A continuous scraper crystallizer with a single water-cooling passage

Abstract

This invention relates to the field of crystallizer technology and discloses a continuous scraper crystallizer with a single water-cooling path. It includes a crystallizer shell, inside which multiple cooling plates are fixed. Each cooling plate has a cooling water flow channel, and adjacent cooling plates are connected in series via connecting pipes. An air-cooled box is installed at the top of the crystallizer shell, and the top portion of the connecting pipe extends into the air-cooled box. A stirring shaft is rotatably mounted inside the crystallizer shell, driven by a rotary motor. A stirring and scraping crystallization mechanism is installed on the outside of the stirring shaft at a position corresponding to the cooling plate. This invention, due to its single cooling water path, provides a uniform temperature gradient, excellent crystallization effect, and high product purity and yield. The inner wall of the crystallizer shell is rigorously polished to ensure a roughness ≤0.1nm, virtually eliminating wall adhesion and facilitating smoother production.

Description

Technical Field

[0001] This invention relates to the field of crystallizer technology, and more particularly to a continuous scraper crystallizer with a single water-cooling passage. Background Technology

[0002] Crystallizers are mainly used for crystallization operations. The container walls are equipped with jackets or the interior is filled with coils to heat or cool the solution in the tank. There are many types of crystallizers. According to the method of obtaining a supersaturated state of the solution, they can be divided into evaporation crystallizers and cooling crystallizers. According to the flow mode, they can be divided into mother liquor circulation crystallizers and crystal slurry (i.e., a mixture of mother liquor and crystals) circulation crystallizers. According to the operation mode, they can be divided into continuous crystallizers and batch crystallizers.

[0003] Crystallization is an important chemical process and one of the main methods for purifying substances. Many chemical, pharmaceutical, and intermediate products exist in crystalline form, and crystallization is often the best and most economical method for large-scale production. Crystallization requires a crystallizer. Therefore, designing a well-structured crystallization device is crucial for the preparation of chemical products that require crystallization.

[0004] Existing cooling plate crystallizers primarily cool molten materials by allowing cooling water to flow through cooling plates, thus causing them to crystallize. However, existing crystallizers suffer from the following problems:

[0005] 1. In the existing crystallizer, the cooling plates are arranged at equal intervals in the cooling container, with three cooling plates sharing one water supply. Furthermore, the inner wall of the cooling container is not smooth enough, resulting in an uneven temperature gradient of the material inside the cooling container. This leads to deviations in the crystallization effect and severe crystallization wall formation, making the crystals difficult to clean.

[0006] 2. In the existing crystallizer, during the flow of cooling water through the cooling plate, the temperature of the cooling water rises sharply in the later stage due to heat exchange. This reduces the cooling effect on the material in the later stage, resulting in a large temperature difference between the material inside the crystallizer. Consequently, this leads to uneven crystallization and a slow overall crystallization rate.

[0007] 3. In the prior art, when the crystals on the surface of the cooling plate are scraped off by a scraper, crystals will accumulate on the surface of the scraper, thus affecting the scraping efficiency of the scraper. Summary of the Invention

[0008] The present invention proposes a continuous scraper crystallizer with a single water-cooling passage, which solves the problems in the prior art.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A continuous scraper crystallizer with a single water-cooling path includes a crystallizer shell, inside which multiple cooling plates are fixed. Each cooling plate has a cooling water flow channel, and adjacent cooling plates are connected in series by a connecting pipe. The cooling water passes through the cooling plates sequentially through the connecting pipe, exchanging heat with the hot molten material through the cooling plates, thereby cooling and crystallizing. Because there is only one cooling water path, the temperature gradient is uniform, resulting in good crystallization effect and improved product purity and yield. The inner wall of the crystallizer shell is strictly polished to ensure a roughness of ≤0.1nm, with virtually no wall formation, making production smoother.

