Low temperature treatment of high concentration and high halogen VOCs tail gas system

Abstract

The present invention discloses a low-temperature treatment system for high-concentration and high-halogen VOCs tail gas, which belongs to the field of environmental protection purification technology, and comprises a condensation adsorption module and a concentration and 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 present invention can grade and condense the tail gas, so that components with different boiling points in the tail gas can be separated and purified respectively, and the system can self-clean without manual cleaning, thereby improving the treatment efficiency, and can grade and reuse energy, thereby reducing energy loss, further reducing cost investment, and being beneficial to energy conservation and emission reduction. At the same time, the evaporation unit can be flexibly increased according to the components of the rich liquid, and the condensation unit can be increased or reduced according to the components in the tail gas, so that the tail gas system can adapt to different occasions, thereby improving the plasticity of the system.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental protection purification, and in particular to a system for treating high-concentration and high-halogen VOCs tail gas at low temperature. Background Art

[0002] In the production process of chemical research and development, pharmaceutical research and development, and biological research and development, many different types of chemical reagents are often used, and a considerable number of chemical reagents are highly volatile and will evaporate into the exhaust gas. Most chemical reagents will cause harm to the human body, damage to equipment, and pollute the environment. Therefore, this exhaust gas cannot be discharged directly into the atmosphere. It needs to be adsorbed by resin or activated carbon and then enter the incinerator for incineration before being discharged. However, the current adsorption and incineration treatment method will bring other problems, such as large system equipment, low adsorption efficiency, and high probability of resin or activated carbon deactivation. At the same time, replacing these resins and activated carbon will cause secondary environmental pollution and treatment load, and the content of halogenated organic matter in VOCs must meet national or international standards before it can be discharged or enter incineration treatment. Otherwise, dioxins and a large amount of hydrogen halides will be generated during the incineration process.

[0003] After searching, Chinese patent No. CN201721385982.6 discloses a multi-stage VOCs tail gas treatment system. Although it can solve the acidic substances in the tail gas and can efficiently complete the treatment of VOCs tail gas, its tail gas treatment process is uncontrollable and cannot effectively separate the tail gas. At the same time, the treatment system has no self-cleaning function and requires manual cleaning, which reduces the treatment efficiency. In addition, the treatment system does not fully consider the graded utilization and reuse of energy in the entire treatment process, thereby increasing energy loss and cost investment, and is not conducive to energy conservation and emission reduction. At the same time, the system has low plasticity and cannot be flexibly adjusted according to the specific composition of the tail gas. The stability of the system is also low and is easily affected by the external environment, which brings about the problem of system defects. Summary of the invention

[0004] The purpose of the present invention is to solve the defects in the prior art and to propose a low-temperature treatment system for high-concentration and high-halogen VOCs tail gas.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A low-temperature treatment system for high-concentration and high-halogen VOCs tail gas includes a condensation adsorption module and a concentration and purification module; the condensation adsorption module includes a primary condensation unit, a secondary condensation unit and a low-temperature adsorption unit; the concentration and purification module includes an evaporation unit, a condensation unit and a circulation unit;

[0007] The primary condensing unit includes a primary condenser and a primary condensation receiving tank; the secondary condensing unit includes a first secondary condenser, a second secondary condenser, a secondary condensation receiving tank, an electric heater, a three-way ventilation valve, a thawing nitrogen inlet valve 1, a thawing nitrogen inlet valve 2, a thawing nitrogen outlet valve 1, a thawing nitrogen outlet valve 2 and a thawing nitrogen flow regulating valve; the low-temperature adsorption unit includes an absorption tower, an absorption liquid circulation pump and an absorption liquid condenser; the evaporation unit includes an evaporator inlet preheater and a thin film evaporator; the condensing unit includes an evaporator steam outlet condenser, a condensate receiving tank, a condensate delivery pump and a liquid collecting barrel; the circulation unit includes a lean liquid circulation pump, a lean liquid receiving tank and a heat recovery device.

[0008] Furthermore, the condensation adsorption module is used to condense and adsorb toxic and harmful components in the exhaust gas; the primary condenser is used to preliminarily condense the exhaust gas to generate the first condensate and the secondary exhaust gas, and transport them to the primary condensation receiving tank and the three-vent valve respectively; the primary condensation receiving tank is used to store the first condensate; the thawing nitrogen flow regulating valve is used to adjust the flow of the thawing nitrogen and transport the thawing nitrogen to the electric heater; the electric heater is used to heat the thawing nitrogen and send it to the thawing nitrogen inlet valve one and the thawing nitrogen inlet valve two.

