CN216778403U

CN216778403U - High-concentration high-halogen VOCs tail gas low-temperature treatment system

Info

Publication number: CN216778403U
Application number: CN202122636556.8U
Authority: CN
Inventors: 向兵; 张燕霞; 陈志华
Original assignee: Shanghai Youyin Chemical Technology Co ltd
Current assignee: Shanghai Youyin Chemical Technology Co ltd
Priority date: 2021-10-29
Filing date: 2021-10-29
Publication date: 2022-06-21
Anticipated expiration: 2031-10-29

Abstract

The utility model discloses a system for treating high-concentration and high-halogen VOCs tail gas at low temperature, which belongs to the technical field of environmental protection and purification and comprises a condensation adsorption module and a concentration purification module; the condensation adsorption module comprises a primary condensation unit, a secondary condensation unit and a low-temperature adsorption unit; the concentration and purification module comprises an evaporation unit, a condensation unit and a circulation unit, tail gas can be condensed in a grading manner, so that components with different boiling points in the tail gas are separated and purified respectively, meanwhile, the system can be cleaned by itself without manual cleaning, the treatment efficiency is improved, energy can be utilized in a grading manner and recycled, the energy loss is reduced, the cost investment is further reduced, the energy conservation and emission reduction are facilitated, meanwhile, the evaporation unit can be flexibly increased according to the components of a pregnant solution, the condensation unit can be increased or reduced according to the components in the tail gas, the tail gas system can adapt to different occasions, and the plasticity of the system is improved.

Description

High-concentration high-halogen VOCs tail gas low-temperature treatment system

Technical Field

The utility model relates to the technical field of environmental protection and purification, in particular to a system for treating high-concentration and high-halogen VOCs tail gas at low temperature.

Background

In the production processes of chemical research and development, pharmaceutical research and development and biological research and development, a plurality of different types of chemical reagents are often used, and a part of the chemical reagents have strong volatility and can volatilize into tail gas, most of the chemical reagents can cause harm to human bodies, damage to equipment and pollution to the environment, so that the tail gas cannot be directly discharged into the atmosphere and needs to be adsorbed by resin or active carbon and then enters an incinerator for incineration and then discharged, however, the current adsorption incineration treatment mode brings other problems, such as large system device, low adsorption efficiency and high inactivation probability of the resin or the active carbon, secondary environmental pollution and treatment load can be generated by replacing the resin and the active carbon, and the halogen-containing organic matter content in the detected VOCs can be discharged or enters the incineration treatment only when reaching national or international standards, otherwise, dioxin and a large amount of hydrogen halide are generated during incineration.

Through retrieval, chinese patent No. CN201721385982.6 discloses a multistage VOCs tail gas treatment system, which can solve the problem of acidic substances in the tail gas and efficiently complete the treatment of VOCs tail gas, but the process of treating tail gas is uncontrollable and cannot effectively separate tail gas, and meanwhile, the treatment system does not have a self-cleaning function and needs manual cleaning, thereby reducing the treatment efficiency.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the defects in the prior art and provides a system for treating tail gas of high-concentration and high-halogen VOCs at low temperature.

In order to achieve the purpose, the utility model adopts the following technical scheme:

the system for treating the high-concentration and high-halogen VOCs tail gas at low temperature comprises a condensation adsorption module and a concentration purification module; the condensation adsorption module comprises a primary condensation unit, a secondary condensation unit and a low-temperature adsorption unit; the concentration and purification module comprises an evaporation unit, a condensation unit and a circulation unit;

the primary condensation unit comprises a primary condenser and a primary condensation receiving tank; the second-stage condensation unit comprises a first second-stage condenser, a second-stage condenser, a second-stage condensation receiving tank, an electric heater, a three-way air valve, a unfreezing nitrogen inlet valve I, a unfreezing nitrogen inlet valve II, a unfreezing nitrogen outlet valve I, a unfreezing nitrogen outlet valve II and a unfreezing nitrogen flow regulating valve; the low-temperature adsorption unit comprises an absorption tower, an absorption liquid circulating pump and an absorption liquid condenser; the evaporation unit comprises an evaporator inlet preheater and a thin film evaporator; the condensing unit comprises an evaporator steam outlet condenser, a condensate receiving tank, a condensate delivery pump and a condensate collecting barrel; the circulation unit comprises a barren liquor circulation pump, a barren liquor receiving tank and a heat recoverer.