[0011] The top of the crystallizer shell is equipped with an air-cooled box, and the top part of the connecting pipe extends into the air-cooled box. The air-cooled box can cool the cooling water inside the connecting pipe by air cooling, thereby reducing the temperature of the cooling water and improving the crystallization effect.

[0012] A stirring shaft is rotatably installed inside the crystallizer shell. The stirring shaft is driven by a rotary motor. A stirring and scraping crystallization mechanism is installed on the outside of the stirring shaft at a position corresponding to the cooling plate. The rotary motor drives the stirring shaft to rotate, thereby driving the stirring and scraping crystallization mechanism to rotate. On the one hand, it can stir the material to make the material temperature more uniform, and on the other hand, it can scrape off the crystals formed on the surface of the cooling plate.

[0013] Preferably, the two ends of the crystallizer shell are respectively connected to the hot melt material inlet and the hot melt material outlet, and the bottom of the cooling plate is provided with a material flow channel, in which the hot melt material can flow and exchange heat with each cooling plate in turn. The cooling plate is provided with baffle channels to improve the heat exchange efficiency between the cooling water and the hot melt material.

[0014] Preferably, a heat-conducting sleeve is fitted on the outer side of the section of the connecting pipe inside the air-cooled box. The heat-conducting sleeve is provided with heat dissipation fins. Preferably, there are multiple heat dissipation fins, which are distributed parallel and equidistantly on the heat-conducting sleeve. Low-temperature air is introduced into the air-cooled box. By adding heat dissipation fins, the heat exchange area between the low-temperature air and the heat dissipation fins can be increased, thereby promoting the cooling of the cooling water inside the connecting pipe.

[0015] Preferably, the air-cooled box includes an air-cooled box body, on which a cold air inlet pipe and a hot air outlet pipe are provided. A circulation pipe extends from the air-cooled box body and communicates with the hot air outlet pipe. The cold air inlet pipe is connected to a cold air blower, thereby forming an airflow inside the air-cooled box. The direction of the airflow is parallel to the heat dissipation fins, and the cold airflow can exchange heat with the heat dissipation fins, thereby cooling the cooling water.

[0016] Preferably, a first electric air valve is installed on the hot air exhaust pipe, a second electric air valve is installed on the circulation pipe, and a temperature sensor is also installed on the hot air exhaust pipe. The temperature sensor can monitor the temperature of the air discharged from the hot air exhaust pipe. When the temperature of the air discharged from the hot air exhaust pipe is low, the cold air can be reused. At this time, the second electric air valve is opened and the first electric air valve is closed, so that the cold air can be recirculated in the air-cooled box through the circulation pipe, thus being reused and more energy-efficient. A fan is installed in the circulation pipe to promote airflow. When the temperature of the air discharged from the hot air exhaust pipe is high, the second electric air valve is closed and the first electric air valve is opened, so that the hot air is discharged from the hot air exhaust pipe and new low-temperature air is introduced through the cold air inlet pipe.

[0017] Preferably, a fan is installed between the cold air inlet pipe and the air-cooled box, and a first pulley is connected to the fan shaft of the fan. The fan can increase the airflow velocity inside the air-cooled box and improve the air-cooling heat exchange effect.

[0018] Preferably, one end of the stirring shaft extends to the outside of the crystallizer shell and is fixed with a second pulley. The first pulley and the second pulley are driven by a belt, and the diameter of the first pulley is smaller than the diameter of the second pulley. When the rotating motor drives the stirring shaft to rotate, it can drive the fan to run through the belt drive. Since the diameter of the first pulley is smaller than that of the second pulley, the fan can run at a relatively higher speed.

[0019] Preferably, the stirring and scraping crystallization mechanism includes two first crystallization scrapers symmetrically arranged on both sides of the cooling plate. The first crystallization scrapers are fixedly connected to the stirring shaft. When the stirring shaft drives the first crystallization scrapers to rotate relative to the cooling plate, the crystals formed on the surface of the cooling plate can be scraped off because one side of the first crystallization scraper is in contact with the surface of the cooling plate.