[0009] Furthermore, the three-ventilation valve is used to select the destination of the secondary exhaust gas; wherein the specific operation of selecting the destination of the secondary exhaust gas is:

[0010] S1, determining whether the first and second condensers and the second and second condensers are frosted or frozen;

[0011] S2. If the first and second condensers are frosted and frozen, and the second and second condensers are not frosted and frozen, the three-way ventilation valve transports the secondary tail gas to the second and second condensers, and opens the thawing nitrogen inlet valve 1 and the thawing nitrogen outlet valve 1, so that the thawing nitrogen enters the first and second condensers to melt the frost of the first and second condensers;

[0012] S3, if the opposite to step S2, the three-ventilation valve delivers the secondary tail gas to the first and second condensers, and opens the second thawing nitrogen inlet valve and the second thawing nitrogen outlet valve, so that the thawing nitrogen enters the second and second condensers to melt the frost in the second and second condensers;

[0013] The first secondary condenser and the second secondary condenser are both used to condense the secondary tail gas to generate secondary condensate and tertiary tail gas, which are transported to the secondary condensation receiving tank and the bottom of the absorption tower respectively; the secondary condensation receiving tank is used to store the secondary condensate; the absorption liquid circulation pump provides circulation kinetic energy for the absorption liquid, and transports the absorption liquid to the absorption liquid condenser; the absorption liquid condenser is used to condense the absorption liquid and transport it to the top of the absorption tower; the absorption tower is used to dissolve and absorb the tertiary tail gas with the absorption liquid to generate rich liquid and dischargeable gas, and transport the rich liquid to the evaporator steam outlet condenser.

[0014] Furthermore, the temperature of the thawed nitrogen after heating is 10° C.; the absorption liquid is transported to the top of the absorption tower and then sprayed downward to form convection with the tertiary tail gas.

[0015] Furthermore, the cooling medium of the first-stage condenser is 0°C chilled water; the cooling medium of the first-stage condenser and the second-stage condenser are both liquid nitrogen; the cooling medium of the absorption liquid cooler is liquid nitrogen, and the temperature of the absorption liquid after cooling is -80°C.

[0016] Furthermore, the evaporator steam outlet condenser is used for condensing volatile vapor from rich liquid to generate harmful liquid, and transporting the harmful liquid to the condensate receiving tank, while the rich liquid is transported to the heat recovery device; the heat recovery device is used for the rich liquid to absorb heat from the lean liquid, and transport the lean liquid to the lean liquid receiving tank, while the rich liquid is transported to the evaporator inlet preheater; the evaporator inlet preheater is used to heat the rich liquid and transport it to the thin film evaporator; the thin film evaporator is used for evaporation and separation of the rich liquid to generate volatile vapor and lean liquid.

[0017] Furthermore, the condensate receiving tank is used to store harmful liquid and transport it to the condensate delivery pump; the condensate delivery pump provides delivery kinetic energy for the harmful liquid and transports it to the liquid collecting barrel; the liquid collecting barrel is used to store harmful liquid; the lean liquid receiving tank is used to store lean liquid and transport it to the lean liquid circulation pump; the lean liquid circulation pump provides circulation kinetic energy for the lean liquid and sends it to the absorption tower.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The present invention achieves the purpose of graded condensation of tail gas through a primary condensation unit and a secondary condensation unit, can effectively inhibit the secondary volatilization of harmful substances, control the total content of harmful substances in the exhaust gas, and can separate and purify components with different boiling points in the tail gas respectively. At the same time, the first secondary condenser or the second secondary condenser will be frosted and frozen. At this time, nitrogen is transported to the electric heater through the thawing nitrogen flow regulating valve, so that the electric heater heats the nitrogen to 10°C, and then passes it into the first secondary condenser or the second secondary condenser, so that the frost in the first secondary condenser or the second secondary condenser melts, achieving the purpose of self-cleaning, without manual cleaning, and improving the processing efficiency.

