Ion exchange device for producing potassium nitrate

Abstract

The invention provides an ion exchange device for producing potassium nitrate, which comprises a frame body, an upper seal head, a lower seal head and a tank body, an ion exchange medium is arranged in the tank body and is used for producing potassium nitrate through ion exchange, and the frame body is provided with an accommodating space for supporting the tank body; the tank body is a vertical tank, the upper portion and the lower portion of the tank body are provided with an upper sealing head and a lower sealing head respectively, the upper sealing head is provided with a first feeding port and a first discharging port, the lower sealing head is provided with a second feeding port and a second discharging port, the side face of the tank body is provided with an overflow port, the overflow port is additionally provided with a T-shaped wire winding pipe, a lining pipe is additionally arranged in the T-shaped wire winding pipe, and through holes are distributed in the circumferential direction of the lining pipe. And the flow area of the through hole is 2.5-4.5 times of the flow area of the overflow pipe. The T-shaped wire winding pipe is additionally arranged through the overflow port, the structure of the T-shaped wire winding pipe is improved, the lining pipe is additionally arranged in the wire winding pipe, the through hole is formed in the wire winding pipe, and compared with the mode that only the T-shaped wire winding pipe is additionally arranged, the technical effect that the resin loss is reduced while it is guaranteed that liquid is discharged thoroughly can be achieved.

Description

Technical Field

[0001] This invention relates to the field of ion exchange device technology, specifically an ion exchange device for producing potassium nitrate. Background Technology

[0002] Potassium nitrate, as an important chemical raw material, has wide applications in agriculture, chemical industry, medicine, and many other fields. Ion exchange is a commonly used method in the production of potassium nitrate. The main equipment for potassium nitrate production via ion exchange includes a reaction tank, a high-level tank, an ion exchanger, an evaporator, and a centrifuge. The suitability of the ion exchange equipment directly affects many crucial process parameters in potassium nitrate production.

[0003] In the prior art, CN104353505A provides a large-scale ion exchange device that features uniform water distribution, minimal resin loss, and low resistance during backwashing. The device includes a cylinder, an upper water distribution device, and a lower water distribution device. The cylinder is composed of a column, a top cover, and a bottom cover. An upper feed inlet and an exhaust outlet are provided on the top cover, and a lower feed inlet is provided on the bottom cover. Inside the cylinder, the upper water distribution device is located near the top cover, and the lower water distribution device is located near the bottom cover. A manhole and a recovery port are provided on the column. The upper water distribution device is a side-mounted upper water distributor, and the lower water distribution device is a water cap type water distributor. Ion exchange resin is placed in the cylinder, and when the cylinder is in a vertical position, the height of the ion exchange resin is below the recovery port.

[0004] CN1064228A provides an ion exchange device for producing inorganic salts such as potassium nitrate and potassium carbonate. The exchange column body has a rotating shaft, one end of which is fitted with a flange that matches a reducer gear. The cavity of the exchange column body is filled with 732 cation exchange resin. Both ends of the exchange column body are equipped with valve joints, allowing the exchange column to rotate 180° along the shaft. This ion exchange column not only solves environmental pollution problems but also significantly increases the concentration of liquid ammonium chloride and shortens the production cycle by one-fifth, making it an ideal device for the production of potassium nitrate and potassium carbonate ion exchange.

[0005] CN208022749U provides an ion exchange device, including a primary heating pool, a dissolving pool, a warm air blower, and a secondary heating pool. A potassium nitrate detector is fixedly connected to the upper outer surface of the primary heating pool, and a primary conduit is provided on one side of the primary heating pool. A primary cooling pool is located on the outer surface of one end of the primary conduit, and a three-phase motor is fixedly connected to the upper outer surface of the primary cooling pool. Second and third conduits are provided on one side of the dissolving pool, and a secondary cooling pool is located on the outer surface of one end of the secondary conduit. This ion exchange device, equipped with a three-phase motor, a baffle plate, and a grid plate, can separate solidified potassium nitrate molten salt from the wall of the primary cooling pool, automatically add raw materials according to the liquid level in the secondary heating pool, and screen raw materials in a crusher, offering better application prospects.

