A process and device for concentrating and purifying potassium hydroxide

Abstract

The application relates to the technical field of concentration and purification in chemical production, and discloses a potassium hydroxide concentration and refining process and device, which comprises a shell, the inside of the shell is provided with a concentration assembly for concentrating multi-stage clarified solutions, and the top end of the shell is provided with a water inlet pipe in communication with an inner cavity space. The equipment is matched by various parts in the concentration assembly, firstly utilizes the liquid level difference between the water inlet pipe and the overflow port to form a gravity water supply principle, makes the solution flow through a first-stage middle cavity in sequence to realize primary slow flow sedimentation, secondary slow flow collection under the guidance of a water guide cone cylinder, and spiral slow flow separation matched by an inner cone cylinder and a spiral strip, finally completes multi-stage clarification and refining of the solution, realizes the purpose of removing different particle size impurities in the solution, utilizes the mutual cooperation of slow flow and gravity sedimentation, can targetedly separate different particle size impurities, significantly improves the refining purity of the potassium hydroxide solution, and avoids the problem of incomplete impurity removal caused by a single clarification structure.

Description

Technical Field

[0001] This invention relates to the field of chemical production concentration and purification technology, and in particular to a potassium hydroxide concentration and refining process and apparatus. Background Technology

[0002] Potassium hydroxide (chemical formula KOH, commonly known as caustic potassium) is an important inorganic alkali chemical product. It is a white flaky or granular solid that is hygroscopic, soluble in water, and its aqueous solution is strongly alkaline. It is widely used in the manufacture of high-grade soaps, synthetic dyes, and pharmaceutical intermediates. It can also be used as an etchant for electronic chips and a raw material for the preparation of potassium salts, supporting the development of the chemical and electronics industries.

[0003] The concentration and refining of potassium hydroxide is a key step in its industrialization. It requires the purification and concentration of low-concentration crude liquid: First, the crude raw material (such as potassium chloride) is dissolved in a salt pond, while large particulate impurities such as mud and sand are removed by sedimentation. Then, the suspended impurities are further separated by a clarification device, such as a Dorr tank, to obtain a clarified liquid. The clarified liquid then enters a reaction tank, where reagents such as calcium chloride are added to react with soluble impurities such as sulfate to form a precipitate. The precipitate is then retained by a membrane filter to obtain a high-purity clear liquid. Finally, the water is evaporated by a multi-effect or MVR evaporator to increase the concentration. The solid product needs to be concentrated to a molten state. With the help of an automatic control system, the parameters are controlled to ensure stable production and the production of qualified products.

[0004] Regarding the aforementioned and existing potassium hydroxide solution clarification and concentration equipment, the inventors believe that the following defects often exist: the flow channel of the equipment lacks targeted slowing and guiding optimization design, there is no suitable structure to accurately control the solution flow rate, and it is unable to guide the formation of a stable separation environment. This may lead to insufficient settling of large particles of impurities, difficulty in separating fine suspended impurities, and easy re-suspension of settled precipitates due to flow rate disturbance, which greatly reduces the clarification effect. Summary of the Invention

[0005] The technical problem to be solved by this invention is that the flow channel of existing potassium hydroxide solution clarification and concentration equipment is difficult to control precisely to achieve efficient separation of impurities, and is prone to causing secondary suspension of precipitates. To address this, we propose a potassium hydroxide concentration and refining process and apparatus.

