Chloromethane-containing waste gas purification treatment device

Abstract

The utility model discloses a kind of chloromethane waste gas purification treatment devices, including the gas filter, hot water tower, demister, condenser, at least one absorption tower, molecular sieve absorption device connected in sequence by pipeline;Gas filter and hot water tower between the pipeline on and exhaust pipeline are respectively provided with chloromethane on-line measuring device;Absorption tower gas inlet and gas outlet place connected pipeline are respectively provided with methanol-chloromethane on-line analyzer;Overall, the utility model has the advantages of mild working condition, small risk coefficient, high processing efficiency, high data transmission efficiency, fast analysis, high degree of automation.

Description

Technical Field

[0001] This utility model belongs to the field of chloromethane-containing waste gas treatment technology, specifically relating to a chloromethane-containing waste gas purification and treatment device. Background Technology

[0002] The synthesis of chemical products such as glyphosate and dimethyl phosphite produces tail gas containing chloromethane. While most of the higher-content chloromethane can be stored after net compression, a certain amount of tail gas is still generated during production. This tail gas contains a relatively small amount of chloromethane, typically between 1% and 5%. Since chloromethane is a flammable and explosive gas, it reaches its explosive limit at a concentration of 8.1% to 17.2%. When mixed with air and encountering an ignition source, it will explode, posing a high risk. If this gas is released directly without purification, it will not only increase the concentration of chloromethane in the air, increasing the risk of explosion, but also pollute the environment.

[0003] There are many existing technologies for treating organic waste gas, mainly including oxidation, combustion (RCO), and activated carbon adsorption. Among them, combustion (RCO) is the most commonly used, but it also generates certain dangers during the treatment process, especially flammable and explosive gases. In addition, the combustion product hydrogen chloride also needs to be treated, increasing the treatment cost. Oxidation is relatively cumbersome and the process is relatively complex. Activated carbon adsorption has a low absorption effect on chloromethane gas and poor efficiency. In the treatment of chloromethane-containing tail gas, data collection is incomplete and lacks timeliness.

[0004] Therefore, it is necessary to develop a chlorinated methane-containing waste gas purification and treatment device to solve the above problems. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a chlorinated methane-containing waste gas purification and treatment device for treating chlorinated methane-containing waste gas. This device solves the problems of high risk, cumbersome process, low treatment efficiency, and incomplete data detection in the process of treating chlorinated methane-containing waste gas, thereby reducing the emission of toxic and harmful pollutants and protecting the environment.

[0006] The purpose of this utility model is achieved as follows: a chlorinated methane waste gas purification and treatment device, comprising a gas filter, a hot water tower, a demister, a condenser, at least one absorption tower, and a molecular sieve absorption device connected in sequence by pipelines;

[0007] The gas filter has an inlet pipe connected to its inlet, and its outlet is connected to the inlet of the hot water tower via a pipe. A gas-liquid separator is installed at the top of the hot water tower, and its outlet is connected to the inlet of a demister via a pipe. The demister's outlet is connected to the inlet of a condenser via a pipe, and the condenser's outlet is connected to the inlet of an absorption tower via a pipe. A gas-liquid separator is also installed at the top of the absorption tower, and its outlet is connected to the inlet of a molecular sieve absorption device via a pipe. An exhaust pipe is connected to the outlet of the molecular sieve absorption device.

[0008] Among them, an online chloromethane measuring device is installed on the pipe between the gas filter and the hot water tower and on the exhaust pipe respectively;

[0009] Online methanol-chloromethane analyzers are installed on the pipes connecting the inlet and outlet of the absorption tower, respectively.

[0010] Furthermore, the hot water tower includes a tower body and a tower bottom, with a circulation pipe between the tower body and the tower bottom. A plate heat exchanger is connected to the circulation pipe, and a circulation pump transports hot water from the tower bottom through the circulation pipe to a distributor located at the top of the tower body. Pall ring packing is installed in the middle of the tower body, and the packing is supported by a grid plate below it. The packing is made of corrosion-resistant ceramic packing or polytetrafluoroethylene packing.

[0011] Furthermore, the hot water in the hot water tower is alkaline, the hot water temperature is controlled at 70℃, and the sodium hydroxide content is between 2.5% and 10%, which neutralizes the hydrogen chloride generated by the reaction of chloromethane.

[0012] Furthermore, the condenser is a graphite condenser, the condenser's freezing medium is frozen brine, and the collected condensate enters the distillation system.