[0006] However, existing ion exchange devices for potassium nitrate production have many problems. Some devices are complex in structure and cumbersome to operate, hindering efficient operation and maintenance during production. Cleaning the ion exchange medium often requires a long time, typically 6-8 hours, and consumes a large amount of water. Furthermore, the regeneration of the ion exchange medium is incomplete, requiring frequent replacement and reducing production efficiency. In addition, overflow of the exchange medium and damage to the support device are prone to occur during operation, which not only affects product quality and yield but may also pose safety hazards and increase production costs. Therefore, developing an ion exchange device that is simple in structure, easy to operate, efficient, fast, safe, and reliable, capable of efficiently producing molten salt-grade potassium nitrate while solving all the aforementioned problems, is of significant practical importance. Summary of the Invention

[0007] To achieve the above objectives, the technical solution of the present invention is as follows: An ion exchange device for producing potassium nitrate includes a frame, an upper head, a lower head, and a tank. An ion exchange medium is placed inside the tank for ion exchange to produce potassium nitrate. The frame has a space to support the tank. The tank is vertical, with an upper head and a lower head at the top and bottom, respectively. The upper head has a first inlet and a first outlet, and the lower head has a second inlet and a second outlet. An overflow port is located on the side of the tank. A T-shaped wire-wound tube is installed on the overflow port, with a liner inside the T-shaped wire-wound tube. The liner has circumferentially distributed through-holes, the flow area of ​​which is 2.5-4.5 times the flow area of ​​the overflow tube.

[0008] As an improvement, the gap between the T-shaped wire-wound tubes is 0.35-0.55mm.

[0009] As an improvement, the lower end cap is provided with a backwash water inlet and a liquid outlet, wherein the second feed inlet and the second discharge outlet are the backwash water inlet and the liquid outlet, respectively.

[0010] As an improvement, the liquid outlet adopts a T-shaped wire-wound tube structure with a wire-wound gap of 0.25-0.45mm.

[0011] As an improvement, the lower part of the ion exchange device is equipped with three layers of backwash water and compressed air devices, and the operating power of each layer can be controlled independently.

[0012] As an improvement, along the direction from the inside of the tank outwards, the area of ​​a single through hole becomes larger and the distribution density of the through holes becomes smaller and smaller.

[0013] As an improvement, along the direction from the inside of the tank outwards, the area of ​​a single through hole increases by a certain margin, while the distribution density of the through holes decreases by a certain margin.

[0014] As an improvement, the first discharge port is a gas outlet for acid vapor volatilization.

[0015] As an improvement, the gap between the T-shaped wire-wound tubes is 0.35-0.55mm.

[0016] As an improvement, an upper water distribution device is installed inside the tank.

[0017] Compared with the prior art, the present invention has the following advantages: The design of T-shaped wire-wound tubes with varying gaps and liner tubes with through holes ensures that resin precipitates during backwashing while intercepting normally functioning resin, reducing resin loss during backwashing. The overflow port is located above the resin level, ensuring sufficient expansion height for the resin during backwashing and guaranteeing thorough backwashing. Separate backwash water inlets and outlets, along with a wire-wound tube at the outlet, ensure complete effluent discharge and minimize resin loss. A backwash water and compressed air unit is installed at the bottom of the ion exchange device for water-air mixed backwashing, ensuring resin loosening, reducing water consumption, and rearranging the resin exchange layer, thus improving regeneration efficiency. In summary, the ion exchange device described in this invention has a relatively simple structure, is easy to operate, and facilitates efficient operation and maintenance during production. Regarding the cleaning of the ion exchange medium, the backwash water and compressed air unit provides water-air mixed backwashing, resulting in significant cleaning effects. The operating power and area of ​​the backwash water and compressed air unit can be selected based on the concentration detection device, resulting in shorter processing time and lower water consumption. The above technologies can effectively solve the problems of incomplete regeneration and frequent replacement of ion exchange media, while also solving the problems of overflow of exchange media and damage to the support device, thereby improving product quality and yield, reducing production costs, and increasing production efficiency. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of an ion exchange device; Figure 2 This is a schematic diagram of a T-shaped wire winding structure; Figure 3This is a schematic diagram of the liner and its circumferential perforation structure. Figure 4 This is a schematic diagram of the backwash water and compressed air device. Detailed Implementation

