Device for treating VOCs waste gas in ultra-high molecular weight polyethylene fiber production through resin adsorption

Abstract

The utility model relates to a device for treating VOCs waste gas in ultra-high molecular weight polyethylene fiber production through resin adsorption, which comprises two absorption units, a condenser and a receiving tank, an air inlet and an air outlet are formed in the upper end and the lower end of the tank body respectively, the compressible material layer is laid in the tank body, the microporous nets are arranged on the inner sides of the air inlet and the air outlet respectively and located in the shell, the tank body is filled with the resin, and the temperature control pipes are inserted into the resin. The temperature control pipe is connected with a steam source, air inlets of the two absorption units are connected with a VOCs waste gas source through pipelines, air outlets of the two absorption units are connected with an exhaust pipeline and a recovery pipeline, and the exhaust pipeline and the recovery pipeline are both provided with valves; the recovery pipeline is connected with a condenser, and the condenser is connected with the receiving tank; waste gas enters the tank body through the gas inlet, and purified gas formed after resin adsorption operation is discharged from the gas outlet; after resin adsorption saturation, the exhaust pipeline is closed, the recovery pipeline is opened, high-temperature steam is input into the temperature control pipe to enable the resin to be analyzed to generate tetrachloroethylene gas, and the tetrachloroethylene gas enters the recovery pipeline and is condensed and recovered.

Description

Technical Field

[0001] The utility model relates to a device for treating waste gas containing tetrachloroethylene (VOCs) in the production process of ultra-high molecular weight polyethylene fibers, belonging to the field of ultra-high molecular weight polyethylene fiber production equipment. Background Art

[0002] High-strength and high-modulus polyethylene fiber, also known as ultra-high molecular weight polyethylene (PE) fiber, is the third generation of high-performance fiber after carbon fiber and aramid fiber. In the production process of ultra-high molecular weight polyethylene fiber, tetrachloroethylene is used as an extractant to extract solvent white oil. VOCs waste gas is generated during the recovery of tetrachloroethylene. Most of the tetrachloroethylene can be recovered through condensation and absorption, greatly reducing the VOCs concentration of the waste gas, but it still contains trace amounts of tetrachloroethylene, which requires deep purification to achieve standard emissions.

[0003] The industry mainly uses granular carbon or activated carbon fiber processes to adsorb and recover VOCs in tetrachloroethylene-containing waste gas. The activated carbon or activated carbon fiber adsorption process has major disadvantages: there is a risk of temperature increase and combustion during adsorption, it is difficult to meet emission standards for single-chamber adsorption, incomplete regeneration leads to low adsorption efficiency of granular carbon and activated carbon fiber, and the service life of granular carbon and activated carbon fiber is short. The regeneration process generally adopts the method of direct steam analysis. The recovered tetrachloroethylene solvent and steam condensate are mixed together, and the secondary wastewater generated needs further treatment. In addition, if the boiling point of the solvent to be desorbed is high, ordinary steam desorption cannot completely desorb it. Then, during the re-adsorption process, the exhaust gas still contains trace amounts of VOCs, making it difficult to achieve tail gas emission standards. Conventional resin adsorption and carbon fiber adsorption processes are similar, and the above-mentioned process problems still exist. Summary of the invention

[0004] The purpose of the utility model is to provide a new type of resin adsorption device, optimize the resin filling method, strengthen the desorption process, make the desorption more thorough, ensure the VOCs purification effect of the treatment device, achieve tail gas emission standards, and avoid the generation of secondary wastewater. The technical solution of the utility model is:

[0005] A device for treating VOCs waste gas in ultra-high molecular weight polyethylene fiber production by resin adsorption comprises two absorption units, a condenser and a receiving tank, wherein the absorption unit comprises a tank body with an air inlet and an air outlet respectively opened at the upper and lower ends, a compressible material layer laid in the tank body, a microporous mesh respectively arranged inside the air inlet and the air outlet and located in the shell, a resin filled in the tank body and a plurality of temperature control tubes inserted in the resin; the temperature control tube is connected to a steam source, the air inlets of the two absorption units are connected to the VOCs waste gas source through pipelines, the air outlets of the two absorption units are connected to an exhaust pipeline and a recovery pipeline, and the exhaust pipeline and the recovery pipeline are both provided with valves; the recovery pipeline is connected to the condenser, and the condenser is connected to the receiving tank; the waste gas enters the tank body through the air inlet, and the purified gas formed after the resin adsorption operation is discharged from the air outlet; after the resin adsorption is saturated, the exhaust pipeline is closed, the recovery pipeline is opened, and high-temperature steam is input into the temperature control tube so that the tetrachloroethylene gas generated by resin decomposition enters the recovery pipeline and is recovered through condensation.

[0006] The device for treating VOCs waste gas in the production of ultra-high molecular weight polyethylene fibers by resin adsorption is further designed in that the compressible material layer is a carbon fiber felt layer.

[0007] The device for treating VOCs waste gas in the production of ultra-high molecular weight polyethylene fibers by resin adsorption is further designed in that the thickness of the carbon fiber felt layer is not less than 10 cm.

[0008] The device for treating VOCs waste gas in the production of ultra-high molecular weight polyethylene fibers by resin adsorption is further designed in that the recovery pipeline is connected to the air inlet of the absorption unit, and the residual gas after condensation and recovery enters the tank body again.

[0009] The resin adsorption device for treating VOCs waste gas in the production of ultra-high molecular weight polyethylene fibers is further designed in that there are two condensers, which are connected in series in the recovery pipeline, and a vacuum pump is arranged between the two condensers; the outlets of the two condensers are respectively connected to the receiving tanks.

[0010] Compared with the granular carbon and activated carbon fiber devices in the industry and conventional resin adsorption devices, the utility model has the following advantages:

[0011] 1. The adsorption efficiency of granular carbon and activated carbon fiber is not high, and single-chamber adsorption cannot meet the emission standards, while the resin adsorption of the utility model can achieve near-zero emission of VOCs;

[0012] 2. Granular carbon and activated carbon fiber have a short service life, generally only two years, while resin can have a service life of more than five years;

[0013] 3. Granular carbon and activated carbon fiber have the risk of heating up and burning during adsorption, while resin is non-flammable, eliminating the fire hazard and improving the intrinsic safety performance;

[0014] 4. The utility model adopts an optimized resin filling process and is equipped with compressible carbon fiber felt around the periphery, which solves the problem that the device is difficult to fill due to the expansion of the resin volume during the resin adsorption process;

[0015] 5. The mainstream regeneration adopts the direct steam desorption process, and the recovered solvent and steam condensate are mixed together, generating secondary wastewater that needs further treatment. In the utility model, the steam and the resin are not in direct contact, and the steam condensate and the tetrachloroethylene are not mixed, thus avoiding the generation of secondary wastewater;

[0016] 6. For high-boiling-point solvents, ordinary steam desorption cannot completely desorb them. This process, supplemented by negative pressure desorption, can completely desorb them, thereby improving the use efficiency of the resin and ensuring that the tail gas meets the emission standards. Therefore, this process has a greater advantage in the treatment of high-boiling-point VOCs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of an embodiment of the utility model. DETAILED DESCRIPTION

[0018] The present invention is further described below with reference to the accompanying drawings and embodiments:

[0019] As shown in the figure, a resin adsorption device for treating VOCs waste gas in ultra-high molecular weight polyethylene fiber production includes two absorption units, namely absorption unit 1 and absorption unit 2, a condenser 3 and a receiving tank 4, wherein the absorption unit includes a tank body 5 with an air inlet 51 and an air outlet 52 respectively opened at the upper and lower ends, a compressible material layer 6 laid in the tank body, a microporous mesh 7 respectively arranged on the inner side of the air inlet and the air outlet and located in the shell, a resin 8 filled in the tank body and a plurality of temperature control tubes 9 inserted in the resin; the temperature control tube is connected to a steam source, the air inlets of the two absorption units are connected to a VOCs waste gas source through pipelines, the air outlets of the two absorption units are connected to an exhaust pipeline 10 and a recovery pipeline 11, and the exhaust pipeline and the recovery pipeline are both provided with valves; the recovery pipeline 11 is connected to the condenser 3, and the condenser is connected to the receiving tank 4.

