Freezing crystallizer

Abstract

The freezing crystallizer comprises a tank body, and an inner cavity of the tank body sequentially comprises a settlement area, a cooling area and a cooling area from bottom to top, and the settlement area is arranged at the bottom of the inner cavity of the tank body and is configured to be used for settling crystallization; the crystallization area is located above the settlement area, a circulating pipeline is arranged in the crystallization area, an inlet of the circulating pipeline is constructed to be arranged at the upper part of the crystallization area, an outlet of the circulating pipeline is constructed to be arranged at the lower part of the crystallization area, and liquid in the crystallization area is configured to flow out from the inlet of the circulating pipeline, then is cooled and then flows into the crystallization area from the outlet of the circulating pipeline; the clarification area is located above the crystallization area, a liquid outlet is formed in the clarification area, and the liquid outlet is configured to discharge liquid in the clarification area. According to the freezing crystallizer, the areas in the tank body are arranged in a grading mode, crystallization and sedimentation of crystals are better facilitated, the number of fine crystals in clear liquid can be effectively reduced due to the arrangement of the circulating pipeline, the purity and the recycling rate of subsequent products are improved, and cost is reduced.

Description

Technical Field

[0001] The present disclosure relates to the technical field of sewage treatment, and more precisely, to a freezing crystallizer. Background Art

[0002] The freezing crystallization technology is a commonly used treatment process in sewage treatment and chemical production. In industrial production processes such as salt production, chlor-alkali, and lithium hydroxide, the freezing crystallization technology is often used to separate sodium sulfate from other substances such as sodium chloride and lithium hydroxide, reduce the sulfate content in the sodium chloride and lithium hydroxide solutions, and thus achieve purification or recycling.

[0003] However, in the actual use of existing freezing crystallizers, many fine mirabilite crystal particles are often formed, which eventually turn into floating nitre, making it difficult to fully separate from the clear liquid, resulting in a high content of fine crystals in the clear liquid and affecting the purity and recovery of subsequent products. Summary of the Utility Model

[0004] In view of this, the embodiments of the present disclosure provide a freezing crystallizer to solve the technical defects existing in the prior art.

[0005] To achieve the above object, the present disclosure adopts the following technical solutions:

[0006] The present disclosure provides a freezing crystallizer, including a tank body, and the inner cavity of the tank body successively includes from bottom to top:

[0007] A sedimentation zone, which is arranged at the bottom of the inner cavity of the tank body and is configured to sediment crystals;

[0008] A crystallization zone, which is located above the sedimentation zone. A circulation pipeline is arranged in the crystallization zone. The inlet of the circulation pipeline is configured to be arranged at the upper part of the crystallization zone, and the outlet of the circulation pipeline is arranged at the lower part of the crystallization zone. The liquid in the crystallization zone is configured to flow out through the inlet of the circulation pipeline, be cooled, and then flow into the crystallization zone from the outlet of the circulation pipeline;

[0009] A clarification zone, which is located above the crystallization zone. A liquid discharge port is arranged in the clarification zone, and the liquid discharge port is configured to discharge the liquid in the clarification zone.

[0010] In an embodiment of the present disclosure, a grading zone is arranged between the crystallization zone and the clarification zone. The inner diameter of the grading zone is configured to gradually increase from the crystallization zone to the clarification zone; a crystal discharge port is arranged at a position adjacent to the boundary between the grading zone and the crystallization zone, and the crystals falling from the grading zone are configured to be discharged through the crystal discharge port.

[0011] In one embodiment of the present disclosure, a perforated pipe is provided in the clarification zone, and the perforated pipe extends from the clarification zone to the upper part of the classification zone, and the liquid in the classification zone is configured to flow into the clarification zone through the perforated pipe.

[0012] In one embodiment of the present disclosure, a feed inlet lower than the inlet of the circulation pipeline is provided at the upper part of the crystallization zone, and the liquid in the raw material tank is configured to enter the crystallization zone through the feed inlet.

[0013] In one embodiment of the present disclosure, the circulation pipeline includes a feed pipeline, and the feed pipeline is configured to at least include a first section extending downward, and the outlet of the first section is provided at the bottom of the crystallization zone.

[0014] In one embodiment of the present disclosure, a first thermometer and a second thermometer are provided above the feed inlet and below the feed pipeline. The first thermometer is configured to detect the temperature of the feed inlet, and the second thermometer is configured to detect the outlet temperature of the feed pipeline. The outlet temperature of the feed pipeline is lower than the temperature of the feed inlet.

