Evaporative crystallization tank

Abstract

The utility model belongs to the technical field of chemical equipment, and particularly relates to an evaporative crystallization tank which comprises a kettle body, a feeding pipe and a pure water pipeline are arranged at the bottom of the kettle body, a preheater, an evaporative heat exchanger and a separator are sequentially connected to the lower portion of the kettle body, and the lower portion of the preheater is connected with the bottom of a steam heat exchanger. A tubular heater is arranged at the lower part of the inner side of the kettle body; a vertical stirring assembly is arranged in the kettle body, penetrates through the top of the kettle body and is connected with a motor; the upper part of the kettle body is connected with a steam pipeline; the top of the kettle body is connected with a vacuum condenser; and the vacuum condenser is connected with a vacuum pump. According to the utility model, heat exchange is carried out through secondary steam at the lower part of the kettle body, and a sugar solution is heated inside and returns to the kettle body after being circulated outside the kettle, so that the mixing degree of the sugar solution and the contact area between the sugar solution and air can be increased.

Description

Technical Field

[0001] This utility model belongs to the field of chemical equipment technology, and specifically relates to an evaporation crystallizer. Background Technology

[0002] Sugar boiling and crystallization is a key process in sugar production, involving complex processes such as the formation of supersaturated syrup, crystal nucleation, and crystal growth. Its working principle involves indirect heating with steam, causing the solvent to continuously evaporate under a stable vacuum. The continuous reduction of solvent maintains the solution in a supersaturated state, thereby precipitating crystals and promoting crystal growth. This working principle ensures high purity and uniformity of the crystals. Therefore, based on the above criteria, an evaporation crystallizer capable of stable operation is selected during the sugar boiling and crystallization process.

[0003] Chinese patent CN102676704A discloses a sugar boiling and crystallization tank. It includes a tank body, an evaporator inside, a discharge port at the bottom, a feed port and a vent pipe on the side wall, and a drive device mounted on the top via a support base. The portion of the tank body corresponding to the evaporator is a heating chamber, and the portion above the evaporator is an evaporation chamber. A steam input pipe and a seed input pipe are connected to the heating chamber. A main shaft extending into the tank body is connected to the drive device. A forced circulation impeller located in the center of the evaporator is mounted on one end of the main shaft extending into the tank body. A vacuum tube is connected to one side of the support base.

[0004] The aforementioned patent has several drawbacks during the crystallization process, including a single evaporation temperature, which makes it difficult to control temperature changes in the crystallization tank and can easily affect product quality; and a relatively simple stirring method, which can lead to uneven stirring and large differences in crystal size. Utility Model Content

[0005] In view of the shortcomings of the prior art, the technical problem to be solved by this utility model is to provide an evaporation crystallizer that can achieve precise control of the crystallizer temperature and form a product with uniform particle size.

[0006] The technical solution adopted by this utility model to solve its technical problem is:

[0007] The evaporation crystallization tank of this utility model includes a vessel body. A feed pipe and a pure water pipe are provided at the bottom of the vessel body. A preheater, a steam heat exchanger, and a separator are connected in sequence at the lower part of the vessel body. The lower part of the preheater is connected to the bottom of the steam heat exchanger, the top of the steam heat exchanger is connected to the middle of the separator, and the bottom of the separator is connected to the middle of the vessel body. A shell-and-tube heater is provided in the lower part of the inner side of the vessel body. A vertical stirring assembly is provided inside the vessel body. The vertical stirring assembly passes through the top of the vessel body and is connected to a motor. A steam pipe is connected to the upper part of the vessel body. A vacuum condenser is connected to the top of the vessel body, and a vacuum pump is connected to the vacuum condenser.

[0008] in:

[0009] The steam heat exchanger is provided with a non-condensable gas inlet at the top and a non-condensable gas outlet at the bottom. A secondary steam pipe is provided at the top of the separator. The secondary steam pipe is connected to the non-condensable gas inlet through a steam compressor and the non-condensable gas outlet is connected to the preheater.

[0010] The tube heater is provided with a low-pressure steam inlet at one end and a condensate outlet at the other end.

[0011] The vertical stirring assembly includes a rotating gear and a connecting gear that meshes perpendicularly with the rotating gear. The connecting gear is fixedly mounted at one end of a connecting plate, and the other end of the connecting plate is connected to a stirrer.

[0012] The top of the rotating gear is connected to the output end of the motor, the stirrer is set in the middle of the vessel body, and the bottom of the stirrer is connected to the bottom of the vessel body through an adapter plate, which is rotatably connected to the bottom of the vessel body.

[0013] A seed crystal channel is provided on the middle side wall of the reactor body.

[0014] The tubular heater is arranged around the inner wall of the vessel.

