Sugar cooling vertical crystallizer

Abstract

The utility model discloses a sugar cooling vertical crystallizer which comprises a vertical tank body, a top cover is arranged at the top of the tank body, a syrup inlet is formed in the top cover, a conical hopper is arranged at the bottom of the tank body, a syrup outlet is formed in the conical hopper, a plurality of heat exchange coil pipes are arranged in an inner cavity of the tank body in the height direction, each heat exchange coil pipe adopts a circular pipe distribution mode, and six concave arcs are evenly distributed on the periphery of each heat exchange coil pipe. A vertical column extending in the vertical direction is arranged in each concave arc, each heat exchange coil pipe is supported on a radial support, and the outer end of each radial support is fixedly connected to the corresponding vertical column. A lifting mechanism for driving the stand columns and the heat exchange coil to ascend and descend is arranged above the top cover. An upper stirring mechanism for uniformly distributing syrup on the cross section of the tank body is arranged above the top-layer heat exchange coil pipe, and a lower stirring mechanism is arranged in the conical hopper. The sugar cooling vertical crystallizer is high in crystallization efficiency, short in crystallization time, high in single productivity and low in operation failure rate.

Description

Technical Field

[0001] This utility model relates to a crystallizer, and more particularly to a vertical sugar cooling crystallizer, belonging to the technical field of sugar production equipment. Background Technology

[0002] In China, the production of glucose, sorbitol, mannitol, and other materials from grains or other raw materials generally employs small horizontal cooling crystallizers or existing vertical cooling crystallizers. Small horizontal cooling crystallizers, due to their structural limitations, suffer from insufficient cooling and heat exchange, and poor shaft end sealing, leading to easy material leakage. Therefore, they have been replaced by existing vertical cooling crystallizers. Existing vertical continuous crystallizers use hexagonal heat exchange coils, resulting in uneven distribution across the cylinder's circumference. In actual use, the high viscosity and poor fluidity of the syrup cause slower cooling of the syrup further away from the coils on the outer periphery of the cylinder, while the syrup closer to the coils cools faster, resulting in uneven crystallization speed and affecting the crystallization effect. Furthermore, clumping easily occurs at the sharp corners of the hexagons, impacting heat exchange efficiency and increasing resistance during lifting and lowering. Moreover, the 120° butt welding process used for the heat exchange tubes results in numerous welds with poor welding reliability, making them prone to welding defects and leaks, thus affecting performance. Although protective plates are installed around the hexagonal coils, the sharp corners are prone to collisions with the shell. The middle channel of the heat exchange coil is usually designed without obstruction, which causes the syrup in the center of the equipment to sink too quickly and flow to the next layer before the temperature reaches the set temperature, affecting the crystallization effect.

[0003] Vertical crystallizers are traditional and mature glucose cooling and crystallization equipment, and there is a lot of publicly available literature, papers, patents and other information in the industry. However, although there are some local improvements to address the above pain points, there is no good overall system solution.

[0004] For example, patent publication number CN 207324136U describes a high crystallization rate vertical crystallizer, outlining its structural design but without specifying the heat exchange coil. The unobstructed design of the central channel causes the syrup in the center of the equipment to sink rapidly, flowing to the next layer before reaching the set temperature, thus affecting the crystallization effect. The upper stirring blades are straight, resulting in poor stirring and mixing, preventing the newly fed material from being evenly distributed across the cylinder cross-section in a timely manner, and hindering the thorough mixing of the seed crystals with the syrup. The lower stirring blades are also straight; due to the high viscosity and large amount of crystals in the syrup at the bottom, the syrup near the cylinder flows slowly by gravity to the outlet, easily causing accumulation and clumping at the bottom of the cone near the cylinder.