[0006] To achieve the above objectives, this application adopts the following technical solution: a potassium hydroxide concentration and refining device, including a shell, a concentration component for concentrating multi-stage clarified solutions is provided inside the shell, a water inlet pipe communicating with the inner cavity space is provided at the top of the shell, and a waste discharge device is provided at the bottom of the shell. The concentration assembly includes an upper cone fixedly mounted to the inner wall of the outer shell via a bracket. A lower cone is movably inserted into the bottom axis of the upper cone. A fixed base is fixedly mounted to the bottom of the inner wall of the outer shell. A circular through hole for impurities to sink through is opened in the center of the fixed base. An inner cone is fixed to the center of the upper surface of the fixed base, and the outer wall of the top of the inner cone extends and penetrates to the upper surface of the lower cone. The conical curved outer wall of the inner cone and the inner wall of the lower cone together form a three-stage fluid cavity. The outer wall of the inner cone and its position... Multiple sets of spiral strips for slowing down the flow rate of the solution are fixed at equal angles around the axis inside the three-stage fluid cavity. A water-guiding cone is fixed on the upper surface of the fixed base and at the center of the inner cone. The outer wall of the conical curved surface of the water-guiding cone and the inner wall of the inner cone together form a secondary fluid cavity. Multiple sets of primary central cavities are opened vertically along the axis inside the inner cone. The primary central cavities are connected vertically. The top of the primary central cavity is provided with an outlet that communicates with the secondary fluid cavity. The bottom center of the primary central cavity is provided with an inlet that communicates with a circular through hole. The inner wall of the bottom end of the upper cone is connected to a water outlet pipe near the lower cone, and the installation height of the water inlet pipe is higher than the horizontal height of the joint between the upper and lower cones and the water outlet pipe.

[0007] Preferably, the lower surface of the fixed chassis is fixed with multiple sets of hydrophobic sheets arranged in an array around the axis, and the hydrophobic sheets are generally V-shaped.

[0008] Preferably, the openings of the gaps between two adjacent sets of hydrophobic sheets are of different sizes, and the gaps between two adjacent sets of hydrophobic sheets are trapezoidal when viewed from below.

[0009] Preferably, an overflow hole of matching size and shape is provided at the contact position between the top of the inner wall of the lower cone and the inner cone cylinder. Multiple sets of lower perforations for connecting the tertiary fluid cavity and the secondary fluid cavity are arranged in an equal-angle array around the axis on the outer wall of the bottom end of the inner cone cylinder and close to the fixed base. Multiple sets of upper perforations for connecting the tertiary fluid cavity and the overflow hole are arranged in an equal-angle array around the axis on the outer wall of the top end of the inner cone cylinder, and the upper perforations are located inside the tertiary fluid cavity.

[0010] Preferably, the inner cavity shape of each group of primary central cavities is an inverted bucket shape to guide impurities to slide down the sidewall, and the internal volume gradually decreases from top to bottom.

[0011] Preferably, the spiral strip is spiral in shape, and the outer wall of the end of the spiral strip away from the inner cone is in contact with the inner wall of the lower cone.

[0012] Preferably, a chamfered surface is provided at the lower surface edge of the fixed chassis corresponding to the inclined inner wall of the outer shell, and the inclined inner wall of the outer shell and the chamfered surface are parallel. The fixed chassis is fixed to the inclined inner wall of the outer shell by multiple sets of support rods and bolts.

[0013] Preferably, the lower cone is threadedly connected to the upper surface of the fixed base, and the upper surface of the fixed base has a recessed threaded mounting groove at its center that matches the size of the bottom end of the lower cone.

[0014] Preferably, the water outlet pipe is inclined, and one end of the water outlet pipe penetrates and extends to the outer wall of the outer shell. Multiple sets of spiral water guide patterns are fixed around the axis on the inner wall of the bottom end of the outer shell and below the fixed chassis.

[0015] A concentration and refining process for a potassium hydroxide concentration and refining apparatus includes the following steps: S1. Raw material input, primary pretreatment, mixing reaction and large particle sedimentation: The crude potassium hydroxide solution in the front-end brine tank is slowly transported to the inner cavity of the outer shell through the inlet pipe. At the same time, an appropriate amount of calcium chloride solution is added in proportion through the bypass pipe of the inlet pipe. The natural liquid level difference between the inlet pipe and the overflow outlet forms a stable water flow. The crude solution accumulates in the annular cavity formed by the outer shell, the upper cone and the lower cone. When the liquid level reaches the height of the inlet of the primary intermediate cavity, the solution enters multiple primary intermediate cavities in the inner cone under the action of gravity. With the help of the inverted bucket-shaped structure of the primary intermediate cavity, which is larger at the top and smaller at the bottom, and the resistance of gravity, the solution flow rate decreases rapidly from a higher level. Larger particles of mud and sand and unreacted impurities in the crude solution settle due to gravity and slide down the side wall of the chamber to the circular through hole of the fixed base, thus completing the initial clarification.

