid blocking plate 4 moves upward to increase the liquid inlet flow rate, the hollow connecting rod 8 can smoothly drive the rotary disperser 9 downward. After the rotary disk 92 moves downward, the gap between it and the conical inner wall of the lower part of the connecting pipe 2 increases, ensuring that the liquid is evenly distributed on the inner wall of the heat exchange tube 3 when the liquid inlet flow rate increases. When the liquid blocking plate 4 moves down with the ring frame 56 to reduce the liquid inlet, the hollow connecting rod 8 is pulled by the pull rope 11 to drive the rotary disperser 9 to move up, compressing the spring 13. After the rotating disk 92 moves up, the gap between it and the conical inner wall of the lower part of the connecting pipe 2 is reduced, ensuring that the liquid is evenly distributed on the inner wall of the heat exchange tube 3 when the liquid inlet decreases. In this way, whether the liquid inlet is increased or decreased, the liquid can be evenly and effectively attached to the wall of the heat exchange tube 3, improving the uniformity of the film distribution and thus improving the heat transfer efficiency.

[0027] In practice, an appropriate number of film-laying devices for this falling film evaporator can be installed on tube sheet 1 as needed.

[0028] The embodiments described above are merely preferred embodiments of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications, improvements, and substitutions without departing from the concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A film-forming device for a falling film evaporator, comprising a tube sheet (1), a connecting pipe (2) embedded in the bottom of the tube sheet (1), a heat exchange tube (3) located below the tube sheet (1) connected to the bottom end of the connecting pipe (2), and liquid inlets (21) evenly spaced along the circumference on the upper part of the connecting pipe (2), characterized in that, The lower diameter of the connecting pipe (2) is larger than the upper diameter, forming a cone shape with a smaller upper diameter and a larger lower diameter. The upper part of the connecting pipe (2) is evenly spaced along the circumference with liquid-blocking plates (4) for sealing the liquid inlet (21). The pipe plate (1) is equipped with a drive mechanism for raising and lowering the liquid-blocking plates (4). A hollow column (6) is connected inside the connecting pipe (2) via a spiral guide plate (7). The hollow column (6) is located inside the liquid-blocking plate (4). Multiple spiral guide plates (7) are provided, distributed circumferentially along the hollow column (6). A hollow connecting rod capable of raising and lowering is slidably connected inside the hollow column (6). 8) A rotary disperser (9) is provided at the lower part of the hollow connecting rod (8). The rotary disperser (9) is located in the conical area at the lower part of the connecting pipe (2). The spiral guide plate (7) guides the liquid downward to the rotary disperser (9). Under the impact of the liquid, the rotary disperser (9) is driven to rotate and split the liquid so that the liquid is evenly distributed on the inner wall of the heat exchange tube (3). The upper part of the connecting pipe (2) is connected to the wire frame (10) located above the liquid blocking plate (4). The top of the liquid blocking plate (4) is connected to the pull rope (11). The pull rope (11) passes around the wire frame (10) and is connected to the top of the hollow connecting rod (8).

2. The film-laying device for a falling film evaporator according to claim 1, characterized in that, The rotary diffuser (9) includes a rotating shaft (91) rotatably connected to the lower part of the hollow connecting rod (8). The bottom end of the rotating shaft (91) extends out of the hollow connecting rod (8) and is connected to a rotating disk (92). The rotating disk (92) is located in the conical area at the bottom of the connecting pipe (2). The top of the rotating disk (92) is connected with fan blades (93) at intervals along the circumference.

3. The film-laying device for a falling film evaporator according to claim 2, characterized in that, The rotating disk (92) is evenly spaced along the circumference with guide rods (12), which are used to guide the liquid to the inner wall of the heat exchange tube (3).

4. The film-laying device for a falling film evaporator according to claim 3, characterized in that, The drive mechanism includes an electric push rod (51) installed on the outer wall of the tube sheet (1). The extension rod of the electric push rod (51) is connected to a lifting plate (52) located on the upper side of the tube sheet (1). The lifting plate (52) is connected to a lifting rod (55). The bottom end of the lifting rod (55) passes through the guide frame (10) and is connected to a ring frame (56). The liquid blocking plate (4) is fixedly connected to the ring frame (56).

5. A film-laying device for a falling film evaporator according to claim 4, characterized in that, A spring (13) connects the hollow connecting rod (8) to the ring frame (56).

6. The film-laying device for a falling film evaporator according to claim 5, characterized in that, Each spiral guide plate (7) is connected to a baffle (14) at its top. The baffle (14) is in contact with the outer wall of the hollow column (6) and the inner wall of the connecting pipe (2). Each baffle (14) is located between two adjacent liquid inlets (21).

Images