Plate type vacuum evaporation mother liquor circulating system

Abstract

The utility model relates to the technical field of vacuum evaporation mother liquor circulation, in particular to a plate type vacuum evaporation mother liquor circulation system, which comprises a stock solution tank, a hot water tank, a heat exchange heat exchanger, an evaporation separation tank, a cold exchange heat exchanger, a cooling water tank and a mother liquor recovery tank, the heat exchanger is communicated with the evaporation separation tank, the evaporation separation tank is connected with the mother liquor recovery tank, the mother liquor recovery tank is communicated with the stock solution tank, and the mother liquor recovery tank is connected with a vacuum pump; the evaporation separation tank is communicated with the cold exchange heat exchanger, and the cooling water tank is connected to the cold exchange heat exchanger, so that the problems that in the prior art, a vacuum evaporation system mostly adopts single-time evaporation concentration in a pilot test device, a solution needing to be evaporated is not repeatedly concentrated, and a concentrated solution needs to be additionally placed for cooling crystallization; and the process is not suitable for products with relatively small influence of temperature on solubility.

Description

Technical Field

[0001] This utility model relates to the field of vacuum evaporation mother liquor circulation technology, specifically to a plate-type vacuum evaporation mother liquor circulation system. Background Technology

[0002] Evaporators are widely used in industries such as chemical, pharmaceutical, and environmental protection. The heating method involves heating a solution containing non-volatile solutes to boiling point, causing some of the solvent to vaporize and be removed. Evaporators can process a wide variety of materials, each with different properties.

[0003] Chinese Patent Publication No. CN214971877U discloses a vacuum heat pump evaporator crystallizer, comprising a heat pump compressor, a heater, a crystallizer separator, a forced circulation pump, a condenser, a cooling water circulation pump, and a condensate storage tank. The crystallizer separator has a material inlet with a first solenoid valve. The forced circulation pump is connected to the crystallizer separator and also to the heater. The heater is connected to the crystallizer separator, and the top of the crystallizer separator is connected to the condenser. The condenser is connected to the condensate storage tank and also to the cooling water circulation pump. The heat pump compressor has a heat medium inlet, a heat medium outlet, a chilled water inlet, and a chilled water outlet. The cooling water circulation pump is connected to the chilled water inlet, and the condenser is connected to the chilled water outlet. The heater is connected to both the heat medium inlet and the heat medium outlet. This invention has a small footprint and low energy consumption.

[0004] Vacuum evaporation systems like those described above often employ single-stage evaporation concentration in pilot-scale testing, without repeatedly concentrating the solution to be evaporated. Furthermore, the concentrated solution needs to be cooled and crystallized separately. This single-stage evaporation concentration process is not suitable for products where temperature has little effect on solubility. Utility Model Content

[0005] The purpose of this invention is to provide a plate-type vacuum evaporation mother liquor circulation system, which overcomes the problem that existing vacuum evaporation systems in pilot-scale test devices mostly use single-stage evaporation and concentration, without repeated concentration of the solution to be evaporated, and the concentrated liquid needs to be placed separately for cooling and crystallization. This process is not suitable for products whose solubility is not significantly affected by temperature.

[0006] To achieve the above objectives, the technical solution adopted by this utility model to solve its technical problem is as follows:

[0007] A plate-type vacuum evaporation mother liquor circulation system was designed. This system combines a mother liquor recovery tank and a raw liquor tank via a mother liquor circulation pump. Through continuous concentration, the yield of the evaporated crystallized product is greatly improved, while reducing equipment investment and energy consumption, and significantly minimizing the required floor space. The specific scheme is as follows:

[0008] A plate-type vacuum evaporation mother liquor circulation system includes a raw liquid tank, a hot water tank, a heat exchanger, an evaporation separation tank, a cold exchanger, a cooling water tank, and a mother liquor recovery tank. The raw liquid tank is connected to the cold material inlet of the heat exchanger via a pipeline, a feed valve, and a feed pump. The hot water tank is connected between the cold material outlet and the hot material inlet of the heat exchanger.