[0005] A novel optimized multi-stage coil vibration-type continuous cooling crystallizer, patent publication number CN 207445649U, uses hexagonally distributed heat exchange coils. However, this uneven distribution across the circumference of the cylinder leads to uneven cooling of the syrup, which has a high viscosity and poor fluidity during actual use. This results in slower cooling of the syrup further from the coils on the outer periphery of the cylinder, while the syrup closer to the coils cools faster. This uneven crystallization speed negatively impacts the crystallization effect and causes clumping at the sharp corners of the hexagons, further reducing heat exchange efficiency and increasing resistance during lifting and lowering.

[0006] Furthermore, the heat exchange tubes employ a 120° butt welding process, resulting in numerous welds and poor welding reliability. Welding defects are prone to occur at these seams, leading to leaks and affecting performance. The hexagonal coil distribution, despite the outer protective plate, is susceptible to collisions with the shell at its sharp corners. The baffle opening design in the central channel of the heat exchange coil results in excessively low flow velocity at the center, causing crystal accumulation at the cover plate and increasing resistance both vertically and horizontally. Additionally, the upper stirring blades are straight, resulting in poor stirring and mixing, preventing the newly added syrup from being evenly distributed across the cylinder cross-section in a timely manner, and hindering the thorough mixing of seed crystals with the syrup. The lower stirring blades are also straight; due to the high viscosity and large amount of crystals in the syrup at the bottom, the syrup near the cylinder flows slowly by gravity to the outlet, leading to accumulation and clumping at the bottom of the cone. Utility Model Content

[0007] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, and such simplifications or omissions should not be construed as limiting the scope of the present invention.

[0008] In view of the problems existing in the above and / or prior art, this utility model is proposed.

[0009] The purpose of this invention is to overcome the problems existing in the prior art and provide a vertical sugar cooling crystallizer with high crystallization efficiency, short crystallization time, high single-unit capacity, and low failure rate.

[0010] To solve the above technical problems, this utility model provides a vertical sugar cooling crystallizer, comprising a vertical tank, a top cover with a syrup inlet on the top cover, a conical hopper at the bottom of the tank with a syrup outlet on the conical hopper, and multiple heat exchange coils arranged along the height of the tank's inner cavity. Each heat exchange coil adopts a circular tube arrangement and has six concave arcs evenly distributed on its outer circumference. Each concave arc has a vertically extending column, and each heat exchange coil is supported on a radial support. The outer end of each radial support is fixedly connected to the corresponding column. A lifting mechanism is provided above the top cover to drive the columns and heat exchange coils to rise and fall. An upper stirring mechanism is provided above the top heat exchange coil to evenly distribute the syrup across the cross-section of the tank, and a lower stirring mechanism is provided in the conical hopper.

[0011] As an improvement of this utility model, the lifting mechanism includes three lifting beams and six lifting cylinders. Each lifting beam is connected to the top of two adjacent columns, and the top of the piston rod of each lifting cylinder is connected to the bottom of both ends of the corresponding lifting beam. The cylinder body of each lifting cylinder is fixed to the top cover.

[0012] As a further improvement of this utility model, each heat exchange coil is provided with a central cylinder, and several horizontal pipe fittings are welded into each central cylinder.

[0013] As a further improvement of this utility model, each heat exchange coil is connected to a plurality of evenly distributed straightening blocks on its outer periphery, and the outer edge of each straightening block is close to the inner wall of the tank.

[0014] As a further improvement of this utility model, the upper stirring mechanism includes an upper stirring shaft and a plurality of upper stirring blades that are centrally symmetrically connected to the lower end of the upper stirring shaft. Each upper stirring blade is a two-section bent blade with the outer end bent at a certain angle toward the rear of the rotation direction. Each upper stirring blade has a plurality of through holes on its cross section. The upper end of the upper stirring shaft extends above the top cover and is driven by an upper stirring reduction motor.

[0015] As a further improvement of this utility model, two to three heat exchange coils are connected in series as a group, and each group is connected to a cooling water inlet pipe and a cooling water outlet pipe at its end. The cooling water inlet pipe and cooling water outlet pipe of each group enter the adjacent column cavity and go up to the top of the top cover.