[0020] Preferably, a stirrer is installed on the side of the first crystallization scraper away from the cooling plate. The stirrer has multiple through holes and can rotate with the stirring shaft to stir the molten material. The through holes of the stirrer can improve the stirring effect of the stirrer.

[0021] Preferably, a lifting drive box is provided between the first crystallizing scraper and the agitator. The output end of the lifting drive box is connected to a second crystallizing scraper. The second crystallizing scraper is in contact with the first crystallizing scraper and can move up and down to scrape off the crystals accumulated on the surface of the first crystallizing scraper, thereby improving the crystallization removal effect of the first crystallizing scraper.

[0022] Preferably, a reciprocating screw is rotatably installed inside the lifting drive box. A lifting sleeve is threaded onto the outer side of the reciprocating screw, and a crossbar is connected to the lifting sleeve. The crossbar extends to the outside of the lifting drive box through a vertical guide port and is fixed to the second crystallizing scraper. One end of the reciprocating screw extends to the outside of the lifting drive box and is fixed with a first gear. A second gear is fixed on the rotating shaft of the stirrer and meshes with the first gear. Gear rings are fixed on both sides of the cooling plate and mesh with the first gear. When the stirring and scraping crystallization mechanism rotates with the stirring shaft, the first gear moves on the gear ring, thereby driving the reciprocating screw to rotate, which in turn drives the lifting sleeve to move up and down, thereby driving the second crystallizing scraper to move up and down, thus scraping away the crystals accumulated on the surface of the first crystallizing scraper and improving the crystallization scraping effect of the first crystallizing scraper.

[0023] The beneficial effects of this invention are:

[0024] 1. Because there is only one cooling water, the temperature gradient is uniform, the crystallization effect is good, and the product purity and yield can be improved. The inner wall of the crystallizer shell is strictly polished to ensure that the roughness is ≤0.1nm, and there is basically no wall formation, making the production smoother.

[0025] 2. By adding an air-cooled box, the cooling water inside the connecting pipe can be cooled by air, thereby reducing the temperature of the cooling water, resulting in better crystallization effect and reducing the temperature difference of the material inside the crystallizer, making the crystal particles more uniform.

[0026] 3. Through the design of the stirring and scraping crystallization mechanism, when the stirring and scraping crystallization mechanism rotates with the stirring shaft, the first gear moves on the gear ring, which drives the reciprocating screw to rotate, thereby driving the lifting sleeve to move up and down, which in turn drives the second crystallization scraper to move up and down, thereby scraping away the crystals accumulated on the surface of the first crystallization scraper, thus improving the crystallization scraping effect of the first crystallization scraper. Attached Figure Description

[0027] Figure 1 This is a front-view sectional view of a continuous scraper crystallizer with a single water-cooling passage proposed in this invention.

[0028] Figure 2 This is a top view of a continuous scraper crystallizer with a single water-cooling passage proposed in this invention.

[0029] Figure 3 This is a broken view of a continuous scraper crystallizer with a single water-cooling passage proposed in this invention.

[0030] Figure 4 This is an enlarged structural schematic diagram of the stirring and scraping crystallization mechanism of a continuous scraper crystallizer with a single water-cooling passage proposed in this invention.

[0031] Figure 5 This is an enlarged perspective view of the stirring and scraping crystallization mechanism of a continuous scraper crystallizer with a single water-cooling passage proposed in this invention.

[0032] Figure 6 This is a cross-sectional view of the lifting drive box of the stirring and scraping crystallization mechanism of a continuous scraper crystallizer with a single water-cooling passage proposed in this invention.

[0033] Figure 7 This is a cross-sectional view of the cooling plate of a continuous scraper crystallizer with a single water-cooling passage proposed in this invention.

[0034] Figure 8 This is a schematic diagram showing the series connection between adjacent cooling plates of a continuous scraper crystallizer with a single water-cooling path proposed in this invention.