[0016] S2, Secondary Clarification, Flow Buffering, and Medium Particle Separation: The potassium hydroxide solution after primary clarification enters the secondary fluid chamber through the outlet at the top of the primary intermediate chamber. It flows slowly down the conical outer wall of the guide cone, and the flow rate is further reduced to a lower level. During this process, the residual calcium sulfate flocs in the solution fully aggregate to form medium-sized particles. When the solution flows into the tertiary fluid chamber through the lower perforation, the medium-sized particles are intercepted at the bottom of the secondary fluid chamber due to inertia. They flow back to the primary intermediate chamber with a small amount of waste liquid and are finally discharged through the circular through-hole, completing the secondary clarification and impurity separation.

[0017] S3, Three-stage Refining, Spiral Slow Flow and Refined Liquid Diversion: The solution entering the three-stage fluid chamber flows spirally along the chamber under the guidance of the spiral strips. The design of the spiral strips and the inner wall of the lower cone forms a closed flow channel, which stabilizes the solution flow rate within a low range and avoids excessive stirring that would cause secondary suspension of the sediment. The solution generates a weak centrifugal force in the spiral flow, which throws the remaining fine impurities toward the chamber wall and settles them onto the fixed base. When the solution in the three-stage fluid chamber is full, the solution that meets the refining requirements flows into the overflow hole of the lower cone through the upper perforation at the top of the inner cone and finally enters the inner cavity of the upper cone, completing the three-stage refining.

[0018] S4. Drainage and Waste Discharge, Refined Liquid Output and Centralized Impurity Treatment: When the refined liquid in the upper cone accumulates to the height of the outlet pipe, it flows out naturally along the inclined outlet pipe and is directly transported to the subsequent membrane filter for deep treatment. Impurities deposited below the fixed chassis first achieve slow flow through the trapezoidal gap of the V-shaped hydrophobic plate, and then are guided by the spiral water guide to form a small-range centrifugal flow, which throws the dispersed impurities toward the inner wall of the outer shell and gathers at the input end of the waste discharge device. When the impurities accumulate to a certain extent, the waste discharge device is activated to quickly discharge them to avoid clogging the flow channel. The detachable lower cone and fixed chassis structure of the device can be disassembled regularly for internal cleaning and maintenance to ensure long-term stable operation of the equipment.

[0019] The technical effects and advantages of this invention are as follows: In this invention, the equipment utilizes the coordination of various components in the concentration module. First, it uses the liquid level difference between the inlet pipe and the overflow port to form a gravity water supply principle, allowing the solution to flow sequentially through the primary central chamber to achieve initial slow-flow sedimentation, secondary slow-flow collection under the guidance of the water-guiding cone, and spiral slow-flow separation through the cooperation of the inner cone and spiral strips. Finally, it completes the multi-stage clarification and purification of the solution, achieving the purpose of removing impurities of different particle sizes from the solution. By utilizing the combination of stage slow flow and gravity sedimentation, impurities of different particle sizes can be separated in a targeted manner, significantly improving the purification purity of potassium hydroxide solution and avoiding the problem of incomplete impurity removal caused by a single clarification structure.

[0020] In this invention, the device utilizes a combination of components such as a V-shaped hydrophobic plate, a spiral water-guiding pattern, a waste discharge device, and a detachable lower cone and fixed chassis. The solution first flows slowly and decelerates through the trapezoidal gap of the hydrophobic plate to prevent impurities from being suspended due to turbulent flow, thus stabilizing the clarification effect. Then, the spiral water-guiding pattern guides the flow to form a small-scale centrifugal turbulence, which throws impurities toward the inner wall of the outer shell and then discharges them through the waste discharge device. The detachable structure facilitates internal cleaning and maintenance. At the same time, its slow-flow and centrifugal-assisted waste discharge design can prevent the flow channel from being blocked by sediment, ensuring smooth waste discharge and cleaning efficiency. It also simplifies the maintenance process and reduces maintenance time and labor costs. Attached Figure Description

