Continuous evaporative crystallization equipment for producing monopotassium phosphate

Abstract

The utility model relates to the technical field of monopotassium phosphate, in particular to continuous evaporative crystallization equipment for producing monopotassium phosphate, which comprises a feed liquid storage tank, a discharge port of the feed liquid storage tank is communicated with a heater, a heating medium inlet of the heater is communicated with a steam pipeline, a discharge port of the heater is communicated with a separator, and an exhaust port of the separator is communicated with a centrifugal compressor. An exhaust port of the centrifugal compressor communicates with a heating medium inlet of the heater; the separator is communicated with the crystallization device through a discharging pipeline, an exhaust port of the crystallization device is communicated with the steam ejector, and an exhaust port of the steam ejector is communicated with the centrifugal compressor; a discharge port of the crystallization device is communicated with the cyclone separator, and a discharge port of the cyclone separator is communicated with the centrifugal machine. The continuous evaporative crystallization equipment is reasonable in design, continuous evaporative concentration and crystallization of monopotassium phosphate feed liquid are achieved, steam discharged from the separator and the crystallization device is compressed by the centrifugal compressor and serves as a heating medium of the first heater and the second heater again, and energy consumption is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of potassium dihydrogen phosphate, in particular to continuous evaporation and crystallization equipment for the production of potassium dihydrogen phosphate. Background Art

[0002] Corn soaking water is left to settle, the collected supernatant is passed through a resin column, and then analyzed by potassium chloride. The collected analyzed solution is then hydrolyzed, separated, and other operations to obtain inositol solution and potassium dihydrogen phosphate solution. Currently, potassium dihydrogen phosphate solution is evaporated and concentrated using a single-effect or multi-effect concentrator, which has high energy consumption, high carbon emissions, and cannot operate continuously. Therefore, in view of the above problems, it is necessary to establish a continuous evaporation and crystallization equipment for potassium dihydrogen phosphate production. Utility Model Content

[0003] The technical problem to be solved by the utility model is: in view of the deficiencies of the prior art, a continuous evaporation crystallization device for the production of potassium dihydrogen phosphate is provided, by which the continuous evaporation, concentration and crystallization of the feed liquid are realized, and the use of steam is greatly reduced.

[0004] In order to solve the above technical problems, the technical solution of the utility model is:

[0005] A continuous evaporation crystallization device for producing potassium dihydrogen phosphate comprises a liquid storage tank, a discharge port of the liquid storage tank is connected to a heater, a heat medium inlet of the heater is connected to a steam pipeline, a discharge port of the heater is connected to a separator, an exhaust port of the separator is connected to a centrifugal compressor, and an exhaust port of the centrifugal compressor is connected to the heat medium inlet of the heater; the separator is connected to a crystallization device through a discharge pipeline, an exhaust port of the crystallization device is connected to a steam ejector, and an exhaust port of the steam ejector is connected to a centrifugal compressor; the discharge port of the crystallization device is connected to a cyclone separator, and the discharge port of the cyclone separator is connected to a centrifuge.

[0006] As an improved technical solution, the heater includes a first heater and a second heater, and both the first heater and the second heater are tube-in-tube heaters.

[0007] As an improved technical solution, the exhaust ports of the first heater and the second heater are connected to the condenser, and the condensate outlet of the condenser is connected to the condensate storage tank.

[0008] As an improved technical solution, the liquid storage tank is connected to the heater through a material conveying pipeline, and a material conveying pump and an axial flow pump are sequentially arranged on the material conveying pipeline.

[0009] As an improved technical solution, a discharge pump and a density meter are sequentially provided on the discharge pipeline, and the discharge pipeline is connected to the material conveying pipeline through a circulation pipeline.

[0010] As an improved technical solution, the crystallization device is an Oslo crystallizer, and the upper outlet of the cyclone separator is connected to the reflux port of the Oslo crystallizer through a reflux pipe.

[0011] As an improved technical solution, the separator includes a main body, a material inlet is provided on the lower side of the main body, a discharge port is provided at the bottom of the main body, an exhaust port is provided on the top side of the main body, a spray head is provided above the interior of the main body, a material baffle plate is provided above the spray head, and the material baffle plate is provided with a through hole.