[0015] In one embodiment of the present disclosure, the outlet pipe diameter of the first section is configured to gradually increase in the direction from the crystallization zone to the sedimentation zone.

[0016] In one embodiment of the present disclosure, a baffle is provided below the pipe outlet of the first section, and the baffle is connected to the pipe outlet.

[0017] In one embodiment of the present disclosure, the sedimentation zone is configured as a conical structure, the cone angle at the bottom of the sedimentation zone is 50° to 90°, and a discharge port is provided at the bottom of the sedimentation zone.

[0018] In one embodiment of the present disclosure, a liquid level gauge is provided at the upper part of the crystallization zone, and the liquid level gauge is provided above the inlet of the circulation pipeline.

[0019] A freeze crystallizer provided by the present disclosure is more conducive to the crystallization and sedimentation of crystals through the hierarchical setting of each area in the tank body. The setting of the circulation pipeline can effectively reduce the number of fine crystals in the clear liquid, improve the purity and recycling rate of subsequent products, and reduce costs.

[0020] Other features and advantages of the present disclosure will become clear through the following detailed description of the exemplary embodiments of the present disclosure with reference to the accompanying drawings. Description of the Drawings

[0021] Figure 1 is a schematic structural diagram of a freeze crystallizer provided by an embodiment of the present disclosure;

[0022] Figure 2It is a schematic structural diagram of a freeze crystallizer provided by another embodiment of the present disclosure;

[0023] Figure 3 It is a top view of a freeze crystallizer provided by an embodiment of the present disclosure;

[0024] Figure 4 It is Figure 2 a sectional view of a certain freeze crystallizer along the A-A direction;

[0025] Figure 5 It is Figure 2 a sectional view of a certain freeze crystallizer along the B-B direction;

[0026] Figure 6 It is a schematic structural diagram of a circulation pipeline of a freeze crystallizer provided by an embodiment of the present disclosure;

[0027] Figure 7 It is a schematic structural diagram of a circulation pipeline of a freeze crystallizer provided by another embodiment of the present disclosure;

[0028] Figure 8 It is a schematic structural diagram of a circulation pipeline of a freeze crystallizer provided by another embodiment of the present disclosure;

[0029] Figure 9 It is a schematic structural diagram of a perforated pipe of a freeze crystallizer provided by an embodiment of the present disclosure.

[0030] 1 - settling zone; 2 - crystallization zone; 3 - circulation pipeline; 4 - clarification zone; 5 - liquid discharge port; 6 - classification zone; 7 - crystal discharge port; 8 - perforated pipe; 9 - feed inlet; 10 - feed pipeline; 11 - first stage; 12 - baffle; 13 - liquid level gauge; 14 - water pump; 15 - heat exchanger; 16 - first thermometer; 17 - second thermometer; 18 - discharge port; 19 - manhole; 20 - flushing port; 21 - observation port; 22 - overflow baffle; 23 - backwashing port. Detailed Embodiments

[0031] Now, various exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. It should be noted that: unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present disclosure.

[0032] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way a limitation on the present disclosure or its application or use.

[0033] Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be regarded as part of the specification.

[0034] It should be noted that like reference numerals and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof in subsequent figures is not required.

[0035] The following describes the specific embodiments of the present disclosure with reference to the accompanying drawings.

[0036] In this document, "upper", "lower", "front", "rear", "left", "right", etc. are only used to represent the relative positional relationship between relevant parts, rather than defining the absolute positions of these relevant parts.

[0037] In this document, "first", "second", etc. are only used for distinction from each other, rather than indicating importance, order, and the premise of mutual existence, etc.

[0038] In this document, "equal", "same", etc. are not strict mathematical and / or geometric limitations, and also include the allowable errors that can be understood by those skilled in the art and are allowed in manufacturing or using, etc.

[0039] The present disclosure provides a freeze crystallizer, including a tank body. The inner cavity of the tank body sequentially includes from bottom to top: a sedimentation zone, which is arranged at the bottom of the inner cavity of the tank body and is configured to sediment crystals; a crystallization zone, which is located above the sedimentation zone. A circulation pipeline is arranged in the crystallization zone. The inlet of the circulation pipeline is configured to be arranged at the upper part of the crystallization zone, and the outlet of the circulation pipeline is arranged at the lower part of the crystallization zone. The liquid in the crystallization zone is configured to flow out through the inlet of the circulation pipeline, be cooled, and then flow into the crystallization zone through the outlet of the circulation pipeline; a clarification zone, which is located above the crystallization zone. A liquid discharge port is arranged in the clarification zone, and the liquid discharge port is configured to discharge the liquid in the clarification zone.