[0021] The disclosure of this invention is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. In the drawings, the same reference numerals are used to refer to the same parts: Figure 1 This is a schematic diagram of the external structure of the present invention; Figure 2 This is a schematic diagram of the internal structure of the outer shell of the present invention; Figure 3 This is a schematic diagram of the internal structure of the lower cone of the present invention; Figure 4 This is a schematic diagram of the inner conical cylinder structure of the present invention; Figure 5This is a schematic diagram of the internal structure of the inner cone and the water-guiding cone of the present invention; Figure 6 This is a plan view of the device structure of the present invention; Figure 7 This is a schematic diagram of the top cross-sectional structure of the outer casing of the present invention; Figure 8 This is a schematic diagram of the fixed chassis, lower cone, and internal structure of the present invention; Figure 9 This is a schematic diagram of the fixed chassis and hydrophobic sheet structure of the present invention; Figure 10 This is a schematic diagram of the planar structure of the fixed chassis and hydrophobic sheet of the present invention.

[0022] Legend: 1. Outer shell; 11. Inlet pipe; 111. Spiral water guide pattern; 12. Outlet pipe; 13. Waste discharge device; 2. Concentration component; 21. Upper cone; 22. Lower cone; 23. Fixed base; 231. Water-repellent plate; 24. Inner cone; 241. Spiral strip; 242. Water guide cone. Detailed Implementation

[0023] It is readily understood that, based on the technical solution of this invention, those skilled in the art can propose various interchangeable structural methods and implementations without altering the essential spirit of the invention. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative examples of the technical solution of this invention and should not be considered as the entirety of the invention or as limitations or restrictions on the technical solution of this invention.

[0024] Reference Figure 1-10As shown, the present invention provides a technical solution: a potassium hydroxide concentration and refining device, including a shell 1, inside which a concentration component 2 for concentrating a multi-stage clarified solution is provided, specifically a potassium hydroxide solution. A water inlet pipe 11 is provided at the top of the shell 1, communicating with the inner cavity space. The input end of the water inlet pipe 11 is connected to the output end of equipment such as a brine tank at the front end. A waste discharge device 13 is provided at the bottom of the shell 1, used to promptly filter and discharge impurities accumulated during the multi-stage clarification process. The input end corresponds vertically to the circular through hole in the center of the fixed base 23, and the output end of the waste discharge device 13 is connected to the external discharge pipe; the concentration component 2 includes an upper cone 21 fixedly installed on the inner wall of the outer shell 1 by a bracket, the upper cone 21 coincides with the axis of the outer shell 1, and a lower cone 22 is movably inserted at the bottom axis of the upper cone 21. The internal spaces of the upper cone 21 and the lower cone 22 are connected and are detachable plug-in structures. The bottom of the inner wall of the outer shell 1 is fixedly installed on the fixed base 23 by multiple sets of bolts, and the center of the fixed base 23 is provided for impurities to sink. Through a circular through-hole, an inner cone 24 is fixed at the center of the upper surface of the fixed base 23, and the outer wall of the top of the inner cone 24 extends and penetrates to the upper surface of the lower cone 22. The conical curved outer wall of the inner cone 24 and the inner wall of the lower cone 22 together form a three-stage fluid cavity. Multiple sets of spiral strips 241 for slowing down the flow rate of the solution are fixed at equal angles around the axis on the outer wall of the inner cone 24 and inside the three-stage fluid cavity. A water-guiding cone 242 is fixed at the center of the inner cone 24 on the upper surface of the fixed base 23. The conical curved outer wall of the water-guiding cone 242 and the inner cone 22 together form a three-stage fluid cavity. The inner walls of the cone 24 together form a secondary fluid cavity. Multiple primary central cavities are opened vertically along the axis inside the inner cone 24. The primary central cavities are connected vertically, and the top of the primary central cavity is provided with an outlet that communicates with the secondary fluid cavity. The bottom center of the primary central cavity is provided with an inlet that communicates with a circular through hole. The bottom inner wall of the upper cone 21 is connected to the water outlet pipe 12 near the lower cone 22. The installation height of the water inlet pipe 11 and the inner wall of the outer shell 1 is higher than the horizontal height of the joint between the upper cone 21 and the lower cone 22 and the connection between the water outlet pipe 12 and the upper cone 21.

[0025] Reference Figure 2-10 As shown in this embodiment: multiple sets of hydrophobic sheets 231 are fixed in an array around the axis on the lower surface of the fixed chassis 23, and the hydrophobic sheets 231 are generally V-shaped.

