Film distribution optimization device of efficient falling film evaporator and control method

Abstract

The invention relates to the technical field of film distribution of falling-film evaporators, and discloses a film distribution optimizing device of an efficient falling-film evaporator, which comprises a barrel, a material distribution plate is fixedly mounted at the upper part of the inner wall of the barrel, and a plurality of groups of heat exchange tubes penetrating through and extending to the lower part of the material distribution plate are mounted on the material distribution plate. Materials can enter a heat exchange tube area in a preliminary dispersion mode through a plurality of liquid inlet through holes evenly formed in a material distribution plate, the materials can be more evenly attached to the inner wall of the heat exchange tube through a circular-truncated-cone-shaped material distributor fixed to the inner wall of the top of the heat exchange tube through a connecting rod, and the problem that the materials are locally stacked or distributed unevenly is effectively avoided; the rotating rod is driven to rotate, then the lifting plate is driven to move up and down along the guide rod, accurate adjustment of the position of the adjusting pipe is achieved, the relative position of the adjusting pipe and the heat exchange pipe can be changed, then the flow and distribution of materials entering the heat exchange pipe are flexibly adjusted, the film distribution effect is further optimized, and the requirements of different materials and technologies for film distribution are met.

Description

Technical Field

[0001] The present invention relates to the technical field of film distribution for falling film evaporators, and in particular to a film distribution optimization device and a control method for a high-efficiency falling film evaporator. Background Art

[0002] Falling film evaporators, as highly efficient heat exchange equipment, are widely used in industries such as food, pharmaceuticals, chemicals, and metallurgy for material concentration, solution dehydration, and evaporation of heat-sensitive substances. Their core principle is that liquid material is distributed across the inner walls of vertically arranged heat exchange tubes through a film distribution mechanism. Under the influence of gravity and heat, a continuous liquid film forms and flows down the inner walls, simultaneously completing the heat exchange and evaporating a portion of the material. Due to its advantages such as high heat transfer efficiency, short material residence time, and low energy consumption, falling film evaporation has gradually become the mainstream equipment type in various continuous evaporation processes in recent years.

[0003] However, in practical applications, the operating efficiency and evaporation quality of falling film evaporators are critically influenced by the "film effect." This refers primarily to the distribution and flow pattern of the material on the inner wall of the heat exchange tube. A uniform film distribution ensures a moderate film thickness, sufficient heat exchange, and effectively increases the evaporation rate. Conversely, an uneven film distribution can easily lead to areas that are too thick or too thin, causing problems such as uneven heat exchange, tube wall scaling, dry wall formation, and material coking, impacting product quality and even damaging the equipment. Therefore, the design and controllability of the film structure are key factors in determining the performance of a falling film evaporator.

[0004] Currently, most falling film evaporator film distribution methods use fixed-aperture distribution plates, single distributors, or simple flow guides for initial distribution. These traditional structures have several limitations: First, the film distribution path and tube flow rate lack adjustment methods, making it impossible to dynamically optimize the flowability, viscosity, or process conditions of different materials. Second, the distribution is often affected by uneven liquid inflow and localized accumulation, resulting in excessively thick liquid film on the inner walls of some heat exchange tubes or partially empty tubes, severely reducing thermal efficiency. Furthermore, if the equipment structure is fixed and lacks adjustment mechanisms, operators cannot flexibly adjust it according to on-site needs during production, resulting in poor versatility and adaptability of the equipment, which is particularly unfavorable for production models with multiple materials and multiple working conditions.

[0005] Furthermore, in demanding scenarios such as evaporating new materials, heat-sensitive substances, or highly concentrated solutions, the material's film-forming state and evaporation rate directly impact product yield and quality. Especially when the material viscosity is high or the flow rate varies widely, traditional film-forming systems struggle to ensure a stable, continuous, and uniform liquid film forms within the heat exchange tubes, leading to incomplete evaporation or reduced heat reduction efficiency. Furthermore, in some systems, the material flow rate must be adjusted in real time to control the evaporation intensity based on energy-saving and consumption-reduction requirements, posing a significant technical challenge to the controllability of the film-forming device.

