Continuous crystallization device for sodium nitrate

Abstract

The utility model relates to the technical field of chemical production equipment, and provides a sodium nitrate continuous crystallization device which comprises a tank body and a partition plate, the partition plate is arranged at the bottom of the inner side of the tank body and divides the tank body into a crystallization area and a settlement area, and the crystallization area and the settlement area are communicated through a through groove; the stirring rod is rotationally arranged in the crystallization area; a plurality of slow flow check rings are arranged on the partition plate at intervals and located below the stirring rod, a plurality of through holes are formed in the side wall of each slow flow check ring, the through holes of every two adjacent slow flow check rings are arranged in a staggered mode, and the slow flow check rings slow down the flow speed of a sodium nitrate solution passing through the slow flow check rings through the through holes arranged in the staggered mode; and the slow flow check ring is also used for intercepting sodium nitrate crystals passing through the slow flow check ring. According to the technical scheme, the technical problems that in a sodium nitrate solution in the prior art, the crystal precipitation speed is low, and formed sodium nitrate crystals are prone to being rapidly washed by the solution to be broken are solved.

Description

TECHNICAL FIELD

[0001] Embodiments of the present disclosure relate to the technical field of chemical production equipment, in particular to a sodium nitrate continuous crystallization device. BACKGROUND

[0002] Sodium nitrate crystallization is essentially based on the difference in solubility at different temperatures, by changing the external conditions, prompting sodium nitrate to precipitate from the solution in the form of crystals. Common crystallization methods include cooling crystallization, evaporation crystallization, etc., and for sodium nitrate, cooling crystallization is widely used due to its energy saving, less corrosion to equipment, etc.

[0003] However, the traditional sodium nitrate crystallization device has many problems in the running process. On the one hand, the crystallization efficiency is low, and the sodium nitrate solution in the crystallization process lacks effective flow rate control and crystal interception means, resulting in slow precipitation of crystals. On the other hand, during the flow of the solution, the formed sodium nitrate crystals are easily broken by the rapid scouring of the solution, or cannot be smoothly settled in the designated area, thereby affecting the purity and crystal morphology of the final product. CONTENT OF THE INVENTION

[0004] To overcome the above defects, the embodiments of the present disclosure provide a sodium nitrate continuous crystallization device, which solves the technical problems of slow precipitation of crystals and easy breaking of formed sodium nitrate crystals by rapid scouring of the solution in the prior art.

[0005] According to one aspect, at least one embodiment of the present disclosure provides a sodium nitrate continuous crystallization device for adding cooled brine to make sodium nitrate solution precipitate sodium nitrate crystals, comprising:

[0006] a tank body;

[0007] a partition plate arranged on the inside bottom of the tank body, the partition plate divides the tank body into a crystallization zone and a settling zone, the partition plate has a through slot, the crystallization zone and the settling zone are communicated through the through slot, the crystallization zone is used for storing sodium nitrate solution to be crystallized or being crystallized, and the settling zone is used for accommodating sodium nitrate crystals;

[0008] a stirring rod rotatably arranged in the crystallization zone;

[0009] a plurality of slow-flow blocking rings, the plurality of slow-flow blocking rings are all arranged on the partition plate in a spaced manner, and the plurality of slow-flow blocking rings are all located below the stirring rod, a plurality of through holes are formed in the side wall of each slow-flow blocking ring, and adjacent two slow-flow blocking rings are arranged in a staggered manner to slow down the flow rate of the sodium nitrate solution passing through the slow-flow blocking ring and intercept the sodium nitrate crystals passing through the slow-flow blocking ring.

[0010] Optionally, a plurality of through holes are formed in the side wall of each said flow retarding ring, and the through holes of two adjacent said flow retarding rings are arranged in a staggered manner, so as to slow down the flow rate of the sodium nitrate solution passing through the flow retarding ring and intercept the sodium nitrate crystals passing through the flow retarding ring.

[0011] Optionally, the top of the tank body is provided with a feed inlet, the feed inlet is in communication with the crystallization zone, the feed inlet is used for feeding in cooling brine and sodium nitrate solution; the bottom of the tank body is provided with a discharge outlet, the baffle is located above the discharge outlet, the discharge outlet is in communication with the sedimentation zone, and the discharge outlet is used for discharging sodium nitrate crystals.