[0026] The gaps between two adjacent sets of hydrophobic sheets 231 have openings of different sizes, and the gaps between the two adjacent sets of hydrophobic sheets 231 are trapezoidal when viewed from below.

[0027] The solution can achieve a slow flow at the front end by passing through the gap space of the trapezoidal structure, which prevents the solution from generating a large range of centrifugal turbulence when passing through the spiral strip 241 due to excessive flow velocity. This can avoid the disturbance of impurities and reduce the clarification effect.

[0028] Reference Figure 2-10 As shown in this embodiment: an overflow hole of matching size and shape is provided at the contact position between the top of the inner wall of the lower cone 22 and the inner cone 24; multiple sets of lower perforations for connecting the tertiary fluid cavity and the secondary fluid cavity are arranged in an equal-angle array around the axis on the outer wall of the bottom end of the inner cone 24 and close to the fixed base 23; multiple sets of upper perforations for connecting the tertiary fluid cavity and the overflow hole are arranged in an equal-angle array around the axis on the outer wall of the top end of the inner cone 24, and the upper perforations are located inside the tertiary fluid cavity.

[0029] The inner cavity of each primary central cavity is shaped like an inverted bucket to guide impurities to slide down the sidewall, and the internal volume gradually decreases from top to bottom.

[0030] The spiral strip 241 is spiral in shape, and the outer wall of the end of the spiral strip 241 away from the inner cone 24 is in contact with the inner wall of the lower cone 22.

[0031] A chamfered surface is provided at the lower surface edge of the fixed chassis 23 corresponding to the inclined inner wall of the outer shell 1, and the inclined inner wall of the outer shell 1 is parallel to the chamfered surface. The fixed chassis 23 is fixed to the inclined inner wall of the outer shell 1 by multiple sets of support rods and bolts.

[0032] The lower cone 22 is threaded to the upper surface of the fixed base 23, and a recessed threaded mounting groove matching the bottom size of the lower cone 22 is provided at the center of the upper surface of the fixed base 23.

[0033] The detachable lower cone 22 and fixed chassis 23 facilitate subsequent maintenance by maintenance personnel.

[0034] Reference Figure 1-10 As shown in this embodiment: the water outlet pipe 12 is inclined as a whole, and one end of the water outlet pipe 12 penetrates and extends to the outer wall of the outer shell 1. Multiple sets of spiral water guide patterns 111 are fixed around the axis on the inner wall of the bottom end of the outer shell 1 and below the fixed chassis 23.

[0035] A concentration and refining process for a potassium hydroxide concentration and refining apparatus includes the following steps: S1. Raw material input, primary pretreatment, mixing reaction and large particle sedimentation: The crude potassium hydroxide solution in the front-end brine tank is slowly transported to the inner cavity of the outer shell 1 through the inlet pipe 11. At the same time, an appropriate amount of calcium chloride solution is added in proportion through the bypass pipe of the inlet pipe 11. The natural liquid level difference between the inlet pipe 11 and the overflow outlet forms a stable water flow. The crude solution accumulates in the annular cavity formed by the outer shell 1, the upper cone 21 and the lower cone 22. When the liquid level reaches the height of the inlet of the primary intermediate cavity, the solution enters multiple primary intermediate cavities in the inner cone 24 under the action of gravity. With the help of the inverted bucket-shaped structure of the primary intermediate cavity, which is larger at the top and smaller at the bottom and the resistance of gravity, the solution flow rate is rapidly reduced from a higher level. Larger particles of mud and sand and unreacted impurities in the crude solution settle due to gravity and slide down the side wall of the cavity to the circular through hole of the fixed base 23, thus completing the initial clarification.

[0036] S2, Secondary Clarification, Flow Buffering, and Medium Particle Separation: The potassium hydroxide solution after primary clarification enters the secondary fluid chamber through the outlet at the top of the primary intermediate chamber. It flows slowly down the conical outer wall of the water guide cone 242, and the flow rate is further reduced to a lower level. During this process, the residual calcium sulfate flocs in the solution fully aggregate to form medium-sized particles. When the solution flows into the tertiary fluid chamber through the lower perforation, the medium-sized particles are intercepted at the bottom of the secondary fluid chamber due to inertia. They flow back to the primary intermediate chamber with a small amount of waste liquid and are finally discharged through the circular through-hole, completing the secondary clarification and impurity separation.