[0013] Furthermore, the absorption tower includes a tower body and a tower bottom, and a circulation pipeline is provided between the tower body and the tower bottom. A circulation pump is used to transport the absorbent from the tower bottom through the circulation pipeline to the distributor at the top of the tower body.

[0014] Furthermore, the absorbent used to absorb methanol in the absorption tower is water or concentrated sulfuric acid, and the packing material of the absorption tower is polytetrafluoroethylene packing.

[0015] Furthermore, when multiple absorption towers are configured, the multiple absorption towers are connected in series.

[0016] Furthermore, the main body of the molecular sieve absorption device is a cuboid structure, with an air inlet and an air outlet on the left and right sides, respectively, and a water outlet at the bottom; the packing of the molecular sieve absorption device adopts a drawer-type structure, with several round holes of 2mm in diameter at the bottom of the drawer, and the packing layer is set to 4-6 layers, with air ducts between adjacent packing layers, and the height of each packing layer is 20-40cm, with a packing diameter of 2.5-3.5mm.

[0017] Furthermore, it also includes a DCS computer remote control system, which controls the gas filter, hot water tower, demister, condenser, absorption tower, molecular sieve absorption device, chloromethane online determination device, and methanol-chloromethane online analyzer, respectively, to realize remote control and data acquisition and analysis.

[0018] The beneficial effects of this utility model are:

[0019] (1) By setting up a gas filter to pre-treat the gas, the solid and powdery impurities in the gas are removed, which improves the purity of the gas, reduces the impact on the analytical instrument, ensures the analytical results, and at the same time reduces the impact on subsequent processing steps and improves processing efficiency.

[0020] (2) A hot water tower, multiple absorption towers, and molecular sieve absorption devices are used as a chloromethane purification system. The hot water tower generates methanol and hydrogen chloride from chloromethane through a chemical reaction. The methanol and hydrogen chloride are then absorbed and treated by multiple absorption towers and molecular sieve absorption devices. The working conditions are mild, the risk factor is low, and the treatment efficiency is effectively improved.

[0021] (3) By setting up various on-site online measuring instruments and transmitting the measuring data to the DCS computer remote control system in a timely manner, the measuring instrument data is compared and analyzed online to ensure the accuracy and timeliness of data analysis. The data transmission efficiency is high, the analysis is fast, and the degree of automation is high.

[0022] In summary, this utility model has the advantages of mild working conditions, low risk factor, high processing efficiency, high data transmission efficiency, fast analysis, and high degree of automation. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of this utility model.

[0024] In the diagram: 1. Gas filter; 2. Hot water tower; 3. Demister; 4. Condenser; 5. Absorption tower; 6. Molecular sieve absorption device; 7. Gas-liquid separator.

[0025] 01. Intake pipe; 02. Exhaust pipe;

[0026] a. Chloromethane online measuring device; b. Methanol-chloromethane online analyzer; c. Online gas flow meter; d. Control valve; e. Online liquid flow meter; f. Online thermometer. Detailed Implementation

[0027] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings.

[0028] like Figure 1 As shown, a chloromethane-containing waste gas purification and treatment device includes a gas filter 1, a hot water tower 2, a demister 3, a condenser 4, at least one absorption tower 5, and a molecular sieve absorption device 6, which are connected in sequence by pipelines.

[0029] The gas filter 1 is primarily used to purify the incoming gas, removing solid and powdery impurities to improve gas purity, reduce the impact on analytical instruments, and ensure analytical results. An inlet pipe 01 connects to the inlet of the gas filter 1, and the outlet of the gas filter 1 connects to the inlet of the hot water tower 2 via a pipe. Gas enters the gas filter 1 from the inlet pipe 01, undergoes pre-treatment filtration, and then enters the hot water tower 2 for decomposition. An online gas flow meter c and an online chloromethane measuring device a are sequentially installed on the pipe between the gas filter 1 and the hot water tower 2. The online gas flow meter c is installed on the pipe after the gas filter to measure the incoming gas flow rate and transmit the measurement data remotely. The online chloromethane measuring device a is installed after the online gas flow meter c, allowing for real-time gas sampling, analysis of chloromethane content, and transmission of the data analysis results to the DCS computer remote control system.

[0030] The hot water tower 2 is used to decompose chloromethane into methanol and hydrogen chloride for easy absorption and treatment. A gas-liquid separator 7 is installed at the top of the hot water tower 2 to separate gas and liquid, reducing the impact of materials entering the pipeline on gas analysis. The gas outlet at the top of the hot water tower 2 is connected to the inlet of the demister 3 through a pipeline. Gas enters the hot water tower 2 from the inlet, passes through the gas-liquid separator 7, and then exits from the outlet into the demister 3.