[0006] In summary, the existing technology has significant deficiencies in the adjustment ability, distribution uniformity, adaptability and evaporation control flexibility of the membrane structure. To this end, we propose a membrane optimization device and control method for a high-efficiency falling film evaporator to solve the above problems. Summary of the Invention

[0007] In view of the deficiencies in the prior art, the present invention provides a film distribution optimization device and a control method for a high-efficiency falling film evaporator to solve the problems raised by the above-mentioned background technology.

[0008] The present invention provides the following technical solution: a film optimization device for a high-efficiency falling film evaporator, comprising a cylinder, a distribution plate fixedly installed on the upper part of the inner wall of the cylinder, a plurality of groups of heat exchange tubes penetrating and extending to the lower part of the distribution plate are installed on the distribution plate, a lifting plate is provided inside the cylinder and on the upper part of the distribution plate, a plurality of regulating tubes are evenly fixedly installed on the bottom surface of the lifting plate, a connecting rod is fixedly installed on the top inner wall of the heat exchange tube, a distributor is fixedly installed on the bottom end of the connecting rod, guide rods penetrating and extending to the upper part of the cylinder are fixedly installed on both sides of the top of the lifting plate, a top plate is fixedly installed on the top of the guide rod, a limiting plate is fixedly installed on the outer ring of one side of the guide rod located inside the cylinder, and the top of the cylinder is rotatably connected to a rotating rod penetrating the lifting plate.

[0009] As a preferred technical solution of the present invention, the lower outer ring of the rotating rod is provided with a thread, the central part of the lifting plate is provided with a threaded hole, and the thread set on the rotating rod matches the threaded hole provided in the central part of the lifting plate, and a handwheel is installed on the top of the rotating rod.

[0010] As a preferred technical solution of the present invention, the multiple regulating tubes fixedly installed at the bottom of the lifting plate correspond one-to-one to the multiple heat exchange tubes, and the regulating tubes can be sleeved on the top of the heat exchange tubes.

[0011] As a preferred technical solution of the present invention, the heat exchange tube is located on the top outer ring of the distribution plate and is evenly provided with multiple liquid inlet holes. The distributor is located at the lower part of the distribution plate and is in the shape of a truncated cone.

[0012] As a preferred technical solution of the present invention, a feed pipe is installed on the upper right side of the cylinder and located above the cloth plate, and a steam inlet pipe is installed in the middle left side of the cylinder.

[0013] As a preferred technical solution of the present invention, a discharge pipe is installed at the bottom of the cylinder, and a secondary steam pipe is installed on the right side of the top of the cylinder.

[0014] The present invention also provides a control method for a film distribution optimization device for a high-efficiency falling film evaporator, which is characterized by comprising the following steps:

[0015] S1. The material is injected into the cylinder through the feed pipe and initially dispersed into the heat exchange tube through the liquid inlet holes on the distribution plate;

[0016] S2. Steam is introduced through the steam inlet pipe to achieve falling film evaporation of the material in the heat exchange tube.

[0017] As a preferred technical solution of the present invention, during the film laying process, the rotating rod is driven to rotate by turning the handwheel, so that the lifting plate moves up and down along the guide rod, thereby changing the insertion depth of the regulating tube and the heat exchange tube to adjust the flow and distribution state of the material entering the heat exchange tube.

[0018] As a preferred technical solution of the present invention, when processing high-viscosity materials, the lifting plate moves upward to reduce the overlapping length of the regulating tube and the heat exchange tube, expand the material flow channel, thereby avoiding local accumulation and improving film uniformity.