[0037] S3. Three-stage purification, spiral slow flow and purification liquid diversion: The solution entering the three-stage fluid chamber flows spirally along the chamber under the guidance of the spiral strip 241. The design of the spiral strip 241 and the inner wall of the lower cone 22 forms a closed flow channel, which stabilizes the solution flow rate in a low range and avoids excessive stirring that would cause secondary suspension of the sediment. The solution generates a weak centrifugal force in the spiral flow, which throws the remaining fine impurities toward the chamber wall and settles them onto the fixed base plate 23. When the solution in the three-stage fluid chamber is full, the solution that meets the purification requirements flows into the overflow hole of the lower cone 22 through the upper perforation at the top of the inner cone 24, and finally enters the inner cavity of the upper cone 21, completing the three-stage purification.

[0038] S4. Liquid and waste discharge, refined liquid output and impurity centralized treatment: When the refined liquid in the upper cone 21 accumulates to the height of the outlet pipe 12, it flows out naturally along the inclined outlet pipe 12 and is directly transported to the subsequent membrane filter for deep treatment. Impurities deposited below the fixed base 23 are first slowed down by the trapezoidal gap of the V-shaped hydrophobic plate 231, and then guided by the spiral water guide 111 to form a small-range centrifugal flow, which throws the dispersed impurities toward the inner wall of the outer shell 1 and gathers them at the input end of the waste discharge device 13. When the impurities accumulate to a certain extent, the waste discharge device 13 is activated to quickly discharge them to avoid clogging the flow channel. The detachable lower cone 22 and fixed base 23 structure of the device can be disassembled regularly for internal cleaning and maintenance to ensure long-term stable operation of the equipment.

[0039] Working principle: First, the solution slowly flows into the inner cavity of the outer shell 1 from the inlet pipe 11. Then, the solution continuously accumulates in the annular cavity formed by the upper cone 21, the lower cone 22, and the inner wall of the outer shell 1. When the liquid level is close to the height of the joint between the inlet pipe 11 and the outer shell 1, the liquid level is much higher than the horizontal height at the joint between the upper cone 21 and the lower cone 22 and the connection between the outlet pipe 12 and the upper cone 21. Utilizing the principle of "gravity water supply," which is existing technology, it will not be elaborated further. The solution continuously rises along the circular through-hole and enters the primary intermediate cavity through the inlet, and then continuously passes through multiple sets of primary intermediate cavities. The current "multi-stage slow flow" refers to the process where, during the continuous upward flow of the solution, the liquid level inside the fixed space rises only due to the pressure of the surrounding liquid. During the upward flow, the solution, which was originally in a high-speed flow state, needs to continuously resist gravity. Combined with the structure of multiple primary intermediate chambers that are "larger at the top and smaller at the bottom, wider at the top and narrower at the bottom", the flow rate of the solution is further reduced. Inside the primary intermediate chamber, larger impurities in the upward flowing solution will continuously sink and fall through the circular through-hole to the output end of the waste discharge device 13, thereby completing the primary clarification of the potassium hydroxide solution. After primary clarification, the potassium hydroxide solution enters the secondary fluid chamber through the outlet. The solution flows slowly down the inclined inner wall of the secondary fluid chamber, dissolves, and then flows into the secondary fluid chamber through the lower perforation. The solution level continues to rise, and during the rise, it is slowed down by the spiral strip 241. The solution needs to continuously resist its own gravity during the rise. The combined effect of the spiral strip 241 and the gravity of the solution further reduces the flow rate of the solution. During this process, impurities in the solution are deposited again, achieving secondary clarification of the potassium hydroxide solution. The solution after secondary clarification continues to accumulate until the solution in the tertiary fluid chamber is full. During the continued accumulation, the solution flows up through the upper perforation and overflow hole. When the solution flows up into the upper cone 21 and accumulates to a certain height, the relatively pure solution will slowly be discharged through the outlet pipe 12 to enter the next process. It should be noted that as the solution slowly flows down the conical inner wall of the outer shell 1, it first passes through the V-shaped slit space formed by multiple sets of hydrophobic plates 231. Since the solution enters from the narrow opening into the wide opening, the flow rate of the solution can be reduced to a certain extent. Then, the solution continues to flow along the inclined inner wall of the outer shell 1. When the solution hits the multiple sets of spiral water guides 111, it will generate a small-scale centrifugal turbulence. Impurities in the solution are thrown up by the small-scale centrifugal turbulence. Then, when the larger mass impurities are in the static area above the input end of the waste discharge device 13, they will settle naturally due to gravity. After the deposited impurities accumulate to a certain extent, the waste discharge device 13 can be opened in time to discharge the deposited impurities and complete the cleaning of the impurities.

