A continuous high-efficiency freezing crystallization device

Abstract

The utility model discloses a kind of continuous high-efficiency frozen crystallization devices, including frozen crystallizer, circulating crystallization unit and spare circulating unit, circulating crystallization unit includes first crystal slurry circulating pump, first frozen heat exchanger and first frozen liquid circulating pump, spare circulating unit includes second crystal slurry circulating pump, second frozen heat exchanger and second frozen liquid circulating pump;The outlet pipe of frozen crystallizer is connected with the inlet pipe of first crystal slurry circulating pump and the inlet pipe of second crystal slurry circulating pump, and the inlet pipe of first crystal slurry circulating pump and the inlet pipe of second crystal slurry circulating pump are respectively installed with regulating valve, heat exchanger uses one spare switching design, completely solve the parking problem caused by walling up, realize long-term continuous operation, good stability, after completing switching, differential pressure transmitter sends out alarm through signal, convenient for staff to maintain blocked heat exchanger.

Description

Technical Field

[0001] This utility model relates to the field of chemical crystallization technology, specifically a continuous and efficient freeze crystallization device. Background Technology

[0002] Freeze-crystallization is a physical separation technique that utilizes the differences in solubility of substances at low temperatures or the differences in freezing points of different components to crystallize the target substance from a solution or molten mixture through a controlled cooling process, thereby achieving separation, purification, or concentration. It can be used for the crystallization separation of organic or inorganic salt solutions.

[0003] Freeze crystallization technology utilizes the characteristic that the solubility of materials decreases with temperature to achieve crystallization. However, traditional crystallization devices are prone to shutdown due to heat exchanger blockage, making long-term continuous operation impossible. Furthermore, the devices are bulky and require high investment in equipment and civil engineering. Therefore, this utility model proposes a continuous and efficient freeze crystallization device that can solve the above problems. Utility Model Content

[0004] The purpose of this invention is to provide a continuous and efficient cryogenic crystallization device to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a continuous and efficient cryogenic crystallization device, comprising a cryogenic crystallizer, a circulating crystallization unit and a standby circulating unit, wherein the circulating crystallization unit comprises a first crystal slurry circulating pump, a first cryogenic heat exchanger and a first cryogenic liquid circulating pump, and the standby circulating unit comprises a second crystal slurry circulating pump, a second cryogenic heat exchanger and a second cryogenic liquid circulating pump;

[0006] The outlet pipe of the cryogenic crystallizer is connected to the inlet pipe of the first crystal slurry circulation pump and the inlet pipe of the second crystal slurry circulation pump. The inlet pipes of the first and second crystal slurry circulation pumps are respectively equipped with regulating valves. The outlet pipe of the first crystal slurry circulation pump is connected to the inlet pipe of the first refrigeration heat exchanger, and the outlet pipe of the second crystal slurry circulation pump is connected to the inlet pipe of the second refrigeration heat exchanger. The outlet pipes of the first and second refrigeration heat exchangers are connected to the inlet pipe of the cryogenic crystallizer. The first and second refrigeration heat exchangers detect the voltage drop through current detection. The two sets of regulating valves are connected to the first and second crystal slurry circulation pumps via signal connection.

[0007] The first refrigerant circulation pump is used to deliver refrigerant through the shell side of the first refrigeration heat exchanger for heat exchange of the crystal slurry entering the first refrigeration heat exchanger. The second refrigerant circulation pump is used to deliver refrigerant through the shell side of the second refrigeration heat exchanger for heat exchange of the crystal slurry entering the second refrigeration heat exchanger.

[0008] Preferably, the outlet pipe of the freeze crystallizer is connected to the feed pipe, and the feed pipe is equipped with a flow meter.

[0009] Preferably, the freeze crystallizer is provided with an observation window at the top.

[0010] Preferably, the top of the cryo-crystallizer is connected to a cryo-cleaning liquid drain.

[0011] Preferably, the cryo-crystallizer is equipped with a density meter and a temperature meter for detecting the concentration and temperature of the crystal slurry.

[0012] Preferably, the outlet pipes of the first and second refrigeration heat exchangers are respectively connected to crystal slurry pipes via diversion pipes, and a discharge valve is installed on the diversion pipe.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] The heat exchanger adopts a one-in-one-out switching design, which completely solves the shutdown problem caused by wall blockage, realizes long-term continuous operation, and has good stability. After the switching is completed, the differential pressure transmitter sends an alarm signal to facilitate the maintenance of the blocked heat exchanger by the staff.

