Chlorine-containing tail gas byproduct sodium hypochlorite production device

Abstract

The utility model relates to a chlorine-containing tail gas byproduct sodium hypochlorite production device which is characterized in that chlorine-containing tail gas is connected with a gas inlet of a purification tower through a pipeline, a gas phase outlet at the lower part of the purification tower is connected with a gas inlet of a demister through a pipeline, and a gas outlet of the demister is connected with a gas inlet at the lower part of a primary liquid alkali absorption tower through a pipeline; the top of the first-stage liquid alkali absorption tower is connected with a gas inlet in the lower part of the second-stage liquid alkali absorption tower through one pipeline, and the other pipeline is connected with the top of the second-stage liquid alkali circulation tank; and the second-stage liquid alkali circulation tank is connected with the second-stage liquid alkali circulation tank. The device is a device for continuously producing sodium hypochlorite mainly by purifying tail gas containing chlorine and then reacting caustic soda liquid with a certain concentration with chlorine in the absorption device, and can be widely applied to treatment of the tail gas containing chlorine and realize continuous byproduct sodium hypochlorite solution production.

Description

Technical Field

[0001] This utility model provides a device for producing sodium hypochlorite as a byproduct of chlorine-containing tail gas, belonging to the field of chemical equipment technology. Background Technology

[0002] In the chlor-alkali industry, chlorine is widely used in the production of plastics, pesticides, and other products. In these industrial plants where chlorine is used as a raw material, many reactions are organic and cannot completely react with the chlorine, resulting in excess unreacted chlorine in the tail gas. This excess chlorine needs to be absorbed by liquid alkali to meet emission standards. However, the resulting waste alkali solution has low utilization value and is usually treated as wastewater in sewage treatment plants, leading to a waste of chlorine resources and liquid alkali. Meanwhile, sodium hypochlorite solution is widely used in the production of disinfectants, bleaching agents, and water treatment products, typically produced by directly reacting chlorine with liquid alkali. This design aims to achieve comprehensive utilization of the tail gas by reacting chlorine with liquid alkali to produce sodium hypochlorite solution, reducing the amount of sodium hypochlorite produced by the direct reaction of chlorine with liquid alkali, and simultaneously reducing the generation of waste gas, wastewater, and solid waste from chlorine-containing tail gas treatment. Summary of the Invention

[0003] A sodium hypochlorite production device using chlorine-containing tail gas as a byproduct is disclosed. The chlorine-containing tail gas is connected to the inlet of a purification tower via a pipeline. The tail gas outlet at the bottom of the purification tower is connected to the top of the purification tower's circulating tank via a pipeline. The gas phase outlet at the bottom of the purification tower is connected to the inlet of a demister via a pipeline. The discharge port at the bottom of the demister is connected to the purification tower's circulating tank via a U-shaped water seal and an insertion pipe. The outlet of the demister is connected via a pipeline, one path to the lower inlet of a primary liquid alkali absorption tower and another path to the top of the primary liquid alkali absorption tower's circulating tank. The primary liquid alkali absorption tower is connected via a pipeline to the lower inlet of a secondary liquid alkali absorption tower and another path to the top of the secondary liquid alkali circulating tank. The tail gas outlet at the top of the secondary liquid alkali absorption tower is connected to a vent pipe via a pipeline.

[0004] Fresh liquid caustic soda is connected to the secondary liquid caustic soda circulation tank via pipelines, automatic valves, and flow meters. Process water is also connected to the secondary liquid caustic soda circulation tank via pipelines, automatic valves, and flow meters. The secondary liquid caustic soda circulation tank is connected to the secondary liquid caustic soda circulation pump via pipelines, valves, and filters. The secondary liquid caustic soda circulation pump is connected to the secondary liquid caustic soda absorption tower via one pipeline. The lower outlet of the secondary liquid caustic soda absorption tower is connected to the secondary liquid caustic soda circulation tank via a sight glass and pipeline. Another pipeline is connected to the upper spray port of the primary liquid caustic soda absorption tower via an automatic valve and flow meter, and the third pipeline is connected to the secondary liquid caustic soda circulation tank.