[0035] Figure 9 This diagram illustrates the connection relationship between the heat dissipation fins and the connecting pipe of a continuous scraper crystallizer with a single water-cooling path proposed in this invention.

[0036] The diagram labels are as follows: 1. Crystallizer outer shell; 101. Hot molten material inlet; 102. Hot molten material outlet; 2. Stirring shaft; 201. Rotary motor; 202. Second pulley; 3. Cooling plate; 301. Material flow channel; 302. Connecting pipe; 303. Heat-conducting sleeve; 304. Heat dissipation fins; 305. Gear ring; 4. Stirring and scraping crystallization mechanism; 401. First crystallization scraper; 402. Lifting drive box; 4021. 4022. Reciprocating lead screw; 4023. Lifting sleeve; 4024. Crossbar; 4025. Second crystallization scraper; 4026. First gear; 403. Stirrer; 4031. Second gear; 5. Air-cooled box; 501. Cold air inlet pipe; 502. Hot air outlet pipe; 5021. First electric air valve; 5022. Temperature sensor; 503. Circulation pipe; 5031. Second electric air valve; 6. Fan; 601. First pulley. Detailed Implementation

[0037] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0038] Reference Figure 1-9A continuous scraper crystallizer with a single water-cooling path includes a crystallizer shell 1, with multiple cooling plates 3 fixed inside the crystallizer shell 1. The cooling plates 3 are provided with cooling water flow channels, and adjacent cooling plates 3 are connected in series by a connecting pipe 302. The connecting pipe 302 can be a U-shaped structure. The cooling water passes through the cooling plates 3 sequentially through the connecting pipe 302, and exchanges heat with the hot molten material through the cooling plates 3, thereby cooling and crystallizing. Since there is only one cooling water path, the temperature gradient is uniform, the crystallization effect is good, and the product purity and yield can be improved. The inner wall of the crystallizer shell 1 is strictly polished to ensure a roughness of ≤0.1nm, with virtually no wall formation, making production smoother.

[0039] A cooling box is installed at the top of the crystallizer shell 1. The top part of the connecting pipe 302 extends into the cooling box. The cooling box can cool the cooling water inside the connecting pipe 302 by air cooling, thereby reducing the temperature of the cooling water and making the crystallization effect better.

[0040] A stirring shaft 2 is rotatably installed inside the crystallizer shell 1. The stirring shaft 2 is driven by a rotary motor 201. A stirring scraping crystallization mechanism 4 is installed on the outside of the stirring shaft 2 at a position corresponding to the cooling plate 3. The rotary motor 201 drives the stirring shaft 2 to rotate, thereby driving the stirring scraping crystallization mechanism 4 to rotate. On the one hand, it can stir the material to make the material temperature more uniform, and on the other hand, it can scrape off the crystals formed on the surface of the cooling plate 3.

[0041] The crystallizer shell 1 is connected to a hot melt material inlet 101 and a hot melt material outlet 102 at both ends. The bottom of the cooling plate 3 is provided with a material flow channel 301, in which the hot melt material can flow and exchange heat with each cooling plate 3 in sequence. The cooling plate 3 is provided with a baffle channel to improve the heat exchange efficiency between the cooling water and the hot melt material.

[0042] The connecting pipe 302 is fitted with a heat-conducting sleeve 303 on the outer side of a section inside the air-cooled box. The heat-conducting sleeve 303 is provided with heat dissipation fins 304. Multiple heat dissipation fins 304 are provided and are distributed parallel and equidistantly on the heat-conducting sleeve 303. Low-temperature air is introduced into the air-cooled box. By adding heat dissipation fins 304, the heat exchange area between the low-temperature air and the heat dissipation fins 304 can be increased, thereby promoting the cooling of the cooling water inside the connecting pipe 302.