[0009] The heat exchanger's hot material outlet is connected to the inlet of the evaporation separator via a pipe. The liquid outlet of the evaporation separator is connected to the mother liquor recovery tank via a pipe. The lower outlet of the mother liquor recovery tank is connected to the raw liquid tank via a pipe. A vacuum pump is connected to the upper end of the mother liquor recovery tank via a pipe.

[0010] The upper end of the evaporation separator is connected to the hot material inlet of the cold exchange heat exchanger, and the cooling water tank is connected between the cold material inlet and the hot material outlet of the cold exchange heat exchanger.

[0011] Preferably, the raw liquid tank is equipped with a raw liquid valve, and the raw liquid tank is equipped with a partition to separate the mother liquor and the crystallized product, and the partition is equipped with a filter cloth.

[0012] Preferably, the lower end of the mother liquor recovery tank is connected to the original liquid tank via a pipeline, which in turn connects to a mother liquor collection valve, a mother liquor circulation pump, and a mother liquor circulation valve.

[0013] Preferably, an electric heating rod is installed inside the hot water tank, and a hot water valve and a heat circulation pump are installed between the hot water tank and the hot material inlet of the heat exchanger.

[0014] Preferably, the cold material outlet of the cold exchange heat exchanger is connected to a distillate recovery tank, the lower end of the distillate recovery tank is connected to a distillate collection valve, and the upper end of the distillate recovery tank is connected between the vacuum pump and the mother liquor recovery tank through a pipeline.

[0015] Preferably, the mother liquor recovery tank is provided with a vent valve at the upper end, and the mother liquor recovery tank and the vacuum pump are connected in sequence by a pipeline via a connecting valve and a vacuum valve.

[0016] Preferably, the cooling water tank is connected to the cold material inlet of the cold exchange heat exchanger via a pipeline, which is then connected in sequence via a cooling water valve and a cold circulation pump.

[0017] The beneficial effects of this utility model are:

[0018] 1. The mother liquor circulation system of this utility model adopts a combination of mother liquor recovery tank and raw liquor tank through mother liquor circulation pump. Through continuous concentration, the yield of evaporation crystallization product is greatly improved, while reducing equipment investment and energy consumption, and the footprint is greatly reduced.

[0019] 2. This utility model can achieve the effects of evaporation, concentration and crystallization using only one evaporation separation tank and one mother liquor circulation system, which reduces equipment investment and energy consumption. At the same time, the hot water and circulating cooling water do not come into contact with the feed liquid and the separated liquid, and the hot water and circulating cooling water are not contaminated, ensuring the stable, clean and efficient operation of the entire process. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0021] In the diagram: 1-Soil liquid tank, 2-Hot water tank, 3-Heat exchanger, 4-Evaporation separator, 5-Cold exchanger, 6-Cooling water tank, 7-Mother liquor recovery tank, 8-Distillate recovery tank, 9-Vacuum pump, 10-Feed pump, 11-Mother liquor circulation pump, 12-Heat circulation pump, 13-Cold circulation pump, 14-Baffle plate, 15-Electric heating rod, 16-Feed valve, 17-Hot water valve, 18-Cooling water valve, 19-Mother liquor collection valve, 20-Distillate collection valve, 21-Mother liquor circulation valve, 22-Soil liquid valve, 23-Vent valve, 24-Connecting valve, 25-Vacuum valve. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of this utility model are only used to explain this utility model and are not intended to limit this utility model.

[0023] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to implement the present invention. In other embodiments, well-known structures, circuits, materials, or methods are not specifically described in order to avoid obscuring the present invention.

[0024] Throughout this specification, references to "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "an embodiment," "an example," "an example," or "an example" appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. Moreover, those skilled in the art will understand that the illustrations provided herein are for illustrative purposes and are not necessarily drawn to scale. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0025] In the description of this utility model, the terms "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this utility model.