[0005] Fresh liquid caustic soda is connected to the primary liquid caustic soda circulation tank via pipelines, automatic valves, and flow meters. Process water is also connected to the primary liquid caustic soda circulation tank via pipelines, automatic valves, and flow meters. The primary liquid caustic soda circulation tank is connected to the inlet of the primary liquid caustic soda circulation pump via pipelines, valves, and filters. The outlet of the primary liquid caustic soda circulation pump is connected to the primary liquid caustic soda condenser via pipelines and valves. The primary liquid caustic soda condenser is connected to the spray port in the middle of the primary liquid caustic soda absorption tower via pipelines. The lower outlet of the primary liquid caustic soda absorption tower is connected to the top inlet of the primary liquid caustic soda circulation tank via a sight glass and pipelines.

[0006] The primary liquid alkali circulation tank is connected to the product extraction pump inlet via valves, filters, and pipelines. The product extraction pump is connected via pipelines to the liquid alkali detection device and the upper feed inlet of the primary liquid alkali circulation tank, and via pipelines through an automatic valve and flow meter to the product storage tank.

[0007] The cooling water inlet is connected to the cooling water inlet of the first-stage liquid alkali condenser via a pipe and an automatic valve. The cooling water outlet of the first-stage liquid alkali condenser is connected to the cooling water return pipe via a pipe. The process water is connected to the purification tower circulation tank via a pipe, an automatic valve, and a flow meter. The purification tower circulation tank is connected to the purification tower circulation pump inlet via a valve, a pipe, and a filter. One outlet of the purification tower circulation pump is connected to the top spray port of the tail gas purification tower via a valve and a pipe. The other outlet of the purification tower circulation pump is connected to the previous stage absorption device via a valve, a flow meter, and a pipe. The bottom discharge port of the tail gas purification tower is connected to the top inlet of the purification tower circulation tank via a sight glass and a pipe.

[0008] A device for producing sodium hypochlorite from chlorine-containing tail gas byproducts includes the following steps:

[0009] (1) Before starting the front-end unit, add process water to the purification tower circulation tank at 50% level, start the purification tower circulation pump, set the purification tower outlet regulating valve and water replenishment regulating valve to automatic, and automatically extract the absorbent and replenish the process water.

[0010] (2) When starting the machine, add liquid alkali and process water to the primary liquid alkali circulation tank in a certain proportion to 50% liquid level, and turn on the primary liquid alkali circulation pump to adjust the flow rate to circulate the primary liquid alkali absorption tower.

[0011] (3) Add liquid alkali and process water to the secondary liquid alkali circulation tank in a certain proportion to 50% liquid level, and turn on the secondary liquid alkali circulation pump to adjust the flow rate to circulate the secondary liquid alkali absorption tower;

[0012] (4) Turn on the tail gas and introduce tail gas into the device, start the product extraction pump and turn on the liquid alkali detection device to detect the reaction process, and set the product extraction valve interlock to automatic; turn on the circulating water inlet regulating valve and turn on the regulating valve to regulate the circulating liquid temperature, and adjust the opening of the cooling water regulating valve according to the temperature to control the circulating liquid temperature within the process control requirements; after the first-stage liquid alkali extraction circulation detection reaches the extraction control index, the product extraction valve is opened and the flow rate is automatically adjusted according to the process control index to transport qualified products to the product storage tank through the pipeline.

[0013] (5) After the product starts to be extracted, the regulating valve of the secondary liquid alkali circulation to the primary liquid alkali absorption tower is turned on. The secondary liquid alkali is replenished to the top of the primary liquid alkali absorption tower through automatic liquid level control, and then sprayed into the primary liquid alkali absorption tower for reaction.

[0014] (6) Open the interlock of the secondary liquid alkali and process water regulating valve, replenish the liquid alkali and process water in proportion, and control the secondary liquid alkali to a constant level.

[0015] (7) Maintain continuous product output, regularly sample and analyze the properties of the extracted products, and compare the accuracy of the liquid alkali detection device.

[0016] This utility model has the following advantages:

[0017] (1) The device is connected by a pipeline, which makes it easy to install and has a wide range of applications. It can be used for various exhaust gas treatments.

[0018] (2) The device controls the circulating pump and regulating valve through the DCS control system to control process indicators such as flow rate, liquid level and product control parameters, which can realize automatic control of product production and ultimately achieve one-button operation, effectively reducing labor intensity.

