Hydrofluoric acid recovery system

Abstract

This utility model discloses a hydrofluoric acid recovery and utilization system, including a recovery tank, a cooler, and a pump set. The recovery tank has an acid inlet, a water inlet, and a mixed outlet. The cooler includes a tube side and a shell side for introducing a refrigerant. The tube side has a tube inlet and a tube outlet, with the tube inlet connected to the mixed outlet. The pump set has a pump inlet connected to the tube outlet and a pump outlet for connecting to a water scrubbing tower. This hydrofluoric acid recovery and utilization system can achieve the recovery and utilization of low-concentration aqueous hydrofluoric acid.

Description

Technical Field

[0001] This utility model relates to the technical field of equipment for treating fluorine-containing waste acid, and specifically to a hydrofluoric acid recovery and utilization system. Background Technology

[0002] The production of fluorinated refrigerants uses chloroform and hydrogen fluoride as raw materials. The two react catalytically to produce primary refrigerant products, byproduct hydrogen fluoride, and greenhouse gases. The primary refrigerant products and byproduct hydrogen fluoride are washed with water in a water washing tower to remove the hydrogen fluoride (hydrogen fluoride can be dissolved in water to obtain hydrofluoric acid with a concentration of 12% to 13%). After alkaline washing, fractionation, and other processes, high-purity fluorinated refrigerants can be obtained. The byproduct greenhouse gases are incinerated using an incineration unit.

[0003] During the combustion of greenhouse gases as byproducts, low-concentration hydrofluoric acid with a concentration of 2% to 5% is generated. Because the concentration of this hydrofluoric acid is low and does not meet the sales demand, it is usually treated as fluoride-containing wastewater, which requires storage and batch processing, resulting in a significant waste of resources. Utility Model Content

[0004] This utility model aims to at least partially solve one of the technical problems in the related art.

[0005] Therefore, embodiments of this utility model propose a hydrofluoric acid recovery and utilization system that can realize the recovery and utilization of low-concentration aqueous hydrofluoric acid.

[0006] The hydrofluoric acid recovery system of this utility model includes a recovery tank, a cooler, and a pump set. The recovery tank has an acid inlet, a water inlet, and a mixed outlet. The cooler includes a tube side and a shell side for introducing a refrigerant. The tube side has a tube inlet and a tube outlet. The tube inlet is connected to the mixed outlet. The pump set has a pump inlet connected to the tube outlet and a pump outlet for connecting to a water scrubbing tower.

[0007] In some embodiments, the hydrofluoric acid recovery system further includes a first level gauge and a water valve. The first level gauge is connected to the recovery tank to monitor the level of the recovery tank. The water valve is connected to the water inlet to control the opening of the water inlet. The first level gauge is electrically connected to the water valve.

[0008] In some embodiments, the hydrofluoric acid recovery system further includes a second level gauge connected to the recovery tank to monitor the level of the recovery tank.

[0009] In some embodiments, the hydrofluoric acid recycling system further includes a first pressure sensor connected to the recycling tank to monitor the pressure inside the recycling tank.

[0010] In some embodiments, the shell side has a shell side inlet, and the hydrofluoric acid recovery system further includes a temperature sensor and a cooling valve. The temperature sensor is connected to the tube side outlet, and the cooling valve is connected to the shell side inlet. The temperature sensor is electrically connected to the cooling valve.

[0011] In some embodiments, the sidewalls of the tube are made of graphite or silicon carbide.

[0012] In some embodiments, the pump assembly includes a first pump body and a second pump body, wherein the inlet of the first pump body and the inlet of the second pump body form the pump inlet, and the outlet of the first pump body and the outlet of the second pump body form the pump outlet.

[0013] In some embodiments, a reflux pipe is provided between the pump outlet and the recovery tank; the hydrofluoric acid recovery system further includes a second pressure sensor and a reflux valve, the second pressure sensor being connected to the pump outlet, the reflux valve being connected to the reflux pipe, and the second pressure sensor being electrically connected to the reflux valve.

[0014] In some embodiments, the hydrofluoric acid recovery system further includes an outlet valve and a third pressure sensor for monitoring the pressure at the bottom of the water washing tower. The outlet valve is connected to the pump outlet to control the opening of the pump outlet. Both the second pressure sensor and the third pressure sensor are electrically connected to the outlet valve.

[0015] In some embodiments, the hydrofluoric acid recovery system further includes a flow control unit, and the pump outlet is connected to the outlet valve via the flow control unit.