[0012] Optionally, a jacket is arranged on the outer wall of the tank body in a circumferential direction, a placing space is formed between the inner wall of the jacket and the outer wall of the tank body, a heat exchange coil is installed in the placing space, the heat exchange coil is provided with a water inlet and a water outlet, the water inlet is located at the bottom of the side wall of the tank body, the water outlet is located at the top of the side wall of the tank body, and cold water is fed into the heat exchange coil.

[0013] Optionally, the heat exchange coil is a vertical heat exchange coil.

[0014] Optionally, the flow retarding ring comprises:

[0015] an outer ring body in the shape of a circular ring, the through holes are arranged on the side wall of the outer ring body in an interval manner;

[0016] a plurality of baffle plates, one end of each said baffle plate is located in one said through hole, the other end of each said baffle plate extends to the axis of the outer ring body, a baffle passage is formed between two adjacent said baffle plates, the baffle passage is used for slowing down the flow rate of the sodium nitrate solution passing through the baffle passage, and the baffle passage is also used for intercepting the sodium nitrate crystals passing through the baffle passage.

[0017] Optionally, the baffle plate is in any one of an L shape, a C shape and a Z shape.

[0018] Optionally, the sodium nitrate continuous crystallization device further comprises:

[0019] a driver arranged outside the top of the tank body, a power output end of the driver is in transmission connection with the stirring rod, and the driver is used for driving the stirring rod to rotate.

[0020] Optionally, the top of the tank body is provided with an observation window for observing the inside of the tank body.

[0021] Optionally, the bottom of the tank body is provided with a discharge valve, and the discharge valve is in communication with the discharge outlet.

[0022] Optionally, the paddle of the stirring rod is a rectangular frame.

[0023] The embodiments of the present disclosure have the following beneficial effects:

[0024] In the present disclosure, when the crystallization of sodium nitrate is carried out, the sodium nitrate solution to be crystallized is first delivered to the crystallization zone. The stirring rod is driven by a motor, and when the sodium nitrate solution enters the crystallization zone, the stirring rod starts to rotate, causing the solution to flow in a vortex shape and accelerating the mixing of the cooling brine and the sodium nitrate solution. As the stirring proceeds, the temperature of the solution gradually decreases, and the sodium nitrate begins to crystallize and precipitate. The sodium nitrate crystals in the solution that are in the process of crystallization flow downward under the combined action of stirring force and gravity, and when passing through the slow-flow blocking ring, the solution flows between adjacent slow-flow blocking rings due to the staggered arrangement of the slow-flow blocking ring, and the flow direction of the solution is forced to change, and the flow rate is greatly reduced. In this process, the crystals have more time to grow and aggregate. Larger crystals are intercepted by the slow-flow blocking ring, adhering to the surface of the blocking ring or falling into the interior of the blocking ring, and the crystals and part of the solution enter the settling zone through the through slot of the partition plate. In the settling zone, the crystals further settle and form a relatively pure sodium nitrate crystalline layer.

[0025] The present disclosure clearly defines the functions of the crystallization zone and the settling zone by providing a partition plate to separate the tank body. The slow-flow blocking ring effectively slows down the flow rate of the sodium nitrate solution, which is beneficial to the precipitation of crystals, while intercepting the crystals, reducing the situation of the crystals being washed and broken by the solution, improving the integrity of the crystals, and thus improving the purity of the product and the quality of the crystal morphology. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings needed in the description of the embodiments of the present disclosure will be briefly introduced. Obviously, the drawings in the following description are only some exemplary embodiments of the present disclosure. Those skilled in the art can obtain other drawings according to the content of the exemplary embodiments of the present disclosure and these drawings without creating any creative labor.

[0027] Figure 1 The structure schematic diagram of the tank body in an embodiment of the present disclosure is shown in the figure.

[0028] Figure 2 The structure schematic diagram of the tank body in an embodiment of the present disclosure is shown in the figure.

[0029] Figure 3 The structure schematic diagram of the tank body in an embodiment of the present disclosure is shown in the figure. Figure 2 The sectional view of the tank body A-A in an embodiment of the present disclosure is shown in the figure.

[0030] Figure 4 The structure schematic diagram of the heat exchange coil in an embodiment of the present disclosure is shown in the figure. Figure 1 The structure schematic diagram of the heat exchange coil in an embodiment of the present disclosure is shown in the figure.

