A falling film evaporator suitable for DMF

Abstract

The utility model provides a kind of falling film evaporator suitable for DMF, including shell side and pipe passage;Shell side includes the No. one cylinder body, expansion joint and No. two cylinder body sequentially connected from top to bottom, built-in heat exchange tube;Pipe passage includes the No. three cylinder body below shell side and the upper tube unit located above shell side, upper tube unit includes the No. four cylinder body connected on upper tube plate and the No. five cylinder body and No. six cylinder body connected with each other, the No. five cylinder body and No. six cylinder body are set on the outside of No. four cylinder body, No. four cylinder body is provided with feed inlet by tube distributor assembly, the top of No. six cylinder body is provided with gas phase outlet by upper head.The utility model passes through shell side and pipe passage structure, significantly improves heat exchange efficiency, the turbulence effect of fluid is enhanced by the odd baffle and even baffle built-in shell side, promotes the effective transmission of heat;In pipe passage, liquid distributor ensures that liquid is vertically dropped into heat exchange tube in uniform fine stream, avoids local overheating, improves heat exchange uniformity.

Description

Technical Field

[0001] This utility model relates to the field of thin film evaporation, and in particular to the field of liquid-liquid purification technology, specifically a falling film evaporator suitable for DMF. Background Technology

[0002] Falling film evaporators are highly efficient evaporation devices widely used in industries such as chemical, pharmaceutical, and food processing. Traditional evaporators suffer from high energy consumption and low evaporation efficiency, while falling film evaporators, by forming a thin liquid film, can significantly improve evaporation efficiency and reduce energy consumption.

[0003] Currently, there are many types of falling film evaporators on the market, but most of them have certain limitations in structural design and material selection, making it difficult to meet the high-efficiency evaporation requirements under specific process conditions. For example, although the existing single-cylinder structure evaporator can increase the processing capacity by increasing the diameter, the evaporation efficiency is limited due to the uniformity of fluid distribution. On the other hand, series multi-stage equipment has the disadvantages of large footprint and cumulative energy consumption. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide a falling film evaporator suitable for DMF, so as to solve the difficulties of the prior art.

[0005] To achieve the above and other related objectives, this utility model provides a falling film evaporator suitable for DMF, including a shell side and a tube side;

[0006] The shell side includes a first cylinder 24, an expansion joint 51 and a second cylinder 14 connected sequentially from top to bottom, with an internal heat exchanger 22. An upper tube sheet 25 is installed on the top of the first cylinder 24, and a lower tube sheet 11 is installed on the bottom of the second cylinder 14. A steam inlet S1 is located on the first cylinder 24, and a condensate outlet S2 is located on the second cylinder 14.

[0007] The tube side includes a No. 3 cylinder 4 below the shell side and an upper tube unit located above the shell side. The upper end of the No. 3 cylinder 4 is connected to the lower tube sheet 11. A liquid outlet N1 is opened at the bottom of the No. 3 cylinder 4. The upper tube unit includes a No. 4 cylinder 26 connected to the upper tube sheet 25 and a No. 5 cylinder 29 and a No. 6 cylinder 35 connected to each other. The No. 5 cylinder 29 and the No. 6 cylinder 35 are sleeved on the outside of the No. 4 cylinder 26. A feed inlet N2 is provided on the No. 4 cylinder 26 through a tube distributor assembly 30. A gas phase outlet N3 is provided on the top of the No. 6 cylinder 35 through an upper end cap 36.

[0008] According to the preferred embodiment, an odd number of baffles 20 and an even number of baffles 15 are also installed inside the shell side, and the heat exchange tubes 22 are arranged through the odd number of baffles 20 and the even number of baffles 15.

[0009] According to the preferred scheme, multiple pressure gauge ports P, thermometer ports T, level gauge ports L, and sight glass ports N are installed on the shell side and tube side.

[0010] According to the preferred embodiment, the first cylinder 24 protrudes outward in the circumferential direction to form a first cone 23, and the steam inlet S1 is installed on the first cone 23.

[0011] According to the preferred embodiment, the liquid outlet N1 is equipped with an anti-vortex component 1 located inside the third cylinder 4.

[0012] According to the preferred embodiment, a liquid distributor 43 is installed inside the fourth cylinder 26.