[0015] The lower part of the vessel body is connected to a vacuum condenser, and the top and lower parts of the vessel body are both connected to the vacuum condenser inlet.

[0016] The vacuum condenser is provided with an ice water inlet at the bottom and an ice water outlet at the top.

[0017] The vacuum pump is connected to both ends of the vacuum condenser.

[0018] The beneficial effects of this utility model are:

[0019] This invention utilizes an external heat exchange structure at the bottom of the vessel to exchange heat using secondary steam. While the sugar solution is heated internally, it circulates back into the vessel after passing through the external heat exchange structure, increasing the mixing degree of the sugar solution and the contact area between the sugar solution and air, thus increasing water evaporation. Furthermore, the secondary steam temperature is set to avoid excessively high temperatures that could damage product quality. A vertical stirring component inside the vessel promotes the vertical movement of the sugar solution, continuously agitating it from the center upwards and then flowing to both sides of the vessel, promoting crystal formation. Because the agitation is consistent, the resulting product has more uniform crystal size, reducing the occurrence of uneven crystal formation. The combined use of a vacuum pump and a vacuum condenser promotes the separation of water from the sugar solution, improving the efficiency of sugar crystallization. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of this utility model;

[0021] Figure 2This is a structural schematic diagram of the rotating gear, connecting gear, and connecting plate of this utility model.

[0022] In the diagram: 1. Reactor body; 2. Feed pipe; 3. Steam heat exchanger; 4. Separator; 5. Pure water pipe; 6. Shell and tube heater; 7. Steam pipe; 8. Motor; 9. Rotating gear; 10. Connecting gear; 11. Connecting plate; 12. Connecting stirrer; 13. Adapter plate; 14. Seed pipe; 15. Vacuum pump; 16. Vacuum condenser; 101. Preheater; 301. Non-condensable gas inlet; 302. Non-condensable gas outlet; 401. Secondary steam pipe; 402. Steam compressor; 601. Low-pressure steam inlet; 602. Condensate outlet; 1601. Chilled water inlet; 1602. Chilled water outlet. Detailed Implementation

[0023] The embodiments of this utility model will be further described below with reference to the accompanying drawings.

[0024] Example 1

[0025] like Figure 1-2 As shown, the evaporation crystallizer of this utility model includes a vessel body 1. A feed pipe 2 and a pure water pipe 5 are provided at the bottom of the vessel body 1. A preheater 101, a steam heat exchanger 3, and a separator 4 are connected in sequence at the lower part of the vessel body 1. The lower part of the preheater 101 is connected to the bottom of the steam heat exchanger 3. The top of the steam heat exchanger 3 is connected to the middle of the separator 4. The bottom of the separator 4 is connected to the middle of the vessel body 1. A tubular heater 6 is provided at the lower inner side of the vessel body 1. A vertical stirring assembly is provided inside the vessel body 1. The vertical stirring assembly passes through the top of the vessel body 1 and is connected to a motor 8. A steam pipe 7 is connected to the upper part of the vessel body 1. A vacuum condenser 16 is connected to the top of the vessel body 1. A vacuum pump 15 is connected to the vacuum condenser 16.

[0026] The steam heat exchanger 3 has a non-condensable gas inlet 301 at its upper part and a non-condensable gas outlet 302 at its lower part. The separator 4 has a secondary steam pipe 401 at its top, which is connected to the non-condensable gas inlet 301 via a steam compressor 402. The non-condensable gas outlet 302 is connected to the preheater 101. The steam heat exchanger 3 and the separator 4 extract the sugar solution from the vessel 1 for external heating, and the secondary steam in the separator 4 can fully heat the sugar solution. When the sugar solution is returned to the vessel 1, it can increase the degree of mixing.

[0027] The tube heater 6 has a low-pressure steam inlet 601 at one end and a condensate outlet 602 at the other end.

[0028] The vertical stirring assembly includes a rotating gear 9 and a connecting gear 10 that meshes perpendicularly with the rotating gear 9. The connecting gear 10 is fixedly mounted on one end of a connecting plate 11, and the other end of the connecting plate 11 is connected to a stirrer 12.

[0029] The top of the rotating gear 9 is connected to the output end of the motor 8. The stirrer 12 is located in the middle of the vessel body 1, and the bottom of the stirrer 12 is connected to the bottom of the vessel body 1 through a transition plate 13. The transition plate 13 is rotatably connected to the bottom of the vessel body 1. The rotating plate 13 moves in the same direction as the connecting plate 11, so that the stirrer 12 can operate stably.

[0030] A seed crystal channel 14 is provided on the middle side wall of the vessel body 1.

[0031] The tubular heater 6 is arranged around the inner wall of the vessel body 1.