[0020] 2. The refrigerant medium in the secondary condensation unit of the present invention is the low-temperature nitrogen discharged from the absorption liquid condenser in the low-temperature adsorption unit, which fully utilizes the cold capacity of the liquid nitrogen in two stages. In the concentration and purification module, the cooling medium of the evaporator steam outlet condenser in the condensation unit and the heat recovery device in the circulation unit are both low-temperature rich liquid to be treated, which fully utilizes both cold and hot energy to achieve the purpose of graded and reused energy, thereby reducing energy loss, further reducing cost investment, and facilitating energy conservation and emission reduction. At the same time, the evaporation unit can be flexibly increased according to the components of the rich liquid, and the condensation unit can be increased or reduced according to the components in the tail gas, so that the tail gas system can adapt to different occasions and improve the plasticity of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0022] Figure 1 This is a flow chart of the condensation adsorption module of the low-temperature treatment system for high-concentration and high-halogen VOCs tail gas proposed by the present invention;

[0023] Figure 2 This is a flow chart of the concentration and purification module of the low-temperature treatment of high-concentration and high-halogen VOCs tail gas system proposed in the present invention. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0025] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0026] Embodiment 1:

[0027] See also Figure 1 The present invention provides a technical solution: a low-temperature treatment system for high-concentration and high-halogen VOCs tail gas, including a condensation adsorption module and a concentration and purification module; the condensation adsorption module includes a primary condensation unit, a secondary condensation unit and a low-temperature adsorption unit; the concentration and purification module includes an evaporation unit, a condensation unit and a circulation unit;

[0028] The primary condensing unit includes a primary condenser and a primary condensing receiving tank; the secondary condensing unit includes a first secondary condenser, a second secondary condenser, a secondary condensing receiving tank, an electric heater, a three-way ventilation valve, a thawing nitrogen inlet valve 1, a thawing nitrogen inlet valve 2, a thawing nitrogen outlet valve 1, a thawing nitrogen outlet valve 2 and a thawing nitrogen flow regulating valve; the low-temperature adsorption unit includes an absorption tower, an absorption liquid circulation pump and an absorption liquid condenser; the evaporation unit includes an evaporator inlet preheater and a thin film evaporator; the condensation unit includes an evaporator steam outlet condenser, a condensate receiving tank, a condensate delivery pump and a liquid collecting barrel; the circulation The unit includes a lean liquid circulation pump, a lean liquid receiving tank and a heat recovery device. The condensation adsorption module is used to condense and adsorb toxic and harmful components in the tail gas; the primary condenser is used to preliminarily condense the tail gas to generate the first condensate and the secondary tail gas, and transport them to the primary condensate receiving tank and the three-vent valve respectively; the primary condensate receiving tank is used to store the first condensate; the thawing nitrogen flow regulating valve is used to adjust the flow of the thawing nitrogen and transport the thawing nitrogen to the electric heater; the electric heater is used to heat the thawing nitrogen and send it to the thawing nitrogen inlet valve 1 and the thawing nitrogen inlet valve 2, and the three-vent valve is used to select the destination of the secondary tail gas;

[0029] In this embodiment, the specific operation of selecting the destination of the secondary tail gas is:

[0030] S1, determining whether the first and second condensers and the second and second condensers are frosted or frozen;

[0031] S2. If the first and second condensers are frosted and frozen, and the second and second condensers are not frosted and frozen, the three-way ventilation valve transports the secondary tail gas to the second and second condensers, and opens the thawing nitrogen inlet valve 1 and the thawing nitrogen outlet valve 1, so that the thawing nitrogen enters the first and second condensers to melt the frost of the first and second condensers;

[0032] S3, if the opposite to step S2, the three-ventilation valve delivers the secondary tail gas to the first and second condensers, and opens the second thawing nitrogen inlet valve and the second thawing nitrogen outlet valve, so that the thawing nitrogen enters the second and second condensers to melt the frost in the second and second condensers;

[0033] The first and second condensers and the second condensers are used to condense the secondary tail gas to generate secondary condensate and tertiary tail gas, which are transported to the second condensation receiving tank and the bottom of the absorption tower respectively; the second condensation receiving tank is used to store the secondary condensate; the absorption liquid circulation pump provides circulation kinetic energy for the absorption liquid and transports the absorption liquid to the absorption liquid condenser; the absorption liquid condenser is used to condense the absorption liquid and transport it to the top of the absorption tower; the absorption tower is used to dissolve and absorb the tertiary tail gas with the absorption liquid to generate rich liquid and dischargeable gas, and transport the rich liquid to the evaporator steam outlet condenser, and the temperature of the thawed nitrogen after heating is 10°C; after the absorption liquid is transported to the top of the absorption tower, it is sprayed downward and forms convection with the tertiary tail gas, and the cooling medium of the first condenser is 0°C chilled water; the cooling medium of the first and second condensers and the second condensers 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°C.

