A falling film evaporator's film distribution mechanism

Abstract

The utility model discloses a kind of membrane distribution mechanism of falling film evaporator, it is related to falling film evaporator technical field.Its structure includes the isolation plate located above the heat exchange chamber of falling film evaporator, the heat exchange evaporation pipe and membrane distribution disc of several fixedly penetrating below isolation plate;The connecting portion of isolation plate and heat exchange evaporation pipe is provided with first tapered notch;Membrane distribution disc includes disc;Second tapered notch is set in the same shaft with the same number of first tapered notch and is set in disc;The circumferential side of each second tapered notch on disc upper surface is respectively fixed with a bracket.The utility model is cooperated with the design of multistage membrane distribution rod and tapered notch, realizes the uniform membrane distribution of solution in heat exchange evaporation pipe inner wall and the accurate control of membrane layer thickness, stabilizes evaporation rate;Uniform and thin membrane layer has been formed before liquid film enters heat exchange evaporation pipe, increase the contact area of solution and heat exchange evaporation pipe inner wall, reduce thermal resistance, to significantly improve heat exchange efficiency.

Description

Technical Field

[0001] This utility model belongs to the field of falling film evaporator technology, and in particular relates to a film distribution mechanism for a falling film evaporator. Background Technology

[0002] In industries such as chemical, food, and pharmaceutical, falling film evaporators are widely used as highly efficient heat exchange equipment in processes such as solution concentration and purification. Their core principle is to evenly distribute the solution on the inner wall of the heat exchange evaporation tube, forming a thin liquid film. Heat exchange occurs between the external heating medium (such as steam) and the internal liquid film, causing the solvent in the solution to evaporate, thereby achieving solution concentration.

[0003] However, most existing falling film evaporators employ a single-stage film distribution design, meaning the solution flows directly into the heat exchange evaporator tubes after passing through the film distribution device only once. Because single-stage film distribution devices cannot perform multi-stage dispersion of the solution or control the film thickness, the liquid film formed on the inner wall of the heat exchange evaporator tubes is often uneven in thickness. Locally excessively thick liquid films increase thermal resistance and reduce heat exchange efficiency; while locally excessively thin films may lead to dry walls or scaling due to rapid evaporation, further affecting the stable operation of the equipment and product quality. For example, in the food processing industry, uneven film distribution can result in inconsistent product concentrations, affecting the final product's taste and shelf life. The structural design of single-stage film distribution devices often neglects ease of cleaning. During long-term operation, impurities and residues in the solution easily accumulate on the film distribution device and the inner wall of the heat exchange evaporator tubes, forming a fouling layer. To address the above shortcomings of existing film distribution designs, this invention proposes a film distribution mechanism for a falling film evaporator. Utility Model Content

[0004] The purpose of this invention is to provide a film distribution mechanism for a falling film evaporator. Through the combined design of multi-stage film distribution rods and conical grooves, uniform film distribution of the solution on the inner wall of the heat exchange evaporation tube and precise control of the film thickness are achieved.

[0005] To solve the above-mentioned technical problems, this utility model is achieved through the following technical solution:

[0006] This utility model relates to a film distribution mechanism for a falling film evaporator, comprising an isolation plate located above the heat exchange chamber of the falling film evaporator, a plurality of heat exchange evaporation tubes and a film distribution disc fixedly connected below the isolation plate; the connection between the isolation plate and the heat exchange evaporation tubes is provided with a first conical groove; the film distribution disc comprises a disc; the disc has the same number of second conical grooves as the first conical grooves and is coaxially arranged; a bracket is fixed on the upper surface of the disc around each of the second conical grooves; a multi-stage film distribution rod that mates with the second and first conical grooves is fixed on the bracket; four stepped shafts are fixed on the isolation plate; and four through holes that mate with the upper ends of the stepped shafts are provided on the disc.

[0007] As a preferred embodiment of this utility model, four cylindrical support rods are fixed in the middle of the disc; and a receiving and diverting circular plate is fixed at the upper end of the four cylindrical support rods.