[0012] After adopting the above technical solution, the beneficial effects of the utility model are:

[0013] The continuous evaporation crystallization equipment for the production of potassium dihydrogen phosphate comprises a liquid storage tank, a discharge port of the liquid storage tank is connected to a heater, a heat medium inlet of the heater is connected to a steam pipeline, a discharge port of the heater is connected to a separator, an exhaust port of the separator is connected to a centrifugal compressor, and an exhaust port of the centrifugal compressor is connected to the heat medium inlet of the heater; the separator is connected to a crystallization device through a discharge pipeline, an exhaust port of the crystallization device is connected to a steam ejector, and an exhaust port of the steam ejector is connected to a centrifugal compressor; the discharge port of the crystallization device is connected to a cyclone separator, and the discharge port of the cyclone separator is connected to a centrifuge. In actual production, at the beginning of concentration, part of the new steam first enters the interior of the heater, and the potassium dihydrogen phosphate solution in the liquid storage tank enters the interior of the heater along the material conveying pipeline, enters the interior of the separator along the pipeline after steam heating and concentration, and the steam separated by the separator enters the interior of the centrifugal compressor along the pipeline. The steam after compression and temperature increase enters the interior of the heater as a heat medium. At this time, the pipeline valve of the new steam is closed, and the potassium dihydrogen phosphate liquid in the separator enters the interior of the heater for circulation, heating and concentration. When the appropriate concentration is reached, the potassium dihydrogen phosphate concentrate in the separator enters the interior of the crystallization device through the discharge pipeline for crystallization treatment. The crystal liquid after crystallization enters the interior of the cyclone separator, and the separated crystals enter the centrifuge for further centrifugal separation. The crystals obtained after separation are dried to obtain potassium dihydrogen phosphate products. A small amount of new steam enters the interior of the steam ejector, and the steam inside the crystallization device enters the interior of the steam ejector, and then enters the centrifugal compressor along the pipeline after being discharged from the outlet of the steam ejector. The gas after compression and temperature increase enters the first heater and the second heater for heating the liquid. The above-mentioned continuous evaporation crystallization equipment is reasonably designed, realizes the continuous evaporation concentration and crystallization of potassium dihydrogen phosphate liquid, and utilizes the exhaust steam inside the separator and the crystallization device to be compressed by a centrifugal compressor and reused as the heat medium of the first and second heaters for heating the liquid, thereby reducing energy consumption.

[0014] Since the heater includes the first heater and the second heater, both of which are tube-in-tube heaters, the potassium dihydrogen phosphate solution enters the tubes of the first heater and the second heater respectively, and the steam enters the shell side of the first heater and the second heater, so as to heat the feed liquid.

[0015] Since the exhaust ports of the first heater and the second heater are connected to the condenser, the condensate outlet of the condenser is connected to the condensate storage tank. The gas discharged from the first and second heaters after heat exchange enters the condenser, and the condensed water after condensation is stored in the condensate storage tank.

[0016] Since the liquid storage tank is connected to the heater through a material conveying pipeline, a material conveying pump and an axial flow pump are arranged on the material conveying pipeline in sequence. With the help of the material conveying pump and the axial flow pump, the potassium dihydrogen phosphate solution in the liquid storage tank enters the interior of the heater along the material conveying pipeline for heating and concentration.

[0017] Since the discharge pipe is provided with a discharge pump and a density meter in sequence, and the discharge pipe is connected to the material conveying pipe through a circulation pipe. After a period of evaporation and concentration, when the density meter detects that the material concentration reaches an appropriate concentration, the valve on the discharge pipe opens, and the potassium dihydrogen phosphate concentrated liquid in the separator enters the interior of the crystallization device along the discharge pipe for subsequent treatment such as crystallization; when the density meter detects that the appropriate concentration is not reached, the valve on the circulation pipe opens, and the potassium dihydrogen phosphate concentrated liquid enters the interior of the material conveying pipe along the circulation pipe, and then enters the interior of the heater for further evaporation and concentration. The above design is reasonable, which is convenient for detecting the concentration of the potassium dihydrogen phosphate liquid and is more conducive to subsequent crystallization treatment.

[0018] Since the crystallization device is an Oslo crystallizer, and the upper outlet of the cyclone separator is connected to the reflux port of the Oslo crystallizer through a reflux pipe, the potassium dihydrogen phosphate concentrate enters the interior of the Oslo crystallizer, the crystal liquid after crystallization enters the interior of the cyclone separator along the pipe, the supernatant after separation enters the interior of the Oslo crystallizer from the reflux port along the reflux pipe to continue crystallization, and the crystals at the bottom of the cyclone separator enter the interior of the centrifuge for centrifugal treatment. The above design is reasonable and realizes the effective separation of crystals and clear liquid.