[0032] The lower part of the vessel body 1 is connected to a vacuum condenser 16, and both the top and bottom of the vessel body 1 are connected to the inlet of the vacuum condenser 16. After evaporation to a certain extent, the amount of water decreases, and the water in the lower part is not easily discharged from the top of the vessel body 1. Therefore, the evaporated water can be discharged directly from the bottom of the vessel body 1.

[0033] The vacuum condenser 16 has an ice water inlet 1601 at the bottom and an ice water outlet 1602 at the top.

[0034] Vacuum pump 15 is connected to both ends of vacuum condenser 16.

[0035] Working principle and process:

[0036] During sugar crystallization, the sugar solution is fed into the vessel 1 through the feed pipe 2, and pure water at 45°C is added through the pure water pipe 5. Then, seed crystals are added through the seed crystal pipe 14, and low-pressure steam is added to the shell-and-tube heater 6 through the low-pressure steam inlet 601 to heat the sugar solution. The motor 8 is started to drive the vertical stirring component to stir vertically, so that the sugar solution is fully mixed and stirred to prevent the sugar solution at the bottom and sides from sticking to the wall. Finally, secondary steam is used to exchange heat with the sugar solution at the bottom of the vessel 1 and then transported back to the vessel 1 from the middle to further increase the mixing degree of the sugar solution. The steam pipe 7 is opened to add some steam from the top of the vessel 1 into the vessel 1, which intercepts the sugar carried in the water back into the sugar solution to prevent the water from carrying too much sugar when evaporating. The evaporated water is extracted into the vacuum condenser 16 by the vacuum pump 15 to obtain condensed liquid. After evaporation for a period of time, the motor 8 is started to reverse, so that the vertical stirring component stirs in the opposite direction. Then, the solution is continuously heated until the sugar crystallization is completed.

Claims

1. An evaporation crystallization tank, comprising a vessel body (1), characterized in that, The bottom of the vessel body (1) is provided with a feed pipe (2) and a pure water pipe (5). The lower part of the vessel body (1) is connected to a preheater (101), a steam heat exchanger (3) and a separator (4). The lower part of the preheater (101) is connected to the bottom of the steam heat exchanger (3). The top of the steam heat exchanger (3) is connected to the middle of the separator (4). The bottom of the separator (4) is connected to the middle of the vessel body (1). The lower part of the inner side of the vessel body (1) is provided with a shell-and-tube heater (6). The inside of the vessel body (1) is provided with a vertical stirring assembly. The vertical stirring assembly passes through the top of the vessel body (1) and is connected to a motor (8). The upper part of the vessel body (1) is connected to a steam pipe (7). The top of the vessel body (1) is connected to a vacuum condenser (16). The vacuum condenser (16) is connected to a vacuum pump (15).

2. The evaporation crystallizer according to claim 1, characterized in that, The steam heat exchanger (3) is provided with a non-condensable gas inlet (301) at the top and a non-condensable gas outlet (302) at the bottom. The separator (4) is provided with a secondary steam pipe (401) at the top. The secondary steam pipe (401) is connected to the non-condensable gas inlet (301) through a steam compressor (402), and the non-condensable gas outlet (302) is connected to the preheater (101).

3. The evaporation crystallizer according to claim 1, characterized in that, The tube heater (6) has a low-pressure steam inlet (601) at one end and a condensate outlet (602) at the other end.

4. The evaporation crystallizer according to claim 1, characterized in that, The vertical stirring assembly includes a rotating gear (9) and a connecting gear (10) that meshes perpendicularly with the rotating gear (9). The connecting gear (10) is fixedly mounted on one end of the connecting plate (11), and the other end of the connecting plate (11) is connected to the stirrer (12).

5. The evaporation crystallizer according to claim 4, characterized in that, The top of the rotating gear (9) is connected to the output end of the motor (8). The stirrer (12) is set in the middle of the vessel body (1). The bottom of the stirrer (12) is connected to the bottom of the vessel body (1) through the adapter plate (13). The adapter plate (13) is rotatably connected to the bottom of the vessel body (1).

6. The evaporation crystallizer according to claim 1, characterized in that, A seed channel (14) is provided on the middle side wall of the vessel body (1).

7. The evaporation crystallizer according to claim 1, characterized in that, A tubular heater (6) is arranged around the inner wall of the vessel body (1).

8. The evaporation crystallizer according to claim 1, characterized in that, The lower part of the vessel body (1) is connected to the vacuum condenser (16), and the top and lower part of the vessel body (1) are both connected to the inlet of the vacuum condenser (16).

9. The evaporation crystallizer according to claim 1, characterized in that, The vacuum condenser (16) has an ice water inlet (1601) at the bottom and an ice water outlet (1602) at the top.

10. The evaporation crystallizer according to claim 1, characterized in that, The vacuum pump (15) is connected to both ends of the vacuum condenser (16).

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