[0019] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0020] Figure 1 An ion exchange apparatus for the production of potassium nitrate has been disclosed. For example... Figure 1 As shown, an ion exchange device for producing potassium nitrate includes a frame 1, an upper head 6, a lower head 2, and a tank 4. An ion exchange medium 3 is placed inside the tank for ion exchange to produce potassium nitrate. The frame 1 has a space to support the tank 4. The tank 4 is a vertical tank, with the upper head 6 and lower head 2 located at the top and bottom, respectively. The upper head 6 has a first inlet 9 and a first outlet 10, while the lower head 2 has a second inlet 15 and a second outlet 14. An overflow port 12 is located on the side of the tank 4, and a T-shaped wire-wound tube 16 is installed inside the overflow port. A liner 17 is placed inside the T-shaped wire-wound tube, and through holes 18 are distributed circumferentially on the liner. As an improvement, the flow area of ​​the through holes 18 is 2.5-4.5 times the flow area of ​​the overflow pipe. That is, the total area of ​​the liner openings is 2.5-4.5 times the cross-sectional area of ​​the overflow pipe.

[0021] The first discharge port 8 is a gas outlet used for acid vapor volatilization.

[0022] When liquid flows out through the overflow port, it first flows through the wire-wound tube, then through the through-hole on the liner, and finally exits through the overflow port. This invention, by adding a T-shaped wire-wound tube 16 to the overflow port 12 and improving the structure of the T-shaped wire-wound tube, by adding a liner 17 inside the wire-wound tube and providing through-holes 18, achieves the technical effect of ensuring complete liquid discharge while reducing resin loss, compared to simply adding the T-shaped wire-wound tube 16. The total area of ​​the through-holes 18 is 2.5-4.5 times the flow area of ​​the overflow pipe, ensuring sufficient overflow without increasing the pressure inside the tank.

[0023] As an improvement, the gap in the T-shaped winding tube is 0.35-0.55mm. This gap is larger than the resin particle size, intercepting intact resin while ensuring the exudation of broken resin.

[0024] As an improvement, the lower end cap is provided with a backwash water inlet and a liquid outlet, wherein the second feed inlet and the second discharge outlet are the backwash water inlet and the liquid outlet, respectively.

[0025] As an improvement, the outlet adopts a T-shaped wire-wound tube structure with a wire-wound gap of 0.25-0.45mm. Further improvements include an inner liner with circumferentially distributed through holes. This achieves the technical effect of ensuring complete liquid discharge while reducing resin loss.

[0026] As an improvement, the lower part of the ion exchange device is equipped with a backwash water and compressed air device, preferably such as... Figure 1 As shown, multiple layers (preferably three layers) of backwash water and compressed air devices are arranged along the vertical direction. Preferably, the operating power of the backwash water and compressed air devices in each layer can be controlled independently.

[0027] As an improvement, the operating power of the backwash water and compressed air devices gradually decreases from bottom to top. By increasing the power of the backwash water and compressed air in the lower part, the water-air mixing backwashing effect in the lower part can be enhanced, ensuring that the lower resin is looser during the backwashing process and the upper resin flows downward, thus forming a circulation-like mechanism. This allows the resin exchange layer to rearrange more quickly, further reducing water consumption and improving the regeneration effect.

[0028] As an improvement, from bottom to top, the rate of decrease in the operating power of the backwash water and compressed air devices gradually increases with each layer. This configuration allows the resin exchange layers to rearrange more quickly, further reducing water consumption and improving regeneration efficiency. Through this setup, effective regeneration can be achieved with the same energy consumption.

[0029] As an improvement, along the direction from the inside of the tank outwards, the area of ​​a single through-hole increases, while the distribution density of the through-holes decreases, such as... Figure 3 As shown in the diagram, this configuration ensures a uniform distribution of the flow area across the entire length of the through-holes, preventing excessive localized flow resistance. Furthermore, the distribution of through-hole area and density, particularly the smaller area of ​​the inner through-holes, effectively prevents resin outflow. Therefore, this configuration ensures that resin does not easily flow out and that the flow resistance remains essentially constant.

[0030] As an improvement, the area of ​​each individual through-hole increases progressively from the inside of the tank outwards, while the density of the through-holes decreases progressively. This design further ensures that the resin does not easily flow out and also maintains a relatively constant flow resistance.

[0031] As an improvement, the ion exchange device is equipped with a material level detection device 8 and a feed inlet 5. The material level detection device detects the material level, and the feed inlet replenishes the resin. The amount of resin is detected by the material level detection device 8, and if insufficient, it is added through the feed inlet 5 to ensure that there is enough resin in the device to complete the reaction.

