Hydrogen fluoride-containing waste gas and waste water recovery treatment device

Abstract

The utility model discloses a hydrogen fluoride-containing waste gas and waste water recovery treatment device which comprises a hydrogen fluoride-containing waste gas treatment device and a hydrogen fluoride-containing waste water treatment device, the hydrogen fluoride-containing waste gas treatment device comprises a waste gas recovery primary condenser, a waste gas recovery secondary condenser and a waste gas recovery hydrogen fluoride storage tank which are connected in sequence; the hydrogen fluoride-containing wastewater treatment device comprises a waste liquid evaporator, a waste liquid recovery primary condenser, a waste liquid recovery secondary condenser and a waste liquid recovery hydrogen fluoride storage tank which are connected in sequence; outlets of the waste gas recovery hydrogen fluoride storage tank and the waste liquid recovery hydrogen fluoride storage tank are connected with the hydrogen fluoride recovery distillation tower through the same pipeline after meeting. AHF is recycled for HF-containing waste gas and waste liquid, the recycled AHF can be reused at the front end of a production process, resource recycling is achieved on the premise that the production environment is improved, and the production cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of waste water recycling in the fluorine chemical industry, in particular to a device for recycling waste gas and waste water containing hydrogen fluoride. Background Art

[0002] In the fluorine chemical industry, hydrogen fluoride (HF) is usually used as a raw material in the chemical synthesis production process. Hydrogen fluoride is an inorganic compound. Under normal conditions, it is a colorless, pungent, toxic gas with a very strong hygroscopicity. It produces white smoke when it comes into contact with air. It is easily soluble in water and can be infinitely miscible with water to form hydrofluoric acid. Due to the low boiling point of AHF (19.5°C, normal pressure), HF will volatilize during the chemical production process to form chemical production waste gas, and the production process will also produce acidic waste liquid containing HF.

[0003] At present, the wastewater from hydrogen fluoride production in my country is mainly treated by neutralization and then discharged directly after reaching neutrality. The fluoride ion content is mainly controlled by replacement method, that is, replacement with calcium chloride or calcium hydroxide, and the replacement effect is not ideal. In particular, various muds produced by sewage stations have not been well precipitated and filtered. The treatment of hydrogen fluoride process tail gas mainly utilizes its water-soluble characteristics to treat it. At present, the common practice in the industry is to use water washing to wash it step by step. The treatment effect of this method requires manual replacement of saturated mother liquor in time, otherwise it will not be able to absorb further. And the existing technology basically treats waste gas alone or only can treat wastewater; the Chinese invention patent "Comprehensive Treatment Method for Waste Gas and Wastewater Generated in Hydrogen Fluoride Production" with application number CN201510660736.6 discloses a comprehensive treatment method for waste gas and wastewater generated in hydrogen fluoride production, which solves the technical problems of wastewater and waste gas treatment in the existing hydrogen fluoride production, such as failure to achieve zero wastewater discharge, failure to treat the generated solid waste, and failure to achieve the best environmental protection benefits. However, this method has the problems of complex process flow and low comprehensive treatment efficiency.

[0004] In response to the above-mentioned industry pain points, the applicant has developed a hydrogen fluoride waste gas and wastewater recovery and treatment device to recover AHF from HF-containing waste gas and waste liquid. The recovered AHF can be reused in the front end of the production process. While improving the production environment, it also achieves resource recycling and reduces production costs. Utility Model Content

[0005] The utility model aims to provide a device for recovering and treating waste gas and waste water containing hydrogen fluoride, so as to solve the problem that HF ​​waste gas is volatilized or produced as a by-product in the production of the fluorine chemical industry, and acidic waste liquid containing HF is also produced in the production process, and the existing technology cannot simultaneously and efficiently treat the waste gas and waste liquid.