[0043] The air-cooled box includes an air-cooled box body 5, which is provided with a cold air inlet pipe 501 and a hot air outlet pipe 502. A circulation pipe 503 extends from the air-cooled box body and is connected to the hot air outlet pipe 502. The cold air inlet pipe 501 is connected to a cooler, thereby forming an airflow inside the air-cooled box. The direction of the airflow is parallel to the heat dissipation fins 304. The cold airflow can exchange heat with the heat dissipation fins 304, thereby cooling the cooling water.

[0044] The hot air exhaust pipe 502 is equipped with a first electric air valve 5021, and the circulation pipe 503 is equipped with a second electric air valve 5031. A temperature sensor 5022 is also installed on the hot air exhaust pipe 502. The temperature sensor 5022 can monitor the temperature of the air discharged from the hot air exhaust pipe 502. When the temperature of the air discharged from the hot air exhaust pipe 502 is low, the cold air can be reused. At this time, the second electric air valve 5031 is opened and the first electric air valve 5021 is closed, so that the cold air can be recirculated in the air-cooled box through the circulation pipe 503, thus being reused and more energy-efficient. The circulation pipe 503 is equipped with a fan to promote airflow circulation. When the temperature of the air discharged from the hot air exhaust pipe 502 is high, the second electric air valve 5031 is closed and the first electric air valve 5021 is opened, so that the hot air is discharged from the hot air exhaust pipe 502 and new low-temperature air is introduced through the cold air inlet pipe 501.

[0045] A fan 6 is installed between the cold air inlet pipe 501 and the air-cooled box. The fan can increase the airflow velocity inside the air-cooled box and improve the air-cooled heat exchange effect.

[0046] The fan shaft of the blower 6 is connected to a first pulley 601. One end of the stirring shaft 2 extends to the outside of the crystallizer shell 1 and is fixed with a second pulley 202. The first pulley 601 and the second pulley 202 are driven by a belt. The diameter of the first pulley 601 is smaller than the diameter of the second pulley 202. When the rotating motor 201 drives the stirring shaft 2 to rotate, it can drive the blower 6 to run through the belt. Since the diameter of the first pulley 601 is smaller than that of the second pulley 202, the blower 6 can run at a relatively higher speed.

[0047] The stirring and scraping crystallization mechanism 4 includes two first crystallization scrapers 401 symmetrically arranged on both sides of the cooling plate 3. The first crystallization scrapers 401 are fixedly connected to the stirring shaft 2. When the stirring shaft 2 drives the first crystallization scrapers 401 to rotate relative to the cooling plate 3, the crystals formed on the surface of the cooling plate 3 can be scraped off because one side of the first crystallization scraper 401 is in contact with the surface of the cooling plate 3.

[0048] One of the first crystallization scrapers 401 is equipped with a stirrer 403 on the side away from the cooling plate 3. The stirrer 403 has multiple through holes. The stirrer 403 can rotate with the stirring shaft 2 to stir the molten material. The through holes of the stirrer 403 can improve the stirring effect of the stirrer 403.

[0049] A lifting drive box 402 is provided between the first crystallization scraper 401 and the stirrer 403. The output end of the lifting drive box 402 is connected to a second crystallization scraper 4024. The second crystallization scraper 4024 contacts the first crystallization scraper 401 and can move up and down to scrape off the crystals accumulated on the surface of the first crystallization scraper 401, thereby improving the crystallization scraping effect of the first crystallization scraper 401.