[0026] like Figure 1 As shown, this utility model provides a plate-type vacuum evaporation mother liquor circulation system, including a raw liquid tank 1, a hot water tank 2, a heat exchanger 3, an evaporation separation tank 4, a cold exchanger 5, a cooling water tank 6, and a mother liquor recovery tank 7. The raw liquid tank 1 is connected to the cold material inlet of the heat exchanger 3 via a pipeline, a feed valve 16, and a feed pump 10. The hot water tank 2 is connected between the cold material outlet and the hot material inlet of the heat exchanger 3 to facilitate heat energy exchange through the heat exchanger 3. The hot material outlet of the heat exchanger 3 is connected via a pipeline... The evaporator is connected to the inlet of the evaporator 4, through which the liquid is evaporated. The liquid outlet of the evaporator 4 is connected to the mother liquor recovery tank 7 through a pipe. The lower outlet of the mother liquor recovery tank 7 is connected to the raw liquid tank 1 through a pipe. The upper end of the mother liquor recovery tank 7 is connected to the vacuum pump 9 through a pipe. The upper end of the evaporator 4 is connected to the hot material inlet of the cold exchange heat exchanger 5. The cooling water tank 6 is connected between the cold material inlet and the hot material outlet of the cold exchange heat exchanger 5. Energy exchange is achieved through the cooling water tank 6 and the cold exchange heat exchanger 5.

[0027] In the above scheme, the raw liquid tank 2 is equipped with a raw liquid valve 22, and the raw liquid tank 1 is equipped with a partition 14 for separating the mother liquor and the crystallized product. The partition 14 is equipped with a filter cloth. The partition 14 is used to separate the mother liquor and the crystallized product so that the separated liquid can be further concentrated, while the filter cloth is used to prevent the feed pipe from being blocked.

[0028] In the above scheme, the lower end of the mother liquor recovery tank 7 is connected to the raw liquid tank 1 via a pipeline through the mother liquor collection valve 19, the mother liquor circulation pump 11 and the mother liquor circulation valve 21 in sequence. By starting the mother liquor collection valve 19, the mother liquor circulation pump 11 and the mother liquor circulation valve 21, and after confirming that the mother liquor circulation pump 11 is operating normally, the feed valve 16 can be opened. After the heating, feeding and cooling systems are operating normally, the vacuum system can be turned on.

[0029] In the above scheme, an electric heating rod 15 is installed in the hot water tank 2 to heat the water in the hot water tank 2 so that the heat exchanger 3 can exchange heat. A hot water valve 17 and a heat circulation pump 12 are installed between the hot water tank 2 and the hot material inlet of the heat exchanger 3. The heat circulation pump 12 is used to realize the exchange of heat between the hot water tank 2 and the heat exchanger 3.

[0030] In the above scheme, the cold material outlet of the cold exchange heat exchanger 5 is connected to the distillate recovery tank 8. The obtained distillate is collected in the distillate collection tank 8. The lower end of the distillate recovery tank 8 is connected to the distillate collection valve 20. By opening the distillate collection valve 20, the distillate is recovered into the collection bucket. After testing, the distillate is very clean and can be returned to other industrial sections for direct use as industrial water. The upper end of the distillate recovery tank 8 is connected between the vacuum pump 9 and the mother liquor recovery tank 7 through a pipeline.

[0031] In the above scheme, a vent valve 23 is installed at the upper end of the mother liquor recovery tank 7. After the liquid level in the distillate recovery tank 8 reaches a certain level, the vent valve 23 is slowly opened to break the system vacuum, so as to facilitate the recovery of the distillate. The mother liquor recovery tank 7 and the vacuum pump 9 are connected by a pipeline in sequence through a connecting valve 24 and a vacuum valve 25. The connecting valve 24 between the mother liquor recovery tank 7 and the distillate collection tank is opened, the vacuum pump 9 is turned on, and the vacuum valve 25 is slowly opened. As the vacuum degree increases, the feed solution in the evaporation separation tank 4 is observed to increase continuously. When the liquid approaches the edge of the observation window, the opening of the vacuum valve 25 is reduced, and the opening of the feed valve 16 is adjusted appropriately. Subsequently, the solution flow in the evaporation separation tank 4 and the mother liquor recovery tank 7 is normal, with less splashing.