[0006] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a hydrogen fluoride waste gas and wastewater recovery treatment device, comprising a hydrogen fluoride waste gas treatment device and a hydrogen fluoride wastewater treatment device; the hydrogen fluoride waste gas treatment device comprises a waste gas recovery primary condenser, a waste gas recovery secondary condenser and a waste gas recovery hydrogen fluoride storage tank connected in sequence; the hydrogen fluoride wastewater treatment device comprises a waste liquid evaporator, a waste liquid recovery primary condenser, a waste liquid recovery secondary condenser and a waste liquid recovery hydrogen fluoride storage tank connected in sequence; the waste gas recovery hydrogen fluoride storage tank The outlets of the waste liquid recovery tank and the waste liquid recovery hydrogen fluoride storage tank meet and are connected to the hydrogen fluoride recovery distillation tower through the same pipeline; the waste gas containing hydrogen fluoride is condensed by the waste gas recovery primary condenser and the waste gas recovery secondary condenser and then enters the waste gas recovery hydrogen fluoride storage tank; the waste water containing hydrogen fluoride is evaporated by the waste liquid evaporator and then passes through the waste liquid recovery primary condenser and the waste liquid recovery secondary condenser in sequence and then enters the waste liquid recovery hydrogen fluoride storage tank; the recovered hydrogen fluoride in the waste gas recovery hydrogen fluoride storage tank and the waste liquid recovery hydrogen fluoride storage tank enters the hydrogen fluoride recovery distillation tower to distill out anhydrous hydrogen fluoride.

[0007] As a preferred technical solution, the first-stage condenser for waste gas recovery is a condenser that uses chilled brine as the refrigerant, and the second-stage condenser for waste gas recovery is a condenser that uses deep cryogen as the refrigerant; the first-stage condenser for waste liquid recovery is a condenser that uses circulating water as the refrigerant, and the second-stage condenser for waste liquid recovery is a condenser that uses chilled brine as the refrigerant.

[0008] As a preferred technical solution, both the waste gas recovery secondary condenser and the waste liquid recovery secondary condenser are provided with tail gas treatment devices for treating uncondensed tail gas.

[0009] As a preferred technical solution, the waste liquid evaporator is also connected to a waste liquid treatment device for treating the residual liquid after evaporation of the hydrogen fluoride waste liquid.

[0010] As a preferred technical solution, the refrigerant in the first-stage condenser for waste gas recovery is frozen brine at 5 to 7°C; the refrigerant in the second-stage condenser is a cryogen at -30 to -35°C; the refrigerant in the first-stage condenser for waste liquid recovery is circulating water at 28 to 30°C; the refrigerant in the second-stage condenser for waste liquid recovery is frozen brine at 5 to 7°C.

[0011] As a preferred technical solution, the bottom of the hydrogen fluoride recovery distillation tower is also provided with a recovery pipe connected to the waste liquid evaporator for returning the bottom kettle liquid to the waste liquid evaporator for cyclic evaporation and recovery.

[0012] Compared with the prior art, the beneficial effects of the utility model are:

[0013] The utility model discloses a hydrogen fluoride-containing waste gas and waste water recovery and treatment device, which comprises a hydrogen fluoride-containing waste gas treatment device and a hydrogen fluoride-containing waste water treatment device. The hydrogen fluoride-containing waste gas is condensed by a waste gas recovery primary condenser and a waste gas recovery secondary condenser and then enters a waste gas recovery hydrogen fluoride storage tank. The hydrogen fluoride-containing waste water is evaporated by a waste liquid evaporator and then sequentially passes through a waste liquid recovery primary condenser and a waste liquid recovery secondary condenser and then enters a waste liquid recovery hydrogen fluoride storage tank. The recovered hydrogen fluoride in the waste gas recovery hydrogen fluoride storage tank and the waste liquid recovery hydrogen fluoride storage tank enters the hydrogen fluoride recovery distillation tower to distill out anhydrous hydrogen fluoride. The HF-containing waste gas and waste liquid are treated simultaneously, thereby reducing the production loss of hydrogen fluoride in the fluorine chemical industry, and also reducing the treatment scale of the hydrogen fluoride-containing waste liquid, reducing the treatment amount of the fluorine-containing sludge, and protecting the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The utility model is a schematic structural diagram of a device for recovering and treating waste gas and waste water containing hydrogen fluoride.