[0008] As a preferred embodiment of this utility model, the upper end of the stepped shaft is provided with an external thread, and a nut is threadedly connected to the upper end of the stepped shaft.

[0009] As a preferred embodiment of this utility model, the bracket includes three fixed support rods that are vertically fixed to the upper surface of the disc; a triangular plate is fixed to the upper end of the three fixed support rods; and the multi-stage fabric rod is fixed to the center of the lower end face of the triangular plate.

[0010] As a preferred embodiment of this utility model, the multi-stage film-forming rod includes a first cylindrical rod segment, a first frustum-shaped segment, a second cylindrical rod segment, and a second frustum-shaped segment integrally formed from top to bottom; the first cylindrical rod segment is clearance-fitted with the inner wall of the lower end of the second conical groove; the lower end of the second frustum-shaped segment is placed in the lower half of the inner side of the first conical groove and is clearance-fitted with it, and the lower end of the second conical groove is larger than the inner diameter of the heat exchange evaporation tube.

[0011] In a preferred embodiment of this invention, the diameter of the second cylindrical rod segment is twice the diameter of the first cylindrical rod segment; the diameter of the lower end of the second frustum segment is 1.2 times the diameter of the second cylindrical rod segment.

[0012] As a preferred embodiment of this utility model, a conical groove is provided at the lower end of the second conical section, and the diameter of the lower end of the conical groove is larger than the inner diameter of the heat exchange evaporation tube.

[0013] This utility model has the following beneficial effects:

[0014] 1. This invention utilizes a multi-stage film-forming rod design, including a first cylindrical rod segment, a first frustum-shaped segment, a second cylindrical rod segment, and a second frustum-shaped segment. As the solution flows through these structures, the coverage area gradually expands and thins. The liquid film forms a uniform and thin film layer before entering the heat exchange evaporator tube, increasing the contact area between the solution and the inner wall of the heat exchange evaporator tube, reducing thermal resistance, and thus significantly improving heat exchange efficiency.

[0015] 2. The second conical groove on the film-distributing plate of this invention, in conjunction with the multi-stage film-distributing rod, and the design of the receiving and diverting circular plate, ensures that the solution is evenly dispersed and flows to each film-distributing point. The uniform liquid film distribution avoids overheating caused by local solution accumulation, making the evaporation process more stable and controllable, and helping to maintain the temperature balance inside the evaporator.

[0016] 3. The membrane distribution plate, isolation plate, and other components of this utility model are designed with a detachable structure. The multi-stage membrane distribution rod and conical groove design reduce the possibility of solution residue and scaling. The detachable design facilitates regular cleaning and maintenance, reducing cleaning time and difficulty; at the same time, the optimized structural design reduces solution residue and scaling inside the equipment, lowering cleaning costs and equipment failure rate.

[0017] Of course, any product implementing this utility model does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of 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.

[0019] Figure 1 This is a cross-sectional schematic diagram of the film distribution mechanism of the falling film evaporator of this utility model.

[0020] Figure 2 for Figure 1 A magnified view of a portion of point A in the middle.

[0021] Figure 3 for Figure 1 A magnified view of a section at point B.

[0022] Figure 4 This is a schematic diagram of the structure of a falling film evaporator after it has been split.

[0023] Figure 5 This is a schematic diagram of the structure of a falling film evaporator after it has been separated from the film distribution plate.

[0024] Figure 6 This is a schematic diagram of the fabrication disc structure.

[0025] The attached diagram lists the components represented by each number as follows:

[0026] 1-Falling film evaporator, 11-Isolation plate, 12-Heat exchange evaporation tube, 13-First conical groove, 2-Film distribution plate, 21-Disc, 22-Second conical groove, 23-Support, 24-Multi-stage film distribution rod, 25-Circular through hole, 14-Stepped shaft, 26-Cylindrical support rod, 27-Receiver and diverter circular plate, 3-Nut, 231-Fixed support rod, 232-Triangular plate, 241-First cylindrical rod section, 242-First frustum-shaped section, 243-Second cylindrical rod section, 244-Second frustum-shaped section, 245-Conical groove. Detailed Implementation