[0034] Specifically, in the process of graded treatment of tail gas, the tail gas is passed into a primary condenser, and the primary condenser cools the tail gas through 0°C chilled water, so that some toxic and harmful substances in the tail gas are condensed to form a primary condensate, and the primary condensate is collected in a primary condensation receiving tank. At this time, the tail gas becomes secondary tail gas and is transported to the three-ventilation valve, and then passes through the three-ventilation valve to select to enter the first and second condensers or the second and second condensers, and the first and second condensers or the second and second condensers condense the secondary tail gas, so that the components with lower freezing points in the secondary tail gas are condensed into secondary condensate, and the secondary condensate is collected in the secondary condensation receiving tank. At this time, the secondary tail gas becomes tertiary tail gas, achieving the purpose of graded condensation, and can separate and purify components with different boiling points respectively. At the same time, the first and second condensers or the second and second condensers in the above process will be frosted and frozen. At this time, by thawing The nitrogen flow regulating valve transports nitrogen to the electric heater, so that the electric heater heats the nitrogen to 10°C, and then passes it into the first and second condensers or the second and second condensers, so that the frost in the first and second condensers or the second and second condensers melts, and at the same time, this part of the nitrogen enters the emptying system for discharge, so as to achieve the purpose of self-cleaning, without the need for manual cleaning, thereby improving the processing efficiency, and then the tertiary tail gas is transported to the bottom of the absorption tower and enters the absorption tower. At the same time, the absorption liquid is transported to the absorption liquid condenser through the absorption liquid circulation pump, so that the absorption liquid is cooled and cooled, and then it is transported to the top of the absorption tower, so that the absorption liquid is sprayed downward from the top of the absorption tower, and forms convection with the tertiary tail gas entering from the bottom, so that the tertiary tail gas can fully contact with the absorption liquid, and then the harmful components in the tertiary tail gas are fully dissolved in the absorption liquid to form a rich liquid. At this time, the tertiary tail gas becomes a dischargeable gas, thereby achieving the purpose of treating the tail gas.

[0035] Embodiment 2:

[0036] See also Figure 2The present invention provides a technical solution: a low-temperature treatment system for high-concentration and high-halogen VOCs tail gas, wherein the evaporator steam outlet condenser is used for rich liquid to condense volatile vapor to generate harmful liquid, and the harmful liquid is transported to the condensate receiving tank, and the rich liquid is transported to the heat recovery device; the heat recovery device is used for the rich liquid to absorb the heat in the lean liquid, and the lean liquid is transported to the lean liquid receiving tank, and the rich liquid is transported to the evaporator inlet preheater; the evaporator inlet preheater is used to heat the rich liquid and transport it to the thin film evaporator; the thin film evaporator is used for evaporation and separation of the rich liquid to generate volatile vapor and lean liquid, the condensate receiving tank is used to store the harmful liquid, and transport it to the condensate delivery pump; the condensate delivery pump provides the harmful liquid with delivery kinetic energy and transports it to the liquid collecting barrel; the liquid collecting barrel is used to store the harmful liquid; the lean liquid receiving tank is used to store the lean liquid and transport it to the lean liquid circulation pump; the lean liquid circulation pump provides the lean liquid with circulation kinetic energy and sends it to the absorption tower.

[0037] Specifically, in the process of concentrating and purifying the rich liquid, the rich liquid is transported from the bypass of the absorption liquid circulation pump to the evaporator steam outlet condenser, so that the rich liquid condenses the volatile gas, and then the rich liquid is transported to the heat recovery device for heat exchange with the lean liquid coming out of the bottom of the thin film evaporator to recover energy, thereby achieving the purpose of energy graded utilization and reuse, thereby reducing energy loss, further reducing cost investment, and facilitating energy conservation and emission reduction. After passing through the heat recovery device, the rich liquid enters the evaporator inlet preheater for preheating, and then the rich liquid enters the thin film evaporator for evaporation and separation. , forming volatile vapor and lean liquid. The volatile vapor enters the evaporator steam outlet condenser and is condensed to form harmful liquid, which is collected in the condensate receiving tank. The lean liquid recovers part of the heat through the heat recovery device and enters the lean liquid receiving tank. Finally, the lean liquid in the lean liquid receiving tank is transported to the absorption tower through the lean liquid circulation pump to participate in the circulation absorption. In this process, the evaporation unit can be flexibly increased according to the components of the rich liquid, and the condensation unit can be increased or reduced according to the components in the tail gas, so that the tail gas system can adapt to different occasions and improve the plasticity of the system.