[0031] Figure 5 The structure schematic diagram of the slow-flow blocking ring in an embodiment of the present disclosure is shown in the figure. Figure 1 The structure schematic diagram of the slow-flow blocking ring in an embodiment of the present disclosure is shown in the figure.

[0032] Figure 6 For Figure 1 Structure diagram of the partition plate in the embodiment;

[0033] Figure 7 Structure diagram of the whole tank in the disclosure.

[0034] In the figure: 1, tank; 101, crystallization zone; 102, settling zone; 103, feed inlet; 104, discharge outlet; 2, partition plate; 201, through slot; 3, stirring rod; 301, paddle; 4, slow flow baffle ring; 401, outer ring body; 4011, through hole; 402, baffle; 4021, baffle channel; 5, jacket; 501, placement space; 6, heat exchange coil; 601, water inlet; 602, water outlet; 7, driver; 8, observation window; 9, discharge valve. DETAILED DESCRIPTION

[0035] The disclosure will be further described in detail below in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the disclosure, and not to limit the disclosure.

[0036] In order to make the drawing simple, only the parts related to the disclosure are shown in each figure, which does not represent the actual structure of the product. In addition, in order to make the drawing simple and easy to understand, in some figures, only one of the parts with the same structure or function is shown, or only one of them is marked. In this paper, "one" not only means "only one", but also means "more than one", and "several" includes "two" and "more than two".

[0037] In this paper, it should be noted that, unless otherwise specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the disclosure can be understood according to the specific circumstances.

[0038] In the present disclosure, unless specifically defined and limited otherwise, the first feature is "on" or "under" the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature is "on", "above" and "over" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the first feature is higher in horizontal height than the second feature. The first feature is "under", "below" and "under" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the first feature is lower in horizontal height than the second feature.

[0039] In the description of the present embodiment, the terms "upper", "lower", "left", "right", and the like, orientation or positional relationship shown in the drawings, are only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present disclosure.

[0040] In addition, in the description of the present application, the terms "first", "second", and the like are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0041] As Figures 1 to 7 As shown in the figure, it shows a sodium nitrate continuous crystallization device in an embodiment of the present disclosure, for adding cooling brine to precipitate sodium nitrate crystals from sodium nitrate solution, the sodium nitrate continuous crystallization device comprises a tank body 1, a partition plate 2 is arranged on the inside bottom of the tank body 1, the partition plate 2 divides the tank body 1 into an upper crystallization zone 101 and a lower settling zone 102, and the partition plate 2 has a through slot 201 to communicate the crystallization zone 101 and the settling zone 102. A stirring rod 3 is rotatably arranged in the crystallization zone 101. A plurality of slow-flow blocking rings 4 are arranged on the partition plate 2 at intervals, and the slow-flow blocking rings 4 are all located below the stirring rod 3. A plurality of through holes 4011 are formed in the side wall of each slow-flow blocking ring 4, and the through holes 4011 of adjacent two slow-flow blocking rings 4 are arranged in a staggered manner.

[0042] For example, as Figure 1 and Figure 6As shown, during the crystallization of sodium nitrate, the sodium nitrate solution to be crystallized is first transported to the crystallization zone 101. The stirring rod 3 is driven by a motor, the speed of which can be adjusted according to parameters such as solution concentration and temperature. When the sodium nitrate solution enters the crystallization zone 101, the stirring rod 3 begins to rotate, causing the solution to flow in a vortex, accelerating the mixing of the cooling brine with the sodium nitrate solution. The cooling brine enters from the upper or side inlet of the crystallization zone 101, ensuring full contact with the solution. As stirring continues, the solution temperature gradually decreases, and sodium nitrate begins to crystallize. The sodium nitrate crystals in the solution, currently crystallizing, flow downwards under the combined action of stirring force and gravity. When passing through the slow-flow baffle 4, the staggered arrangement of the baffle 4 forces the solution to change its flow direction, significantly slowing the flow rate. During this process, the crystals have more time to grow and aggregate. Larger crystals are intercepted by the slow-flow baffle 4, adhering to the baffle surface or falling into the baffle. The crystals and part of the solution then enter the settling zone 102 through the channel 201 of the partition 2. Within the settling zone 102, the crystals further precipitate, forming a relatively pure sodium nitrate crystal layer.