[0019] As a preferred technical solution of the present invention, the flow rate of the material entering the heat exchange tube is set by adjusting the height of the lifting plate, thereby meeting the control requirements of the evaporation rate of different processes and achieving precise optimization of the film effect.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. This film distribution optimization device for a high-efficiency falling film evaporator allows the material to enter the heat exchange tube area in a dispersed manner through multiple liquid inlet holes evenly opened on the distribution plate. The frustum-shaped material distributor fixed to the inner wall of the top of the heat exchange tube by a connecting rod can perform secondary dispersion on the material entering the heat exchange tube, so that the material adheres more evenly to the inner wall of the heat exchange tube, effectively avoiding the problem of local accumulation or uneven distribution of the material, thereby increasing the contact area between the material and the steam, improving the heat exchange efficiency, and significantly enhancing the evaporation effect.

[0022] 2. This film distribution optimization device for a high-efficiency falling film evaporator drives the rotating rod to rotate by turning the hand wheel, and then drives the lifting plate to move up and down along the guide rod, so as to achieve precise adjustment of the position of the regulating tube. The guide rod and the top plate at its top and the limit plate located on the outer ring of one side of the cylinder provide stable guidance and limiting effects for the movement of the lifting plate, ensuring that the lifting plate will not deviate or shake during the movement, so that the regulating tube can accurately cooperate with the heat exchange tube. The multiple regulating tubes evenly fixed at the bottom of the lifting plate correspond to the heat exchange tube one by one and can be sleeved on the top of the heat exchange tube. By adjusting the position of the lifting plate, the relative position of the regulating tube and the heat exchange tube can be changed, thereby flexibly adjusting the flow and distribution of the material entering the heat exchange tube, further optimizing the film distribution effect, and adapting to the film distribution requirements of different materials and processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1It is a schematic diagram of the three-dimensional structure of the present invention;

[0024] Figure 2 This is a schematic diagram of the cross-sectional structure of the cylinder of the present invention;

[0025] Figure 3 It is a structural schematic diagram of the distributor of the present invention.

[0026] In the figure: 1. Cylinder; 2. Discharge pipe; 3. Steam inlet pipe; 4. Rotating rod; 5. Handwheel; 6. Secondary steam pipe; 7. Top plate; 8. Feed pipe; 9. Adjusting pipe; 10. Distribution plate; 11. Heat exchange tube; 12. Limit plate; 13. Lifting plate; 14. Guide rod; 15. Distributor; 16. Connecting rod. DETAILED DESCRIPTION

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0028] Example 1: Please refer to Figure 1 、 Figure 2 and Figure 3, a film distribution optimization device for a high-efficiency falling film evaporator, including a cylinder 1, first, the material to be evaporated is transported to the inside of the cylinder 1 through the feed pipe 8, and the material will fall on the distribution plate 10. At the same time, steam is introduced into the cylinder 1 through the steam inlet pipe 3 to provide heat for the evaporation process. At this time, in the initial state, the lifting plate 13 is in a suitable position, and the regulating pipe 9 is sleeved at a certain position on the top of the heat exchange tube 11. The material enters the heat exchange tube 11 from the liquid inlet through-hole on the distribution plate 10. During the entry process, the frustum-shaped distributor 15 fixed to the inner wall of the top of the heat exchange tube 11 by the connecting rod 16 will preliminarily disperse the material, so that the material is more evenly distributed around the inner wall of the heat exchange tube 11. As the evaporation process proceeds, the secondary steam generated is discharged from the secondary steam pipe 6, and the evaporated material is discharged from the bottom The material is discharged from the discharge pipe 2. When the film distribution needs to be adjusted, the operator rotates the handwheel 5, and the handwheel 5 drives the rotating rod 4 to rotate. Since the outer ring of the lower part of the rotating rod 4 is provided with a thread, the center of the lifting plate 13 is provided with a threaded hole matching it, and the lifting plate 13 is limited in its rotation freedom by the guide rod 14 and the limit plate 12, the rotation of the rotating rod 4 will cause the lifting plate 13 to move up and down along the guide rod 14, and the raised position of the top plate 7 can be used to judge the raised distance of the regulating tube 9. The movement of the lifting plate 13 drives multiple regulating tubes 9 uniformly fixed at the bottom to move up and down. The regulating tubes 9 correspond to the heat exchange tubes 11 one by one. By changing the depth of the regulating tubes 9 inserted into the top of the heat exchange tubes 11, the flow rate and distribution of the material entering the heat exchange tubes 11 can be adjusted to achieve optimization of the film distribution.