[0031] The hot water tower 2 includes an upper tower body and a lower tower bottom. An air inlet is provided on the tower bottom, and a circulation port is provided at the bottom of the tower bottom. A circulation pipe is provided between the tower body and the tower bottom. A control valve d and a liquid flow meter e are provided on the circulation pipe. A plate heat exchanger is connected to the circulation pipe. A circulation pump transports hot water from the tower bottom through the circulation pipe to a distributor located at the top of the tower body. Pall ring packing is installed in the middle of the tower body. The packing is supported by a grid plate. The packing is made of corrosion-resistant ceramic packing or polytetrafluoroethylene packing, preferably polytetrafluoroethylene packing.

[0032] The hot water in the hot water tower 2 is alkaline, with the water temperature controlled at 70°C and the sodium hydroxide content between 2.5% and 10%, to neutralize the hydrogen chloride generated by the reaction of chloromethane; preferably, online thermometers f are respectively installed at the top of the tower bottom and the top of the tower body to transmit the measured temperature data remotely.

[0033] The demister 3 is used to further separate the gas and liquid. The outlet of the demister 3 is connected to the inlet of the condenser 4 via a pipe. The outlet of the condenser 4 is connected to the inlet of the absorption tower 5 via a pipe. Preferably, the condenser 4 is a graphite condenser, and the refrigeration medium of the condenser 4 is frozen brine. The collected condensate enters the distillation system. Control valves d are respectively installed on the connecting pipes at the outlets of the demister 3 and the condenser 4.

[0034] The absorption tower 5 is used to absorb and treat the small amount of methanol that escapes. A gas-liquid separator 7 is installed at the top of the absorption tower 5 to separate the gas and liquid, reducing the impact of material entering the pipeline on gas analysis. The gas outlet at the top of the absorption tower 5 is connected to the gas inlet of the molecular sieve absorption device 6 through a pipeline. The gas enters the absorption tower 5 from the gas inlet, passes through the gas-liquid separator 7, and is discharged from the gas outlet into the molecular sieve absorption device 6.

[0035] The absorption tower 5 includes a tower body and a tower bottom. A circulation pipe is provided between the tower body and the tower bottom. A control valve d and an online liquid flow meter e are installed on the circulation pipe. A circulation pump is used to transport the absorbent from the tower bottom through the circulation pipe to the distributor at the top of the tower body.

[0036] The absorbent used to absorb methanol in the absorption tower 5 is water or concentrated sulfuric acid, and the packing material of the absorption tower 5 is polytetrafluoroethylene packing.

[0037] When multiple absorption towers 5 are configured, the multiple absorption towers 5 are connected in series.

[0038] The inlet and outlet of the absorption tower 5 are respectively equipped with online methanol-chloromethane analyzers b, which sample and analyze the gas in the pipeline and transmit the data analysis results to the DCS computer remote control system.

[0039] The molecular sieve absorption device 6 is used to further absorb and treat small amounts of methanol and chloromethane to avoid residues and ensure the treatment effect of the exhaust gas. The main body of the molecular sieve absorption device 6 is a cuboid structure. The left and right sides of the molecular sieve absorption device 6 are the air inlet and the air outlet, respectively. The air inlet is connected to the absorption tower 5, and the air outlet is connected to the exhaust pipe 02. The bottom of the molecular sieve absorption device 6 is equipped with a drain outlet to drain accumulated water in time, prevent the molecular sieve inside the device from failing, and ensure the treatment effect. The exhaust pipe 02 is equipped with an online chloromethane measuring device a to measure the gas emission data in real time, analyze the chloromethane content, compare and analyze it with the chloromethane content data in the gas during the intake, and transmit the data analysis results to the DCS computer remote control system.

[0040] The molecular sieve absorption device 6 uses a drawer-type packing structure. The bottom of the drawer has several round holes with a diameter of 2mm. The packing layer is set to 4-6 layers, with each layer having a height of 20-40cm and a diameter of 2.5-3.5mm. The packing type is 13X. There is an air duct between adjacent packing layers, which allows the gas to fully contact the packing and facilitates the absorption and treatment of tail gas. It can thoroughly treat chloromethane, and the packing replacement and maintenance are more convenient and quick.

