Tail gas treatment system for ammonium bifluoride electrolyte batching kettle

Abstract

The utility model belongs to the technical field of tail gas treatment of ammonium bifluoride electrolyte batching kettles, and particularly relates to a tail gas treatment system of an ammonium bifluoride electrolyte batching kettle, which comprises a batching kettle, a condenser and a primary water scrubber, the ammonia gas inlet is connected with an ammonia gas supply pipeline, the hydrogen fluoride inlet is connected with a hydrogen fluoride supply pipeline, the condenser is provided with a tail gas inlet, a tail gas outlet and a liquid discharge port, the tail gas inlet is connected with a tail gas discharge port through a first exhaust pipe, and the tail gas outlet is connected with a gas inlet of the first-stage water washing tower through a second exhaust pipe. According to the tail gas treatment system for the ammonium bifluoride electrolyte batching kettle, the condenser is additionally arranged in front of the first-stage water scrubber, hydrogen fluoride gas in tail gas can be liquefied into a liquid phase, nitrogen and ammonia gas in the tail gas are still gas phases at the moment, and therefore the purpose of completely separating hydrogen fluoride in the tail gas can be achieved; the utilization rate of hydrogen fluoride is effectively improved.

Description

Technical Field

[0001] The utility model relates to an ammonium bifluoride electrolyte batching kettle tail gas treatment system, belonging to the technical field of ammonium bifluoride electrolyte batching kettle tail gas treatment. Background Art

[0002] At present, the ingredients of ammonium bifluoride electrolyte are mostly prepared in a batching kettle, specifically: liquid ammonia is vaporized into ammonia gas through a liquid ammonia vaporizer, and then the ammonia gas enters the batching kettle to react with hydrogen fluoride to form molten ammonium bifluoride. Since this reaction is an exothermic reaction, the reaction temperature is controlled at 120-130°C during batching, and the boiling point of hydrogen fluoride is 19.51°C, so when batching, the main components of the tail gas formed in the batching kettle are hydrogen fluoride, ammonia and nitrogen. In the prior art, the treatment method for tail gas is usually: the tail gas is directly passed into a primary water scrubber, and the hydrogen fluoride in the tail gas is adsorbed by the primary water scrubber to form hydrofluoric acid, which is stored and taken away. Although this process can recover hydrogen fluoride, ammonia will also dissolve in water to form ammonia water during the water washing process, and ammonia water will react with hydrofluoric acid to form ammonium fluoride, which will cause the hydrogen fluoride to be unable to be fully recovered, reducing the utilization rate of hydrogen fluoride. Utility Model Content

[0003] In view of the above deficiencies in the prior art, the technical problem to be solved by the utility model is to provide an ammonium bifluoride electrolyte batching kettle tail gas treatment system which can completely recover hydrogen fluoride.

[0004] The utility model discloses an ammonium bifluoride electrolyte batching kettle tail gas treatment system, comprising a batching kettle, a condenser and a primary water scrubber, wherein the batching kettle is provided with an ammonia inlet, a hydrogen fluoride inlet, an ammonium bifluoride outlet and a tail gas discharge port, the ammonia inlet is connected to an ammonia supply pipeline, the hydrogen fluoride inlet is connected to the hydrogen fluoride supply pipeline, the condenser is provided with a tail gas inlet, a tail gas outlet and a liquid discharge port, the tail gas inlet is connected to the tail gas discharge port through a first exhaust pipe, and the tail gas outlet is connected to the air inlet of the primary water scrubber through a second exhaust pipe.

[0005] Furthermore, a heating jacket is provided on the side wall of the batching kettle, and a heat medium inlet and a heat medium outlet are provided on the heating jacket.

[0006] Furthermore, the condenser is a vertical shell and tube condenser, the exhaust gas inlet and exhaust gas outlet are both arranged on the upper tube box of the condenser, the drain port is U-shaped and arranged on the lower tube box of the condenser, and the shell of the condenser is provided with a cold medium inlet and a cold medium outlet.

[0007] Furthermore, the batching kettle is provided with an air return port, the liquid discharge port is connected to a gas booster device via an air return pipe, and the air outlet of the gas booster device is connected to the air return port.

[0008] Furthermore, the air return pipe is connected to an air storage box.

