Potassium dihydrogen phosphate crystallizer and its usage method

Abstract

The present invention discloses a crystallizer for potassium dihydrogen phosphate and its usage method, including: a feed pipe; a first motor; a gear pair, the first motor is drivingly connected to the feed pipe through the gear pair; an outer cylinder body, the outer cylinder body is located below the feed pipe and the lower part of the feed pipe extends into the outer cylinder body; a sliding groove; a sliding block, the sliding block is slidably matched up and down in the sliding groove; a discharge pipe, the discharge pipe is opened on the outer wall of the feed pipe and communicated with the sliding groove; an inner cylinder body, the inner cylinder body accommodates the lower part of the feed pipe therein; a second motor, the second motor is located at the inner bottom of the outer cylinder body and is drivingly connected to the inner cylinder body; a discharge pipe, the discharge pipe is opened at the bottom of the inner cylinder body and is offset from the second motor; an annular opening, the annular opening is opened at the inner bottom of the outer cylinder body, and the discharge pipe extends into the annular opening. The beneficial effect of the present invention is to change the previous one-step growth into two-step growth to ensure the uniform growth of crystals. At the same time, the discharge pipe is located at the bottom of the inner cylinder body, and it is not easy to block the discharge pipe as the inner cylinder body rotates.

Description

Technical Field

[0001] The present invention relates to the field of potassium dihydrogen phosphate preparation, and particularly to a crystallizer for potassium dihydrogen phosphate and a method for using the same. Background Art

[0002] In industrial production, potassium dihydrogen phosphate has a wide range of applications. It can be used as a raw material for producing metaphosphoric acid potassium or other potassium salts, and can also be used as a yeast culture agent, a leavening agent, a fortifying agent, a fermentation aid, etc. As a strong buffer, it can effectively stabilize the liquid phase in the medium within a certain pH value range and play a good regulatory role in electroplating, electrolysis, and salt chemical industries. In the fermentation industry, it is mainly used in the production of monosodium glutamate, wine, alcohol, citric acid, enzyme preparations, yeast, starch, and sugar, and is widely used in the biomedical industry. In the pharmaceutical field, potassium dihydrogen phosphate is mainly used as a bacterial culture agent and is also used in the production of penicillin, oxytetracycline, inosine, etc. In the feed industry, potassium dihydrogen phosphate is mainly used as a mineral additive for phosphorus and potassium, especially commonly used in fish and shrimp feeds. For example, adding potassium dihydrogen phosphate to shrimp feed can improve the survival rate of shrimp larvae, enhance their disease resistance, and also greatly improve the growth rate of body length.

[0003] There are many production methods for potassium dihydrogen phosphate, which can be roughly summarized as neutralization method, extraction method, ion exchange method, double decomposition method, direct method, crystallization method, electrolysis method, etc. In China, the production process mostly adopts the neutralization method. The neutralization method is to prepare a 30% solution of caustic potassium or potassium carbonate and send it to a neutralizer, where it is neutralized with a 50% phosphoric acid solution under stirring, controlling the temperature at 80 - 100 °C and the pH at 4 - 5. The neutralization product is filtered, concentrated, cooled and crystallized, centrifugally separated, and dried to obtain the finished product, and the crystallization mother liquor is returned to the concentration section for reuse.

[0004] Chinese Patent Publication No. CN106167253A discloses a method for recrystallization purification of potassium dihydrogen phosphate. The filtered potassium dihydrogen phosphate solution enters a cooling tank for cooling crystallization treatment; the potassium dihydrogen phosphate solution in a solid solution state obtained after cooling crystallization is introduced into a centrifuge for centrifugal water removal to obtain potassium dihydrogen phosphate crystals with uniform particles.

[0005] Chinese Utility Model Patent Publication No. CN215026151U discloses a crystallization kettle for producing potassium dihydrogen phosphate, including: a barrel body and an upper fixing block clamped at the top of the barrel body, the upper fixing block is used to fix the components for stirring potassium dihydrogen phosphate in the barrel body, and a rotating shaft is penetrated and rotatably connected at the center of the fixing block; a stirring component, the stirring component is installed on the rotating shaft, the stirring component includes a sliding cap, the sliding cap is slidably connected to the rotating shaft, and the stirring component is used to stir the potassium dihydrogen phosphate in the barrel body during processing.

[0006] The crystallization in the above patents is carried out by stirring, which is also the current common crystallization method. It is generally carried out in an Oslo crystallizer. However, this stirring crystallization method will cause the crystals to be uneven and of different sizes, and it is easy to get blocked when discharging from the crystallizer. Summary of the invention

[0007] The technical problem to be solved by the present invention is that the existing potassium dihydrogen phosphate crystallization method will lead to uneven crystal growth and easy blockage during material discharge. For this purpose, a potassium dihydrogen phosphate crystallizer and a use method thereof are provided.