[0016] The hydrofluoric acid recovery and utilization system of this utility model uses a mixture of low-concentration aqueous hydrofluoric acid produced by the incineration device and water as water for a water washing tower to remove hydrogen fluoride from the refrigerant product. After the hydrogen fluoride in the refrigerant product dissolves in water, the concentration of hydrofluoric acid increases to obtain aqueous hydrofluoric acid with a concentration of 12% to 13% (which can meet sales requirements). It is then discharged as a by-product of the water washing tower, thereby realizing the recovery and utilization of low-concentration aqueous hydrofluoric acid. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the hydrofluoric acid recovery and utilization system according to one embodiment of the present invention.

[0018] Figure label:

[0019] 100. Hydrofluoric acid recovery and utilization system;

[0020] 1. Recovery tank; 11. Acid inlet; 12. Water inlet; 13. Mixing outlet;

[0021] 2. Cooler; 21. Tube-side inlet; 22. Tube-side outlet; 23. Shell-side inlet;

[0022] 3. Pump unit; 31. Pump inlet; 32. Pump outlet; 33. First pump body; 34. Second pump body;

[0023] 41. First level gauge; 42. Water valve; 43. Second level gauge; 44. First pressure sensor;

[0024] 51. Temperature sensor; 52. Cooling valve;

[0025] 6. Return pipe; 61. Second pressure sensor; 62. Return valve;

[0026] 71. Outlet valve; 72. Third pressure sensor;

[0027] 81. Flow meter; 82. Flow valve. Detailed Implementation

[0028] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0029] like Figure 1 As shown, the hydrofluoric acid recovery system 100 of this utility model embodiment includes a recovery tank 1, a cooler 2, and a pump set 3. The recovery tank 1 has an acid inlet 11, a water inlet 12, and a mixing outlet 13. The cooler 2 includes a tube side and a shell side for introducing a refrigerant. The tube side has a tube inlet 21 and a tube outlet 22. The tube inlet 21 is connected to the mixing outlet 13. The pump set 3 has a pump inlet 31 connected to the tube outlet 22 and a pump outlet 32 ​​for connecting to a water scrubbing tower.

[0030] The hydrofluoric acid recovery and utilization system 100 of this utility model uses a mixture of low-concentration aqueous hydrofluoric acid produced by the incineration device and water as water for a water washing tower to remove hydrogen fluoride from refrigerant products. After the hydrogen fluoride in the refrigerant products dissolves in water, the concentration of hydrofluoric acid increases to obtain aqueous hydrofluoric acid with a concentration of 12% to 13% (which can meet sales requirements). It is then discharged as a by-product of the water washing tower, thereby realizing the recovery and utilization of low-concentration aqueous hydrofluoric acid.

[0031] Specifically, such as Figure 1 As shown, hydrofluoric acid is supplied to the acid inlet 11 of the recovery tank 1, and deoxygenated water is supplied to the water inlet 12. The mixing outlet 13 of the recovery tank 1 is connected to the tube inlet 21 of the cooler 2 through a pipeline. The tube outlet 22 of the cooler 2 is connected to the pump inlet 31 through a pipeline. The pump outlet 32 ​​is connected to the water washing tower through a pipeline.

[0032] The low-concentration aqueous hydrofluoric acid produced by the incineration unit is recovered into recovery tank 1, where it is mixed and diluted with deoxygenated water. The mixture is then discharged from mixing outlet 13 and cooled in cooler 2. Afterward, it enters a water scrubbing tower under the action of pump unit 3 to remove hydrogen fluoride from the refrigerant product, thereby recovering and reusing the low-concentration aqueous hydrofluoric acid produced by the incineration unit. The use of cooler 2 to cool the water (containing low-concentration aqueous hydrofluoric acid) entering the water scrubbing tower further facilitates the stratification of the organic and inorganic phases within the water scrubbing tower.

[0033] In some embodiments, such as Figure 1 As shown, the hydrofluoric acid recovery system 100 also includes a first level gauge 41 and a water valve 42. The first level gauge 41 is connected to the recovery tank 1 to monitor the level of the recovery tank 1. The water valve 42 is connected to the water inlet 12 to control the opening degree of the water inlet 12. The first level gauge 41 and the water valve 42 are electrically connected.