Further, the condensation adsorption module is used for condensing and adsorbing toxic and harmful components in the tail gas; the primary condenser is used for primarily condensing the tail gas to generate primary condensate and secondary tail gas, and respectively conveying the primary condensate and the secondary tail gas to the primary condensation receiving tank and the three-way air valve; the primary condensation receiving tank is used for storing primary condensate; the unfreezing nitrogen flow regulating valve is used for regulating the flow of the unfreezing nitrogen and conveying the unfreezing nitrogen to the electric heater; the electric heater is used for heating unfreezing nitrogen and sending the unfreezing nitrogen to the first unfreezing nitrogen inlet valve and the second unfreezing nitrogen inlet valve.

Further, the three-way air valve is used for selecting the direction of the secondary tail gas; wherein, the specific operation of selecting the direction of the secondary tail gas is as follows:

s1, judging whether the first secondary condenser and the second secondary condenser frost and freeze;

s2, if the first secondary condenser is frosted and frozen and the second secondary condenser is not frosted and frozen, the three-way air valve conveys the secondary tail gas into the second secondary condenser, and the unfreezing nitrogen inlet valve I and the unfreezing nitrogen outlet valve I are opened, so that unfreezing nitrogen enters the first secondary condenser, and frost of the first secondary condenser is melted;

s3, if the process is opposite to the step S2, the three-way air valve conveys the secondary tail gas to the first secondary condenser, and the unfreezing nitrogen inlet valve II and the unfreezing nitrogen outlet valve II are opened, so that the unfreezing nitrogen enters the second secondary condenser, and frost in the second secondary condenser is melted;

the first secondary condenser and the second secondary condenser are used for condensing secondary tail gas to generate secondary condensate and tertiary tail gas, and the secondary condensate and the tertiary tail gas are respectively conveyed to the secondary condensation receiving tank and the bottom of the absorption tower; the secondary condensation receiving tank is used for storing secondary condensate; the absorption liquid circulating pump provides circulating kinetic energy for the absorption liquid and conveys the absorption liquid to the absorption liquid condenser; the absorption liquid condenser is used for condensing the absorption liquid and conveying the absorption liquid to the top of the absorption tower; the absorption tower is used for dissolving and absorbing the tertiary tail gas by the absorption liquid to generate a rich liquid and dischargeable gas, and the rich liquid is conveyed to the evaporator steam outlet condenser.

Further, the temperature of the unfreezing nitrogen gas after heating is 10 ℃; and the absorption liquid is conveyed to the top of the absorption tower, sprayed downwards and forms convection with the tertiary tail gas.

Further, the cooling medium of the primary condenser is 0 ℃ chilled water; the cooling medium of the first secondary condenser and the second secondary condenser is liquid nitrogen; the cooling medium of the absorption liquid cooler is liquid nitrogen, and the temperature of the absorption liquid after cooling is-80 ℃.

Further, the evaporator steam outlet condenser is used for condensing the volatile steam by the rich liquid to generate harmful liquid, and conveying the harmful liquid to the condensate receiving tank, and meanwhile conveying the rich liquid to the heat recoverer; the heat recoverer is used for absorbing heat in the lean solution by the rich solution, conveying the lean solution to the lean solution receiving tank and conveying the rich solution to the evaporator inlet preheater; the evaporator inlet preheater is used for heating the rich liquid and conveying the rich liquid to the thin film evaporator; the thin film evaporator is used for evaporation and separation of rich liquid to generate volatile gas and barren liquid.

Further, the condensate receiving tank is used for storing harmful liquid and conveying the harmful liquid to a condensate conveying pump; the condensate liquid conveying pump provides conveying kinetic energy for harmful liquid and conveys the harmful liquid to the liquid collecting barrel; the liquid collecting barrel is used for storing harmful liquid; the barren liquor receiving tank is used for storing barren liquor and conveying the barren liquor to the barren liquor circulating pump; the barren liquor circulating pump provides circulating kinetic energy for barren liquor and sends the barren liquor to the absorption tower.

Compared with the prior art, the utility model has the beneficial effects that:

1. according to the utility model, the purpose of tail gas fractional condensation is achieved through the primary condensation unit and the secondary condensation unit, secondary volatilization of harmful substances can be effectively inhibited, the total content of the harmful substances in the discharged tail gas is controlled, components with different boiling points in the tail gas can be respectively separated and purified, meanwhile, the first secondary condenser or the second secondary condenser can be frosted and frozen, nitrogen is conveyed into the electric heater through the unfreezing nitrogen flow regulating valve, the electric heater heats the nitrogen to 10 ℃, and then the nitrogen is introduced into the first secondary condenser or the second secondary condenser, so that frost in the first secondary condenser or the second secondary condenser is melted, the purpose of self-cleaning is achieved, manual cleaning is not needed, and the treatment efficiency is improved.