[0013] According to the preferred embodiment, the liquid distributor 43 adopts a serrated weir groove with a disc rim. The liquid is divided into thin streams by the serrated weir groove and falls vertically into the heat exchange tube 22 below.

[0014] According to the preferred embodiment, the bottom of the fifth cylinder 29 is configured as a second cone 27, and the angle between the second cone 27 and the fourth cylinder 26 is an acute angle. The refluxed liquid flows into the fourth cylinder 26 through the second cone 27 and enters the heat exchange tube 22 below.

[0015] According to the preferred scheme, the No. 5 cylinder 29 and the No. 6 cylinder 35 are connected by a flange.

[0016] According to the preferred embodiment, a wire mesh demister 62 is installed inside the sixth cylinder 35 below the gas phase outlet N3.

[0017] According to the preferred scheme, spacer tubes 18 and 19 are also installed inside the first cylinder 24, the expansion joint 51, and the second cylinder 14.

[0018] This invention significantly improves heat exchange efficiency through its shell-side and tube-side structure. The odd-numbered and even-numbered baffles built into the shell side enhance the turbulence effect of the fluid, promoting effective heat transfer. In the tube side, a liquid distributor ensures that the liquid falls vertically into the heat exchange tube in a uniform, fine stream, avoiding local overheating and improving heat exchange uniformity. The application of anti-vortex components reduces vortex phenomena at the liquid outlet, while the wire mesh demister effectively removes bubbles at the gas phase outlet, ensuring product purity. In addition, monitoring points such as pressure gauge ports and thermometer ports allow for real-time monitoring of the equipment's operating status, ensuring safe and stable operation.

[0019] The preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings, so as to facilitate an understanding of the features and advantages of the present invention. Attached Figure Description

[0020] Figure 1 The diagram shown is a structural schematic of this utility model.

[0021] Figure 2 This is a top view of the present invention;

[0022] Figure 3 The image shown is an enlarged view of a partial structure of this utility model;

[0023] Label Explanation

[0024] 1. Anti-vortex component; 4. No. 3 cylinder; 11. Lower tube sheet; 14. No. 2 cylinder; 15. Even-numbered baffles; 18, 19. Fixed-distance tubes; 20. Odd-numbered baffles; 22. Heat exchange tubes; 23. No. 1 cone; 24. No. 1 cylinder; 25. Upper tube sheet; 26. No. 4 cylinder; 27. No. 2 cone; 29. ​​No. 5 cylinder; 30. Tube distributor assembly; 35. No. 6 cylinder; 36. Upper head; 43. Liquid distributor; 62. Wire mesh demister. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. The same reference numerals in the drawings represent the same components. It should be noted that the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the described embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0026] Compared to the embodiments shown in the accompanying drawings, feasible embodiments within the scope of protection of this utility model may have fewer components, have other components not shown in the drawings, different components, components arranged differently, or components with different connections, etc. Furthermore, two or more components shown in the drawings may be implemented in a single component, or a single component shown in the drawings may be implemented as multiple separate components.

[0027] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, “an” or “a” and similar terms do not necessarily indicate a quantity limitation. Terms such as “comprising” or “including” mean that the element or object preceding the word encompasses the element or object listed following the word and its equivalents, without excluding other elements or objects. Terms such as “connected” or “linked” are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as “upper,” “lower,” “left,” and “right” are used only to indicate relative positional relationships; these relative positional relationships may change accordingly when the absolute position of the described object changes.

[0028] This invention proposes a falling film evaporator suitable for DMF, applicable to the chemical and pharmaceutical fields. This invention does not limit the type of product, but the structure of this falling film evaporator is particularly suitable for high-viscosity, high-concentration materials, such as in the purification of DMF.

[0029] In general, the falling film evaporator suitable for DMF proposed in this utility model mainly includes a shell side and a tube side. See also... Figure 1 It shows the arrangement of the shell side and the tube side.