[0043] By setting baffle 2 to separate tank 1, the functions of crystallization zone 101 and settling zone 102 are clearly defined. The setting of the slow-flow baffle ring 4 effectively slows down the flow rate of sodium nitrate solution, which is conducive to crystal precipitation. At the same time, it intercepts crystals, reduces the occurrence of crystal breakage due to solution erosion, improves crystal integrity, and thus improves product purity and crystal morphology quality.

[0044] In some examples, each flow-retarding baffle ring 4 has several through holes 4011 on its sidewall. The through holes 4011 of two adjacent flow-retarding baffle rings 4 are staggered to slow down the flow rate of the sodium nitrate solution passing through the flow-retarding baffle ring 4 and to intercept sodium nitrate crystals passing through the flow-retarding baffle ring 4. The through holes 4011 are strip-shaped holes, and each flow-retarding baffle ring 4 has at least four through holes 4011.

[0045] For example, such as Figure 1 and Figure 6 As shown, sodium nitrate crystals in the solution are flowing downwards under the combined action of stirring and gravity. When passing through the slow-flow baffle 4, the solution is forced to change its flow direction due to the misaligned arrangement of the through holes 4011, and the flow rate is significantly reduced. During this process, the crystals have more time to grow and aggregate. Larger crystals are intercepted by the slow-flow baffle 4, adhering to the surface of the baffle or falling into the baffle. The crystals and part of the solution enter the settling zone 102 through the through groove 201 of the partition 2. In the settling zone 102, the crystals further precipitate, forming a relatively pure sodium nitrate crystal layer.

[0046] In some examples, the top of the tank 1 has a feed inlet 103, which is connected to the crystallization zone 101; the bottom of the tank 1 has a discharge outlet 104, and the baffle 2 is located above the discharge outlet 104, which is connected to the settling zone 102.

[0047] For example, such as Figure 2 and Figure 3 As shown, the flow ratio of the cooling brine and sodium nitrate solution is controlled by a flow control valve before entering the crystallization zone 101. After entering the crystallization zone 101, the solution is rapidly mixed under the action of the stirring rod 3 and the crystallization process begins. As crystallization proceeds, the formed sodium nitrate crystals gradually settle and enter the settling zone 102 through the baffle 2. When the crystals in the settling zone 102 accumulate to a certain height, the valve of the discharge port 104 is opened, and most of the crystals located in the settling zone 102 are discharged from the device under gravity. However, the crystals adhering to the baffle 2, the slow-flow baffle ring 4, and the inner wall of the tank 1 need to be manually handled by opening the tank 1. During the discharge process, a vibration device or a screw conveyor can be used to assist in ensuring smooth discharge of the crystals and avoiding blockage.

[0048] In some examples, a jacket 5 is provided on the outer wall of the tank 1 in the circumferential direction. A placement space 501 is formed between the inner wall of the jacket 5 and the outer wall of the tank 1. A heat exchange coil 6 is installed in the placement space 501. The heat exchange coil 6 has an inlet 601 and an outlet 602. The inlet 601 is located at the bottom of the side wall of the tank 1, and the outlet 602 is located at the top of the side wall of the tank 1.

[0049] For example, such as Figure 4 As shown, cold water enters the heat exchange coil 6 through inlet 601. During its flow within the coil, the cold water exchanges heat with the sodium nitrate solution inside the tank 1 through the tank wall. After absorbing heat from the solution, the cold water's temperature rises, and hot water flows out through outlet 602. Throughout the process, a temperature sensor monitors the water temperature at inlet 601 and outlet 602 in real time, and the flow control valve automatically adjusts the cold water flow rate according to the set temperature range. When the solution temperature is too high, the cold water flow rate is increased; when the temperature approaches the set crystallization temperature, the cold water flow rate is appropriately reduced to maintain a stable decrease in solution temperature and promote the formation of sodium nitrate crystals.

[0050] In some examples, the heat exchange coil 6 is a vertical heat exchange coil, that is, the heat exchange coil 6 is arranged in the vertical direction of the tank 1 within the placement space 501.