[0041] The DCS computer remote control system controls and connects to the gas filter 1, hot water tower 2, demister 3, condenser 4, absorption tower 5, molecular sieve absorption device 6, chloromethane online measuring device a, methanol-chloromethane online analyzer b, online gas flow meter c, control valve d, online liquid flow meter e, and online thermometer f, respectively, to realize remote control and data acquisition and analysis.

[0042] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A device for purifying and treating chloromethane-containing waste gas, characterized in that: It includes a gas filter (1), a hot water tower (2), a demister (3), a condenser (4), at least one absorption tower (5), and a molecular sieve absorption device (6) connected in sequence by pipelines. Among them, the gas filter (1) is connected to the air inlet pipe (01) and the gas filter (1) is connected to the air inlet of the hot water tower (2) through a pipe. The hot water tower (2) is equipped with a gas-liquid separator (7) at the top. The air outlet of the hot water tower (2) is connected to the air inlet of the demister (3) through a pipe. The air outlet of the demister (3) is connected to the air inlet of the condenser (4) through a pipe. The air outlet of the condenser (4) is connected to the air inlet of the absorption tower (5) through a pipe. The absorption tower (5) is equipped with a gas-liquid separator (7) at the top. The air outlet of the absorption tower (5) is connected to the air inlet of the molecular sieve absorption device (6) through a pipe. The air outlet of the molecular sieve absorption device (6) is connected to an exhaust pipe (02). Among them, an online chloromethane measuring device (a) is installed on the pipe between the gas filter (1) and the hot water tower (2) and on the exhaust pipe (02); The absorption tower (5) is equipped with an online methanol-chloromethane analyzer (b) on the pipes connected to the inlet and outlet of the absorption tower (5).

2. The chlorinated methane-containing waste gas purification and treatment device according to claim 1, characterized in that: The hot water tower (2) includes a tower body and a tower bottom. A circulation pipe is provided between the tower body and the tower bottom. A plate heat exchanger is connected to the circulation pipe. A circulation pump transports hot water from the tower bottom through the circulation pipe to a distributor located at the top of the tower body. Pall ring packing is installed in the middle of the tower body. The packing is supported by a grid plate. The packing is made of corrosion-resistant ceramic packing or polytetrafluoroethylene packing.

3. The chlorinated methane-containing waste gas purification and treatment device according to claim 1, characterized in that: The hot water in the hot water tower (2) is alkaline, the hot water temperature is controlled at 70℃, and the sodium hydroxide content is between 2.5% and 10%, which neutralizes the hydrogen chloride generated by the reaction of chloromethane.

4. The chlorinated methane-containing waste gas purification and treatment device according to claim 1, characterized in that: The condenser (4) is a graphite condenser, and the refrigeration medium of the condenser (4) is frozen brine. The collected condensate enters the distillation system.

5. The chlorinated methane-containing waste gas purification and treatment device according to claim 1, characterized in that: The absorption tower (5) includes a tower body and a tower bottom. A circulation pipe is provided between the tower body and the tower bottom. A circulation pump is used to transport the absorbent from the tower bottom through the circulation pipe to the distributor at the top of the tower body.

6. The chlorinated methane-containing waste gas purification and treatment device according to claim 1, characterized in that: The absorbent liquid used to absorb methanol in the absorption tower (5) is water or concentrated sulfuric acid, and the packing material of the absorption tower (5) is polytetrafluoroethylene packing.

7. The chlorinated methane-containing waste gas purification and treatment device according to claim 1, characterized in that: When multiple absorption towers (5) are set, the multiple absorption towers (5) are connected in series.

8. The chlorinated methane-containing waste gas purification and treatment device according to claim 1, characterized in that: The molecular sieve absorption device (6) has a rectangular parallelepiped structure. The left and right sides of the molecular sieve absorption device (6) are respectively the air inlet and the air outlet, and the bottom is provided with a water outlet. The filling material of the molecular sieve absorption device (6) adopts a drawer-type structure. The bottom of the drawer is provided with several round holes with a diameter of 2mm. The filling material layer is set to 4-6 layers. There is an air duct between adjacent filling material layers. The height of each layer of filling material is 20-40cm and the diameter of the filling material is 2.5-3.5mm.

9. A chlorinated methane-containing waste gas purification and treatment device according to any one of claims 1-8, characterized in that: It also includes a DCS computer remote control system, which controls the gas filter (1), hot water tower (2), demister (3), condenser (4), absorption tower (5), molecular sieve absorption device (6), chloromethane online determination device (a), and methanol-chloromethane online analyzer (b), respectively, to realize remote control and data acquisition and analysis.

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