Crystallization device for producing monopotassium phosphate
By designing a crystallization device including a thermal crystallizer, a cyclone separator and a heat pump injector, the thermal concentration crystallization and reduced pressure and cooling crystallization are used to solve the problems of low production efficiency and high energy consumption in the traditional potassium dihydrogen phosphate production process, and high efficiency and low energy consumption of potassium dihydrogen phosphate production are achieved.
Patent Information
- Application Number
- CN202421818022.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-30
- Publication Date
- 2025-05-09
- Estimated Expiration
- 2034-07-30
AI Technical Summary
In the traditional potassium dihydrogen phosphate production process, the evaporation and crystallization process is complex, resulting in low production efficiency, large material losses, high energy consumption of equipment, high carbon emissions, and lack of automatic control, large labor consumption and low production capacity.
A crystallization device including a liquid storage tank, a thermal crystallizer, a cyclone, a cyclone separator, a cold crystallizer and a heat pump injector was designed. Through thermal concentration crystallization and decompression and cooling crystallization, the crystallization efficiency and yield are improved, and the energy reuse is realized through heat pump technology.
It improves the crystallization efficiency and yield of potassium dihydrogen phosphate, reduces energy consumption, reduces material losses, realizes automatic control, and improves production efficiency and capacity.
Smart Images
Figure CN222841541U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of potassium dihydrogen phosphate production, and specifically relates to a crystallization device for producing potassium dihydrogen phosphate. Background Art
[0002] In the production process of potassium dihydrogen phosphate, evaporation and crystallization is a common process. The traditional process of evaporation and concentration of potassium dihydrogen phosphate liquid generally uses a single-effect or multi-effect evaporator, and the solution is first concentrated by an evaporation device and then crystallized by a crystallization device; however, the above device has the following problems: 1. The material passes through the evaporation device and then enters the crystallization device for crystallization treatment. The process is complicated, which will affect the production efficiency of the product, and the material loss will also occur during the transfer process, thereby affecting the product yield; 2. The multi-effect evaporator occupies a large area, has high energy consumption and high carbon emissions; 3. The current device cannot achieve automatic control, consumes a lot of manpower, and has low production capacity. Summary of the invention
[0003] The technical problem to be solved by the utility model is to provide a crystallization device for producing potassium dihydrogen phosphate, which overcomes the defects in the prior art, can reduce energy consumption, and improve production efficiency and product yield.
[0004] In order to solve the above technical problems, the technical solution of the utility model is:
[0005] A crystallization device for producing potassium dihydrogen phosphate comprises a feed liquid storage tank, which is connected to a material inlet at the bottom of a hot crystallizer (evaporator) through a pipeline and an axial flow pump. The bottom of the hot crystallizer is also provided with an elutriation column and a low-concentration saturated feed liquid outlet, the discharge port of the elutriation column is connected to a first cyclone separator through a pipeline; the low-concentration saturated feed liquid outlet is connected to a cold crystallizer through a pipeline, and the discharge port at the bottom of the cold crystallizer is sequentially connected to a first cyclone separator and a second cyclone separator through a pipeline (after the material passes through the first cyclone separator, most of the large particles are separated to the bottom of the first cyclone separator, and the clear liquid and small particles are sucked into the second cyclone separator for further separation. After the small particles are separated, the clear liquid is separated and enters the cold crystallizer; because after the hot material enters the cold crystallizer, the flashed steam of the material is pumped away by the heat pump under the action of the heat pump, thereby reducing the material temperature, and since the feed liquid is a saturated solution, Therefore, crystallization will continue as the temperature drops, and the crystals will be further separated by the second cyclone separator), and the middle discharge port is connected to the second cyclone separator through a pipeline; the discharge ports of the first cyclone separator and the second cyclone separator are both connected to the centrifuge (potassium dihydrogen phosphate enters the centrifuge for separation, and the potassium dihydrogen phosphate crystals obtained by centrifugation are sent to the drying equipment for drying, and the mother liquor is further separated by chromatography); a circulating feed liquid outlet is provided in the middle of the hot crystallizer, and the circulating feed liquid outlet forms a cycle through a pipeline, a heater, an axial flow pump and a material inlet; a steam outlet is provided at the top of the hot crystallizer (the steam outlet is to extract the steam in the hot crystallizer, and after being compressed by a fan, the temperature rises by 6 to 8 degrees Celsius and then continues to enter the heater to heat the material), and the steam outlet is connected to the steam inlet of the heater through a pipeline and a compression fan; a heat pump ejector is provided at the top of the cold crystallizer, and the heat pump ejector is connected to the steam inlet of the heater through a pipeline.