[0032] As an improvement, an overflow port 12 and a concentration detection device 11 are provided on the side of the tank. Backwash water is fed into the tank 4 through the inlet 15, passing through the backwash water and compressed air device 13. After the reaction, it flows out through the overflow port 12 and is detected by the concentration detection device 11. -Based on the monitoring results, the next backwash area and backwash power are determined, and then the waste is collected and reused from the overflow outlet.

[0033] The tank is equipped with an upper water distribution device 7.

[0034] As an improvement, the lower part of the ion exchange device is equipped with a backwash water and compressed air device, and multiple independent zones are arranged along the left and right directions. As an improvement, each zone is equipped with a backwash water and compressed air device, preferably as follows: Figure 4 As shown. The backwash water and compressed air devices for each zone can be controlled independently. Each zone is equipped with an independent concentration detection device 11 and an overflow port 12. The concentration of Cl detected by the concentration detection device... - The concentration is automatically controlled to regulate the operating power of the backwash water and compressed air devices in each zone.

[0035] As an improvement, the liquids discharged from multiple overflow ports 12 are mixed together and discharged from the main overflow port 12.

[0036] The controller collects data from multiple regions Cl - Concentration data were collected, and the corresponding weighted average was calculated. When Cl in a certain region was detected... - If the concentration is higher than the average, the power of the backwash water and compressed air devices in that area will be increased. When the Cl concentration in a certain area is detected... - If the concentration is below the average, the power of the backwash water and compressed air devices in that area will be reduced. This setup ensures that the Cl concentration in multiple areas is maintained. - Maintain a basic balance in concentration to avoid excessive local deviations that could lead to uneven distribution after mixing.

[0037] The internal ion exchange medium 3 is cation exchange resin, and its height does not exceed the overflow port to ensure the expansion height of the resin during backwashing.

[0038] The process of producing potassium nitrate using an ion exchange device is as follows: During potassium nitrate production, the valve at the inlet 15 is opened, and the potassium chloride solution is fed into the tank 4 through the inlet 15, backwash water, and compressed air device 13. Inside the tank 4, the material undergoes a full ion exchange reaction with the cation exchange resin. The cation exchange resin adsorbs potassium chloride. + After the reaction, the first backwash uses the effluent from the forward wash, and subsequent backwashes use deionized water to remove Cl. - The concentration detection device displays the Cl concentration in each region. - To determine the concentration, control the operating area and power of the backwash water and compressed air device, determine the number of backwashes, and ensure thorough backwashing. Backwash water enters the tank 4 through the inlet 15, passes through the backwash water and compressed air device 13, and then flows out through the overflow port 12 after reaction. The concentration is detected by the concentration detection device 11. -Each area is equipped with an independent concentration detection device 11 and an overflow port 12. The Cl concentration is detected by the concentration detection device. - The concentration is automatically controlled to regulate the operating power of the backwash water and compressed air devices in each zone, and then collected and reused through the main overflow port 12. The overflow port 12 is equipped with a T-shaped wire winding tube, with a liner inside. The liner has circumferentially distributed through-holes, the number of which is 2.5-4.5 times the flow area of ​​the overflow pipe. The gaps in the T-shaped wire winding tube are selected based on the resin particle size, and in principle, should not exceed the resin particle size, ensuring that resin is broken up and precipitated during backwashing while intercepting normally functioning resin. The resin quantity is detected by the material level detection device 8, and if insufficient, it is added through the feed port 5 to ensure sufficient resin in the device to complete the reaction. A three-layer backwash water and compressed air device 13 is installed at the bottom for water-air mixing backwashing, ensuring resin loosening, reducing water consumption, and rearranging the resin exchange layer during backwashing, thus improving the regeneration effect. Further demineralized water is used for forward washing to remove Cl. - Ensure Cl again - Thorough removal is achieved. The prewash water is fed into the tank 4 through the inlet 9 and the upper water distribution device 7. After the reaction, it flows out through the outlet 14 and is used for the initial backwash, reducing water consumption. The outlet 14 and inlet 15 are separately configured, with a wire-wound tube at the outlet to ensure thorough effluent discharge while minimizing resin loss. The valve at the inlet 9 is opened, allowing the nitric acid solution to be fed into the tank 4 through the inlet 9 and the upper water distribution device 7. The material undergoes an ion exchange reaction with the cation exchange resin in the tank 4. After the cation exchange resin adsorbs H+, potassium nitrate solution is discharged through the outlet 14, which is then further processed to obtain molten salt-grade potassium nitrate. Demineralized water is fed into the tank 4 through the inlet 9 and the upper water distribution device 7 to maintain sufficient moisture in the cation exchange resin.