[0040] The freeze crystallizer provided by the present disclosure, through the hierarchical setting of each area in the tank body, is more conducive to the crystallization and sedimentation of sodium sulfate. Moreover, the setting of the circulation pipeline can effectively reduce the number of crystals in the clear liquid, improve the purity and recycling rate of the product, and reduce costs.

[0041] For the sake of easy understanding, the following Figures 1 to 9 will, in conjunction with an embodiment, elaborate in detail on the specific structure and working principle of the freeze crystallizer of the present disclosure.

[0042] Such as Figure 1As shown in the figure, the freeze crystallizer in this embodiment includes a tank body. The inner cavity of the tank body successively includes from bottom to top: a settling zone 1, which is arranged at the bottom of the inner cavity of the tank body and is configured to settle crystals; a crystallization zone 2, which is located above the settling zone 1. A circulation pipeline 3 is arranged in the crystallization zone 2. The inlet of the circulation pipeline 3 is configured to be arranged at the upper part of the crystallization zone 2, and the outlet of the circulation pipeline 3 is arranged at the lower part of the crystallization zone 2. The liquid in the crystallization zone 2 is configured to flow out from the inlet of the circulation pipeline 3, be cooled, and then flow into the crystallization zone 2 from the outlet of the circulation pipeline 3; a clarification zone 4, which is located above the crystallization zone 2. A liquid discharge port 5 is arranged in the clarification zone 4, and the liquid discharge port 5 is configured to discharge the liquid in the clarification zone 4.

[0043] Specifically, the freeze crystallizer includes a tank body. The inner cavity of the tank body successively includes a settling zone 1, a crystallization zone 2, and a clarification zone 4 from top to bottom. The solution in this embodiment is a mixed solution containing sodium chloride and sodium sulfate. A circulation pipeline 3 is arranged in the crystallization zone 2. A water pump 14 and a heat exchanger 15 are arranged on the circulation pipeline 3. Under the action of the water pump 14, the solution in the upper part of the crystallization zone 2 flows out from the inlet of the circulation pipeline 3. After being cooled by the heat exchanger 15, sodium sulfate in the solution begins to crystallize, and the solution condenses into a crystal slurry containing sodium sulfate crystals. The crystal slurry flows into the crystallization zone 2 from the outlet of the circulation pipeline 3. As Figures 6 to 8 shown, in this embodiment, there are 2 - 4 evenly distributed inlets on the circulation pipeline 3, and the inlets of the circulation pipeline 3 are arranged at the upper part of the crystallization zone 2, which can make the solution containing fine crystals in the upper part of the crystallization zone 2 enter the circulation pipeline 3 evenly. In the crystallization zone 2, the solution moves upward under the action of lift, and the crystals move downward based on their own gravity. Larger crystals move downward due to their own gravity being greater than the lift and enter the settling zone 1, where they settle and crystallize at the bottom of the settling zone 1, and the larger crystals are discharged through the settling zone 1. The remaining fine crystals move upward mixed in the solution because their own gravity is less than or equal to the lift. In the crystallization zone 2, the fine crystals combine into larger crystals under the action of mutual force, move towards the settling zone 1 and settle, and the remaining solution continues to move upward and enters the clarification zone 4 for clarification. There is a groove in the clarification zone 4, and the depth of the groove is 200 - 400 millimeters. A liquid discharge port 5 is arranged at the groove, which is convenient for the clarified liquid to gather at the groove and be discharged from the liquid discharge port 5.

[0044] Considering that the liquid entering the clarification zone 4 from the crystallization zone 2 will also carry some sodium sulfate crystals, therefore, as Figure 2 shown, in an embodiment of the present disclosure, a grading zone 6 is arranged between the crystallization zone 2 and the clarification zone 4. The inner diameter of the grading zone 6 is configured to gradually increase in the direction from the crystallization zone 2 to the clarification zone 4; a crystal discharge port 7 is arranged at a position adjacent to the boundary between the grading zone 6 and the crystallization zone 2, and the crystals falling from the grading zone 6 are configured to be discharged through the crystal discharge port 7.