[0009] Compared with the prior art, the utility model has the following beneficial effects:

[0010] The tail gas treatment system of the ammonium bifluoride electrolyte batching kettle of the utility model can liquefy the hydrogen fluoride gas in the tail gas into a liquid phase by adding a condenser before the primary water washing tower. At this time, the nitrogen and ammonia in the tail gas are still in the gas phase, so the purpose of completely separating the hydrogen fluoride in the tail gas can be achieved, and the utilization rate of the hydrogen fluoride is effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the structure of Embodiment 1 of the present utility model;

[0012] Figure 2 It is a structural schematic diagram of embodiment 2 of the present utility model.

[0013] In the figure: 1, batching kettle; 2, heating jacket; 3, ammonia supply pipeline; 4, hydrogen fluoride supply pipeline; 5, ammonia inlet; 6, hydrogen fluoride inlet; 7, return air port; 8, gas booster; 9, ammonium bifluoride outlet; 10, tail gas discharge port; 11, first exhaust pipe; 12, tail gas inlet; 13, upper pipe box; 14, tail gas outlet; 15, lower pipe box; 16, drain port; 17, return air pipe; 18, air storage box; 19, condenser; 20, second exhaust pipe; 21, primary water scrubber; 22, air inlet; 23, hot medium inlet; 24, hot medium outlet; 25, cold medium inlet; 26, cold medium outlet. DETAILED DESCRIPTION

[0014] The following is a further description of the embodiments of the present invention in conjunction with the accompanying drawings:

[0015] Embodiment 1:

[0016] like Figure 1 As shown, the tail gas treatment system of the ammonium bifluoride electrolyte batching kettle described in the utility model comprises a batching kettle 1, a condenser 19 and a primary water scrubber 21, the batching kettle 1 is provided with an ammonia inlet 5, a hydrogen fluoride inlet 6, an ammonium bifluoride outlet 9 and a tail gas discharge port 10, the ammonia inlet 5 is connected to the ammonia supply pipeline 3, the hydrogen fluoride inlet 6 is connected to the hydrogen fluoride supply pipeline 4, the condenser 19 is provided with a tail gas inlet 12, a tail gas outlet 14 and a liquid discharge port 16, the tail gas inlet 12 is connected to the tail gas discharge port 10 through a first exhaust pipe 11, and the tail gas outlet 14 is connected to the air inlet 22 of the primary water scrubber 21 through a second exhaust pipe 20.

[0017] During use, ammonia is introduced into the batching kettle 1 through the ammonia supply pipeline 3, and hydrogen fluoride is introduced into the batching kettle 1 through the hydrogen fluoride supply pipeline 4, and the temperature in the batching kettle 1 is controlled at 120° C.-130° C. Ammonia and hydrogen fluoride react in the batching kettle 1 to generate molten ammonium bifluoride, which can be discharged through the ammonium bifluoride outlet 9; tail gas containing hydrogen fluoride, ammonia and nitrogen is generated in the batching kettle 1, and the tail gas enters the condenser 19 through the first exhaust pipe 11, and the temperature in the condenser 19 is controlled between -33.5° C.-19.5° C. (the most economical control temperature can be selected according to the amount of tail gas), at which time the hydrogen fluoride gas in the tail gas is liquefied into a liquid phase, and the nitrogen and ammonia are still in a gas phase, and the liquid phase hydrogen fluoride can be discharged through the drain port 16, so as to achieve the purpose of completely separating the hydrogen fluoride in the tail gas, and the gas phase nitrogen and ammonia enter the primary water scrubber 21 through the second exhaust pipe 20 for further subsequent treatment.

[0018] The tail gas treatment system of the ammonium bifluoride electrolyte batching kettle of the utility model can liquefy the hydrogen fluoride gas in the tail gas into a liquid phase by adding a condenser 19 before the primary water washing tower 21. At this time, the nitrogen and ammonia in the tail gas are still in the gas phase, so the purpose of completely separating the hydrogen fluoride in the tail gas can be achieved, and the utilization rate of the hydrogen fluoride is effectively improved.