[0032] In the above scheme, the cooling water tank 6 and the cold material inlet of the cold exchange heat exchanger 5 are connected by a pipeline in sequence through the cooling water valve 18 and the cold circulation pump 13 to realize heat exchange between the cooling water tank 6 and the cold exchange heat exchanger 5 and ensure normal cooling water flow.

[0033] The specific process flow of the mother liquor circulation system for this plate-type vacuum evaporation is as follows:

[0034] Before evaporation, ensure the pipes are clear, the pumps and valves are functioning properly, and there are no leaks. Confirm the water level in hot water tank 2 is normal, and start the electric heating rod 15 to begin heating. Open the hot water valve 17 and the heat circulation pump 12, and check for any backflow in hot water tank 2 to ensure the hot water system operates smoothly. Heat the heating system to 80-95℃ as a backup heat source. Add circulating cooling water to the cooling water tank 6 as a medium for cooling the distillate. Open the cooling water valve 18 and the cold circulation pump 13 to ensure normal cooling water flow. Open the raw liquid valve 22, allowing the solution to be evaporated to enter the raw liquid tank 1. Once the solution in the raw liquid tank 1 reaches a certain level, open the feed valve 16.

[0035] At this point, the openings of the raw liquid valve 22 and the feed valve 16 need to be adjusted simultaneously to ensure a stable liquid level in the raw liquid tank 1 and smooth operation of the feeding system. Power on and start the mother liquor collection valve 19, mother liquor circulation pump 11, and mother liquor circulation valve 21, confirming that the mother liquor circulation pump 11 is operating normally. Open the feed valve 16, and after the heating, feeding, and cooling systems are operating normally, the vacuum system can be turned on.

[0036] Close the vent valve 23 on the mother liquor recovery tank 7, and open the connecting valve 24 between the mother liquor recovery tank 7 and the distillate collection tank 6. Turn on the vacuum pump 9 and slowly open the vacuum valve 25. As the vacuum level increases, observe the continuous increase of the feed solution in the evaporation separator 4. When the liquid approaches the edge of the observation window, reduce the opening of the vacuum valve 25 and appropriately adjust the opening of the feed valve 16. Subsequently, the solution flow in the evaporation separator 4 and the mother liquor recovery tank 7 will be normal, with minimal splashing. At this point, the system enters a stable state, with the pressure controlled between -0.04 and 0 Pa. Regularly check and replenish the vacuum to prevent the vacuum from disappearing and affecting the evaporation effect. The feed pump 10 delivers the feed liquid to the heat exchanger 3, and then into the evaporation separator 4. The feed liquid can be continuously circulated and heated through the mother liquor recovery system, reaching an evaporation temperature of 80-90℃.

[0037] The liquid material reaching the evaporation temperature undergoes gas-liquid separation in the evaporation separator 4. The gas flows upward and enters the cold exchange heat exchanger 5. The resulting distillate accumulates in the distillate collection tank 8. Once a certain liquid level is reached, the vent valve 23 is slowly opened to break the system vacuum. Subsequently, the distillate collection valve 20 is opened to recover the distillate into the collection bucket. The distillate, after testing, is very clean and can be returned to other industrial sections for direct use as industrial water. After the distillate collection is complete, the distillate collection valve 20 and the vent valve 23 are closed. The vacuum is then evacuated again to a suitable level to accelerate the evaporation rate and improve efficiency. The liquid material after gas-liquid separation flows downward into the mother liquor recovery tank 7, and then the mother liquor circulation pump 11 returns the liquid material to the evaporation system for another gas-liquid separation.