[0016] As a further improvement of this utility model, the lower stirring mechanism is in the shape of an inverted triangle, with the top edge horizontal and the middle part connected to the upper end of the lower stirring shaft. The two waist sides are parallel to the bottom wall of the cone and the lower end is connected to the middle of the lower stirring shaft. The top edge and the two waist sides are connected as a whole by multiple support rods. The two waist sides are T-shaped steels, with the central convex rib of the T-shaped steel facing the bottom wall of the cone. Multiple scraping blades for scraping material towards the center of the cone bottom are fixed along one side of the central convex rib of the T-shaped steel along the length direction. The lower end of the lower stirring shaft extends out of the cone and is connected to the output end of the lower stirring gearbox.

[0017] As a further improvement of this utility model, the free ends of each scraper blade are tilted downwards and close to the bottom wall of the cone bucket, and the root of each scraper blade is fixed to the central convex rib of the T-shaped steel by bolts.

[0018] Compared to existing technologies, the advantages or beneficial effects of the embodiments of this application include at least the following: 1. The heat exchange coil adopts a more reasonable circular distribution, reducing the number of welds. The use of butt welds enables automated mechanical welding, improving the stability of weld quality and reducing the risk of leakage at the welds. Furthermore, the more uniform distribution of the heat exchange tubes improves crystallization uniformity and efficiency. The addition of several pipes in the middle channel makes the resistance experienced by the syrup in the middle channel similar to that in the heat exchange coil, thereby balancing the flow rate of the syrup between the center of the cylinder and the heat exchange coil.

[0019] 2. The upper agitator uses two bent blades with openings in the cross-section, which allows the newly added syrup to be distributed more quickly on the cylinder interface. The openings in the blades also cause some convection in the syrup, resulting in more uniform mixing of the seed crystals and syrup, thereby improving crystallization uniformity and efficiency.

[0020] 3. Multiple bent scraper blades are installed on both sides of the lower stirring mechanism. While scraping the bottom, the syrup near the bottom of the cone is pushed towards the center of the cone, thereby accelerating the flow of the syrup on the outside, reducing the accumulation and clumping of syrup on the outside, and thus improving the crystallization efficiency. Each scraper blade is installed independently and is easy to replace, which facilitates the adjustment of the scraping angle and reduces maintenance costs. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this utility model, the 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. The drawings are provided for reference and illustration only and are not intended to limit this utility model. Wherein:

[0022] Figure 1 This is a front view of the vertical sugar cooling crystallizer of this utility model;

[0023] Figure 2 This is a top view of the top cover of this utility model;

[0024] Figure 3 This is a top view of the heat exchange coil in this utility model;

[0025] Figure 4 This is a perspective view of the heat exchange coil in this utility model;

[0026] Figure 5This is a front view of the upper stirring blade in this utility model;

[0027] Figure 6 for Figure 5 Top view;

[0028] Figure 7 This is a front view of the lower stirring structure in this utility model;

[0029] Figure 8 for Figure 7 A bottom view;

[0030] Figure 9 for Figure 7 A three-dimensional image;

[0031] In the diagram: 1. Lifting beam; 2. Lifting cylinder; 3. Upper stirring reducer motor; 4. Top cover; 4a. Syrup inlet; 5. Tank body; 6. Upper stirring shaft; 7. Upper stirring blade; 8. Heat exchange coil; 8a. Cooling water inlet pipe; 8b. Cooling water outlet pipe; 9. Column; 10. Central cylinder; 11. Horizontal pipe fitting; 12. Radial support; 13. Straightening block; 14. Lower stirring reducer; 15. Lower stirring shaft; 16. Lower stirring mechanism; 16a. T-shaped steel; 16b. Scraper blade; 17. Conical hopper; 17a. Syrup outlet; 18. Support. Detailed Implementation

[0032] In the following description of this utility model, the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not mean that the device must have a specific orientation.