[0040] The technical scope of this invention is not limited to the content described above. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this invention, and all such modifications and variations should fall within the protection scope of this invention.

Claims

1. A potassium hydroxide concentration and purification apparatus, characterized in that, The device includes an outer shell, inside which is a concentration assembly for concentrating a multi-stage clarified solution. The top of the outer shell is provided with a water inlet pipe communicating with the inner cavity space, and the bottom of the outer shell is provided with a waste discharge device. The concentration assembly includes an upper cone fixedly mounted to the inner wall of the outer shell via a bracket. A lower cone is movably inserted into the bottom axis of the upper cone. A fixed base is fixedly mounted to the bottom of the inner wall of the outer shell. A circular through hole for impurities to sink through is opened in the center of the fixed base. An inner cone is fixed to the center of the upper surface of the fixed base, and the outer wall of the top of the inner cone extends and penetrates to the upper surface of the lower cone. The conical curved outer wall of the inner cone and the inner wall of the lower cone together form a three-stage fluid cavity. The outer wall of the inner cone and its position... Multiple sets of spiral strips for slowing down the flow rate of the solution are fixed at equal angles around the axis inside the three-stage fluid cavity. A water-guiding cone is fixed on the upper surface of the fixed base and at the center of the inner cone. The outer wall of the conical curved surface of the water-guiding cone and the inner wall of the inner cone together form a secondary fluid cavity. Multiple sets of primary central cavities are opened vertically along the axis inside the inner cone. The primary central cavities are connected vertically. The top of the primary central cavity is provided with an outlet that communicates with the secondary fluid cavity. The bottom center of the primary central cavity is provided with an inlet that communicates with a circular through hole. The bottom inner wall of the upper cone is connected to a water outlet pipe near the lower cone, and the installation height of the water inlet pipe is higher than the horizontal height of the joint between the upper and lower cones and the water outlet pipe. The water outlet pipe is inclined, and one end of the water outlet pipe extends through and to the outer wall of the outer shell. Multiple sets of spiral water guiding patterns are fixed around the axis on the inner wall of the bottom end of the outer shell and below the fixed chassis. The lower surface of the fixed chassis is fixed with multiple sets of hydrophobic sheets arranged in an array around the axis. The hydrophobic sheets are generally V-shaped. The openings of the gaps between two adjacent sets of hydrophobic sheets are of different sizes, and the gaps between two adjacent sets of hydrophobic sheets are trapezoidal when viewed from below.

2. The potassium hydroxide concentration and purification apparatus according to claim 1, characterized in that: An overflow hole of matching size and shape is provided at the contact position between the top of the inner wall of the lower cone and the inner cone cylinder. Multiple sets of lower perforations for connecting the tertiary fluid cavity and the secondary fluid cavity are arranged in an equal-angle array around the axis of the bottom outer wall of the inner cone cylinder and close to the fixed base. Multiple sets of upper perforations for connecting the tertiary fluid cavity and the overflow hole are arranged in an equal-angle array around the axis of the top outer wall of the inner cone cylinder, and the upper perforations are located inside the tertiary fluid cavity.

3. The potassium hydroxide concentration and refining apparatus according to claim 2, characterized in that: The inner cavity of each primary central cavity is shaped like an inverted bucket to guide impurities to slide down the sidewall, and the internal volume gradually decreases from top to bottom.