[0015] The equipment has a compact layout, reducing the volume by more than 50% for the same output, which significantly reduces equipment procurement, installation space and civil engineering investment. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0017] Figure 2 This is a schematic diagram of the structure of the freeze crystallizer of this utility model;

[0018] In the diagram: 1. Cryogenic crystallizer; 11. Observation window; 12. Thermometer interface; 13. Densitometer interface; 14. Cryogenic liquid drain; 2. First crystal slurry circulation pump; 3. First refrigeration heat exchanger; 4. First refrigerant circulation pump; 5. Second crystal slurry circulation pump; 6. Second refrigeration heat exchanger; 7. Second refrigerant circulation pump. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] Please see Figure 1-2

[0021] Provide a continuous and efficient cryo-crystallization apparatus:

[0022] The outlet pipe of the freeze crystallizer 1 is connected to the feed pipe, and the feed pipe is equipped with a flow meter.

[0023] The circulating crystallization unit includes a first crystal slurry circulating pump 2, a first refrigeration heat exchanger 3, and a first refrigerant circulating pump 4. The standby circulating unit includes a second crystal slurry circulating pump 5, a second refrigeration heat exchanger 6, and a second refrigerant circulating pump 7.

[0024] The outlet pipe of the cryo-crystallizer 1 is connected to the inlet pipe of the first crystal slurry circulation pump 2 and the inlet pipe of the second crystal slurry circulation pump 5. The inlet pipes of the first crystal slurry circulation pump 2 and the second crystal slurry circulation pump 5 are respectively equipped with regulating valves. By controlling the two sets of regulating valves, the direction of the crystal slurry can be controlled, so that the circulating cryo-crystallization of the crystal slurry can be transferred from the circulating crystallization unit to the standby circulating unit. The circulation rate of the first crystal slurry circulation pump 2 and the second crystal slurry circulation pump 5 can be controlled and adjusted.

[0025] The outlet pipe of the first crystal slurry circulation pump 2 is connected to the inlet pipe of the first refrigeration heat exchanger 3, the outlet pipe of the second crystal slurry circulation pump 5 is connected to the inlet pipe of the second refrigeration heat exchanger 6, the outlet pipes of the first refrigeration heat exchanger 3 and the second refrigeration heat exchanger 6 are connected to the inlet pipe of the refrigeration crystallizer 1, and the first refrigeration heat exchanger 3 and the second refrigeration heat exchanger 6 detect the voltage drop through current detection, and the two sets of regulating valves are connected to the first crystal slurry circulation pump 2 and the second crystal slurry circulation pump 5 via signal connection.

[0026] The first refrigerant circulation pump 4 is used to transport refrigerant through the shell side of the first refrigerant heat exchanger 3 for heat exchange of the crystal slurry entering the first refrigerant heat exchanger 3. The second refrigerant circulation pump 7 is used to transport refrigerant through the shell side of the second refrigerant heat exchanger 6 for heat exchange of the crystal slurry entering the second refrigerant heat exchanger 6. The outlet pipes of the first refrigerant circulation pump 4 and the second refrigerant circulation pump 7 are connected to the refrigerant inlet pipe, and the inlet pipes of the first refrigerant circulation pump 4 and the second refrigerant circulation pump 7 are connected to the refrigerant return pipe.

[0027] During the freeze crystallization process, the pressure drop of the first freeze heat exchanger 3 is detected by current. When the set high current is reached, the system determines that the first freeze heat exchanger 3 is blocked by wall clogging. It will control two sets of regulating valves and the first crystal slurry circulation pump 2 and the second crystal slurry circulation pump 5 through signals. The regulating valve on the inlet pipe of the second crystal slurry circulation pump 5 is opened, and the regulating valve on the inlet pipe of the first crystal slurry circulation pump 2 is closed. The first crystal slurry circulation pump 2 stops, and the second crystal slurry circulation pump 5 starts. Then the second refrigerant circulation pump 7 and the refrigerant inlet and outlet regulating valves are opened. The crystal slurry is circulated to the second freeze heat exchanger 6 and the freeze crystallizer 1 for crystallization, so as to avoid shutdown due to wall clogging of the heat exchanger.

[0028] After the switchover is completed, close the inlet and outlet valves of the refrigerant and the material discharge valve of the blocked first refrigeration heat exchanger 3, and then open the drain valve. After the material is drained, open the steam heating valve of the refrigerant circulation pipe jacket to heat the refrigerant and control the refrigerant temperature at 50°C. After the shell side of the first refrigeration heat exchanger 3 is heated, the blockage material is dissolved by the indirect wall heating. When the steam valve opening is less than 10%, the blockage is cleared. Finally, close the steam heating valve and the drain valve, and then open the refrigerant inlet and outlet valves for use when switching over again.