[0045] Specifically, as described above, before the solution enters the clarification zone 4 from the crystallization zone 2, it also passes through the classification zone 6. Since the inner diameter of the classification zone 6 is configured to gradually increase in the direction from the crystallization zone 2 to the clarification zone 4, the flow rate of the solution in the classification zone 6 gradually slows down in the direction from the crystallization zone 2 to the clarification zone 4, and crystal particles can be further separated from the solution. In addition, a crystal discharge port 7 is provided at a position adjacent to the junction of the classification zone 6 and the crystallization zone 2. The crystals falling from the classification zone 6 are discharged from the crystal discharge port 7 and enter the raw material tank for recycling again. The setting of the crystal discharge port 7 also further removes the crystal particles in the solution.

[0046] As Figure 2 and Figure 9 shown, in an embodiment of the present disclosure, a perforated pipe 8 is provided in the clarification zone 4. The perforated pipe 8 extends from the clarification zone 4 to the upper part of the classification zone 6, and the liquid in the classification zone 6 is configured to flow into the clarification zone 4 through the perforated pipe 8.

[0047] Specifically, in the clarification zone 4, some crystal particles with very small particle sizes are also carried. Therefore, a perforated pipe 8 is provided in the clarification zone 4, and an overflow baffle 22 is provided in the clarification zone 4. The perforated pipes 8 are uniformly arranged in a rectangle or triangle or ring at the center of the overflow baffle 22, and the perforated pipe 8 extends from the clarification zone 4 to the upper part of the classification zone 6. The liquid in the classification zone 6 flows into the clarification zone 4 through the perforated pipe 8, specifically to the top of the overflow baffle 22 in the clarification zone 4. In addition, the perforated pipe 8 includes a straight pipe section and an opening section. The perforated pipe 8 can be arranged with the opening facing upward or downward. When the perforated pipe 8 is arranged with the opening facing upward or downward, the straight pipe section is located below the liquid level. In this embodiment, the distance between the straight pipe section and the overflow baffle 22 is greater than or equal to 300 mm. The settings of the perforated pipe 8 and the overflow baffle 22 can further remove the small particle size crystals and impurities, and can effectively ensure the clarity of the liquid in the clarification zone 4.

[0048] As Figure 2 shown, in an embodiment of the present disclosure, a feed inlet 9 lower than the inlet of the circulation pipeline 3 is provided in the upper part of the crystallization zone 2, and the liquid in the raw material tank is configured to enter the crystallization zone 2 through the feed inlet 9.

[0049] As Figure 2 shown, in an embodiment of the present disclosure, the circulation pipeline 3 includes a feed pipeline 10, and the feed pipeline 10 is configured to at least include a first section 11 extending downward, and the outlet of the first section 11 is provided at the bottom of the crystallization zone 2.

[0050] Specifically, the crystal slurry cooled by the circulation pipeline 3 enters the feed pipeline 10. The feed pipeline 10 at least includes a first section 11 extending downward. The outlet of the first section 11 is arranged at the bottom of the crystallization zone 2. The crystal slurry flows out from the outlet of the first section 11 of the feed pipeline 10 to the bottom of the crystallization zone 2, and then the crystals with larger particle sizes directly enter the settling zone 1 from the crystallization zone 2 for settling.

[0051] As Figure 2 shown, in an embodiment of the present disclosure, a first thermometer 16 and a second thermometer 17 are arranged above the feed inlet 9 and below the feed pipeline 10. The first thermometer 16 is configured to detect the temperature of the feed inlet 9, and the second thermometer 17 is configured to detect the outlet temperature of the feed pipeline 10. The outlet temperature of the feed pipeline 10 is lower than the temperature of the feed inlet 9.

[0052] Specifically, in this embodiment, a first thermometer 16 and a second thermometer 17 are respectively arranged at the upper and lower parts of the crystallization zone 2. The first thermometer 16 is used to detect the temperature of the liquid at the feed inlet 9. In this embodiment, the temperature of the feed inlet 9 is 10°C to 15°C. The second thermometer 17 is used to detect the temperature of the liquid at the outlet of the feed pipeline 10. The outlet temperature of the feed pipeline 10 is -2°C to 0°C. Since the feed temperature at the feed inlet 9 is higher than the crystallization temperature of sodium sulfate crystals, when the liquid in the crystallization zone 2 flows to the vicinity of the feed inlet 9, some fine crystals will be dissolved and enter the circulation pipeline 3 again for condensation crystallization treatment. Due to the setting of different local temperatures, the number of fine crystals in the solution can be further reduced.