[0033] To make the technical means, creative features, achieved objectives and effects of this utility model easier to understand, the present utility model will be further described below with reference to specific illustrations. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0035] like Figures 1 to 6As shown, the sugar cooling vertical crystallizer of this utility model includes a tank body 5, the bottom of which is supported on the ground by a support 18. The top of the tank body 5 is provided with a top cover 4, and a syrup inlet 4a is provided on the top cover 4. The bottom of the tank body 5 is provided with a conical hopper 17, in which a lower stirring mechanism 16 is provided, and a syrup outlet 17a is provided on the bottom wall of the conical hopper 17. An upper stirring reduction motor 3 is located at the center of the top cover 4. The upper stirring shaft 6 of the upper stirring reduction motor 3 extends downward along the axis of the tank body 5. Multiple upper stirring blades 7 are centrally symmetrically connected to the lower end of the upper stirring shaft 6. Each upper stirring blade 7 is a two-section bent blade, with the outer end bent at a certain angle towards the rear of the rotation direction. Furthermore, each upper stirring blade 7 has multiple small holes on its cross-section, which allows the syrup after feeding to be quickly and evenly distributed on the cross-section of the tank body. Due to the influence of the openings, the upper syrup generates a certain relative flow, allowing the syrup and seed crystals to mix more thoroughly, thereby improving crystallization stability and increasing production efficiency.

[0036] The inner cavity of the tank 5 is equipped with multiple heat exchange coils 8. Each heat exchange coil 8 adopts a circular tube arrangement instead of the traditional hexagonal tube arrangement, making it more evenly distributed on the cross-section of the cylinder, thereby making the syrup heat exchange uniform and improving the crystallization uniformity.

[0037] Each heat exchange coil 8 has six concave arc sections symmetrically arranged on its outer circumference. Each concave arc section has a vertically extending column 9. The center of each heat exchange coil 8 has a central cylinder 10 of the same height, which is the minimum inner diameter of the heat exchange coil 8. Radial supports 12 are connected between the outer wall of each central cylinder 10 and the six columns 9. Each heat exchange coil 8 is fixed to the corresponding radial support 12. Each heat exchange coil 8 is coiled outward from the outer circumference of the central cylinder 10 and has four layers in the height direction. The top layer rests on the radial supports 12, and the bottom three layers pass through the circular holes of each radial support 12. In this way, each heat exchange coil 8 is fixed to the column 9 by the radial supports 12.

[0038] Three lifting beams 1 are provided above the top cover 4. The tops of two adjacent columns 9 are fixedly connected to the bottom of the lifting beams 1 near both ends. The bottom ends of each lifting beam 1 are connected to the top of the piston rod of the corresponding lifting cylinder 2. The bottom of the cylinder body of each lifting cylinder 2 is fixed to the top cover 4. When the piston rods of the six lifting cylinders 2 rise synchronously, the three lifting beams 1 lift each column 9 and each heat exchange coil 8 synchronously. After reaching the top, the piston rods of the six lifting cylinders 2 retract synchronously, causing each column 9 and each heat exchange coil 8 to descend synchronously, thus driving each heat exchange coil 8 to reciprocate up and down.

[0039] The three heat exchange coils 8 at the bottom are connected in series to form a group. Each group consists of two heat exchange coils 8 connected in series to form a group. Each group is equipped with a cooling water inlet pipe 8a and a cooling water outlet pipe 8b. The cooling water inlet pipe 8a and the cooling water outlet pipe 8b of each group enter the inner cavity of the adjacent column 9 and are welded and sealed at the passage. The cooling water inlet pipe 8a and the cooling water outlet pipe 8b of each group enter the inner cavity of the column 9 and go up along the inner cavity of the column 9 to exit the top cover 4. They are connected to the corresponding cooling water inlet source pipe and cooling water outlet source pipe through a hose.

