Photovoltaic hydrofluoric acid diluting device

Abstract

The photovoltaic hydrofluoric acid diluting device comprises a tank body, a circulating liquid inlet and a pure water inlet are formed in the top of the tank body, the circulating liquid inlet is connected with an insertion pipe, and the insertion pipe is located in the tank body; a coil pipe is arranged in the tank body; an anhydrous hydrofluoric acid inlet is formed in the side surface of the tank body; a hydrofluoric acid outlet is formed in the bottom of the tank body. The photovoltaic-grade hydrofluoric acid production process is stable, and multiple safety protection including weight interlocking protection, liquid level interlocking protection and temperature interlocking protection is achieved; the process and the operation method are simple, the equipment investment is low, and the leakage risk is very low.

Description

Technical Field

[0001] This device belongs to the field of hydrofluoric acid production, specifically involving a photovoltaic-grade hydrofluoric acid dilution device. Background Technology

[0002] Anhydrous hydrofluoric acid, also known as anhydrous hydrogen fluoride, is a widely used chemical product. It is a colorless, fuming liquid with a purity of over 99%, boiling at 19°C. It readily vaporizes under reduced pressure or at room temperature and is an important raw material for the preparation of fluoride salts, fluoroalkanes, fluorinated refrigerants, electrolytic elemental fluorine, and etching solutions for the photovoltaic and semiconductor industries. Both anhydrous hydrofluoric acid and its diluted aqueous form are extremely corrosive and permeable. When anhydrous hydrofluoric acid dissolves in water, it releases heat dramatically. Therefore, the heat resistance, corrosion resistance, and leak-proof properties of hydrofluoric acid dilution equipment and its associated heat exchangers are crucial. Utility Model Content

[0003] To address the aforementioned issues, this invention provides a photovoltaic-grade hydrofluoric acid dilution device, which can achieve clean dilution of photovoltaic-grade hydrofluoric acid, ensuring product quality and production safety.

[0004] A photovoltaic-grade hydrofluoric acid dilution device includes a tank, with a circulating liquid inlet and a pure water inlet at the top of the tank. The circulating liquid inlet is connected to an insertion pipe located inside the tank. A coil is installed inside the tank. An anhydrous hydrofluoric acid inlet is provided on the side of the tank. A hydrofluoric acid outlet is provided at the bottom of the tank.

[0005] The top of the tank is provided with a cooling water inlet and a cooling water outlet, and the two ends of the coil are connected to the cooling water inlet and the cooling water outlet, respectively.

[0006] The tank is equipped with an upper interface for a level gauge at the top and a lower interface for a level gauge at the bottom. The upper and lower interfaces for the level gauge are connected to the level gauge.

[0007] The tank has a nitrogen inlet and an exhaust outlet at the top, and a thermometer interface on the side, which is connected to a thermometer.

[0008] The insertion tube is located at the center of the coil, and the bottom end of the insertion tube is located at 1 / 3 to 2 / 3 of the height of the groove.

[0009] The sides of the tank are symmetrically connected with floor plates, which are connected to weighing devices.

[0010] The tank is made of 304 stainless steel lined with PTFE or PFA.

[0011] The coil is made of PFA material.

[0012] The bottom of the tank is an arc-shaped bottom, and the upper flange is flat-sealed.

[0013] The beneficial effects of this utility model are as follows:

[0014] (1) The process control of photovoltaic grade hydrofluoric acid produced by this utility model is stable and has multiple safety protections, including weight interlock, liquid level interlock and temperature interlock protection; the process and operation method are simple, the equipment investment is small and the risk of leakage is very low.

[0015] (2) This utility model uses stainless steel lined PTFE+PFA coils, which can avoid the relatively expensive external heat exchanger, and has the characteristics of higher safety, simple process, low cost and convenient use. With the addition of nitrogen sealing device, it can realize the dilution preparation of high-end photovoltaic grade hydrofluoric acid. Attached Figure Description

[0016] Figure 1 Front view of the device;

[0017] Figure 2 A schematic diagram of the top of this device;

[0018] Figure 3 A schematic diagram of the bottom of this device;

[0019] The diagram shows the following labels: 1. Tank body; 2. Coil; 3. Insertion pipe; 4. Grounding plate; 5. Circulating liquid inlet N1; 6. Cooling water inlet N2; 7. Level gauge upper interface N3a; 8. Level gauge lower interface N3b; 9. Nitrogen inlet N4; 10. Exhaust port N5; 11. Pure water inlet N6; 12. Cooling water outlet N7; 13. Thermometer interface N8; 14. Anhydrous hydrofluoric acid inlet N9; 15. Hydrofluoric acid outlet N10. Detailed Implementation

[0020] The embodiments of this utility model will be described in detail below with reference to the examples. The following examples are only used to illustrate this utility model and should not be regarded as limiting the scope of this utility model.

[0021] Example 1

[0022] A photovoltaic-grade hydrofluoric acid dilution device includes a tank 1. The top of the tank 1 is provided with a circulating liquid inlet N1 and a pure water inlet N6. The circulating liquid inlet N1 is connected to an insertion pipe 3, which is located inside the tank 1. A coil 2 is provided inside the tank 1. An anhydrous hydrofluoric acid inlet N9 is provided on the side of the tank 1. A hydrofluoric acid outlet N10 is provided at the bottom of the tank 1.

[0023] The top of the tank 1 is provided with a cooling water inlet N2 and a cooling water outlet N7, and the two ends of the coil 2 are respectively connected to the cooling water inlet N2 and the cooling water outlet N7.