[0051] For example, such as Figure 5As shown, cold water enters the vertical heat exchange coil through inlet 601. Due to gravity and water pressure, the cold water flows along the serpentine coil and then exits through outlet 602. During the flow, the cold water undergoes thorough heat exchange with the tank wall 1, carrying away the heat from the sodium nitrate solution. Throughout the heat exchange process, the upward velocity of the cold water within the heat exchange coil 6 is controlled by adjusting the flow rate and pressure of the cold water through inlet 601 to achieve the optimal heat exchange effect.

[0052] In some examples, the flow-retardant baffle 4 includes an annular outer ring body 401, with through holes 4011 spaced apart on the sidewall of the outer ring body 401; it has a plurality of baffles 402, one end of each baffle 402 is located in a through hole 4011, and the other end of each baffle 402 extends to the axis of the outer ring body 401, with a flow-reducing channel 4021 formed between adjacent baffles 402.

[0053] For example, such as Figure 6 As shown, the outer ring 401 is made of the same material as the tank 1, possessing good corrosion resistance and strength. The thickness of the outer ring 401 must meet the required solution pressure. The baffle 402 is made of high-strength metal with a smooth surface to reduce resistance to the flow of solution and crystals.

[0054] The sodium nitrate solution flows downwards under the strong stirring of the stirring rod 3. When the solution comes into contact with the outer ring 401 of the flow-retarding baffle 4, part of the solution enters the baffle channel 4021 through the through hole 4011. Inside the baffle channel 4021, the solution is blocked and guided by the baffles 402, and the flow direction changes continuously, causing the flow rate to slow down sharply. During this process, sodium nitrate crystals are more likely to aggregate and grow. Larger crystals are intercepted by the baffles 402 and remain in the baffle channel 4021. As the crystals accumulate, they can be collected periodically by manual cleaning or an automatic cleaning device. Smaller crystals or solution continue to enter the settling zone 102 through the baffle 2. This structure of the flow-retarding baffle 4 further enhances the effect of slowing down the flow rate of the sodium nitrate solution, and the setting of the baffle channel 4021 more effectively intercepts sodium nitrate crystals, improves the crystal collection rate, reduces the situation where crystals are washed away by the solution, and ensures the quality of the product.

[0055] In some examples, the baffle 402 is any one of L-shape, C-shape, and Z-shape.

[0056] For example, such as Figure 5As shown, assuming the baffle 402 is L-shaped, the short side length of the L-shaped is generally 1 / 3 - 1 / 2 of the diameter of the through hole 4011, and the long side length is adjusted according to the radius of the outer ring body 401 to ensure that the baffle 402 can extend to the vicinity of the axis of the outer ring body 401. The thickness of the baffle 402 is moderate, which can ensure its strength and will not cause too much obstruction to the solution flow. The connection between the baffle 402 and the outer ring body 401 adopts welding or bolt connection, which ensures firm connection and will not fall off under long-term solution scouring.

[0057] When the sodium nitrate solution enters the baffle passage 4021, it first encounters one side of the L-shaped baffle 402, and the solution is forced to change direction and flow in the direction of the other side. In the process of flowing, the solution encounters the blockage of the L-shaped baffle 402 again and needs to change direction again. In this process, the flow rate of the solution is greatly reduced, and the shape of the L-shaped baffle 402 makes it have a better interception effect on sodium nitrate crystals. The crystals are more likely to adhere to the baffle 402 or remain in the baffle passage 4021 when they collide with the baffle 402, while smaller crystals or solution continue to pass through the partition 2 into the settling zone 102. Baffles 402 of different shapes can more effectively change the flow path of the solution, further slow down the flow rate of the solution, and better intercept sodium nitrate crystals, improving the performance of the slow-flow blocking ring 4 and positively affecting the improvement of product purity and crystal morphology.

[0058] In some examples, the sodium nitrate continuous crystallization device further comprises a driver 7 arranged outside the top of the tank body 1, and the power output end of the driver 7 is in transmission connection with the stirring rod 3. The driver 7 usually adopts an energy-efficient motor, and the power of the motor is selected according to parameters such as the length, diameter of the stirring rod 3 and the viscosity of the solution to ensure that enough power can be provided to drive the stirring rod 3 to rotate. The driver 7 and the stirring rod 3 are connected through a coupling, and the coupling adopts an elastic coupling which can effectively transmit torque and compensate for the slight deviation of the stirring rod 3 during rotation. A rotation speed sensor is installed on the output shaft of the driver 7 to monitor the rotation speed of the stirring rod 3 in real time and adjust it through the control system.