[0019] Since the separator includes a body, a material inlet is provided on one side of the lower part of the body, a material outlet is provided at the bottom of the body, an exhaust port is provided on one side of the top of the body, a spray head is provided on the upper part of the body, a material baffle is provided on the upper part of the spray head, and a through hole is provided on the material baffle. The potassium dihydrogen phosphate solution evaporated and concentrated by the first and second heaters enters the interior of the body from the material inlet along the pipeline, and the spray liquid is sprayed out through the spray head to avoid the formation of foam. Part of the hot steam passes through the through hole of the material baffle plate upward, is discharged from the exhaust port, enters the centrifugal compressor along the pipeline for compression and temperature increase, and continues to be used as a heat medium in the heater. After the spray liquid is sprayed out through the spray head, the foam formed by the material inside the body can be eliminated, and the material baffle can prevent the steam from carrying the material out. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic structural diagram of a continuous evaporation and crystallization device for potassium dihydrogen phosphate of the utility model;

[0021] Among them, 1-liquid storage tank, 2-first heater, 3-second heater, 4-steam pipe, 5-separator, 50-spray head, 51-baffle plate, 6-centrifugal compressor, 7-discharge pipe, 8-crystallization device, 9-steam ejector, 10-cyclone separator, 11-centrifuge, 12-condenser, 13-condensate storage tank, 14-material conveying pipe, 15-material conveying pump, 16-axial flow pump, 17-discharge pump, 18-density meter, 19-circulation pipe, 20-reflux pipe. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0023] A continuous evaporation crystallization device for producing potassium dihydrogen phosphate, such as Figure 1 As shown, it includes a liquid storage tank 1, the discharge port of the liquid storage tank 1 is connected to the first heater 2 (tube heater) and the second heater 3 (tube heater), the heat medium inlets of the first heater 2 and the second heater 3 are respectively connected to the steam pipe 4, the discharge ports of the first heater 2 and the second heater 3 are connected to the separator 5, the exhaust port of the separator 5 is connected to the centrifugal compressor 6, and the exhaust port of the centrifugal compressor 6 is connected to the heat medium inlets of the first heater 2 and the second heater 3; the separator 5 is connected to the crystallization device 8 through the discharge pipe 7, the exhaust port of the crystallization device 8 is connected to the steam ejector 9, and the exhaust port of the steam ejector 9 is connected to the centrifugal compressor 6 (purchased from the manufacturer); the discharge port of the crystallization device 8 is connected to the cyclone separator 10 (purchased from the manufacturer), and the discharge port of the cyclone separator 10 is connected to the centrifuge 11 (purchased from the manufacturer).

[0024] In actual production, at the beginning of concentration, part of the new steam first enters the interior of the heater, and the potassium dihydrogen phosphate solution in the liquid storage tank enters the tubes of the first heater and the second heater along the material conveying pipeline, and enters the interior of the separator along the pipeline after steam heating and concentration. The steam separated by the separator enters the interior of the centrifugal compressor along the pipeline, and the steam re-enters the interior of the first heater and the second heater as a heat medium. At this time, the pipeline valve of the new steam is closed, and the potassium dihydrogen phosphate liquid in the separator enters the interior of the heater for circulation heating and concentration. When the appropriate concentration is reached, the potassium dihydrogen phosphate concentrated liquid in the separator enters the interior of the crystallization device through the discharge pipeline for crystallization treatment, and the crystal liquid after crystallization enters the interior of the cyclone separator. The crystals after separation enter the centrifuge for further centrifugal separation. The crystals obtained after separation are dried to obtain potassium dihydrogen phosphate products. A small amount of new steam enters the interior of the steam ejector, and the steam inside the crystallization device enters the interior of the steam ejector, and then enters the centrifugal compressor along the pipeline after being discharged from the outlet of the steam ejector. The gas after compression and heating enters the first heater and the second heater for heating the liquid.

[0025] The exhaust ports of the first heater 2 and the second heater 3 are connected to the condenser 12 (tube-in-tube condenser), and the condensate outlet of the condenser 13 is connected to the condensate storage tank 13. The gas discharged from the first and second heaters after heat exchange enters the condenser, and the condensed water after condensation is stored in the condensate storage tank.

[0026] The liquid storage tank 1 is connected to the first heater 2 and the second heater 3 through the material conveying pipeline 14, and the material conveying pipeline 15 is provided with a material conveying pump 15 and an axial flow pump 16 in sequence. With the help of the material conveying pump and the axial flow pump, the potassium dihydrogen phosphate solution in the liquid storage tank enters the interior of the heater along the material conveying pipeline for heating and concentration.