[0015] In the figure: 11. Waste gas recovery primary condenser; 12. Waste gas recovery secondary condenser; 13. Waste gas recovery hydrogen fluoride storage tank; 21. Waste liquid evaporator; 22. Waste liquid recovery primary condenser; 23. Waste liquid recovery secondary condenser; 24. Waste liquid recovery hydrogen fluoride storage tank; 3. Hydrogen fluoride recovery distillation tower; 4. Tail gas treatment device; 5. Waste liquid treatment device. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0017] See also Figure 1The utility model provides a technical solution: a hydrogen fluoride waste gas and waste water recovery treatment device, including a hydrogen fluoride waste gas treatment device and a hydrogen fluoride waste water treatment device; the hydrogen fluoride waste gas treatment device includes a waste gas recovery primary condenser 11, a waste gas recovery secondary condenser 12 and a waste gas recovery hydrogen fluoride storage tank 13 connected in sequence; the hydrogen fluoride waste water treatment device includes a waste liquid evaporator 21, a waste liquid recovery primary condenser 22 and a waste liquid recovery secondary condenser 23 and a waste liquid recovery hydrogen fluoride storage tank 24 connected in sequence; the waste gas recovery hydrogen fluoride storage tank 13 and the waste liquid recovery hydrogen fluoride storage tank 14 are connected in sequence. The outlets of the hydrogen storage tank 24 are connected to the hydrogen fluoride recovery distillation tower 3 through the same pipeline after the meeting; the hydrogen fluoride-containing waste gas is condensed by the waste gas recovery primary condenser 11 and the waste gas recovery secondary condenser 12 and then enters the waste gas recovery hydrogen fluoride storage tank 13; the hydrogen fluoride-containing waste water is evaporated by the waste liquid evaporator 21 and then sequentially passes through the waste liquid recovery primary condenser 22 and the waste liquid recovery secondary condenser 23 and then enters the waste liquid recovery hydrogen fluoride storage tank 24; the recovered hydrogen fluoride in the waste gas recovery hydrogen fluoride storage tank 13 and the waste liquid recovery hydrogen fluoride storage tank 24 enters the hydrogen fluoride recovery distillation tower 3 to distill out anhydrous hydrogen fluoride.

[0018] The waste gas recovery secondary condenser 12 and the waste liquid recovery secondary condenser 23 are both provided with an exhaust gas treatment device 4 for treating uncondensed exhaust gas; the waste liquid evaporator 21 is also connected to a waste liquid treatment device 5 for treating the residual liquid after evaporation of the hydrogen fluoride waste liquid.

[0019] The main process flow of waste gas and wastewater treatment is as follows: For HF-containing waste gas, the boiling point characteristics of HF are fully utilized, and a two-stage condenser is used to fully condense the HF in the waste gas. The first-stage condenser uses frozen brine (5-7°C) for condensation, and the second-stage condenser uses cryogenic agent (-30-35°C) for condensation. The condensed liquid HF is collected in a storage tank, and the uncondensed exhaust gas is sent to the exhaust gas treatment system for treatment to meet the emission standards.

[0020] For the HF-containing waste liquid, the waste liquid evaporator 21 is first used to separate HF from the waste liquid, the evaporation temperature is controlled at 30-70° C., and the pressure is controlled at 90-100 kPa (A). The separated HF-containing gas is condensed by two-stage condensation, wherein the first-stage condenser uses circulating water (28-30° C.) for condensation, and the second-stage condenser uses chilled brine (5-7° C.) for condensation. The HF solution under the two-stage condensation is collected in a storage tank, and the uncondensed tail gas is sent to the tail gas treatment system for treatment to meet the discharge standards. The residual waste liquid in the evaporator is sent to the sewage treatment device for treatment.

[0021] HF recovered from waste gas and HF recovered from waste liquid are then distilled into AHF through a distillation tower, the tower top temperature is controlled at 10-25°C, the tower bottom temperature is controlled at 30-70°C, and the tower top pressure is controlled at 90-100 kPa (A). The bottom kettle liquid is returned to the HF-containing waste liquid evaporator 21 for recycling evaporation and recovery; the AHF recovered from the tower top can be directly reused in the original production system or sold.