[0019] Embodiment 2:

[0020] like Figure 2 As shown, based on Example 1,

[0021] Furthermore, a heating jacket 2 is provided on the side wall of the batching kettle 1, and a heat medium inlet 23 and a heat medium outlet 24 are provided on the heating jacket 2. By introducing heat medium into the heat medium inlet 23, the batching kettle 1 can be heated by the heating jacket 2, so as to achieve the purpose of controlling the reaction temperature in the batching kettle 1. The structure is simple and the operation effect is good.

[0022] Further, the condenser 19 is a vertical shell and tube condenser, the tail gas inlet 12 and the tail gas outlet 14 are both arranged on the upper tube box 13 of the condenser 19, the drain port 16 is U-shaped and arranged on the lower tube box 15 of the condenser 19, and the shell of the condenser 19 is provided with a cold medium inlet 25 and a cold medium outlet 26, the tail gas enters the upper tube box 13 through the tail gas inlet 12 and flows along the tube side, and by introducing the cold medium into the cold medium inlet 25, the cold medium inlet 25 can flow along the shell side and exchange heat with the tail gas flowing along the tube side, so that the hydrogen fluoride in the tail gas is liquefied into a liquid phase and flows into the lower tube box 15 and flows into the drain port 16. Since the drain port 16 is U-shaped, a liquid self-sealing can be formed to prevent the tail gas from being discharged through the drain port 16, and the nitrogen and ammonia in the tail gas still remain in the gas phase and are discharged through the tail gas outlet 14;

[0023] Furthermore, the batching kettle 1 is provided with a gas return port 7, the liquid discharge port 16 is connected to a gas booster 8 through a gas return pipe 17, the gas outlet of the gas booster 8 is connected to the gas return port 7, the liquid hydrogen fluoride in the liquid discharge port 16 will vaporize at room temperature and turn back into gas phase, and then be pressurized by the gas booster 8 and transported to the batching kettle 1 for reuse, thereby realizing online recovery and reuse of hydrogen fluoride;

[0024] Furthermore, the gas return pipe 17 is connected to a gas storage box 18, which can buffer the vaporized hydrogen fluoride gas and effectively improve the use effect.

Claims

1. An ammonium bifluoride electrolyte batching kettle tail gas treatment system, characterized in that: The invention comprises a batching kettle (1), a condenser (19) and a primary water washing tower (21). The batching kettle (1) is provided with an ammonia inlet (5), a hydrogen fluoride inlet (6), an ammonium hydrogen fluoride outlet (9) and a tail gas discharge port (10). The ammonia inlet (5) is connected to an ammonia supply pipeline (3), the hydrogen fluoride inlet (6) is connected to a hydrogen fluoride supply pipeline (4), the condenser (19) is provided with a tail gas inlet (12), a tail gas outlet (14) and a liquid discharge port (16), the tail gas inlet (12) is connected to the tail gas discharge port (10) through a first exhaust pipe (11), and the tail gas outlet (14) is connected to an air inlet (22) of the primary water washing tower (21) through a second exhaust pipe (20).

2. The tail gas treatment system of the ammonium bifluoride electrolyte batching kettle according to claim 1, characterized in that: A heating jacket (2) is provided on the side wall of the batching kettle (1), and a heat medium inlet (23) and a heat medium outlet (24) are provided on the heating jacket (2).

3. The tail gas treatment system of the ammonium bifluoride electrolyte batching kettle according to claim 1, characterized in that: The condenser (19) is a vertical shell and tube condenser, the exhaust gas inlet (12) and the exhaust gas outlet (14) are both arranged on the upper tube box (13) of the condenser (19), the drain port (16) is U-shaped and arranged on the lower tube box (15) of the condenser (19), and the shell of the condenser (19) is provided with a cold medium inlet (25) and a cold medium outlet (26).

4. The tail gas treatment system of the ammonium bifluoride electrolyte batching kettle according to any one of claims 1 to 3, characterized in that: The batching kettle (1) is provided with a gas return port (7), the liquid discharge port (16) is connected to a gas booster (8) via a gas return pipe (17), and the gas outlet of the gas booster (8) is connected to the gas return port (7).

5. The tail gas treatment system of the ammonium bifluoride electrolyte batching kettle according to claim 4, characterized in that: The air return pipe (17) is connected to an air storage box (18).

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