[0034] By electrically connecting the first level gauge 41 to the water valve 42, interlock control of the liquid level in the recovery tank 1 can be achieved. The first level gauge 41 monitors the liquid level in the recovery tank 1 in real time. When the liquid level in the recovery tank 1 is lower than the preset liquid level, the water valve 42 automatically opens or its opening degree is increased, so that the liquid level in the recovery tank 1 rises rapidly and reaches the preset liquid level. When the liquid level in the recovery tank 1 is higher than the preset liquid level, the water valve 42 automatically closes or its opening degree is reduced, so that the liquid level in the recovery tank 1 decreases. Thus, the liquid level in the recovery tank 1 is relatively stable, thereby achieving a stable water supply to the water washing tower.

[0035] In some embodiments, such as Figure 1 As shown, the hydrofluoric acid recovery system 100 also includes a second level gauge 43, which is connected to the recovery tank 1 to monitor the level of the recovery tank 1.

[0036] The second level gauge 43 and the first level gauge 41 can refer to each other to ensure the normal use of the first level gauge 41, thereby improving the stability and safety of the hydrofluoric acid recovery system 100.

[0037] In some embodiments, such as Figure 1As shown, the hydrofluoric acid recycling system 100 also includes a first pressure sensor 44, which is connected to the recycling tank 1 to monitor the pressure inside the recycling tank 1.

[0038] Pressure sensors can monitor the pressure inside recycling tank 1, allowing operators to obtain information on the pressure status at any time, maintain stable pressure inside recycling tank 1, and improve the safety of recycling tank 1.

[0039] In some embodiments, such as Figure 1 As shown, the shell side has a shell side inlet 23, and the hydrofluoric acid recovery system 100 also includes a temperature sensor 51 and a cooling valve 52. The temperature sensor 51 is connected to the tube side outlet 22, and the cooling valve 52 is connected to the shell side inlet 23. The temperature sensor 51 and the cooling valve 52 are electrically connected.

[0040] The temperature of the mixed liquid discharged from the recovery tank 1 can be controlled by electrically connecting the temperature sensor 51 and the cooling valve 52. Specifically, the temperature sensor 51 monitors the temperature of the mixed liquid after it has been cooled by the cooler 2 in real time. When the temperature of the mixed liquid is higher than the preset temperature, the opening of the cooling valve 52 is increased to increase the flow rate of the cooling medium in the shell side. When the temperature of the mixed liquid is lower than the preset temperature, the opening of the cooling valve 52 is decreased to reduce the flow rate of the cooling medium in the shell side. This keeps the temperature of the mixed liquid entering the water washing tower stable and improves the water washing efficiency of the water washing tower.

[0041] Optionally, the cooling medium in the shell side of cooler 2 is ethylene glycol.

[0042] Specifically, the heat exchange area of ​​cooler 2 is 13.8 m². 2 The feed temperature of the tube side of cooler 2 is 50℃, the discharge temperature is 10℃, and the flow rate is 2m³ / s. 3 / h, the feed temperature of the shell side is 0℃, and the discharge temperature is 5℃.

[0043] In some embodiments, the sidewalls of the tube are made of graphite or silicon carbide.

[0044] Since the mixed liquid contains hydrofluoric acid, the tubes are made of graphite or silicon carbide, which can prevent corrosion and extend the service life of cooler 2.

[0045] In some embodiments, such as Figure 1 As shown, the pump set 3 includes a first pump body 33 and a second pump body 34. The inlet of the first pump body 33 and the inlet of the second pump body 34 form the pump inlet 31, and the outlet of the first pump body 33 and the outlet of the second pump body 34 form the pump outlet 32.

[0046] In some embodiments, a reflux pipe 6 is provided between the pump outlet 32 ​​and the recovery tank 1; the hydrofluoric acid recovery system 100 further includes a second pressure sensor 61 and a reflux valve 62, the second pressure sensor 61 is connected to the pump outlet 32, the reflux valve 62 is connected to the reflux pipe 6, and the second pressure sensor 61 is electrically connected to the reflux valve 62.

[0047] By setting the above parameters, the pressure at pump outlet 32 ​​can be adjusted to ensure the pressure balance of the hydrofluoric acid recovery system 100, thereby enabling the stable operation of the hydrofluoric acid recovery system 100.

[0048] In some embodiments, such as Figure 1 As shown, the hydrofluoric acid recovery system 100 also includes an outlet valve 71 and a third pressure sensor 72 for monitoring the pressure of the bottom of the water washing tower. The outlet valve 71 is connected to the pump outlet 32 ​​to control the opening of the pump outlet 32. The second pressure sensor 61 and the third pressure sensor 72 are both electrically connected to the outlet valve 71.