[0059] For example, as shown in Figure 3 The driver 7 is started to drive the stirring rod 3 to rotate in the crystallization zone 101 through the transmission connection, stirs the sodium nitrate solution, and makes it fully mix with the cooled brine to promote the formation of sodium nitrate crystals. The driver 7 provides power for the stirring rod 3 to ensure the stability and continuity of stirring, so that the sodium nitrate solution can be more uniformly mixed with the cooled brine, improving the crystallization efficiency and avoiding the problem of poor crystallization effect caused by local uneven mixing of the solution.

[0060] In some examples, the top of the tank body 1 has an observation window 8 for observing the inside of the tank body 1. The observation window 8 is made of high-strength, corrosion-resistant transparent material, such as tempered glass or transparent polytetrafluoroethylene material. The observation window 8 is generally square or circular, which can provide sufficient observation field of view. The observation window 8 is installed at a conspicuous position on the top of the tank body 1, and is sealed around by a sealing strip to prevent solution leakage and foreign matter from entering. A lighting device is provided outside the observation window 8, which can illuminate the solution in the tank body 1 in low light conditions, facilitating the observation of the operator.

[0061] For example, as shown in Figure 7 , the operator can observe the crystallization of the sodium nitrate solution in the tank body 1 through the observation window 8, such as the state of the solution, the formation and growth of the crystals, etc., so as to timely adjust the process parameters, such as the amount of cooling brine, the stirring speed, etc. The setting of the observation window 8 facilitates the real-time monitoring of the crystallization process by the operator, which helps to timely find problems and make adjustments, ensuring the smooth progress of the crystallization process and improving the product quality and the stability of the production.

[0062] In some examples, the bottom of the tank body 1 is provided with a discharge valve 9, which is in communication with the discharge port 104. The discharge valve 9 is made of corrosion-resistant ball valve or gate valve, and the diameter of the valve matches the pipe diameter of the discharge port 104, so as to ensure the smooth discharge of the crystals.

[0063] For example, as shown in Figure 3 , when the sodium nitrate crystals in the settling zone 102 accumulate to a certain amount, reach the set liquid level height or pass the set time, the control system issues an instruction to open the discharge valve 9. The sodium nitrate crystals are discharged from the discharge port 104 under the action of gravity and transported to the collection device or subsequent processing equipment through the connected conveying pipeline. During the discharge process, if the crystallization is blocked, the valve can be manually operated or the auxiliary dredging device can be started for cleaning. When the crystals do not need to be discharged, the control system closes the discharge valve 9 to prevent solution or crystal leakage. The setting of the discharge valve 9 can conveniently control the discharge of the sodium nitrate crystals, ensure the safety and stability of the device operation, avoid unnecessary leakage and waste, and also facilitate the collection and subsequent treatment of the crystalline product.

[0064] In some examples, the paddle 301 of the stirring rod 3 is a rectangular frame. The material of the frame is the same as that of the stirring rod 3, which is a corrosion-resistant alloy material. The frame can be provided with reinforcing ribs inside as needed to improve the strength of the paddle 301. The connection between the paddle 301 and the stirring rod 3 is by welding or bolt connection, which ensures firm connection and prevents falling off during high-speed stirring.

[0065] For example, as shown in Figure 6As shown, when the driver 7 drives the stirring rod 3 to rotate, the rectangular frame paddle 301 rotates in the sodium nitrate solution, stirs the solution, makes the solution flow, promotes the mixing of the sodium nitrate solution and the cooled brine, and accelerates the formation of sodium nitrate crystals. The rectangular frame paddle 301 has a relatively simple structure and good stirring effect on the solution during stirring, can make the solution more uniformly mixed, improve the crystallization efficiency, and is relatively convenient to manufacture and maintain, thereby reducing the cost of the equipment.

[0066] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, not to limit the present disclosure. Although the present disclosure has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present disclosure can be modified or replaced equivalently without departing from the spirit and scope of the technical solutions of the present disclosure, which should be covered in the scope of the claims of the present disclosure.