[0038] The working principle and use process of the present invention are as follows: when it is necessary to treat the tail gas, the tail gas is passed into the primary condenser, and the primary condenser cools the tail gas through 0°C chilled water, so that part of the toxic and harmful substances in the tail gas are condensed to form a primary condensate, and the primary condensate is collected in the primary condensation receiving tank. At this time, the tail gas becomes secondary tail gas and is transported to the three-ventilation valve, and then passes through the three-ventilation valve to select to enter the first and second condensers or the second and second condensers, and the secondary tail gas is condensed by the first and second condensers or the second and second condensers, so that the components with lower freezing points in the secondary tail gas are condensed into secondary condensate, and the secondary condensate is collected in the secondary condensation receiving tank. At this time, the secondary tail gas becomes tertiary tail gas, achieving graded cooling. The purpose of condensation is to separate and purify components with different boiling points. At the same time, the first and second condensers or the second and second condensers in the above process will be frosted and frozen. At this time, nitrogen is transported to the electric heater through the thawing nitrogen flow regulating valve, so that the electric heater heats the nitrogen to 10°C, and then passes into the first and second condensers or the second and second condensers to melt the frost in the first and second condensers or the second and second condensers. At the same time, this part of the nitrogen enters the emptying system for discharge, so as to achieve the purpose of self-cleaning, without manual cleaning, and improves the processing efficiency. Then the tertiary tail gas is transported to the bottom of the absorption tower and enters the absorption tower. At the same time, the absorption liquid is transported to the absorption liquid condenser through the absorption liquid circulation pump, so that the absorption liquid After cooling, it is transported to the top of the absorption tower, so that the absorption liquid sprays downward from the top of the absorption tower, forming convection with the tertiary tail gas entering from the bottom, so that the tertiary tail gas can fully contact with the absorption liquid, and then the harmful components in the tertiary tail gas are fully dissolved in the absorption liquid to form a rich liquid. At this time, the tertiary tail gas becomes a dischargeable gas, achieving the purpose of treating the tail gas, and then the rich liquid is transported from the bypass of the absorption liquid circulation pump to the evaporator steam outlet condenser, so that the rich liquid condenses the volatile gas, and then the rich liquid is transported to the heat recovery device for heat exchange with the lean liquid coming out of the bottom of the thin film evaporator to recover energy, so as to achieve the purpose of graded utilization and repeated utilization of energy, thereby reducing energy loss and further reducing cost investment. , which is beneficial to energy conservation and emission reduction. After passing through the heat recovery device, the rich liquid enters the evaporator inlet preheater for preheating, and then the rich liquid enters the thin film evaporator for evaporation and separation to form volatile vapor and lean liquid. The volatile vapor enters the evaporator steam outlet condenser to be condensed to form harmful liquid, which is collected in the condensate receiving tank. The lean liquid recovers part of the heat through the heat recovery device and enters the lean liquid receiving tank. Finally, the lean liquid in the lean liquid receiving tank is transported to the absorption tower through the lean liquid circulation pump to participate in the circulation absorption. In this process, the evaporation unit can be flexibly increased according to the components of the rich liquid, and the condensation unit can be increased or reduced according to the components in the exhaust gas, so that the exhaust system can adapt to different occasions, improve the plasticity of the system, and complete the operation.