2. The refrigerant in the secondary condensation unit of the utility model is low-temperature nitrogen discharged from an absorption liquid condenser in the low-temperature adsorption unit, the cold quantity of liquid nitrogen is fully utilized in two stages, in the concentration and purification module, the evaporator steam outlet condenser in the condensation unit and the heat recoverer in the circulation unit are respectively low-temperature rich liquid to be treated, and the refrigerant fully utilizes two kinds of energy, namely cold energy and heat energy, so that the purposes of energy graded utilization and reutilization are achieved, thereby reducing the energy loss, further reducing the cost investment, being beneficial to energy conservation and emission reduction, simultaneously flexibly increasing the evaporation unit according to the components of the rich liquid, and increasing or reducing the condensation unit according to the components in tail gas, so that the tail gas system can adapt to different occasions, and the plasticity of the system is improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the utility model and are incorporated in and constitute a part of this specification, illustrate embodiments of the utility model and together with the description serve to explain the principles of the utility model and not to limit the utility model.

FIG. 1 is a flow chart of a condensation adsorption module of a system for treating tail gas of high-concentration and high-halogen VOCs at low temperature according to the present invention;

fig. 2 is a flow chart of a concentration and purification module of a system for treating tail gas of high-concentration and high-halogen VOCs at low temperature.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.

Example 1:

referring to fig. 1, the present invention provides a technical solution: the system for treating the high-concentration and high-halogen VOCs tail gas at low temperature comprises a condensation adsorption module and a concentration purification module; the condensation adsorption module comprises a primary condensation unit, a secondary condensation unit and a low-temperature adsorption unit; the concentration and purification module comprises an evaporation unit, a condensation unit and a circulation unit;

the primary condensation unit comprises a primary condenser and a primary condensation receiving tank; the secondary condensation unit comprises a first secondary condenser, a second secondary condenser, a secondary condensation receiving tank, an electric heater, a three-way air valve, a unfreezing nitrogen inlet valve I, a unfreezing nitrogen inlet valve II, a unfreezing nitrogen outlet valve I, a unfreezing nitrogen outlet valve II and a unfreezing nitrogen flow regulating valve; the low-temperature adsorption unit comprises an absorption tower, an absorption liquid circulating pump and an absorption liquid condenser; the evaporation unit comprises an evaporator inlet preheater and a thin film evaporator; the condensing unit comprises an evaporator steam outlet condenser, a condensate receiving tank, a condensate delivery pump and a condensate collecting barrel; the circulating unit comprises a barren liquor circulating pump, a barren liquor receiving tank and a heat recoverer, and the condensation adsorption module is used for condensing and adsorbing toxic and harmful components in the tail gas; the primary condenser is used for primarily condensing the tail gas to generate primary condensate and secondary tail gas, and respectively conveying the primary condensate and the secondary tail gas to the primary condensation receiving tank and the three-way air valve; the primary condensation receiving tank is used for storing primary condensate; the unfreezing nitrogen flow regulating valve is used for regulating the flow of the unfreezing nitrogen and conveying the unfreezing nitrogen to the electric heater; the electric heater is used for heating unfreezing nitrogen and sending the unfreezing nitrogen to the first unfreezing nitrogen inlet valve and the second unfreezing nitrogen inlet valve, and the three-way air valve is used for selecting the direction of the secondary tail gas;

in the embodiment, the specific operation of the secondary tail gas is selected as follows:

the first secondary condenser and the second secondary condenser are used for condensing secondary tail gas to generate secondary condensate and tertiary tail gas, and the secondary condensate and the tertiary tail gas are respectively conveyed to the secondary condensation receiving tank and the bottom of the absorption tower; the secondary condensation receiving tank is used for storing secondary condensate; the absorption liquid circulating pump provides circulating kinetic energy for the absorption liquid and conveys the absorption liquid to the absorption liquid condenser; the absorption liquid condenser is used for condensing the absorption liquid and conveying the absorption liquid to the top of the absorption tower; the absorption tower is used for dissolving and absorbing the tertiary tail gas by absorption liquid to generate rich liquid and dischargeable gas, the rich liquid is conveyed to a condenser at a steam outlet of the evaporator, and the temperature of unfrozen nitrogen after heating is 10 ℃; the absorption liquid is conveyed to the top of the absorption tower and then sprayed downwards, and forms convection with the tertiary tail gas, and the cooling medium of the primary condenser is 0 ℃ chilled water; the cooling medium of the first secondary condenser and the second secondary condenser is liquid nitrogen; the cooling medium of the absorption liquid cooler is liquid nitrogen, and the temperature of the absorption liquid after cooling is-80 ℃.