[0019] (3) Applied to the treatment of chlorine-containing tail gas, it can achieve the standard emission of tail gas, and at the same time realize the recycling of chlorine resources to produce sodium hypochlorite products, effectively reduce the amount of wastewater generated by waste liquid alkali treatment, and realize the comprehensive utilization of chlorine resources.

[0020] (4) The first-stage liquid alkali absorption tower adopts a dual-feed setting, which can effectively improve the reaction efficiency and enhance the quality of the product. Attached Figure Description

[0021] Figure 1 This is a flow chart of the production unit, which includes: 1. Secondary liquid alkali circulation tank, 2. Secondary liquid alkali circulation pump, 3. Secondary liquid alkali absorption tower, 4. Primary liquid alkali absorption tower, 5. Liquid alkali detection device, 6. Product collection pump, 7. Primary liquid alkali circulation tank, 8. Primary liquid alkali circulation pump, 9. Primary liquid alkali condenser, 10. Demister, 11. Tail gas purification tower, 12. Purification tower circulation tank, and 13. Purification tower circulation pump. Detailed Implementation

[0022] Example 1

[0023] The chlorine-containing tail gas is connected to the inlet of purification tower 11 via a pipeline. The tail gas outlet at the bottom of purification tower 11 is connected to the top of purification tower circulation tank 12 via a pipeline. The gas phase outlet at the bottom of purification tower 11 is connected to the inlet of demister 10 via a pipeline. The bottom outlet of demister 10 is connected to the purification tower circulation tank via a U-shaped water seal and an insertion pipe. The outlet of demister 10 is connected via a pipeline, one way to the bottom inlet of primary liquid alkali absorption tower 4 and the other way to the top of primary liquid alkali absorption tower circulation tank 7. Primary liquid alkali absorption tower 4 is connected via a pipeline to a secondary... The lower air inlet of liquid alkali absorption tower 3 is connected to the top of the secondary liquid alkali circulation tank 1. The tail gas outlet at the top of the secondary liquid alkali absorption tower 3 is connected to the vent pipe via a pipeline. Fresh liquid alkali is connected to the secondary liquid alkali circulation tank 1 via a pipeline, automatic valve, and flow meter. Process water is also connected to the secondary liquid alkali circulation tank 1 via a pipeline, automatic valve, and flow meter. The secondary liquid alkali circulation tank 1 is connected to the secondary liquid alkali circulation pump 2 via a pipeline, valve, and filter. The secondary liquid alkali circulation pump 2 is connected to the secondary liquid alkali absorption tower 3 via a pipeline. The lower discharge port is connected to the secondary liquid alkali circulation tank 1 via a sight glass and pipe. One path is connected to the upper spray port of the primary liquid alkali absorption tower 4 via an automatic valve and flow meter, and the other path is connected to the secondary liquid alkali circulation tank 7. Fresh liquid alkali is connected to the primary liquid alkali circulation tank 7 via a pipe, automatic valve, and flow meter. Process water is connected to the primary liquid alkali circulation tank 7 via a pipe, automatic valve, and flow meter. The primary liquid alkali circulation tank 7 is connected to the inlet of the primary liquid alkali circulation pump 8 via a pipe, valve, and filter. The outlet of the primary liquid alkali circulation pump 8 is connected to the primary liquid alkali condenser 9 via a pipe and valve. The primary liquid alkali condenser 9 is connected to the middle spray port of the primary liquid alkali absorption tower 4 via a pipe. The lower discharge port of the primary liquid alkali absorption tower 4 is connected to the top inlet of the primary liquid alkali circulation tank 7 via a sight glass and pipe. The primary liquid alkali circulation tank 7 is connected to the inlet of the product collection pump 6 via a valve, filter, and pipe. The extraction pump 6 is connected via pipeline to the liquid alkali detection device 5 and the upper inlet of the primary liquid alkali circulation tank 7, and via pipeline to the product storage tank through an automatic valve and flow meter. The cooling water inlet is connected via pipeline and automatic valve to the cooling water inlet of the primary liquid alkali condenser 9, and the cooling water outlet of the primary liquid alkali condenser 9 is connected via pipeline to the cooling water return pipeline. The process water is connected via pipeline, automatic valve, and flow meter to the purification tower circulation tank 12. The purification tower circulation tank 12 is connected via valve, pipeline, and filter to the inlet of the purification tower circulation pump 13. One outlet of the purification tower circulation pump 13 is connected via valve and pipeline to the top spray port of the tail gas purification tower 11, and the other outlet of the purification tower circulation pump 13 is connected via valve, flow meter, and pipeline to the previous absorption device. The bottom outlet of the tail gas purification tower 11 is connected via sight glass and pipeline to the top inlet of the purification tower circulation tank 12.