[0039] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. Low temperature treatment of high concentration and high halogen VOCs tail gas system, characterized by: It includes a condensation adsorption module and a concentration and purification module; the condensation and adsorption module includes a primary condensation unit, a secondary condensation unit and a low-temperature adsorption unit; the concentration and purification module includes an evaporation unit, a condensation unit and a circulation unit; The primary condensing unit includes a primary condenser and a primary condensation receiving tank; the secondary condensing unit includes a first secondary condenser, a second secondary condenser, a secondary condensation receiving tank, an electric heater, a three-way ventilation valve, a thawing nitrogen inlet valve 1, a thawing nitrogen inlet valve 2, a thawing nitrogen outlet valve 1, a thawing nitrogen outlet valve 2 and a thawing nitrogen flow regulating valve; the low-temperature adsorption unit includes an absorption tower, an absorption liquid circulation pump and an absorption liquid cooler; the evaporation unit includes an evaporator inlet preheater and a thin film evaporator; the condensing unit includes an evaporator steam outlet condenser, a condensate receiving tank, a condensate delivery pump and a liquid collecting barrel; the circulation unit includes a lean liquid circulation pump, a lean liquid receiving tank and a heat recovery device; The condensation adsorption module is used for condensing and adsorbing toxic and harmful components in the tail gas; the primary condenser is used for preliminarily condensing the tail gas to generate the primary condensate and the secondary tail gas, and transport them to the primary condensation receiving tank and the three-vent valve respectively; the primary condensation receiving tank is used to store the primary condensate; the thawing nitrogen flow regulating valve is used to adjust the flow of the thawing nitrogen and transport the thawing nitrogen to the electric heater; the electric heater is used to heat the thawing nitrogen and send it to the thawing nitrogen inlet valve 1 and the thawing nitrogen inlet valve 2; The three-ventilation valve is used to select the destination of the secondary exhaust gas; wherein the specific operation of selecting the destination of the secondary exhaust gas is: S1, determining whether the first and second condensers and the second and second condensers are frosted or frozen; S2. If the first and second condensers are frosted and frozen, and the second and second condensers are not frosted and frozen, the three-way ventilation valve transports the secondary tail gas to the second and second condensers, and opens the thawing nitrogen inlet valve 1 and the thawing nitrogen outlet valve 1, so that the thawing nitrogen enters the first and second condensers to melt the frost of the first and second condensers; S3, if the opposite to step S2, the three-ventilation valve delivers the secondary tail gas to the first and second condensers, and opens the second thawing nitrogen inlet valve and the second thawing nitrogen outlet valve, so that the thawing nitrogen enters the second and second condensers to melt the frost in the second and second condensers; The first secondary condenser and the second secondary condenser are both used to condense the secondary tail gas to generate secondary condensate and tertiary tail gas, and transport them to the secondary condensation receiving tank and the bottom of the absorption tower respectively; the secondary condensation receiving tank is used to store the secondary condensate; the absorption liquid circulation pump provides circulation kinetic energy for the absorption liquid and transports the absorption liquid to the absorption liquid condenser; the absorption liquid cooler is used to cool the absorption liquid and transport it to the top of the absorption tower; the absorption tower is used to dissolve and absorb the tertiary tail gas with the absorption liquid to generate rich liquid and exhaust gas, and transport the rich liquid to the evaporator steam outlet condenser; The evaporator steam outlet condenser is used for rich liquid to condense volatile gas to generate harmful liquid, and the harmful liquid is transported to the condensate receiving tank, and the rich liquid is transported to the heat recovery device; the heat recovery device is used for rich liquid to absorb heat in lean liquid, and the lean liquid is transported to the lean liquid receiving tank, and the rich liquid is transported to the evaporator inlet preheater; the evaporator inlet preheater is used to heat the rich liquid and transport it to the thin film evaporator; the thin film evaporator is used for evaporation and separation of the rich liquid to generate volatile gas and lean liquid; The condensate receiving tank is used to store harmful liquid and transport it to the condensate delivery pump; the condensate delivery pump provides delivery kinetic energy for the harmful liquid and transports it to the liquid collecting barrel; the liquid collecting barrel is used to store harmful liquid; the lean liquid receiving tank is used to store lean liquid and transport it to the lean liquid circulation pump; the lean liquid circulation pump provides circulation kinetic energy for the lean liquid and sends it to the absorption tower.

2. The low temperature treatment system for high concentration and high halogen VOCs tail gas according to claim 1 is characterized in that: The temperature of the thawed nitrogen after heating is 10° C. The absorption liquid is transported to the top of the absorption tower and then sprayed downward to form convection with the tertiary tail gas.

3. The low temperature treatment system for high-concentration and high-halogen VOCs tail gas according to claim 1 is characterized in that: The cooling medium of the first-stage condenser is 0°C chilled water; the cooling medium of the first-stage condenser and the second-stage condenser are both liquid nitrogen; the cooling medium of the absorption liquid cooler is liquid nitrogen, and the temperature of the absorption liquid after cooling is -80°C.

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