[0029] Example 2: Please refer to Figure 1 、 Figure 2 and Figure 3 When the viscosity of the processed material is relatively high, the distribution of the material on the inner wall of the heat exchange tube 11 may be uneven in the initial state, and local accumulation is likely to occur. At this time, the operator rotates the hand wheel 5 counterclockwise to rotate the rotating rod 4, and the lifting plate 13 moves upward under the action of the thread. The lifting plate 13 drives the regulating tube 9 to move upward, reducing the depth of the regulating tube 9 inserted into the top of the heat exchange tube 11. In this way, the channel for the material to enter the heat exchange tube 11 becomes relatively larger, and the material is easier to flow into the heat exchange tube 11. In addition, the distributor 15 can better disperse the material around the inner wall of the heat exchange tube 11, improve the film spreading effect, and make the material The material is heated and evaporated more evenly in the heat exchange tube 11. When the viscosity of the processed material is low, the material fluidity is good, but there may be a problem of low heat exchange efficiency due to excessive dispersion. At this time, the operator rotates the handwheel 5 clockwise, and the rotating rod 4 rotates to move the lifting plate 13 downward, and the regulating tube 9 moves downward accordingly, increasing the depth of the regulating tube 9 inserted into the top of the heat exchange tube 11. The channel for the material to enter the heat exchange tube 11 becomes smaller, and the material will be squeezed and guided to a certain extent when entering the heat exchange tube 11, and will be more concentratedly distributed in a specific area of ​​the inner wall of the heat exchange tube 11, thereby improving the heat exchange efficiency and optimizing the film effect.

[0030] Example 3: Please refer to Figure 1 、 Figure 2 and Figure 3 In some process requirements, it is necessary to control the evaporation rate. When the evaporation rate needs to be accelerated, the operator turns the handwheel 5 to move the lifting plate 13 upward, and the regulating tube 9 moves upward, thereby increasing the flow rate of the material entering the heat exchange tube 11. After more material enters the heat exchange tube 11, it can evaporate faster under the action of steam, thereby improving the evaporation rate. At the same time, the distributor 15 makes the material evenly distributed to avoid local uneven evaporation due to excessive material. When the evaporation rate needs to be reduced, the operator turns the handwheel 5 in the opposite direction to move the lifting plate 13 downward, and the regulating tube 9 moves downward, thereby reducing the flow rate of the material entering the heat exchange tube 11. The residence time of the material in the heat exchange tube 11 is relatively prolonged, and the evaporation process is smoother, meeting the process requirement of reducing the evaporation rate. In addition, during the entire adjustment process, the guide rod 14 and the limit plate 12 ensure the stability of the movement of the lifting plate 13, so that the regulating tube 9 can accurately cooperate with the heat exchange tube 11 to achieve optimal adjustment of the film distribution.

[0031] Implementation effect: Through the multiple liquid inlet holes evenly opened on the distribution plate 10, the material can be initially dispersed into the heat exchange tube 11 area, and the frustum-shaped distributor 15 fixed to the top inner wall of the heat exchange tube 11 by the connecting rod 16 can perform secondary dispersion on the material entering the heat exchange tube 11, so that the material is more evenly attached to the inner wall of the heat exchange tube 11, effectively avoiding the problem of local accumulation or uneven distribution of the material, thereby increasing the contact area between the material and the steam, improving the heat exchange efficiency, and significantly improving the evaporation effect.