[0006] Preferably, the heater is an electric heater. The material in the heater is heated by an external power supply, and the steam discharged from the hot crystallizer is pressurized and heated by a compression fan for auxiliary heating.
[0007] Preferably, the steam outlet of the heater is connected to the cooler through a pipeline. The condensed water is transported to the condensed water collection device, and the obtained tail gas and the tail gas discharged from the hot crystallizer enter the tail gas treatment device together.
[0008] Preferably, the other end of the heat pump ejector is connected to the raw steam supply system. This has two purposes: one is to extract the flashed steam in the cold crystallizer, and the other is to allow the flashed steam to enter the compressor again, and then be sent to the heater after the temperature rises, thus realizing the reuse of energy.
[0009] Preferably, the pipeline between the compressor fan and the heater is connected with a raw steam supply pipeline to supply raw steam to the heater.
[0010] Preferably, the model of the hot crystallizer is DTB-3000, and the manufacturer is Wenzhou Oulong Biochemical Engineering Equipment Co., Ltd.; the model of the cold crystallizer is OSL-OL-3000, and the manufacturer is Wenzhou Oulong Biochemical Engineering Equipment Co., Ltd.; the model of the heat pump ejector is ISP600-14 / 0.6-L(H), and the manufacturer is Saiyipu Petrochemical Equipment Co., Ltd.
[0011] Due to the adoption of the above technical solution, the beneficial effects of the utility model are:
[0012] The crystallization process of the prior art is mainly cooling crystallization, and the material must be quickly cooled down after heat concentration before crystallization, so the crystallization energy consumption of the prior art is large and the efficiency is low. The utility model adopts the method of heat concentration crystallization to crystallize the material in a hot state. Since the liquid after crystallization is still in a saturated state, it further adopts reduced pressure cooling crystallization, thereby improving the efficiency and yield of crystallization; the evaporator of the utility model requires a small amount of steam in the opening stage, and does not require external steam supply after opening. It only needs an external power supply to provide compressor power operation to realize the evaporation and concentration of the liquid, so the utility model can reduce energy consumption compared with the prior art. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 It is a schematic diagram of the structure of the utility model;
[0014] In the figure, 1, liquid storage tank; 2, axial flow pump; 3, hot crystallizer; 4, elutriation column; 5, first cyclone separator; 6, cold crystallizer; 7, second cyclone separator; 8, centrifuge; 9, heater; 10, compression fan; 11, heat pump ejector; 12, cooler. DETAILED DESCRIPTION
[0015] The present invention is further described below in conjunction with the accompanying drawings and embodiments.
[0016] Embodiment 1:
[0017] like Figure 1As shown, a crystallization device for producing potassium dihydrogen phosphate includes a liquid storage tank 1, which is connected to a material inlet (not marked) at the bottom of a hot crystallizer 3 through a pipeline (not marked) and an axial flow pump 2. The hot crystallizer 3 is also provided with an elutriation column 4 and a low-concentration saturated liquid outlet (not marked) at the bottom. The discharge port of the elutriation column 4 is connected to a first cyclone separator 5 through a pipeline; the low-concentration saturated liquid outlet is connected to a cold crystallizer 6 through a pipeline, and the discharge port (not marked) at the bottom of the cold crystallizer 6 is connected to the first cyclone separator 5 and the second cyclone separator 7 in sequence through a pipeline, and the middle discharge port (not marked) is connected to the first cyclone separator 5 and the second cyclone separator 7 in sequence through a pipeline. The hot crystallizer 3 is connected to the second cyclone separator 7 through a pipeline; the discharge ports of the first cyclone separator 5 and the second cyclone separator 7 are both connected to the centrifuge 8; a circulating liquid outlet (not marked) is provided in the middle of the hot crystallizer 3, and the circulating liquid outlet forms a circulation through the pipeline, the heater 9, the axial flow pump 2 and the material inlet; a steam outlet (not marked) is provided at the top of the hot crystallizer 3, and the steam outlet of the hot crystallizer 3 is connected to the steam inlet (not marked) of the heater through a pipeline and a compression fan 10; a heat pump ejector 11 is provided at the top of the cold crystallizer 6, and the heat pump ejector 11 is connected to the steam inlet of the heater 9 through a pipeline.