[0030] To achieve high-purity purification within a single structure, this embodiment addresses the limitations of existing falling film evaporators. While many types exist, their structural design and material selection often restrict efficiency, hindering the fulfillment of high-efficiency evaporation requirements under specific process conditions. For instance, while increasing the diameter of existing single-cylinder evaporators can expand capacity, limited fluid distribution uniformity restricts efficiency improvement. Furthermore, multi-stage, series-connected evaporators suffer from large footprint and cumulative energy consumption. This embodiment addresses these issues by employing a shell-side and tube-side structure to significantly improve heat exchange efficiency. Odd- and even-numbered baffles within the shell side enhance fluid turbulence, promoting effective heat transfer. A liquid distributor in the tube side ensures uniform, fine, vertical flow of liquid into the heat exchange tubes, preventing localized overheating and improving heat exchange uniformity. Anti-vortex components reduce vortex phenomena at the liquid outlet, while a wire mesh demister effectively removes bubbles from the gas phase outlet, ensuring product purity. Additionally, monitoring points such as pressure gauges and thermometers allow real-time monitoring of equipment operation, ensuring safe and stable operation.

[0031] like Figure 1As shown, the evaporator provided in this embodiment adopts a combination of shell side and tube side. The shell side includes a first cylinder 24, an expansion joint 51, and a second cylinder 14 connected sequentially from top to bottom. A heat exchange tube 22 is installed inside the shell side, and the liquid material to be replaced is introduced into the heat exchange tube 22. The steam used to heat the heat exchange tube 22 is located inside the first cylinder 24, the expansion joint 51, and the second cylinder 14. The steam inlet S1 is located on the first cylinder 24, and the condensate outlet S2 is located on the second cylinder 14. The steam transfers heat to the liquid material through the tube wall of the heat exchange tube 22, causing the liquid material to form a thin film flow under gravity and vaporize under heat, thereby achieving efficient evaporation and concentration.

[0032] In addition, spacer tubes 18 and 19 are installed inside the first shell 24, expansion joint 51, and second shell 14 to form a rigid frame. This ensures that the heat exchange tubes maintain a fixed spacing under shell-side fluid impact or pressure fluctuations, preventing adjacent heat exchange tubes from colliding or rubbing against each other. Furthermore, the spacer tubes reduce amplitude by increasing constraint points, preventing fatigue fracture or leakage of the heat exchange tubes. Furthermore, odd-numbered baffles 20 and even-numbered baffles 15 are installed inside the shell side. The heat exchange tubes 22 are arranged through the odd-numbered baffles 20 and even-numbered baffles 15, allowing the flow... The fluid passing through the shell forms a more complex flow channel around the heat exchange tube 22, thereby enhancing the turbulence of the fluid. The increased turbulence can effectively improve the heat transfer efficiency between the fluid and the heat exchange tube 22, allowing heat to be transferred from the fluid to the heat exchange tube more quickly, and then from the heat exchange tube to the fluid on the other side, thus improving the overall heat exchange performance. The baffle plate also helps to optimize the distribution of the fluid in the shell, reduce dead zones, and ensure that the fluid can flow through the heat exchange tube evenly and fully, further improving the uniformity and efficiency of heat exchange.

[0033] Based on this, the first cylinder 24 protrudes outward in the circumferential direction to form the first cone 23. The steam inlet S1 is installed on the first cone 23. Its conical surface can guide the steam to diffuse radially along the shell, avoid the steam directly impacting the tube bundle, reduce uneven heat transfer or tube bundle vibration caused by excessive local flow velocity. The steam inlet S1 is located above the cone 23. The curved surface of the cone guides the steam to turn smoothly, reduce the generation of eddies commonly found in the sudden expansion channel, and reduce pressure drop.

[0034] Next, the tube side includes a third cylinder 4 below the shell side and an upper tube unit above the shell side. The upper end of the third cylinder 4 is connected to the lower tube sheet 11 installed at the bottom of the second cylinder 14. The bottom of the third cylinder 4 has a liquid outlet N1, and an anti-vortex component 1 is installed inside the liquid outlet N1. The upper tube unit includes a fourth cylinder 26 connected to the upper tube sheet 25 on the top of the first cylinder 24, and a fifth cylinder 29 and a sixth cylinder 35 connected to each other. The fifth cylinder 29 and the sixth cylinder 35 are sleeved on the outside of the fourth cylinder 26. The fourth cylinder 26 has an inlet N2 provided through the tube distributor assembly 30 to achieve uniform fluid distribution. The top of the sixth cylinder 35 has a gas phase outlet N3 provided through the upper end cap 36 to ensure smooth discharge of gaseous products.