[0022] This recovery process can reduce the production loss of hydrogen fluoride in the fluorine chemical industry, while also reducing the scale of treatment of hydrogen fluoride-containing waste liquid, reducing the amount of fluorine-containing sludge to be treated, and protecting the environment.

[0023] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A device for recovering and treating waste gas and waste water containing hydrogen fluoride, characterized in that: include: A hydrogen fluoride-containing waste gas treatment device and a hydrogen fluoride-containing waste water treatment device; the hydrogen fluoride-containing waste gas treatment device comprises a waste gas recovery primary condenser (11), a waste gas recovery secondary condenser (12) and a waste gas recovery hydrogen fluoride storage tank (13) which are connected in sequence; the hydrogen fluoride-containing waste water treatment device comprises a waste liquid evaporator (21), a waste liquid recovery primary condenser (22), a waste liquid recovery secondary condenser (23) and a waste liquid recovery hydrogen fluoride storage tank (24) which are connected in sequence; the outlets of the waste gas recovery hydrogen fluoride storage tank (13) and the waste liquid recovery hydrogen fluoride storage tank (24) are connected to the hydrogen fluoride recovery tank (13) through the same pipeline after being joined. distillation tower (3); the waste gas containing hydrogen fluoride is condensed by the waste gas recovery primary condenser (11) and the waste gas recovery secondary condenser (12) and then enters the waste gas recovery hydrogen fluoride storage tank (13); the waste water containing hydrogen fluoride is evaporated by the waste liquid evaporator (21) and then sequentially passes through the waste liquid recovery primary condenser (22) and the waste liquid recovery secondary condenser (23) and then enters the waste liquid recovery hydrogen fluoride storage tank (24); the recovered hydrogen fluoride in the waste gas recovery hydrogen fluoride storage tank (13) and the waste liquid recovery hydrogen fluoride storage tank (24) enters the hydrogen fluoride recovery distillation tower (3) to distill out anhydrous hydrogen fluoride.

2. The device for recycling and treating waste gas and waste water containing hydrogen fluoride according to claim 1, characterized in that: The first-stage waste gas recovery condenser (11) is a condenser that uses frozen brine as a refrigerant, and the second-stage waste gas recovery condenser (12) is a condenser that uses a cryogen as a refrigerant; the first-stage waste liquid recovery condenser (22) is a condenser that uses circulating water as a refrigerant, and the second-stage waste liquid recovery condenser (23) is a condenser that uses frozen brine as a refrigerant.

3. The device for recycling and treating waste gas and waste water containing hydrogen fluoride according to claim 1, characterized in that: The waste gas recovery secondary condenser (12) and the waste liquid recovery secondary condenser (23) are both provided with an exhaust gas treatment device (4) for treating uncondensed exhaust gas.

4. The device for recycling and treating waste gas and waste water containing hydrogen fluoride according to claim 1, characterized in that: The waste liquid evaporator is also connected to a waste liquid treatment device (5) for treating the residual liquid after evaporation of the hydrogen fluoride waste liquid.

5. The device for recycling and treating waste gas and waste water containing hydrogen fluoride according to claim 2, characterized in that: The refrigerant in the first-stage waste gas recovery condenser (11) is refrigerated brine at 5 to 7°C; the refrigerant in the second-stage waste gas recovery condenser (12) is a cryogen at -30 to -35°C; the refrigerant in the first-stage waste liquid recovery condenser (22) is circulating water at 28 to 30°C; and the refrigerant in the second-stage waste liquid recovery condenser (23) is refrigerated brine at 5 to 7°C.

6. The device for recycling and treating waste gas and waste water containing hydrogen fluoride according to claim 1, characterized in that: The bottom of the hydrogen fluoride recovery distillation tower (3) is also provided with a recovery pipe connected to the waste liquid evaporator (21) for returning the bottom kettle liquid to the waste liquid evaporator (21) for cyclic evaporation and recovery.

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