Specifically, in the process of treating tail gas in a grading manner, the tail gas is introduced into a first-stage condenser, the tail gas is cooled by the first-stage condenser through 0 ℃ chilled water, part of toxic and harmful substances in the tail gas are condensed to form a first condensate, the first condensate is collected into a first-stage condensation receiving tank, the tail gas is changed into a secondary tail gas at the moment and is conveyed to a three-way air valve, the secondary tail gas is selected to enter a first second-stage condenser or a second-stage condenser through the three-way air valve and is condensed by the first second-stage condenser or the second-stage condenser, so that components with lower condensation points in the secondary tail gas are condensed into a secondary condensate, the secondary condensate is collected into a second-stage condensation receiving tank, the secondary tail gas is changed into a third tail gas at the moment, the purpose of grading condensation is achieved, the components with different boiling points can be respectively separated and purified, and simultaneously, the first secondary condenser or the second secondary condenser can frost and freeze in the process, nitrogen is conveyed into the electric heater through the unfreezing nitrogen flow regulating valve, the electric heater heats the nitrogen to 10 ℃, then the nitrogen is introduced into the first secondary condenser or the second secondary condenser, frost in the first secondary condenser or the second secondary condenser is melted, meanwhile, part of the nitrogen enters the emptying system to be discharged, the self-cleaning purpose is achieved, manual cleaning is not needed, the treatment efficiency is improved, the third tail gas is conveyed to the bottom of the absorption tower to enter the absorption tower, meanwhile, the absorption liquid is conveyed into the absorption liquid condenser through the absorption liquid circulating pump to be cooled and conveyed to the top of the absorption tower, so that the absorption liquid is sprayed downwards from the top of the absorption tower to form convection with the third tail gas entering from the bottom, and the third tail gas can be fully contacted with the absorption liquid, and then fully dissolving harmful components in the tertiary tail gas into the absorption liquid to form a rich liquid, wherein the tertiary tail gas becomes a dischargeable gas, and the purpose of treating the tail gas is achieved.

Example 2:

referring to fig. 2, the present invention provides a technical solution: in the system for treating the high-concentration and high-halogen VOCs tail gas at low temperature, a condenser at a steam outlet of an evaporator is used for condensing volatile gas from rich liquid to generate harmful liquid, the harmful liquid is conveyed to a condensate receiving tank, and meanwhile, the rich liquid is conveyed to a heat recoverer; the heat recoverer is used for absorbing heat in the lean solution by the rich solution, conveying the lean solution to the lean solution receiving tank and conveying the rich solution to the evaporator inlet preheater; the evaporator inlet preheater is used for heating the rich liquid and conveying the rich liquid to the thin film evaporator; the thin film evaporator is used for evaporating and separating rich liquid to generate volatile vapor and barren liquid, and the condensate receiving tank is used for storing harmful liquid and conveying the harmful liquid to the condensate conveying pump; the condensate liquid delivery pump provides delivery kinetic energy for the harmful liquid and delivers the harmful liquid to the liquid collection barrel; the liquid collecting barrel is used for storing harmful liquid; the barren liquor receiving tank is used for storing barren liquor and conveying the barren liquor to the barren liquor circulating pump; the barren liquor circulating pump provides circulating kinetic energy for barren liquor and sends the barren liquor to the absorption tower.

Specifically, in the process of concentrating and purifying the rich liquid, the rich liquid is conveyed into a steam outlet condenser of an evaporator from a bypass of an absorption liquid circulating pump, so that the rich liquid is condensed into volatilized vapor, then the rich liquid is conveyed into a heat recoverer to exchange heat with the barren liquid coming out of the bottom of the thin film evaporator, the energy is recovered, and the purposes of energy graded utilization and reutilization are achieved, so that the energy loss is reduced, the cost investment is further reduced, the energy conservation and emission reduction are facilitated, after the rich liquid passes through the heat recoverer, the rich liquid enters an evaporator inlet preheater to be preheated, then the rich liquid enters the thin film evaporator to be evaporated and separated to form volatilized vapor and barren liquid, the volatilized vapor enters the steam outlet condenser of the evaporator to be condensed to form harmful liquid, the harmful liquid is collected into a condensate receiving tank, and the barren liquid passes through the heat recoverer to recover partial heat and then enters the barren liquid receiving tank, and finally, the barren liquor in the barren liquor receiving tank is conveyed to an absorption tower through a barren liquor circulating pump to participate in cyclic absorption, in the process, an evaporation unit can be flexibly added according to the components of the pregnant solution, and a condensation unit can be added or reduced according to the components in the tail gas, so that the tail gas system can adapt to different occasions, and the plasticity of the system is improved.