[0020] During operation, absorption unit 1 and absorption unit 2 work alternately, one absorbs waste gas, and the other is on standby for resin analysis. Waste gas enters the tank of absorption unit 1 through the air inlet, and the purified gas formed after the resin adsorption operation is discharged from the air outlet through the exhaust pipe 10; after the resin adsorption is saturated, the exhaust pipe 10 is closed, and the recovery pipe 11 is opened. High-temperature steam is input into the temperature control pipe to make the resin decompose and produce tetrachloroethylene gas, which enters the recovery pipe 11 and is recovered by condensation. When the absorption unit 1 is finished analyzing, the resin needs to be cooled. At this time, the steam is turned off, and the circulating water is turned on to cool the resin. After the temperature cools to below 40°C, it is ready for use.

[0021] The compressible material layer 6 is a carbon fiber felt layer. The thickness of the carbon fiber felt layer is not less than 10 cm. The thickness of the carbon fiber felt layer is sufficient to absorb the pressure generated by the expansion of the resin. The recovery pipeline 11 is connected to the air inlet of the absorption unit, and the residual gas after condensation and recovery still enters the tank again.

[0022] There are two condensers 3, which are connected in series in the recovery pipeline, and a vacuum pump 12 is arranged between the two condensers; the outlets of the two condensers are connected to the receiving tank 4 respectively.

Claims

1. A device for treating VOCs waste gas in the production of ultra-high molecular weight polyethylene fibers by resin adsorption, characterized in that: It comprises two absorption units, a condenser and a receiving tank, wherein the absorption unit comprises a tank body with an air inlet and an air outlet respectively opened at the upper and lower ends, a compressible material layer laid in the tank body, a microporous net respectively arranged inside the air inlet and the air outlet and located in the shell, a resin filled in the tank body and a plurality of temperature control tubes inserted in the resin; the temperature control tube is connected to a steam source, the air inlets of the two absorption units are connected to a VOCs waste gas source through pipelines, the air outlets of the two absorption units are connected to an exhaust pipeline and a recovery pipeline, and both the exhaust pipeline and the recovery pipeline are provided with valves; the recovery pipeline is connected to a condenser, and the condenser is connected to the receiving tank; the waste gas enters the tank body through the air inlet, and the purified gas formed after the resin adsorption operation is discharged from the air outlet; after the resin is saturated with adsorption, the exhaust pipeline is closed, the recovery pipeline is opened, and high-temperature steam is input into the temperature control tube to make the resin decompose to generate tetrachloroethylene gas which enters the recovery pipeline and is recovered through condensation.

2. The device for treating VOCs waste gas in the production of ultra-high molecular weight polyethylene fibers by resin adsorption according to claim 1, characterized in that: The compressible material layer is a carbon fiber felt layer.

3. The device for treating VOCs waste gas in the production of ultra-high molecular weight polyethylene fibers by resin adsorption according to claim 2, characterized in that: The thickness of the carbon fiber felt layer is not less than 10 cm.

4. The device for treating VOCs waste gas in the production of ultra-high molecular weight polyethylene fibers by resin adsorption according to claim 1, characterized in that: The recovery pipeline is connected to the air inlet of the absorption unit, and the residual gas after condensation and recovery enters the tank body again.

5. The device for treating VOCs waste gas in the production of ultra-high molecular weight polyethylene fibers by resin adsorption according to claim 1, characterized in that: There are two condensers, which are connected in series in the recovery pipeline, and a vacuum pump is arranged between the two condensers; the outlets of the two condensers are respectively connected to the receiving tanks.

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