[0008] The technical solution of the present invention is: a crystallizer for potassium dihydrogen phosphate, comprising: a feed pipe, the feed pipe is vertically arranged, the top of the feed pipe is open and the bottom is closed; a first motor; a gear pair, the first motor is connected to the feed pipe through the gear pair; an outer cylinder, the outer cylinder is located below the feed pipe and the lower part of the feed pipe extends into the outer cylinder; a sliding groove, the sliding groove has a plurality of grooves, and the sliding grooves are distributed at intervals along the inner wall of the feed pipe; a sliding block, the sliding block is slidably matched in the sliding groove; a discharge pipe, the A discharge pipe is provided on the outer wall of the feed pipe and is connected with the sliding groove; a support frame, one end of the support frame is fixedly connected with the inner wall of the outer cylinder, and the other end is sleeved with the middle part of the feed pipe through a bearing; an inner cylinder, the inner cylinder accommodates the lower part of the feed pipe; a second motor, the second motor is located at the inner bottom of the outer cylinder and is transmission-connected with the inner cylinder; a discharge pipe, the discharge pipe is provided at the bottom of the inner cylinder and deviates from the second motor; an annular opening, the annular opening is provided at the inner bottom of the outer cylinder, and the discharge pipe extends into the annular opening.

[0009] An improvement of the above solution is that the sliding block is a hollow cavity, and the interior of the hollow cavity is filled with condensate.

[0010] In the above scheme, the top of the inner cylinder is open, and a plurality of cover plates extending toward the feed pipe are fixedly connected to the top of the inner cylinder, and the cover plates are located above the discharge pipe.

[0011] In the above solution, the end of the cover plate contacts the feed pipe.

[0012] The discharge pipe in the above scheme is inclined downward.

[0013] In the above solution, the length of the sliding groove is greater than the length of the sliding block.

[0014] The usage method of the crystallizer for potassium dihydrogen phosphate includes the following steps: Input the potassium dihydrogen phosphate solution into the feed pipe. The liquid level in the feed pipe rises. Start the first motor and the second motor. The first motor drives the feed pipe to rotate. When the liquid level in the feed pipe rises to the sliding block, the sliding block is pushed up and floats, so that the discharge pipe is communicated with the inner cylinder body, and the potassium dihydrogen phosphate solution enters the inner cylinder body. The second motor drives the inner cylinder body to rotate, so that the discharge pipe moves within the annular opening, and the potassium dihydrogen phosphate solution is discharged.

[0015] The beneficial effect of the present invention is that the rotating feed pipe replaces the stirring blades, and the initially grown crystals are discharged into the inner cylinder body through the discharge pipe for continuous growth. The rotation of the inner cylinder body drives the crystals to perform centrifugal motion within the inner cylinder body, and finally they are discharged through the discharge pipe. The previous one-step growth is changed to two-step growth, ensuring that the crystals can grow evenly. At the same time, the discharge pipe is located at the bottom of the inner cylinder body, and it is not easy to block the discharge pipe as the inner cylinder body rotates. Description of the Drawings

[0016] Figure 1 is a schematic diagram of the crystallizer for potassium dihydrogen phosphate of the present invention;

[0017] Figure 2 is Figure 1 a schematic diagram of the annular opening in

[0018] Figure 3 is Figure 1 a schematic diagram of the cooperation between the inner cylinder body and the outer cylinder body in

[0019] In the figure, 1. Feed pipe, 2. First motor, 3. Gear pair, 4. Outer cylinder body, 5. Sliding groove, 6. Sliding block, 7. Discharge pipe, 8. Support frame, 9. Inner cylinder body, 10. Second motor, 11. Discharge pipe, 12. Annular opening, 13. Cover plate. Specific Embodiments

[0020] Next, in conjunction with the drawings, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0021] Embodiment 1: As Figures 1-3As shown in the figure, the crystallizer for potassium dihydrogen phosphate includes: a feed pipe 1, which is vertically arranged with an open top and a closed bottom. When feeding, the potassium dihydrogen phosphate solution to be processed is input from the top; a first motor 2; a gear pair 3, through which the first motor is drivingly connected to the feed pipe. When the first motor rotates, it can drive the feed pipe to rotate; an outer cylinder 4, which is located below the feed pipe and the lower part of the feed pipe extends into the outer cylinder. The top of the outer cylinder is open, and the outer cylinder and the feed pipe are arranged coaxially; three sliding grooves 5, which are circumferentially spaced along the inner wall of the feed pipe; three sliding blocks 6, which are slidably engaged with the corresponding sliding grooves up and down. The length of the sliding groove is greater than that of the sliding block to ensure that when the sliding block rises, the discharge pipe can connect the feed pipe and the inner cylinder; three discharge pipes 7, which are opened on the outer wall of the feed pipe and communicate with the corresponding sliding grooves, and the openings of the discharge pipes are horizontal; a support frame 8, one end of which is fixedly connected to the inner wall of the outer cylinder and the other end is sleeved on the middle part of the feed pipe through a bearing. The support frame is used to stabilize the feed pipe to prevent unstable center of gravity during rotation; an inner cylinder 9, which accommodates the lower part of the feed pipe and thus receives the potassium dihydrogen phosphate solution discharged from the discharge pipe; a second motor 10, which is located at the inner bottom of the outer cylinder and is drivingly connected to the inner cylinder. The rotation direction of the inner cylinder and that of the outer cylinder can be opposite; a discharge pipe 11, which is opened at the bottom of the inner cylinder and deviates from the second motor; an annular opening 12, which is opened at the inner bottom of the outer cylinder, and the discharge pipe extends into the annular opening. When the discharge pipe rotates, it will be constrained within the annular opening.