[0039] The specific steps are as follows: Step 1) Potassium inlet: Open the valve at the inlet 15 and send the potassium chloride solution into the tank 4 through the inlet 15, backwash water and compressed air device 13. The material fully undergoes ion exchange reaction with the cation exchange resin in the tank 4.

[0040] Step 2) Backwash: Backwash water (the initial backwash uses the outflow from the forward wash, and subsequent backwashes use demineralized water) is fed into tank 4 through inlet 15, passing through backwash water and compressed air device 13. After reaction, it flows out through overflow port 12 and is detected by concentration detection device 11. - Each area is equipped with an independent concentration detection device 11, which detects the Cl concentration. - The concentration is automatically controlled to regulate the operating power of the backwash water and compressed air devices in each zone, and then collected and reused by the main overflow port 12.

[0041] Step 3) Forward Wash: The demineralized water is fed into the tank 4 through the inlet 9 and the upper water distribution device 7. After the reaction, it flows out through the outlet 14, ensuring that Cl is present again. - Thorough removal; the water from the forward rinse is used for the initial backwash, reducing water consumption.

[0042] Step 4) Acid Inlet: Open the valve at inlet 9 to feed the nitric acid solution into tank 4 through inlet 9 and the upper water distribution device 7. The material undergoes an ion exchange reaction with the cation exchange resin in tank 4. After the cation exchange resin adsorbs H+, the potassium nitrate solution is discharged through outlet 14. Subsequent processing yields molten salt-grade potassium nitrate.

[0043] Step 5) Water washing: Desalinated water is sent into the tank 4 through the inlet 9 and the upper water distribution device 7 to keep the cation exchange resin full of water.

[0044] While the present invention has been disclosed above with reference to preferred embodiments, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. An ion exchange device for producing potassium nitrate, comprising a frame, an upper head, a lower head, and a tank, wherein an ion exchange medium is disposed inside the tank for producing potassium nitrate by ion exchange, and the frame has an accommodating space for supporting the tank; the tank is a vertical tank, with an upper head and a lower head respectively disposed at the top and bottom, the upper head having a first inlet and a first outlet, and the lower head having a second inlet and a second outlet, and an overflow port on the side of the tank, the overflow port being fitted with a T-shaped wire-wound tube, the T-shaped wire-wound tube being fitted with a liner, the liner having circumferentially distributed through holes, the flow area of ​​the through holes being 2.5-4.5 times the flow area of ​​the overflow tube.

2. The ion exchange device as described in claim 1, characterized in that, The gap between the T-shaped wire-wound tubes is 0.35-0.55mm.

3. The ion exchange device as described in claim 1, characterized in that, The lower end cap is equipped with a backwash water inlet and a liquid outlet, wherein the second feed inlet and the second discharge outlet are the backwash water inlet and the liquid outlet, respectively.

4. The ion exchange device as described in claim 3, characterized in that, The liquid outlet adopts a T-shaped wire-wound tube structure with a wire-wound gap of 0.25-0.45mm.

5. The ion exchange device as described in claim 4, characterized in that, The lower part of the ion exchange device is equipped with three layers of backwash water and compressed air devices, and the operating power of each layer can be controlled independently.

6. The ion exchange device as described in claim 1, characterized in that, Along the direction from the inside of the tank outwards, the area of ​​a single through hole increases, while the distribution density of through holes decreases.

7. The ion exchange apparatus as described in claim 7, characterized in that, Along the direction from the inside of the tank outwards, the area of ​​a single through hole increases at an increasing rate, while the distribution density of the through holes decreases at an decreasing rate.

8. The ion exchange device as described in claim 1, characterized in that, The first discharge port is the gas outlet, used for acid vapor volatilization.

9. The ion exchange device as described in claim 1, characterized in that, The gap between the T-shaped wire-wound tubes is 0.35-0.55mm.

10. The ion exchange device as claimed in claim 1, characterized in that, The tank is equipped with an upper water distribution device.

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