Claims

1. A continuous crystallization apparatus for sodium nitrate, for adding cooled brine to cause sodium nitrate solution to precipitate sodium nitrate crystals, characterized by, The application relates to a crystallization tank for sodium nitrate, which comprises the following components: a tank body (1); a partition plate (2) arranged on the inner bottom of the tank body (1), the partition plate (2) divides the tank body (1) into a crystallization area (101) and a settling area (102), the partition plate (2) is provided with a through groove (201), the crystallization area (101) and the settling area (102) are communicated through the through groove (201), the crystallization area (101) is used for storing sodium nitrate solution to be crystallized or being crystallized, and the settling area (102) is used for containing sodium nitrate crystals; a stirring rod (3) rotatably arranged in the crystallization area (101); a plurality of slow-flow blocking rings (4) which are arranged on the partition plate (2) at intervals and are located below the stirring rod (3), and adjacent two slow-flow blocking rings (4) are arranged in a staggered mode so as to slow down the flow speed of sodium nitrate solution passing through the slow-flow blocking rings (4) and intercept sodium nitrate crystals passing through the slow-flow blocking rings (4).

2. The apparatus for continuous crystallization of sodium nitrate according to claim 1, characterized in that, A plurality of through holes (4011) are formed in the side wall of each slow-flow blocking ring (4), and the through holes (4011) of adjacent two slow-flow blocking rings (4) are arranged in a staggered mode so as to slow down the flow speed of sodium nitrate solution passing through the slow-flow blocking rings (4) and intercept sodium nitrate crystals passing through the slow-flow blocking rings (4).

3. The apparatus for continuous crystallization of sodium nitrate according to claim 1, characterized in that, The tank body (1) is provided with a feeding port (103) at the top, the feeding port (103) is communicated with the crystallization area (101), the feeding port (103) is used for feeding cooling brine and sodium nitrate solution, the tank body (1) is provided with a discharging port (104) at the bottom, the partition plate (2) is located above the discharging port (104), the discharging port (104) is communicated with the settling area (102), and the discharging port (104) is used for discharging sodium nitrate crystals.

4. The apparatus for continuous crystallization of sodium nitrate according to claim 1, characterized in that, A jacket (5) is arranged on the outer wall of the tank body (1) in a circumferential direction, a placing space (501) is formed between the inner wall of the jacket (5) and the outer wall of the tank body (1), a heat exchange coil (6) is arranged in the placing space (501), the heat exchange coil (6) is provided with a water inlet (601) and a water outlet (602), the water inlet (601) is located at the bottom of the side wall of the tank body (1), the water outlet (602) is located at the top of the side wall of the tank body (1), and cold water is fed into the heat exchange coil (6).

5. The apparatus for continuous crystallization of sodium nitrate according to claim 4, characterized in that, The heat exchange coil (6) is a vertical heat exchange coil.

6. The apparatus for continuous crystallization of sodium nitrate according to claim 2, characterized in that, The slow-flow blocking ring (4) comprises: an outer ring body (401) in the shape of a ring, and the through holes (4011) are arranged on the side wall of the outer ring body (401) at intervals. A plurality of baffle plates (402) are arranged, one end of each baffle plate (402) is located in one through hole (4011), the other end of each baffle plate (402) extends to the shaft center of the outer ring body (401), adjacent baffle plates (402) form baffle channels (4021), the baffle channels (4021) are used for slowing down the flow rate of the sodium nitrate solution passing through the baffle channels (4021), and the baffle channels (4021) are also used for intercepting sodium nitrate crystals passing through the baffle channels (4021).

7. The apparatus for continuous crystallization of sodium nitrate according to claim 6, characterized in that, The baffle plate (402) is in any one of L shape, C shape and Z shape.

8. The apparatus for continuous crystallization of sodium nitrate according to claim 1, characterized in that, The sodium nitrate continuous crystallization device further comprises: A driver (7) is arranged outside the top of the tank body (1), a power output end of the driver (7) is in transmission connection with the stirring rod (3), and the driver (7) is used for driving the stirring rod (3) to rotate.

9. The apparatus for continuous crystallization of sodium nitrate according to claim 1, characterized in that, The top of the tank body (1) is provided with an observation window (8) for observing the inside of the tank body (1).

10. The apparatus for continuous crystallization of sodium nitrate according to claim 3, characterized in that, The bottom of the tank body (1) is provided with a discharge valve (9) in communication with the discharge port (104).

Images