[0022] As a preferred example of the present invention, the sliding block is a hollow cavity filled with condensate inside. Heat exchange is carried out between the condensate and potassium dihydrogen phosphate to promote crystal growth.

[0023] As another preferred example of the present invention, the top of the inner cylinder is open, and several covers 13 extending towards the feed pipe are fixedly connected to the top of the inner cylinder. The covers are located above the discharge pipes. The covers can be in contact with the feed pipe or have a clearance fit. The function of the covers is to prevent the potassium dihydrogen phosphate solution from splashing out of the inner cylinder. To ensure that potassium dihydrogen phosphate does not splash out, the discharge pipes are inclined downward.

[0024] The using method of the crystallizer for potassium dihydrogen phosphate includes the following steps: input the potassium dihydrogen phosphate solution into the feed pipe, the liquid level in the feed pipe rises, start the first motor and the second motor. The first motor drives the feed pipe to rotate. When the liquid level in the feed pipe rises to the sliding block, the sliding block is pushed up and floats, so that the discharge pipe is communicated with the inner cylinder, and the potassium dihydrogen phosphate solution enters the inner cylinder. The second motor drives the inner cylinder to rotate, so that the discharge pipe moves within the annular opening. An electromagnetic valve is arranged on the discharge pipe. When the electromagnetic valve is opened after a period of time, the potassium dihydrogen phosphate solution is discharged.

Claims

1. Crystallizer for potassium dihydrogen phosphate, which is characterized in that it includes: a feed pipe (1), the feed pipe is vertically arranged, the top of the feed pipe is open and the bottom is closed; a first motor (2); a gear pair (3), the first motor is drivingly connected to the feed pipe through the gear pair; an outer cylinder (4), the outer cylinder is located below the feed pipe and the lower part of the feed pipe extends into the outer cylinder; sliding grooves (5), there are several sliding grooves, which are circumferentially spaced along the inner wall of the feed pipe; sliding blocks (6), the sliding blocks are slidably matched up and down in the sliding grooves; a discharge pipe (7), the discharge pipe is opened on the outer wall of the feed pipe and communicated with the sliding grooves; a support frame (8), one end of the support frame is fixedly connected to the inner wall of the outer cylinder, and the other end is sleeved on the middle part of the feed pipe through a bearing; an inner cylinder (9), the inner cylinder accommodates the lower part of the feed pipe; a second motor (10), the second motor is located at the inner bottom of the outer cylinder and is drivingly connected to the inner cylinder; a discharge pipe (11), the discharge pipe is opened at the bottom of the inner cylinder and is offset from the second motor; an annular opening (12), the annular opening is opened at the inner bottom of the outer cylinder, and the discharge pipe extends into the annular opening.

2. The crystallizer for potassium dihydrogen phosphate according to claim 1, which is characterized in that: the sliding block is a hollow cavity, and the hollow cavity is filled with condensate.

3. The crystallizer for potassium dihydrogen phosphate according to claim 1, which is characterized in that: the top of the inner cylinder is open, and a plurality of covers (13) extending towards the feed pipe are fixedly connected to the top of the inner cylinder, and the covers are located above the discharge pipe.

4. The crystallizer for potassium dihydrogen phosphate according to claim 3, which is characterized in that: the end of the cover contacts the feed pipe.

5. The crystallizer for potassium dihydrogen phosphate according to claim 1, which is characterized in that: the discharge pipe is inclined downward.

6. The crystallizer for potassium dihydrogen phosphate according to claim 1, which is characterized in that: the length of the sliding groove is greater than the length of the sliding block.

7. The using method of the crystallizer for potassium dihydrogen phosphate according to any one of claims 1-6, which is characterized in that: includes the following steps: Input the potassium dihydrogen phosphate solution into the feed pipe, the liquid level in the feed pipe rises, start the first motor and the second motor, the first motor drives the feed pipe to rotate, when the liquid level in the feed pipe rises to the sliding block, the sliding block is pushed up and floats so that the discharge pipe is communicated with the inner cylinder, the potassium dihydrogen phosphate solution enters the inner cylinder, and the second motor drives the inner cylinder to rotate, so that the discharge pipe moves in the annular opening to discharge the potassium dihydrogen phosphate solution.

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