[0038] As the number of gas-liquid separations increases, more distillate is collected, and the volume of the feed liquid decreases, allowing the feed liquid to be concentrated to a supersaturated state. Because of this supersaturation and subsequent continuous gas-liquid separation, crystals can be directly precipitated in the raw material tank 1. A baffle 14 is embedded in the lower part of the raw material tank 1 to separate the mother liquor from the crystallized product, and a layer of filter cloth is added to the upper part of the baffle to prevent clogging of the feed pipe. The crystals remain on the upper layer of the baffle 14, and the separated feed liquid can be further concentrated.

[0039] The most prominent feature of the entire process is that the evaporation, concentration and crystallization effects can be achieved using only one evaporation separation tank 4 and one mother liquor circulation system, which reduces equipment investment and energy consumption. At the same time, the hot water and circulating cooling water do not come into contact with the feed liquid and the separated liquid, and the hot water and circulating cooling water are not contaminated, ensuring the stable, clean and efficient operation of the entire process.

[0040] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A plate-type vacuum evaporation mother liquor circulation system, comprising a raw liquid tank (1), a hot water tank (2), a heat exchanger (3), an evaporation separation tank (4), a cold exchanger (5), a cooling water tank (6), and a mother liquor recovery tank (7), characterized in that: The raw liquid tank (1) is connected to the cold material inlet of the heat exchanger (3) via a pipeline, a feed valve (16) and a feed pump (10), and the hot water tank (2) is connected between the cold material outlet and the hot material inlet of the heat exchanger (3). The heat exchanger (3) has its hot material outlet connected to the inlet of the evaporation separator (4) via a pipe. The liquid outlet of the evaporation separator (4) is connected to the mother liquor recovery tank (7) via a pipe. The lower outlet of the mother liquor recovery tank (7) is connected to the raw liquid tank (1) via a pipe. The upper end of the mother liquor recovery tank (7) is connected to a vacuum pump (9) via a pipe. The upper end of the evaporation separator (4) is connected to the hot material inlet of the cold exchange heat exchanger (5), and the cooling water tank (6) is connected between the cold material inlet and the hot material outlet of the cold exchange heat exchanger (5).

2. The plate-type vacuum evaporation mother liquor circulation system according to claim 1, characterized in that: The original liquid tank (2) is equipped with an original liquid valve (22), and the original liquid tank (1) is equipped with a partition (14) for separating the mother liquor and the crystallized product. The partition (14) is equipped with a filter cloth.

3. The plate-type vacuum evaporation mother liquor circulation system according to claim 1, characterized in that: The lower end of the mother liquor recovery tank (7) is connected to the original liquid tank (1) via a pipeline through a mother liquor collection valve (19), a mother liquor circulation pump (11), and a mother liquor circulation valve (21).

4. The plate-type vacuum evaporation mother liquor circulation system according to claim 1, characterized in that: An electric heating rod (15) is installed inside the hot water tank (2), and a hot water valve (17) and a heat circulation pump (12) are installed between the hot water tank (2) and the hot material inlet of the heat exchanger (3).

5. A plate-type vacuum evaporation mother liquor circulation system according to claim 4, characterized in that: The cold material outlet of the cold exchange heat exchanger (5) is connected to a distillate recovery tank (8), the lower end of the distillate recovery tank (8) is connected to a distillate collection valve (20), and the upper end of the distillate recovery tank (8) is connected between the vacuum pump (9) and the mother liquor recovery tank (7) through a pipe.

6. The plate-type vacuum evaporation mother liquor circulation system according to claim 1, characterized in that: The mother liquor recovery tank (7) is equipped with a vent valve (23) at the upper end. The mother liquor recovery tank (7) and the vacuum pump (9) are connected by a pipeline via a connecting valve (24) and a vacuum valve (25) in sequence.

7. A plate-type vacuum evaporation mother liquor circulation system according to claim 1, characterized in that: The cooling water tank (6) is connected to the cold material inlet of the cold exchange heat exchanger (5) via a pipeline, which is connected in sequence to the cooling water valve (18) and the cold circulation pump (13).

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