[0024] The tank 1 is provided with a liquid level gauge upper interface N3a at the top and a liquid level gauge lower interface N3b at the bottom, and the liquid level gauge upper interface N3a and liquid level gauge lower interface N3b are connected to the liquid level gauge.

[0025] The top of the tank 1 is provided with a nitrogen inlet N4 and an exhaust port N5, and the side is provided with a thermometer interface N8, which is connected to a thermometer.

[0026] The insertion tube 3 is located at the center of the coil 2, and the bottom end of the insertion tube 3 is located at 1 / 3 to 2 / 3 of the height of the groove 1.

[0027] The tank body 1 has symmetrically connected ground plates 4 on its side, and the ground plates 4 are connected to the weighing device.

[0028] The tank 1 is a tank made of 304 stainless steel lined with PTFE or PFA.

[0029] The coil 2 is made of PFA material.

[0030] The bottom of the tank 1 is an arc-shaped bottom, and the upper flange is flat sealed.

[0031] Example 2

[0032] Tank 1 is cylindrical with a rounded bottom and a flat flange at the top. It is lined with PTFE or PFA and has dimensions of D2000*H3800mm. Tank 1 contains an 8mm PFA coil 2 with a heat exchange area of ​​45m². 2 Each unit has a photovoltaic-grade hydrofluoric acid production capacity of 30t / d.

[0033] Taking the preparation of 9 tons of 50% HF as an example, the specific working process is as follows:

[0034] Cooling water enters coil 2 through cooling water inlet N2 and then flows out through cooling water outlet N7. The hydrofluoric acid outlet N10 is connected to the circulating liquid inlet N1 via an external pipe, which also has a pump connected to it. 4.5t of pure water is added to tank 1 at once through pure water inlet N6, and the pump is started for circulation. Anhydrous hydrofluoric acid slowly enters tank 1 through anhydrous hydrofluoric acid inlet N9. The pure water and anhydrous hydrofluoric acid mix in tank 1, and cooling water circulates inside coil 2 to cool the mixture. Under the action of the pump, the resulting hydrofluoric acid flows out through hydrofluoric acid outlet N10 and then back into tank 1 through circulating liquid inlet N1 until the net weight reaches 9t, at which point the anhydrous hydrofluoric acid inlet N9 is closed. Circulation continues for approximately 2 hours, during which samples can be taken for quality testing. After circulation is complete, the finished hydrofluoric acid flows out and is collected through the bottom hydrofluoric acid outlet N10.

[0035] During operation, the level gauge, thermometer, and weighing device are all interlocked with the system's DSC control.

[0036] The internal pressure of the device is adjusted by introducing nitrogen or venting exhaust gas. Nitrogen enters from the nitrogen inlet N4, and exhaust gas flows out from the exhaust port N5.

[0037] Coil 2 is made of PFA material, and a distributor is installed at the interface to fix multiple PFAs to one outlet.

[0038] During initial operation, use photovoltaic-grade hydrofluoric acid for circulating cleaning until the sample reaches the photovoltaic grade, or directly start production and use the produced products for circulating cleaning until the equipment reaches the photovoltaic grade.

Claims

1. A photovoltaic-grade hydrofluoric acid dilution device, characterized in that, The tank includes a tank body (1), with a circulating liquid inlet (N1) and a pure water inlet (N6) at the top. The circulating liquid inlet (N1) is connected to an insertion pipe (3), which is located inside the tank body (1). A coil (2) is provided inside the tank body (1). An anhydrous hydrofluoric acid inlet (N9) is provided on the side of the tank body (1). A hydrofluoric acid outlet (N10) is provided at the bottom of the tank body (1).

2. The photovoltaic-grade hydrofluoric acid dilution device according to claim 1, characterized in that, The top of the tank (1) is provided with a cooling water inlet (N2) and a cooling water outlet (N7), and the two ends of the coil (2) are connected to the cooling water inlet (N2) and the cooling water outlet (N7) respectively.

3. The photovoltaic-grade hydrofluoric acid dilution device according to claim 1, characterized in that, The tank (1) is provided with a liquid level gauge upper interface (N3a) at the top and a liquid level gauge lower interface (N3b) at the bottom. The liquid level gauge upper interface (N3a) and the liquid level gauge lower interface (N3b) are connected to the liquid level gauge.

4. The photovoltaic-grade hydrofluoric acid dilution device according to claim 1, characterized in that, The tank (1) has a nitrogen inlet (N4) and an exhaust port (N5) at the top, and a thermometer interface (N8) on the side, which is connected to a thermometer.

5. The photovoltaic-grade hydrofluoric acid dilution device according to claim 1, characterized in that, The insertion tube (3) is located at the center of the coil (2), and the bottom end of the insertion tube (3) is located at 1 / 3 to 2 / 3 of the height of the groove (1).

6. The photovoltaic-grade hydrofluoric acid dilution device according to claim 1, characterized in that, The tank (1) has symmetrically connected ground plates (4) on its side, and the ground plates (4) are connected to the weighing device.

7. The photovoltaic-grade hydrofluoric acid dilution device according to claim 1, characterized in that, The tank (1) is made of 304 stainless steel lined with PTFE or PFA.

8. The photovoltaic-grade hydrofluoric acid dilution device according to claim 1, characterized in that, The coil (2) is made of PFA material.

9. The photovoltaic-grade hydrofluoric acid dilution device according to claim 1, characterized in that, The bottom of the tank (1) is an arc-shaped bottom and the upper flange is flat sealed.

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