4. The potassium hydroxide concentration and refining apparatus according to claim 3, characterized in that: The spiral strip is spiral in shape, and the outer wall of the end of the spiral strip away from the inner cone is attached to the inner wall of the lower cone.

5. The potassium hydroxide concentration and refining apparatus according to claim 4, characterized in that: The lower surface edge of the fixed chassis has a chamfered surface corresponding to the inclined inner wall of the outer shell, and the inclined inner wall of the outer shell is parallel to the chamfered surface. The fixed chassis is fixed to the inclined inner wall of the outer shell by multiple sets of support rods and bolts.

6. The potassium hydroxide concentration and refining apparatus according to claim 5, characterized in that: The lower cone is threadedly connected to the upper surface of the fixed base, and the upper surface of the fixed base has a recessed threaded mounting groove that matches the size of the bottom end of the lower cone.

7. The concentration and refining process of a potassium hydroxide concentration and refining apparatus as described in claim 6, characterized in that: Includes the following steps: S1. Raw material input, primary pretreatment, mixing reaction and large particle sedimentation: The crude potassium hydroxide solution in the front-end brine tank is slowly transported to the inner cavity of the outer shell through the inlet pipe. At the same time, an appropriate amount of calcium chloride solution is added in proportion through the bypass pipe of the inlet pipe. The natural liquid level difference between the inlet pipe and the device forms a stable water flow. The crude solution accumulates in the annular cavity formed by the outer shell, the upper cone and the lower cone. When the liquid level reaches the height of the inlet of the primary intermediate cavity, the solution enters multiple primary intermediate cavities in the inner cone under the action of gravity. With the help of the inverted bucket-shaped structure of the primary intermediate cavity, which is larger at the top and smaller at the bottom, and the resistance of gravity, the solution flow rate is rapidly reduced from a higher level. Larger particles of mud and sand and unreacted impurities in the crude solution settle due to gravity and slide down the side wall of the chamber to the circular through hole of the fixed base, thus completing the initial clarification. S2, Secondary Clarification, Flow Buffering and Medium Particle Separation: The potassium hydroxide solution after primary clarification enters the secondary fluid chamber through the outlet at the top of the primary intermediate chamber. It flows slowly down the outer wall of the conical curved surface of the water guide cone, and the flow rate is further reduced to a lower level. During this process, the residual calcium sulfate flocs in the solution fully aggregate to form medium-sized particles. When the solution flows into the tertiary fluid chamber through the lower perforation, the medium-sized particles are intercepted at the bottom of the secondary fluid chamber due to inertia. They flow back to the primary intermediate chamber with a small amount of waste liquid and are finally discharged through the circular through hole, completing the secondary clarification and impurity separation. S3, Three-stage Refining, Spiral Slow Flow and Refined Liquid Diversion: The solution entering the three-stage fluid chamber flows spirally along the chamber under the guidance of the spiral strips. The design of the spiral strips and the inner wall of the lower cone forms a closed flow channel, which stabilizes the solution flow rate in a low range and avoids excessive stirring that would cause secondary suspension of the sediment. The solution generates a weak centrifugal force in the spiral flow, which throws the remaining fine impurities toward the chamber wall and settles them to the fixed base. When the solution in the three-stage fluid chamber is full, the solution that meets the refining requirements flows into the overflow hole of the lower cone through the upper perforation at the top of the inner cone and finally enters the inner cavity of the upper cone, completing the three-stage refining. S4. Drainage and Waste Discharge, Refined Liquid Output and Centralized Impurity Treatment: When the refined liquid in the upper cone accumulates to the height of the outlet pipe, it flows out naturally along the inclined outlet pipe and is directly transported to the subsequent membrane filter for deep treatment. Impurities deposited below the fixed chassis first achieve slow flow through the trapezoidal gap of the V-shaped hydrophobic plate, and then are guided by the spiral water guide to form a small-range centrifugal flow, which throws the dispersed impurities toward the inner wall of the outer shell and gathers at the input end of the waste discharge device. When the impurities accumulate to a certain extent, the waste discharge device is activated to quickly discharge them to avoid clogging the flow channel. The detachable lower cone and fixed chassis structure of the device can be disassembled regularly for internal cleaning and maintenance to ensure long-term stable operation of the equipment.

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