[0053] As Figure 2 shown, in an embodiment of the present disclosure, the outlet pipe diameter of the first section 11 is configured to gradually increase in the direction from the crystallization zone 2 to the settling zone 1.

[0054] Specifically, in order to reduce the impact force of the crystal slurry flowing out from the first section 11 of the feed pipeline 10 on the crystallization zone 2 and the settling zone 1, the outlet pipe diameter of the first section 11 is configured to gradually increase in the direction from the crystallization zone 2 to the settling zone 1, so as to reduce the flow rate of the crystal slurry in the first section 11, and further reduce the impact force of the crystal slurry on the crystallization zone 2 and the settling zone 1.

[0055] As Figure 2 shown, in an embodiment of the present disclosure, a baffle 12 is arranged below the pipe outlet of the first section 11, and the baffle 12 is connected to the pipe outlet.

[0056] Specifically, considering that a large impact force is generated when the crystal slurry flows out of the outlet of the first stage 11, if the crystal slurry directly falls into the sedimentation area 1, the crystals that have already settled will be impacted from the bottom of the sedimentation area 1 to the upper part of the sedimentation area 1, which is not conducive to the sedimentation of the crystals. Therefore, in this embodiment, a baffle 12 is further provided at the pipe outlet of the first stage 11. The baffle 12 is connected to the pipe outlet of the first stage 11. The crystals flowing out of the outlet will first fall onto the baffle 12 for buffering and then enter the sedimentation area 1 for sedimentation. The setting of the baffle 12 can reduce the impact force caused by the crystal slurry on the sedimentation area 1 and is conducive to promoting the sedimentation of the crystals.

[0057] As Figure 2 shown, in an embodiment of the present disclosure, the sedimentation area 1 is configured as a conical structure, the cone angle at the bottom of the sedimentation area 1 is 50° to 90°, and a discharge port 18 is provided at the bottom of the sedimentation area 1.

[0058] Specifically, the sedimentation area 1 is configured as a conical structure, the cone angle at the bottom of the sedimentation area 1 is set to 50° to 90°, a discharge port 18 is provided at the bottom of the sedimentation area 1, and the crystals flow and gather in the sedimentation area 1 and are discharged concentratedly at the discharge port 18.

[0059] As Figure 2 shown, considering that during the actual working process, crystals are likely to accumulate on the side wall of the sedimentation area 1. Therefore, an anti-flushing port 23 is further provided on the side wall of the sedimentation area 1. The anti-flushing port 23 is configured to flush the crystals accumulated on the side wall of the sedimentation area 1. Among them, one or more anti-flushing ports can be set according to actual needs, and no specific limitation is made here. Specifically, the mixture of crystals and solution discharged from the discharge port 18 can be collected and recycled, enter the sedimentation area 1 through the anti-flushing port 23, and flush away the crystals accumulated on the side wall through the impact force. Or the solution can be directly introduced into the anti-flushing port 23 for direct flushing. In another embodiment of the present disclosure, the discharge port 18 and the anti-flushing port 23 can be swapped. The original anti-flushing port 23 is used as the discharge port to connect to the discharge pump, and the original discharge port 18 is used as the anti-flushing port for backwashing.

[0060] As Figure 2 shown, in an embodiment of the present disclosure, a liquid level gauge 13 is provided above the upper part of the crystallization area 2, and the liquid level gauge 13 is provided above the inlet of the circulation pipeline 3.

[0061] Specifically, since the solution in the crystallization area 2 needs to enter the circulation pipeline 3 for circulating condensation crystallization, it is necessary to ensure that the liquid level of the crystallization area 2 is not lower than the inlet position of the circulation pipeline 3. A liquid level gauge 13 is provided above the inlet of the circulation pipeline 3, which can ensure that the liquid level of the crystallization area 2 is always higher than the inlet of the circulation pipeline 3, and further ensure that the solution can flow out from the inlet of the circulation pipeline 3, ensuring the stable operation of the entire device.

[0062] AsFigures 2 to 5 As shown, in an embodiment of the present disclosure, a manhole 19, a flushing port 20 and an observation port 21 are further provided. The manhole 19 is used for staff to enter and exit the equipment for installation, maintenance and safety inspection work. The flushing port 20 is used to flush the equipment, and the observation port 21 is used for staff to observe the flushing state of the equipment during the flushing process.

[0063] A freezing crystallizer provided by the present disclosure is more conducive to the crystallization and sedimentation of crystals through the hierarchical setting of each area in the tank, and the setting of the circulation pipeline can effectively reduce the number of fine crystals in the clear liquid, improve the purity and recycling rate of subsequent products, and reduce costs.