The working principle and the using process of the utility model are as follows: when the tail gas needs to be treated, the tail gas is introduced into a first-stage condenser, so that the first-stage condenser cools the tail gas through 0 ℃ chilled water, part of toxic and harmful substances in the tail gas are condensed to form a first condensate, the first condensate is collected into a first-stage condensation receiving tank, the tail gas is changed into a secondary tail gas and is conveyed to a three-way air valve, the secondary tail gas is selected to enter a first second-stage condenser or a second-stage condenser through the three-way air valve, the first second-stage condenser or the second-stage condenser condenses the secondary tail gas, so that components with lower condensation points in the secondary tail gas are condensed into a secondary condensate, the secondary condensate is collected into a second-stage condensation receiving tank, the secondary tail gas is changed into a tertiary tail gas, the purpose of fractional condensation is achieved, the components with different boiling points can be respectively separated and purified, meanwhile, the first second-stage condenser or the second-stage condenser in the process can be frosted, at the moment, nitrogen is conveyed into the electric heater through the unfreezing nitrogen flow regulating valve, the electric heater heats the nitrogen to 10 ℃, then the nitrogen is introduced into the first secondary condenser or the second secondary condenser, frost in the first secondary condenser or the second secondary condenser is melted, meanwhile, the part of nitrogen enters the emptying system to be discharged, the purpose of self-cleaning is achieved, manual cleaning is not needed, the treatment efficiency is improved, then the three-time tail gas is conveyed to the bottom of the absorption tower to enter the absorption tower, meanwhile, the absorption liquid is conveyed into the absorption liquid condenser through the absorption liquid circulating pump to be cooled, then the absorption liquid is conveyed to the top of the absorption tower to be sprayed downwards from the top of the absorption tower to form convection with the three-time tail gas entering from the bottom, so that the three-time tail gas can be fully contacted with the absorption liquid, and further, harmful ingredients in the three-time tail gas are fully dissolved into the absorption liquid, forming a rich liquid, wherein the tertiary tail gas is changed into dischargeable gas to achieve the purpose of treating the tail gas, then conveying the rich liquid from a bypass of an absorption liquid circulating pump to a steam outlet condenser of an evaporator to enable the rich liquid to condense volatilized vapor, then conveying the rich liquid to a heat recoverer to exchange heat with lean liquid coming out of the bottom of a thin film evaporator, recovering energy, achieving the purposes of energy classification utilization and recycling, further reducing energy loss, further reducing cost investment, facilitating energy conservation and emission reduction, after passing through the heat recoverer, the rich liquid enters an evaporator inlet preheater to be preheated, then the rich liquid enters the thin film evaporator to be evaporated and separated to form volatilized vapor and lean liquid, the volatilized vapor enters an evaporator steam outlet condenser to be condensed to form harmful liquid, the harmful liquid is collected in a condensate receiving tank, and the lean liquid enters a lean liquid receiving tank after passing through the heat recoverer to recover partial heat, and finally, the barren liquor in the barren liquor receiving tank is conveyed to an absorption tower through a barren liquor circulating pump to participate in circulating absorption, and in the process, an evaporation unit can be flexibly added according to the components of the pregnant liquor, and a condensation unit can be added or reduced according to the components in the tail gas, so that the tail gas system can adapt to different occasions, the plasticity of the system is improved, and the operation is completed.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and equivalent alternatives or modifications according to the technical solution of the present invention and the inventive concept thereof should be covered by the scope of the present invention.