[0032] The hand wheel 5 is turned to drive the rotating rod 4 to rotate, thereby driving the lifting plate 13 to move up and down along the guide rod 14 to achieve precise adjustment of the position of the regulating tube 9. The guide rod 14 and the top plate 7 at its top and the limit plate 12 located on the outer ring of one side of the cylinder 1 provide stable guidance and limiting effects for the movement of the lifting plate 13, ensuring that the lifting plate 13 will not deviate or shake during the movement, so that the regulating tube 9 can accurately cooperate with the heat exchange tube 11. The multiple regulating tubes 9 evenly fixed at the bottom of the lifting plate 13 correspond one-to-one with the heat exchange tube 11 and can be sleeved on the top of the heat exchange tube 11. By adjusting the position of the lifting plate 13, the relative position of the regulating tube 9 and the heat exchange tube 11 can be changed, thereby flexibly adjusting the flow and distribution of the material entering the heat exchange tube 11, further optimizing the film spreading effect, and adapting to the film spreading requirements of different materials and processes.

[0033] Example 4: Please refer to Figures 1 to 3 In order to achieve dynamic adaptation of different material processes to the film distribution state, this embodiment proposes a film distribution optimization method based on manual control, which is suitable for the operation and control of a high-efficiency falling film evaporator.

[0034] First, the preheated material is injected into the cylinder 1 through the feed pipe 8. The material is initially dispersed through multiple liquid inlet holes evenly distributed on the distribution plate 10 and flows into the heat exchange tubes 11 below. Steam is introduced into the cylinder 1 through the steam inlet pipe 3 to provide the required heat for the material in the heat exchange tubes 11.

[0035] Before film spreading begins, the operator manually turns handwheel 5 based on the material's properties (such as viscosity and fluidity). This rotates rotating rod 4, which then engages the threaded structure of rotating rod 4 with the central threaded hole of lifting plate 13, causing lifting plate 13 to move up and down along guide rods 14. Multiple regulating tubes 9, evenly distributed at the bottom of lifting plate 13, rise and fall synchronously with the plate and connect to the corresponding tops of heat exchange tubes 11.

[0036] For example, when processing high-concentration juice, which has high viscosity and poor fluidity, inserting the regulating tube 9 too deeply into the heat exchange tube 11 can hinder material entry, resulting in uneven film distribution or localized accumulation. Therefore, the operator rotates the handwheel 5 counterclockwise approximately 90°, raising the lifting plate 13 by approximately 15 mm. This reduces the insertion depth of the regulating tube 9 by approximately 10%, widening the material entry channel and improving flow. At this point, the frustum-shaped distributor 15 attached to the top of the heat exchange tube 11 provides secondary dispersion of the incoming material, further improving film distribution uniformity.

[0037] When turning to process a low-viscosity syrup solution, in order to avoid the material being too sparsely distributed and thus causing a decrease in heat exchange efficiency, the operator rotates the handwheel 5 clockwise to lower the lifting plate 13 by 10 mm, and the adjustment tube 9 penetrates into the top of the heat exchange tube 11, thereby improving the concentration of the material distribution and making the material more concentratedly distributed on the inner wall of the heat exchange tube 11, effectively improving the evaporation efficiency.

[0038] The entire film-forming process features highly precise and flexible adjustments, meeting the demands of materials with varying viscosities and evaporation rates while avoiding process limitations inherent in structural rigidity. Furthermore, the positioning of the limiter plate 12 and the top plate 7 ensures the stability and safety of the lift plate 13 during its vertical movement, preventing any misalignment or accumulated errors caused by wobbling, thus ensuring a consistently stable film-forming effect.