[0040] Cooling water enters the heat exchange coil 8 through the corresponding cooling water inlet pipe 8a, and while it is coiled around the heat exchange coil 8, it cools the syrup, and then flows out from the corresponding cooling water outlet pipe 8b.

[0041] As the syrup flows downwards along the height of tank 5, it is continuously cooled by the heat exchange coils 8, resulting in crystallization. This crystallizer uses circularly distributed heat exchange coils 8 to ensure more uniform and thorough contact between the syrup and the coils, thereby improving crystallization stability and production efficiency. Furthermore, it has fewer weld seams, uses butt welding, and can be automated, ensuring stable and reliable welding and significantly reducing the risk of weld leaks.

[0042] Multiple straightening blocks 13 are evenly fixed on the outer periphery of each heat exchange coil 8. Each straightening block 13 is close to the inner wall of the tank 5 to ensure that each column 9 and each heat exchange coil 8 can move up and down smoothly, so that the outer periphery of the heat exchange coil 8 is kept at a certain distance from the inner wall of the tank 5 to avoid the risk of collision.

[0043] Several horizontal pipes 11 are welded into each central cylinder 10 so that the resistance of the syrup in the central channel of the tank 5 is similar to that at the heat exchange coil 8, thereby balancing the flow rate of the syrup at the center of the cylinder and at the heat exchange coil 8.

[0044] like Figures 7 to 9As shown, the lower stirring mechanism 16 is fixed in the middle to the lower stirring shaft 15. The lower end of the lower stirring shaft 15 extends out of the cone hopper 17 and is driven by the lower stirring reduction gearbox 14. The lower stirring mechanism 16 is inverted triangular in shape, with the top edge horizontal and the middle part connected to the upper end of the lower stirring shaft. The two waist sides are parallel to the bottom wall of the cone hopper 17 and the lower ends are connected to the middle part of the lower stirring shaft. The top edge and the two waist sides are connected as a whole by multiple support rods. The two waist sides are T-shaped steel 16a. The convex rib in the middle of the T-shaped steel 16a faces the bottom wall of the cone hopper 17. Multiple scraping blades 16b are fixed along the length direction of one side of the convex rib in the middle of the T-shaped steel, scraping material towards the center of the cone bottom. The scraping blades 16b on the two waist sides are centrally symmetrically arranged with the axis of the lower stirring shaft as the center. The roots of each scraper blade 16b are bolted to the central rib of the T-shaped steel 16a. The free ends of each scraper blade 16b curve downwards and are close to the bottom wall of the cone hopper 17, pushing the syrup near the cone wall towards the center of the cone bottom. This accelerates the flow of the syrup on the periphery, reduces syrup accumulation and clumping on the periphery, and thus improves crystallization efficiency. Each scraper blade 16b can be replaced independently after wear, avoiding the need to replace the entire lower stirring mechanism 16. Furthermore, scraper blades 16b with corresponding tilt angles can be replaced according to the needs of different materials.

[0045] The above description is merely a preferred embodiment of the present utility model, showing and describing the basic principles, main features, and advantages of the present utility model. It is not intended to limit the scope of patent protection of the present utility model. Those skilled in the art should understand that the present utility model is not limited to the above embodiments. In addition to the above embodiments, the present utility model may have other implementations without departing from the spirit and scope of the present utility model. Various changes and improvements to the present utility model are also possible. All technical solutions formed by equivalent substitutions or equivalent transformations fall within the scope of protection claimed by the present utility model. The scope of protection claimed by the present utility model is defined by the appended claims and their equivalents. Technical features not described in the present utility model can be implemented by or using existing technology, and will not be elaborated here.