Claims

1. The system for treating the high-concentration and high-halogen VOCs tail gas at low temperature is characterized by comprising a condensation adsorption module and a concentration purification module; the condensation adsorption module comprises a primary condensation unit, a secondary condensation unit and a low-temperature adsorption unit; the concentration and purification module comprises an evaporation unit, a condensation unit and a circulation unit;

the primary condensation unit comprises a primary condenser and a primary condensation receiving tank; the second-stage condensation unit comprises a first second-stage condenser, a second-stage condenser, a second-stage condensation receiving tank, an electric heater, a three-way air valve, a unfreezing nitrogen inlet valve I, a unfreezing nitrogen inlet valve II, a unfreezing nitrogen outlet valve I, a unfreezing nitrogen outlet valve II and a unfreezing nitrogen flow regulating valve; the low-temperature adsorption unit comprises an absorption tower, an absorption liquid circulating pump and an absorption liquid cooler; the evaporation unit comprises an evaporator inlet preheater and a thin film evaporator; the condensing unit comprises an evaporator steam outlet condenser, a condensate receiving tank, a condensate delivery pump and a condensate collecting barrel; the circulation unit comprises a barren liquor circulation pump, a barren liquor receiving tank and a heat recoverer.

2. The system for low-temperature treatment of the tail gas containing high-concentration and high-halogen VOCs according to claim 1, wherein the condensation adsorption module is used for condensation adsorption of toxic and harmful components in the tail gas; the primary condenser is used for primarily condensing the tail gas to generate primary condensate and secondary tail gas, and respectively conveying the primary condensate and the secondary tail gas to the primary condensation receiving tank and the three-way air valve; the primary condensation receiving tank is used for storing primary condensate; the unfreezing nitrogen flow regulating valve is used for regulating the flow of the unfreezing nitrogen and conveying the unfreezing nitrogen to the electric heater; the electric heater is used for heating unfreezing nitrogen and sending the unfreezing nitrogen to the first unfreezing nitrogen inlet valve and the second unfreezing nitrogen inlet valve.

3. The system for low-temperature treatment of tail gases containing high-concentration and high-halogen VOCs according to claim 2, wherein the three-way air valve is used for selecting the direction of the secondary tail gases;

the first secondary condenser and the second secondary condenser are used for condensing secondary tail gas to generate secondary condensate and tertiary tail gas, and the secondary condensate and the tertiary tail gas are respectively conveyed to the secondary condensation receiving tank and the bottom of the absorption tower; the secondary condensation receiving tank is used for storing secondary condensate; the absorption liquid circulating pump provides circulating kinetic energy for the absorption liquid and conveys the absorption liquid to the absorption liquid condenser; the absorption liquid cooler is used for cooling the absorption liquid and conveying the absorption liquid to the top of the absorption tower; the absorption tower is used for dissolving and absorbing the tertiary tail gas by the absorption liquid to generate a rich liquid and dischargeable gas, and the rich liquid is conveyed to the evaporator steam outlet condenser.

4. The system for low-temperature treatment of highly concentrated and highly halogenated VOCs tail gas of claim 3, wherein the heated temperature of the unfrozen nitrogen is 10 ℃; and the absorption liquid is conveyed to the top of the absorption tower, sprayed downwards and forms convection with the tertiary tail gas.

5. The system for low-temperature treatment of tail gas containing highly concentrated and highly halogenated VOCs according to claim 3, wherein the cooling medium of the primary condenser is 0 ℃ chilled water; the cooling medium of the first secondary condenser and the second secondary condenser is liquid nitrogen; the cooling medium of the absorption liquid cooler is liquid nitrogen, and the temperature of the absorption liquid after cooling is-80 ℃.

6. The system for low-temperature treatment of tail gas containing highly concentrated and highly halogenated VOCs according to claim 1, wherein the evaporator vapor outlet condenser is used for rich liquid condensation of volatile vapor to generate harmful liquid, and the harmful liquid is delivered to the condensate receiving tank, and the rich liquid is delivered to the heat recovery device; the heat recoverer is used for absorbing heat in the lean solution by the rich solution, conveying the lean solution to the lean solution receiving tank and conveying the rich solution to the evaporator inlet preheater; the evaporator inlet preheater is used for heating the rich liquid and conveying the rich liquid to the thin film evaporator; the thin film evaporator is used for evaporation and separation of rich liquid to generate volatile gas and barren liquid.

7. The system for the cryogenic treatment of highly concentrated, highly halogenated VOCs tail gas of claim 6, wherein the condensate receiver tank is configured to store hazardous liquids and deliver the hazardous liquids to a condensate delivery pump; the condensate liquid conveying pump provides conveying kinetic energy for harmful liquid and conveys the harmful liquid to the liquid collecting barrel; the liquid collecting barrel is used for storing harmful liquid; the barren liquor receiving tank is used for storing barren liquor and conveying the barren liquor to the barren liquor circulating pump; the barren liquor circulating pump provides circulating kinetic energy for barren liquor and sends the barren liquor to the absorption tower.