[0029] That is, the circuit can be cut off between the circulating crystallization unit and the standby circulating unit. The heat exchanger adopts a one-in-one-out switching design, which completely solves the shutdown problem caused by wall blockage, and achieves long-term continuous operation with good stability.

[0030] The equipment has a compact layout, reducing the volume by more than 50% for the same output, which significantly reduces equipment procurement, installation space and civil engineering investment.

[0031] The outlet pipes of the first refrigeration heat exchanger 3 and the second refrigeration heat exchanger 6 are respectively connected to crystal slurry pipes through diversion pipes, and discharge valves are installed on the diversion pipes.

[0032] The top of the freeze crystallizer 1 is equipped with an observation window 11, through which the crystal shape is observed and monitored in real time.

[0033] The top of the cryogenic crystallizer 1 is connected to a cryogenic liquid outlet 14, which is connected to a drain pipe. The liquid is discharged from the top side of the cryogenic crystallizer 1. The cryogenic crystallizer 1 is equipped with a densitometer interface 13 and a thermometer interface 12. The crystal slurry concentration is adjusted by feedback from the densitometer.

[0034] During freeze crystallization, the concentration, supercooling, temperature and circulation rate can be adjusted according to the material characteristics (such as solubility curve) to adapt to different material systems (organic or inorganic salts) and crystallization particle size requirements. The process flexibility is significantly better than that of traditional technology.

[0035] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A continuous, high-efficiency cryo-crystallization apparatus, characterized in that, It includes a cryogenic crystallizer (1), a circulating crystallization unit and a standby circulating unit. The circulating crystallization unit includes a first crystal slurry circulating pump (2), a first cryogenic heat exchanger (3) and a first cryogenic liquid circulating pump (4). The standby circulating unit includes a second crystal slurry circulating pump (5), a second cryogenic heat exchanger (6) and a second cryogenic liquid circulating pump (7). The outlet pipe of the cryogenic crystallizer (1) is connected to the inlet pipe of the first crystal slurry circulation pump (2) and the inlet pipe of the second crystal slurry circulation pump (5). The inlet pipe of the first crystal slurry circulation pump (2) and the inlet pipe of the second crystal slurry circulation pump (5) are respectively equipped with regulating valves. The outlet pipe of the first crystal slurry circulation pump (2) is connected to the inlet pipe of the first cryogenic heat exchanger (3). The outlet pipe of the second crystal slurry circulation pump (5) is connected to the inlet pipe of the second cryogenic heat exchanger (6). The outlet pipe of the first cryogenic heat exchanger (3) and the outlet pipe of the second cryogenic heat exchanger (6) are connected to the inlet pipe of the cryogenic crystallizer (1). The first cryogenic heat exchanger (3) and the second cryogenic heat exchanger (6) detect the voltage drop through current. The two sets of regulating valves are signal connected to the first crystal slurry circulation pump (2) and the second crystal slurry circulation pump (5). The first refrigerant circulation pump (4) is used to transport refrigerant through the shell side of the first refrigeration heat exchanger (3) for heat exchange of the crystal slurry entering the first refrigeration heat exchanger (3). The second refrigerant circulation pump (7) is used to transport refrigerant through the shell side of the second refrigeration heat exchanger (6) for heat exchange of the crystal slurry entering the second refrigeration heat exchanger (6).

2. The continuous high-efficiency freeze crystallization apparatus according to claim 1, characterized in that, The outlet pipe of the freeze crystallizer (1) is connected to the feed pipe, and the feed pipe is equipped with a flow meter.

3. The continuous high-efficiency freeze crystallization apparatus according to claim 1, characterized in that, The top of the cryo-crystallizer (1) is provided with an observation window (11).

4. The continuous high-efficiency freeze crystallization apparatus according to claim 1, characterized in that, The top of the cryo-crystallizer (1) is connected to a cryo-cleaning liquid outlet (14).

5. The continuous high-efficiency freeze crystallization apparatus according to claim 1, characterized in that, The cryo-crystallizer (1) is equipped with a densitometer interface (13) and a thermometer interface (12).

6. The continuous high-efficiency freeze crystallization apparatus according to claim 1, characterized in that, The outlet pipe of the first refrigeration heat exchanger (3) and the outlet pipe of the second refrigeration heat exchanger (6) are respectively connected to crystal slurry pipes through a split pipe, and a discharge valve is installed on the split pipe.

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