[0027] The discharge pipe 7 is provided with a discharge pump 17 and a density meter 18 in sequence, and the discharge pipe 7 is connected to the material conveying pipe 14 through a circulation pipe 19. After a period of evaporation and concentration, when the density meter detects that the material concentration reaches an appropriate concentration, the valve on the discharge pipe is opened, and the potassium dihydrogen phosphate concentrated liquid in the separator enters the interior of the crystallization device along the discharge pipe for subsequent treatment such as crystallization; when the density meter detects that the appropriate concentration is not reached, the valve on the circulation pipe is opened, and the potassium dihydrogen phosphate concentrated liquid enters the interior of the material conveying pipe along the circulation pipe, and then enters the interior of the heater to continue evaporation and concentration. The above design is reasonable, which is convenient for detecting the concentration of the potassium dihydrogen phosphate liquid and is more conducive to subsequent crystallization treatment.

[0028] The crystallization device 8 is an Oslo crystallizer (purchased from the manufacturer), and the upper outlet of the cyclone separator 10 is connected to the reflux port of the Oslo crystallizer through the reflux pipe 20. The potassium dihydrogen phosphate concentrate enters the interior of the Oslo crystallizer, the crystal liquid after crystallization enters the interior of the cyclone separator along the pipe, the supernatant after separation enters the interior of the Oslo crystallizer from the reflux port along the reflux pipe to continue crystallization, and the crystals at the bottom of the cyclone separator enter the interior of the centrifuge for centrifugal treatment. The above design is reasonable and realizes the effective separation of crystals and clear liquid.

[0029] The separator 5 includes a body, a material inlet is provided on one side of the lower part of the body, a discharge port is provided at the bottom of the body, an exhaust port is provided on one side of the top of the body, a spray head 50 is provided on the upper part of the body, a material baffle plate 51 is provided on the upper part of the spray head, and the material baffle plate is provided with a through hole. The potassium dihydrogen phosphate solution evaporated and concentrated by the first and second heaters enters the interior of the body from the material inlet along the pipeline, and the spray liquid is sprayed out through the spray head to avoid the formation of foam. Part of the hot steam passes through the through hole of the material baffle plate upward, is discharged from the exhaust port, and enters the centrifugal compressor along the pipeline for compression and temperature increase, and continues to be used as a heat medium in the heater. After the spray liquid is sprayed out through the spray head, the foam formed by the material inside the body can be eliminated, and the material baffle plate can prevent the steam from carrying the material out.

[0030] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A continuous evaporation crystallization device for the production of potassium dihydrogen phosphate, characterized in that: It comprises a liquid storage tank, the discharge port of the liquid storage tank is connected to a heater, the heat medium inlet of the heater is connected to a steam pipe, the discharge port of the heater is connected to a separator, the exhaust port of the separator is connected to a centrifugal compressor, the exhaust port of the centrifugal compressor is connected to the heat medium inlet of the heater; the separator is connected to a crystallization device through a discharge pipe, the exhaust port of the crystallization device is connected to a steam ejector, the exhaust port of the steam ejector is connected to a centrifugal compressor; the discharge port of the crystallization device is connected to a cyclone separator, the discharge port of the cyclone separator is connected to a centrifuge.

2. The continuous evaporation crystallization equipment for producing potassium dihydrogen phosphate according to claim 1, characterized in that: The heater includes a first heater and a second heater, and both the first heater and the second heater are tube-in-tube heaters.

3. The continuous evaporation crystallization equipment for producing potassium dihydrogen phosphate according to claim 2, characterized in that: The exhaust ports of the first heater and the second heater are connected to the condenser, and the condensate outlet of the condenser is connected to the condensate storage tank.

4. The continuous evaporation crystallization equipment for producing potassium dihydrogen phosphate according to claim 1, characterized in that: The liquid storage tank is connected to the heater through a material conveying pipeline, and a material conveying pump and an axial flow pump are sequentially arranged on the material conveying pipeline.

5. The continuous evaporation crystallization equipment for producing potassium dihydrogen phosphate according to claim 4, characterized in that: The discharge pipeline is provided with a discharge pump and a density meter in sequence, and the discharge pipeline is connected to the material conveying pipeline through a circulation pipeline.

6. The continuous evaporation crystallization equipment for producing potassium dihydrogen phosphate according to claim 1, characterized in that: The crystallization device is an Oslo crystallizer, and the upper outlet of the cyclone separator is connected to the reflux port of the Oslo crystallizer through a reflux pipeline.

7. The continuous evaporation crystallization equipment for producing potassium dihydrogen phosphate according to claim 1, characterized in that: The separator includes a body, a material inlet is provided on one side of the lower part of the body, a material outlet is provided on the bottom of the body, an exhaust port is provided on one side of the top of the body, a spray head is provided above the interior of the body, a material baffle plate is provided above the spray head, and the material baffle plate is provided with a through hole.

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