Claims

1. A vertical crystallizer for sugar cooling, comprising a vertical tank (5), a top cover (4) provided at the top of the tank (5), a syrup inlet (4a) provided on the top cover (4), a conical hopper (17) provided at the bottom of the tank (5), and a syrup outlet (17a) provided on the conical hopper (17), characterized in that: The inner cavity of the tank (5) is provided with multiple heat exchange coils (8) along the height direction. Each heat exchange coil (8) adopts a circular tube arrangement and has six concave arcs evenly distributed on its outer periphery. Each concave arc is provided with a vertically extending column (9). Each heat exchange coil (8) is supported on a radial support (12). The outer end of each radial support (12) is fixedly connected to the corresponding column (9). The top cover is provided with a lifting mechanism that drives the column (9) and the heat exchange coils (8) to rise and fall. The top heat exchange coil (8) is provided with an upper stirring mechanism that evenly distributes the syrup on the cross-section of the tank. The cone hopper (17) is provided with a lower stirring mechanism.

2. Sugar cooling vertical crystallizer according to claim 1, characterized in that: The lifting mechanism includes three lifting beams (1) and six lifting cylinders (2). Each lifting beam (1) is connected to the top of two adjacent columns (9). The top of the piston rod of each lifting cylinder (2) is connected to the bottom of both ends of the corresponding lifting beam (1). The cylinder body of each lifting cylinder (2) is fixed on the top cover (4).

3. Sugar cooling vertical crystallizer according to claim 1, characterized in that: Each heat exchange coil (8) has a central cylinder (10) at its center, and several horizontal pipe fittings (11) are welded into each central cylinder (10).

4. The sugar cooling vertical crystallizer according to claim 1, characterized in that: Each heat exchange coil (8) is connected to a plurality of evenly distributed straightening blocks (13) on its outer periphery, and the outer edge of each straightening block (13) is close to the inner wall of the tank (5).

5. The sugar cooling vertical crystallizer according to claim 1, characterized in that: The upper stirring mechanism includes an upper stirring shaft (6) and multiple upper stirring blades (7) that are centrally symmetrically connected to the lower end of the upper stirring shaft (6). Each upper stirring blade (7) is a two-section bent blade with its outer end bent at a certain angle to the rear of the rotation direction. Each upper stirring blade (7) has multiple through holes (7a) on its cross section. The upper end of the upper stirring shaft (6) extends above the top cover (4) and is driven by the upper stirring reduction motor (3).

6. The sugar cooling vertical crystallizer according to claim 1, characterized in that: Two to three heat exchange coils (8) are connected in series as a group. Each group is connected to a cooling water inlet pipe (8a) and a cooling water outlet pipe (8b). The cooling water inlet pipe (8a) and the cooling water outlet pipe (8b) of each group enter the cavity of the adjacent column (9) and go up to the top cover (4).

7. Sugar cooling vertical crystallizer according to any one of claims 1 to 6, characterized in that: The lower stirring mechanism (16) is in the shape of an inverted triangle. The top edge is horizontal and the middle part is connected to the upper end of the lower stirring shaft (15). The two waist edges are parallel to the bottom wall of the cone bucket (17) and the lower end is connected to the middle part of the lower stirring shaft (15). The top edge and the two waist edges are connected as a whole by multiple support rods. The two waist edges are T-shaped steel (16a). The convex rib in the middle of the T-shaped steel (16a) faces the bottom wall of the cone bucket (17). Along the length direction of one side of the convex rib in the middle of the T-shaped steel, there are multiple scraping blades (16b) that scrape material towards the center of the cone bottom. The lower end of the lower stirring shaft (15) is dynamically sealed and extends out of the cone bucket (17) and is connected to the output end of the lower stirring gearbox (14).

8. Sugar cooling vertical crystallizer according to claim 7, characterized in that: The free ends of each scraper blade (16b) are tilted downwards and close to the bottom wall of the cone hopper (17). The root of each scraper blade (16b) is fixed to the central rib of the T-shaped steel (16a) by bolts.

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