[0027] 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. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model. Specific Implementation Example 1:

[0029] Please see Figure 1-6 As shown, this utility model relates to a film distribution mechanism for a falling film evaporator, comprising an isolation plate 11 located above the heat exchange chamber of the falling film evaporator 1, a plurality of heat exchange evaporation tubes 12 fixedly connected below the isolation plate 11, and a film distribution plate 2. A first conical groove 13 is provided at the connection between the isolation plate 11 and the heat exchange evaporation tubes 12. The film distribution plate 2 includes a disc 21, the outer wall of which is tightly connected to the inner wall of the falling film evaporator 1, ensuring that the solution does not flow directly down from the gap between the disc and the inner wall of the evaporator, but must be evenly distributed through the film distribution mechanism. The disc 21 has the same number of second conical grooves 22 as the first conical grooves 13, and is coaxially arranged. A bracket 23 is fixed to the circumference of each second conical groove 22 on the upper surface of the disc 21. A multi-stage film distribution rod 24, which cooperates with the second conical grooves 22 and the first conical grooves 13, is fixed to the bracket 23. Four stepped shafts 14 are fixed to the isolation plate 11. The disc 21 has four through holes 25 that mate with the upper end of the stepped shaft 14.

[0030] To prevent the solution from directly impacting the disc 21 and its first conical slot 13 upon entering the falling film evaporator 1, thus disrupting the film distribution, four cylindrical support rods 26 are fixed in the middle of the disc 21. A receiving and diverting circular plate 27 is fixed to the upper end of each of the four cylindrical support rods 26. The solution enters from the top of the falling film evaporator and first contacts the receiving and diverting circular plate 27 above the film distribution disc 2.

[0031] In order to ensure the stable installation of the film-forming plate 2 inside the falling film evaporator 1, an external thread is provided on the upper end of the stepped shaft 14, and a nut 3 is threadedly connected to the upper end of the stepped shaft 14.

[0032] The bracket 23 includes three fixed support rods 231 vertically fixed to the upper surface of the disc 21. A triangular plate 232 is fixed to the upper end of the three fixed support rods 231. A multi-stage fabric rod 24 is fixed to the center of the lower end face of the triangular plate 232.

[0033] The multi-stage film-forming rod 24 includes a first cylindrical rod segment 241, a first frustoconical segment 242, a second cylindrical rod segment 243, and a second frustoconical segment 244, integrally formed from top to bottom. The first cylindrical rod segment 241 is clearance-fitted with the inner wall of the lower end of the second conical groove 22. The lower end of the second frustoconical segment 244 is located in the lower half of the inner side of the first conical groove 13 and is clearance-fitted with it. The lower end of the second conical groove 22 is larger than the inner diameter of the heat exchange evaporator tube 12. The diameter of the second cylindrical rod segment 243 is twice the diameter of the first cylindrical rod segment 241. The diameter of the lower end of the second frustoconical segment 244 is 1.2 times the diameter of the second cylindrical rod segment 243.

[0034] To prevent the solution film from dripping and affecting the film distribution at the lower end of the second frustum section 244, a conical groove 245 is provided at the lower end of the second frustum section 244, and the diameter of the lower end of the conical groove 245 is larger than the inner diameter of the heat exchange evaporation tube 12.

[0035] The solution forms a preliminary liquid film on the outer wall of the first cylindrical rod section 241 between the first cylindrical rod section 241 and the second conical groove 22, flowing downwards. As the liquid film passes through the first frustum-shaped section 242, its coverage area doubles, and the film thins. This process ensures that the liquid film has a relatively uniform thickness before entering the heat exchange evaporation tube 12. The liquid film continues to flow along the second cylindrical rod section 243 to the lower second frustum-shaped section 244. As it passes through the second frustum-shaped section 244, its coverage area continues to expand, and the film continues to thin. Finally, it flows slightly narrower through the first conical groove 13 to the inner wall of the heat exchange evaporation tube 12. Because the liquid film has undergone two expansions and thinning processes, its distribution on the inner wall of the heat exchange evaporation tube 12 is more uniform, which is beneficial for improving heat exchange efficiency. By optimizing the distribution and thickness of the liquid film, the evaporation process of the solution within the heat exchange evaporation tube 12 can be more precisely controlled. The uniform liquid film distribution avoids the problems of localized overheating and excessively fast evaporation rates, helping to maintain the stability and controllability of the evaporation process.