[0035] On the one hand, the No. 5 cylinder 29 and the No. 6 cylinder 35 are mounted on the outside of the No. 4 cylinder 26. The No. 5 cylinder 29 and the No. 6 cylinder 35 are connected by a flange, which allows for quick disassembly and maintenance. This modular design not only simplifies the installation and maintenance process of the equipment, but also helps to improve the reliability and stability of the equipment.

[0036] On the other hand, a liquid distributor 43 is installed inside the fourth cylinder 26. The liquid distributor 43 adopts a serrated weir groove on the edge of the disc. The liquid is divided into fine streams by the serrated weir groove on the edge of the disc and falls vertically into the heat exchange tube 22 below. The liquid distributor distributes the material evenly to the inner wall surface of each heat exchange tube through a precisely designed overflow weir, avoiding excessive or insufficient local flow and ensuring maximum heat exchange area.

[0037] It should be specifically noted that the bottom of the No. 5 cylinder 29 is designed in the shape of a No. 2 cone 27. The angle between the No. 2 cone 27 and the No. 4 cylinder 26 is an acute angle. The return liquid flows into the No. 4 cylinder 26 through the No. 2 cone 27 and enters the heat exchange tube 22 below. The acute angle (such as 30° to 45°) guides the return liquid to enter the No. 4 cylinder 26 efficiently, avoiding liquid stagnation or splashing, ensuring full participation in the heat exchange cycle, and improving the evaporation efficiency by 15% to 20%. The inclined surface of the cone can also reduce liquid impact and reduce the risk of wear on components such as the tube distributor.

[0038] As mentioned above, a wire mesh demister 62 is installed inside the No. 6 cylinder 35 below the gas phase outlet N3. The wire mesh demister 62 can capture micron-sized droplets remaining in the gas phase outlet N3 gas flow through the capillary action and collision effect of multiple layers of metal or plastic wire mesh, with a removal efficiency of over 99%, significantly improving the purity of the gas phase.

[0039] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A falling film evaporator suitable for DMF, characterized in that, include: Shell side and tube side; The shell side includes a first shell (24), an expansion joint (51) and a second shell (14) connected sequentially from top to bottom, with an internal heat exchanger tube (22). An upper tube sheet (25) is installed on the top of the first shell (24), and a lower tube sheet (11) is installed on the bottom of the second shell (14). A steam inlet S1 is located on the first shell (24), and a condensate outlet S2 is located on the second shell (14). The tube side includes a No. 3 cylinder (4) below the shell side and an upper tube unit located above the shell side. The upper end of the No. 3 cylinder (4) is connected to the lower tube sheet (11). The bottom of the No. 3 cylinder (4) is provided with a liquid outlet N1. The upper tube unit includes a No. 4 cylinder (26) connected to the upper tube sheet (25) and a No. 5 cylinder (29) and a No. 6 cylinder (35) connected to each other. The No. 5 cylinder (29) and the No. 6 cylinder (35) are sleeved on the outside of the No. 4 cylinder (26). The No. 4 cylinder (26) is provided with a feed port N2 through a tube distributor assembly (30). The top of the No. 6 cylinder (35) is provided with a gas phase outlet N3 through an upper end cap (36).

2. The falling film evaporator suitable for DMF according to claim 1, characterized in that, The first cylinder (24) protrudes outward in the circumferential direction to form a first cone (23), and the steam inlet S1 is installed on the first cone (23).

3. The falling film evaporator suitable for DMF according to claim 2, characterized in that, The liquid outlet N1 is equipped with an anti-vortex component (1) located inside the No. 3 cylinder (4).

4. The falling film evaporator suitable for DMF according to claim 3, characterized in that, A liquid distributor (43) is installed inside the fourth cylinder (26).

5. The falling film evaporator suitable for DMF according to claim 4, characterized in that, The bottom of the No. 5 cylinder (29) is arranged in the shape of a No. 2 cone (27). The angle between the No. 2 cone (27) and the No. 4 cylinder (26) is an acute angle. The refluxed liquid flows into the No. 4 cylinder (26) through the No. 2 cone (27) and enters the heat exchange tube (22) below.

6. The falling film evaporator suitable for DMF according to claim 5, characterized in that, A wire mesh demister (62) is installed inside the No. 6 cylinder (35) below the gas phase outlet N3.

7. The falling film evaporator suitable for DMF according to claim 6, characterized in that, The first cylinder (24), the expansion joint (51), and the second cylinder (14) are also equipped with spacer tubes (18, 19).

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