[0064] It should be noted that for the foregoing method embodiments, for the sake of simplicity of description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the present disclosure is not limited by the described action sequence, because according to the present disclosure, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present disclosure.

[0065] In the above embodiments, the descriptions of each embodiment have their own emphases. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0066] The preferred embodiments of the present disclosure disclosed above are only used to help explain the present disclosure. The optional embodiments do not describe all the details in detail, nor do they limit the disclosure to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of the present disclosure. The present disclosure selects and specifically describes these embodiments to better explain the principles and practical applications of the present disclosure, so that those skilled in the art can well understand and utilize the present disclosure. The present disclosure is only limited by the claims and their full scope and equivalents.

Claims

1. A freezing crystallizer, characterized in that: The tank body comprises a tank body, wherein the inner cavity of the tank body comprises, from bottom to top,: A settling zone (1), the settling zone (1) being arranged at the bottom of the inner cavity of the tank body and configured for settling crystallization; a crystallization zone (2), the crystallization zone (2) being located above the settling zone (1), a circulation pipeline (3) being arranged in the crystallization zone (2), the inlet of the circulation pipeline (3) being arranged at the upper part of the crystallization zone (2), the outlet of the circulation pipeline (3) being arranged at the lower part of the crystallization zone (2), and the liquid in the crystallization zone (2) being arranged to flow out through the inlet of the circulation pipeline (3) and then flow into the crystallization zone (2) from the outlet of the circulation pipeline (3) after being cooled; A clarification zone (4), the clarification zone (4) is located above the crystallization zone (2), a liquid discharge port (5) is provided in the clarification zone (4), and the liquid discharge port (5) is configured to discharge the liquid in the clarification zone (4).

2. The freezing crystallizer according to claim 1, characterized in that A grading zone (6) is provided between the crystallization zone (2) and the clarification zone (4), and the inner diameter of the grading zone (6) is configured to gradually increase in a direction from the crystallization zone (2) to the clarification zone (4); a crystal discharge port (7) is provided at a position adjacent to the boundary between the grading zone (6) and the crystallization zone (2), and crystals falling from the grading zone (6) are configured to be discharged through the crystal discharge port (7).

3. The freezing crystallizer according to claim 1, characterized in that A perforated pipe (8) is provided in the clarification zone (4), and the perforated pipe (8) extends from the clarification zone (4) to the upper part of the classification zone (6), and the liquid in the classification zone (6) is configured to flow into the clarification zone (4) through the perforated pipe (8).

4. The freezing crystallizer according to claim 1, characterized in that A feed inlet (9) is provided at the upper part of the crystallization zone (2) and is lower than the inlet of the circulation pipeline (3). The liquid in the raw material tank is configured to enter the crystallization zone (2) through the feed inlet (9).

5. The freezing crystallizer according to claim 4, characterized in that The circulation pipeline (3) comprises a feed pipeline (10), wherein the feed pipeline (10) is constructed to include at least a first section (11) extending downward, and an outlet of the first section (11) is arranged at the bottom of the crystallization zone (2).

6. The freezing crystallizer according to claim 5, characterized in that: A first thermometer (16) and a second thermometer (17) are arranged above the feed inlet (9) and below the feed pipe (10); the first thermometer (16) is configured to detect the temperature of the feed inlet (9); the second thermometer (17) is configured to detect the outlet temperature of the feed pipe (10); the outlet temperature of the feed pipe (10) is lower than the temperature of the feed inlet (9).

7. The freezing crystallizer according to claim 5, characterized in that: The outlet pipe diameter of the first section (11) is constructed to gradually increase in the direction from the crystallization zone (2) to the sedimentation zone (1).

8. The freezing crystallizer according to claim 7, characterized in that: A baffle (12) is provided below the pipe outlet of the first section (11), and the baffle (12) is connected to the pipe outlet.

9. The freezing crystallizer according to claim 1, characterized in that: The sedimentation zone (1) is constructed as a cone structure, the cone angle at the bottom of the sedimentation zone (1) is 50° to 90°, and a discharge port is provided at the bottom of the sedimentation zone (1).

10. The freezing crystallizer according to claim 1, characterized in that: A liquid level meter (13) is provided on the upper part of the crystallization zone (2), and the liquid level meter (13) is provided above the inlet of the circulation pipeline (3).

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