[0049] Interlocking control can be achieved through the electrical connection of the second pressure sensor 61, the third pressure sensor 72, and the outlet valve 71. Specifically, when the pressure difference between the pressure value detected by the second pressure sensor 61 (pump outlet 32 ​​pressure) and the pressure value detected by the third pressure sensor 72 (bottom pressure of the water washing tower) is ≤0.1MPa, the outlet valve 71 is closed. This prevents liquid backflow caused by the bottom pressure of the water washing tower being lower than the pump outlet 32 ​​pressure, ensuring the stable operation of the hydrofluoric acid recovery system 100 and the water washing tower.

[0050] In some embodiments, the hydrofluoric acid recovery system 100 further includes a flow control unit, and the pump outlet 32 ​​is connected to the outlet valve 71 through the flow control unit.

[0051] Specifically, such as Figure 1 As shown, the flow control unit includes a flow meter 81 and a flow valve 82. The flow valve 82 is located downstream of the flow meter 81, and the flow meter 81 is electrically connected to the flow valve 82. When the flow rate in the pipeline from the pump outlet 32 ​​to the water washing tower is lower than the preset flow rate, the opening of the flow valve 82 is increased to increase the flow rate of the mixed liquid entering the water washing tower. When the flow rate in the pipeline from the pump outlet 32 ​​to the water washing tower is higher than the preset flow rate, the opening of the flow valve 82 is decreased to reduce the flow rate of the mixed liquid entering the water washing tower. This ensures the stable operation of the water washing tower and thus ensures the recovery efficiency of the low-concentration aqueous hydrofluoric acid produced by the incineration unit.

[0052] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0053] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0054] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0055] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0056] In this utility model, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0057] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A hydrofluoric acid recovery and utilization system, characterized in that, The system includes a recovery tank, a cooler, and a pump assembly. The recovery tank has an acid inlet, a water inlet, and a mixed outlet. The cooler includes a tube side and a shell side for introducing a refrigerant. The tube side has a tube inlet and a tube outlet, with the tube inlet connected to the mixed outlet. The pump assembly has a pump inlet connected to the tube outlet and a pump outlet for connecting to a water scrubbing tower.

2. The hydrofluoric acid recycling system according to claim 1, characterized by, The hydrofluoric acid recovery system further includes a first level gauge and a water valve. The first level gauge is connected to the recovery tank to monitor the level of the recovery tank. The water valve is connected to the water inlet to control the opening of the water inlet. The first level gauge is electrically connected to the water valve.

3. The hydrofluoric acid recycling system according to claim 2, characterized by, The hydrofluoric acid recovery system also includes a second level gauge connected to the recovery tank to monitor the level of the recovery tank.

4. The hydrofluoric acid recycling system according to claim 1, characterized by, The hydrofluoric acid recycling system also includes a first pressure sensor connected to the recycling tank to monitor the pressure inside the recycling tank.

5. The hydrofluoric acid recycling system according to claim 1, characterized by, The shell side has a shell side inlet. The hydrofluoric acid recovery system also includes a temperature sensor and a cooling valve. The temperature sensor is connected to the tube side outlet, and the cooling valve is connected to the shell side inlet. The temperature sensor is electrically connected to the cooling valve.

6. The hydrofluoric acid recycling system according to claim 5, characterized by The sidewalls of the tube are made of graphite or silicon carbide.

7. The hydrofluoric acid recycling system according to claim 1, characterized by, The pump assembly includes a first pump body and a second pump body, the inlet of the first pump body and the inlet of the second pump body form the pump inlet, and the outlet of the first pump body and the outlet of the second pump body form the pump outlet.

8. The hydrofluoric acid recycling system according to claim 7, characterized by, A return pipe is provided between the pump outlet and the recovery tank; The hydrofluoric acid recovery system also includes a second pressure sensor and a reflux valve. The second pressure sensor is connected to the pump outlet, and the reflux valve is connected to the reflux pipeline. The second pressure sensor is electrically connected to the reflux valve.

9. The hydrofluoric acid recycling system according to claim 8, characterized by, The hydrofluoric acid recovery system also includes an outlet valve and a third pressure sensor for monitoring the pressure of the bottom of the water washing tower. The outlet valve is connected to the pump outlet to control the opening of the pump outlet. The second pressure sensor and the third pressure sensor are both electrically connected to the outlet valve.

10. The hydrofluoric acid recycling system according to claim 9, characterized by, The hydrofluoric acid recovery system also includes a flow control unit, and the pump outlet is connected to the outlet valve through the flow control unit.

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