[0036] The membrane-laying mechanism is designed with ease of cleaning in mind. Components such as the membrane-laying disc 2 and the separator plate 11 can be easily disassembled and installed, facilitating regular cleaning and maintenance. Meanwhile, the multi-stage membrane-laying rod 24 and the conical groove design reduce the possibility of solution residue and scaling, further lowering the difficulty and cost of cleaning.

[0037] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0038] The preferred embodiments of this utility model disclosed above are merely illustrative of the present utility model. These preferred embodiments do not exhaustively describe all details, nor do they limit the utility model to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of this utility model, thereby enabling those skilled in the art to better understand and utilize it. This utility model is limited only by the claims and their full scope and equivalents.

Claims

1. A film distribution mechanism for a falling film evaporator, comprising an isolation plate (11) located above the heat exchange chamber of the falling film evaporator (1) and a plurality of heat exchange evaporation tubes (12) fixedly inserted below the isolation plate (11), characterized in that: It also includes a cloth film plate (2); The connection between the isolation plate (11) and the heat exchange evaporator (12) is provided with a first conical groove (13). The film tray (2) includes a disc (21); the disc (21) has a second conical slot (22) that is the same number as the first conical slot (13) and is coaxially arranged. On the upper surface of the disk (21), a bracket (23) is fixed on the periphery of each of the second conical slots (22); a multi-stage film rod (24) that cooperates with the second conical slot (22) and the first conical slot (13) is fixed on the bracket (23). Four stepped shafts (14) are fixed on the isolation plate (11); four through holes (25) that mate with the upper end of the stepped shafts (14) are provided on the disc (21).

2. The film distribution mechanism of the falling film evaporator according to claim 1, characterized in that, Four cylindrical support rods (26) are fixed in the middle of the disk (21); a receiving and diverting circular plate (27) is fixed at the upper end of the four cylindrical support rods (26).

3. The film distribution mechanism of the falling film evaporator according to claim 1, characterized in that, The upper end of the stepped shaft (14) is threaded with an external thread, and the upper end of the stepped shaft (14) is threaded with a nut (3).

4. The film distribution mechanism of the falling film evaporator according to claim 1, characterized in that, The bracket (23) includes three fixed support rods (231) that are vertically fixed to the upper surface of the disc (21); a triangular plate (232) is fixed to the upper end of the three fixed support rods (231); and the multi-stage fabric rod (24) is fixed to the center of the lower end face of the triangular plate (232).

5. The film distribution mechanism of the falling film evaporator according to claim 1, characterized in that, The multi-stage membrane rod (24) includes a first cylindrical rod segment (241), a first frustum segment (242), a second cylindrical rod segment (243), and a second frustum segment (244) integrally formed from top to bottom; the first cylindrical rod segment (241) is clearance-fitted with the inner wall of the lower end of the second conical groove (22); the lower end of the second frustum segment (244) is placed in the lower half of the inner side of the first conical groove (13) and clearance-fitted with it, and the lower end of the second conical groove (22) is larger than the inner diameter of the heat exchange evaporator tube (12).

6. The film distribution mechanism of the falling film evaporator according to claim 5, characterized in that, The diameter of the second cylindrical rod segment (243) is twice the diameter of the first cylindrical rod segment (241); the diameter of the lower end of the second frustum segment (244) is 1.2 times the diameter of the second cylindrical rod segment (243).

7. The film distribution mechanism of the falling film evaporator according to claim 6, characterized in that, The lower end of the second frustum section (244) is provided with a conical groove (245), and the diameter of the lower end of the conical groove (245) is larger than the inner diameter of the heat exchange evaporator tube (12).

Images