[0039] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A film distribution optimization device for a high-efficiency falling film evaporator, comprising a cylinder (1), characterized in that: A distribution plate (10) is fixedly mounted on the upper portion of the inner wall of the cylinder (1), and a plurality of heat exchange tubes (11) are mounted on the distribution plate (10) and pass through and extend to the lower portion of the distribution plate (10). A lifting plate (13) is provided inside the cylinder (1) and located on the upper portion of the distribution plate (10), and a plurality of regulating tubes (9) are evenly fixedly mounted on the bottom surface of the lifting plate (13). A connecting rod (16) is fixedly mounted on the top inner wall of the heat exchange tube (11). A distributor (15) is fixedly installed at the bottom end of the connecting rod (16), and guide rods (14) that penetrate and extend to the upper part of the cylinder (1) are fixedly installed on both sides of the top of the lifting plate (13), and a top plate (7) is fixedly installed on the top of the guide rod (14). A limiting plate (12) is fixedly installed on the outer ring of one side of the guide rod (14) located inside the cylinder (1), and the top of the cylinder (1) is rotatably connected to a rotating rod (4) that penetrates the lifting plate (13).

2. The film distribution optimization device for a high-efficiency falling film evaporator according to claim 1, characterized in that: The lower outer ring of the rotating rod (4) is provided with a thread, the central portion of the lifting plate (13) is provided with a threaded hole, and the thread provided on the rotating rod (4) matches the threaded hole provided in the central portion of the lifting plate (13), and a hand wheel (5) is installed on the top of the rotating rod (4).

3. The film distribution optimization device for a high-efficiency falling film evaporator according to claim 1, characterized in that: The plurality of regulating tubes (9) fixedly mounted on the bottom of the lifting plate (13) correspond one-to-one to the plurality of heat exchange tubes (11), and the regulating tubes (9) can be sleeved on the top of the heat exchange tubes (11).

4. The film distribution optimization device for a high-efficiency falling film evaporator according to claim 1, characterized in that: The heat exchange tube (11) is located on the top outer ring of the distribution plate (10) and is evenly provided with a plurality of liquid inlet holes. The distributor (15) is located at the lower part of the distribution plate (10) and is in the shape of a truncated cone.

5. The film distribution optimization device for a high-efficiency falling film evaporator according to claim 1, characterized in that: A feed pipe (8) is installed on the upper right side of the cylinder (1) and located above the material distribution plate (10), and a steam inlet pipe (3) is installed on the middle left side of the cylinder (1).

6. The film distribution optimization device for a high-efficiency falling film evaporator according to claim 1, characterized in that: A discharge pipe (2) is installed at the bottom of the cylinder (1), and a secondary steam pipe (6) is installed on the right side of the top of the cylinder (1).

7. A control method for a film distribution optimization device for a high-efficiency falling film evaporator according to any one of claims 1 to 6, characterized in that: The steps include: S1. The material is injected into the cylinder (1) through the feed pipe (8) and initially dispersed into the heat exchange tube (11) through the liquid inlet holes on the distribution plate (10); S2. Steam is introduced through the steam inlet pipe (3) to achieve falling film evaporation of the material in the heat exchange tube (11).

8. The control method according to claim 7, wherein: During the film spreading process, the hand wheel (5) is turned to drive the rotating rod (4) to rotate, so that the lifting plate (13) moves up and down along the guide rod (14), thereby changing the insertion depth of the regulating tube (9) and the heat exchange tube (11) to adjust the flow rate and distribution state of the material entering the heat exchange tube (11).

9. The control method according to claim 8, characterized in that: When processing high-viscosity materials, the lifting plate (13) moves upward to reduce the overlapping length of the regulating tube (9) and the heat exchange tube (11), expand the material flow channel, thereby avoiding local accumulation and improving film uniformity.

10. The control method according to claim 8, characterized in that: By adjusting the height of the lifting plate (13) to set the flow rate of the material entering the heat exchange tube (11), the control requirements of the evaporation rate of different processes can be met, thereby achieving accurate optimization of the film spreading effect.

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