[0050] The lifting drive box 402 contains a reciprocating screw 4021 rotatably mounted inside. A lifting sleeve 4022 is threaded onto the outer side of the reciprocating screw 4021. A crossbar 4023 is connected to the lifting sleeve 4022. The crossbar 4023 extends through a vertical guide port to the outside of the lifting drive box 402 and is fixed to the second crystallizing scraper 4024. One end of the reciprocating screw 4021 extends to the outside of the lifting drive box 402 and is fixed to a first gear 4025. A stirrer 403 is rotatably connected to the first crystallizing scraper 401. A second gear 4031 is fixed to the shaft of the stirrer 403, and the second gear 4031 meshes with the first gear 4025. Both sides of the cooling plate 3 are fixed... A gear ring 305 is fixed, which meshes with the first gear 4025. When the stirring and scraping crystallization mechanism 4 rotates with the stirring shaft 2, the first gear 4025 moves on the gear ring 305, thereby driving the reciprocating screw 4021 to rotate, which in turn drives the lifting sleeve 4022 to move up and down, thereby driving the second crystallization scraper 4024 to move up and down, thereby scraping away the crystals accumulated on the surface of the first crystallization scraper 401, thus improving the crystallization scraping effect of the first crystallization scraper 401. Furthermore, since the second gear 4031 meshes with the first gear 4025, the stirrer 403 can also rotate on its own axis while rotating with the stirring shaft 2, thereby improving the stirring effect.

[0051] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0052] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0053] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A continuous wiped -film crystallizer with single water cooling circuit, comprising a crystallizer shell (1), characterized in that, Multiple cooling plates (3) are fixed inside the crystallizer shell (1). Cooling water flow channels are provided inside the cooling plates (3), and adjacent cooling plates (3) are connected in series through connecting pipes (302). The top of the crystallizer shell (1) is equipped with an air-cooled box, and the top part of the connecting pipe (302) extends into the air-cooled box; The crystallizer shell (1) is provided with a stirring shaft (2) driven by a rotary motor (201), and a stirring scraping crystallization mechanism (4) is installed on the outside of the stirring shaft (2) at the corresponding position of the cooling plate (3). The air-cooled box includes an air-cooled box body (5), on which a cold air inlet pipe (501) and a hot air outlet pipe (502) are provided, and a circulation pipe (503) extending from the air-cooled box body and communicating with the hot air outlet pipe (502). The stirring and scraping crystallization mechanism (4) includes two first crystallization scrapers (401) symmetrically arranged on both sides of the cooling plate (3), and the first crystallization scrapers (401) are connected to the stirring shaft (2); One of the first crystallization scrapers (401) is equipped with a stirrer (403) on the side away from the cooling plate (3), and the stirrer (403) is provided with multiple through holes; A lifting drive box (402) is provided between the first crystallization scraper (401) and the stirrer (403). The output end of the lifting drive box (402) is connected to a second crystallization scraper (4024) for scraping off the crystals on the surface of the first crystallization scraper (401).

2. A continuous wiped -film crystallizer having a single water cooling passage according to claim 1, characterized in that, The outer side of the connecting pipe (302) located inside the air-cooled box is fitted with a heat-conducting sleeve (303), and heat dissipation fins (304) are provided on the heat-conducting sleeve (303).

3. A continuous wiped -film crystallizer having a single water cooling passage according to claim 1, wherein A first electric air valve (5021) is installed on the hot air exhaust pipe (502), a second electric air valve (5031) is installed on the circulation pipe (503), and a temperature sensor (5022) is also installed on the hot air exhaust pipe (502).

4. A continuous wiped -film crystallizer having a single water cooling passage according to claim 1, wherein A fan (6) is installed between the cold air inlet pipe (501) and the air-cooled box (5).

5. A continuous wiped -film crystallizer having a single water cooling passage according to claim 4, wherein The fan shaft of the blower (6) is connected to a first pulley (601), and one end of the stirring shaft (2) extends to the outside of the crystallizer shell (1) and is fixed with a second pulley (202). The first pulley (601) and the second pulley (202) are driven by a belt.

6. A continuous wiped -film crystallizer having a single water cooling passage according to claim 1, wherein The crystallizer shell (1) is connected to a hot melt material inlet (101) and a hot melt material outlet (102) at both ends, and a material flow channel (301) is opened at the bottom of the cooling plate (3), and the cooling water flow channel is a baffle channel.

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