[0018] The steam outlet of the heater 9 is connected to the cooler 12 through a pipeline.
[0019] In actual production, the liquid is transported from the liquid storage tank 1 to the hot crystallizer 3 through the axial flow pump 2, and the external raw steam is transported to the heater 9 to circulate and heat the material. When the material enters the hot crystallizer, secondary steam is generated. The secondary steam is drawn into the compressor fan 10 and compressed, and the temperature rises to continue to heat the material in the heater 9. At this time, the external raw steam input pipeline is closed and the system enters the circulation heating mode. The cooled secondary steam enters the cooler 12 and is sent to the condensed water storage tank (not shown) after cooling.
[0020] After the material enters the hot crystallizer 3, due to the continuous increase in concentration, the crystals in the material gradually grow under the promotion of the agitator, and finally the concentrated liquid containing crystals is deposited at the bottom of the hot crystallizer 3 and collected by the elutriation column 4; and the saturated liquid with low concentration is transported to the cold crystallizer 6 through the pipeline and the pump. A heat pump injector 11 is provided on the top of the cold crystallizer 6. The heat pump injector 11 forms a negative pressure for the cold crystallizer 6 (taking away the steam at the same time) by injecting external raw steam to the heater 9, forcing the liquid temperature to decrease, so that the material forms crystals at the bottom of the cold crystallizer 6. Finally, the saturated liquid containing crystals in the hot crystallizer 3 and the cold crystallizer 6 are transported to the first cyclone separator 5, and the heavy crystals fall and are sent to the centrifuge 8 for separation; the separated crystals enter the drying equipment (not shown) and are stored in the crystal storage tank (not shown) after drying, and the obtained mother liquor enters the chromatogram for further separation;
[0021] The low-concentration saturated liquid in the cold crystallizer 6 enters the second cyclone separator 7 through the discharge port set in the middle for separation. The second cyclone separator 7 also receives the crystal-containing liquid from the bottom discharge port of the cold crystallizer 6 for separation. The separated crystals fall and are sent to the centrifuge 8 for separation. The separation result is the same as above.
[0022] It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.
Claims
1. A crystallization device for producing potassium dihydrogen phosphate, characterized in that: It includes a liquid storage tank, which is connected to the material inlet at the bottom of the hot crystallizer through a pipeline and an axial flow pump. The bottom of the hot crystallizer is also provided with an elutriation column and a low-concentration saturated liquid outlet, and the discharge port of the elutriation column is connected to the first cyclone separator through a pipeline; the low-concentration saturated liquid outlet is connected to the cold crystallizer through a pipeline, the bottom discharge port of the cold crystallizer is connected to the first cyclone separator and the second cyclone separator in sequence through a pipeline, and the middle discharge port is connected to the second cyclone separator through a pipeline; the discharge ports of the first cyclone separator and the second cyclone separator are both connected to a centrifuge; a circulating liquid outlet is provided in the middle of the hot crystallizer, and the circulating liquid outlet forms a cycle through a pipeline, a heater, an axial flow pump and the material inlet; a steam outlet is provided at the top of the hot crystallizer, and the steam outlet is connected to the steam inlet of the heater through a pipeline and a compression fan; a heat pump ejector is provided at the top of the cold crystallizer, and the heat pump ejector is connected to the steam inlet of the heater through a pipeline.
2. The crystallization device for producing potassium dihydrogen phosphate according to claim 1, characterized in that: The heater is an electric heater.
3. The crystallization device for producing potassium dihydrogen phosphate according to claim 1, characterized in that: The steam outlet of the heater is connected to the cooler through a pipeline.
4. The crystallization device for producing potassium dihydrogen phosphate according to claim 1, characterized in that: The other end of the heat pump ejector is connected to the live steam supply system.
5. The crystallization device for producing potassium dihydrogen phosphate according to claim 1, characterized in that: The pipeline from the compression fan to the heater is connected with a raw steam supply pipeline.