[0024] The device is used to directly produce sodium hypochlorite solution from chlorine. It achieves one-button operation by setting up a program to control the automatic switching valves. Chlorine is introduced into the device, and the sodium hypochlorite solution is continuously produced through the reaction of chlorine with liquid alkali.

[0025] Example 2

[0026] The method and steps are the same as in Example 1. The device is used for the tail gas treatment of the chlorine-to-PVC production plant to realize the production of sodium hypochlorite solution from tail chlorine. The automatic switching valve is controlled by setting a program to achieve one-button operation. The continuous production of sodium hypochlorite solution by-product is achieved through the reaction of chlorine and liquid alkali.

[0027] Example 3

[0028] The method and steps are the same as in Example 1. The device is used for the tail gas treatment of the process of producing chloroacetic acid from chlorine and acetic acid, so as to realize the production of sodium hypochlorite solution from unreacted chlorine in the tail gas. The device achieves one-button operation by setting up a program to control the automatic switching valve, and realizes the continuous production of sodium hypochlorite solution by-product through the reaction of chlorine and liquid alkali.

Claims

1. A device for producing sodium hypochlorite as a byproduct of chlorine-containing tail gas, characterized in that, Chlorine-containing tail gas is connected to the inlet of the purification tower through a pipeline. The gas phase outlet at the bottom of the purification tower is connected to the inlet of the demister through a pipeline. The outlet of the demister is connected to the inlet at the bottom of the primary liquid alkali absorption tower through a pipeline. The top of the primary liquid alkali absorption tower is connected to the inlet at the bottom of the secondary liquid alkali absorption tower through one pipeline and to the top of the secondary liquid alkali circulation tank through another pipeline. The secondary liquid alkali circulation tanks are connected to each other. The primary liquid alkali circulation tank is connected to the product extraction pump inlet via valves, filters, and pipelines. The product extraction pump is connected via pipelines to the liquid alkali detection device and the upper feed inlet of the primary liquid alkali circulation tank, and via pipelines through an automatic valve and flow meter to the product storage tank.

2. The sodium hypochlorite production apparatus for chlorine-containing tail gas byproducts according to claim 1, characterized in that, The exhaust port at the bottom of the purification tower is connected to the top of the purification tower circulation tank via a pipeline, and the discharge port at the bottom of the demister is connected to the purification tower circulation tank via a U-shaped water seal and an insertion pipe; the gas outlet of the demister is also connected to the top of the primary liquid alkali circulation tank via a pipeline.

3. The sodium hypochlorite production apparatus for chlorine-containing tail gas byproducts according to claim 1, characterized in that, The secondary liquid alkali circulation tank is connected to the secondary liquid alkali circulation pump via pipelines, valves, and filters. The secondary liquid alkali circulation pump is connected to the secondary liquid alkali absorption tower via one pipeline. The lower outlet of the secondary liquid alkali absorption tower is connected to the secondary liquid alkali circulation tank via a sight glass and pipeline. Another pipeline is connected to the upper spray port of the primary liquid alkali absorption tower via an automatic valve flow meter. The third pipeline is connected to the secondary liquid alkali circulation tank.

4. The sodium hypochlorite production apparatus for chlorine-containing tail gas byproducts according to claim 1, characterized in that, Fresh liquid caustic soda is connected to the primary liquid caustic soda circulation tank via pipelines, automatic valves, and flow meters. Process water is also connected to the primary liquid caustic soda circulation tank via pipelines, automatic valves, and flow meters. The primary liquid caustic soda circulation tank is connected to the inlet of the primary liquid caustic soda circulation pump via pipelines, valves, and filters. The outlet of the primary liquid caustic soda circulation pump is connected to the primary liquid caustic soda condenser via pipelines and valves. The primary liquid caustic soda condenser is connected to the spray port in the middle of the primary liquid caustic soda absorption tower via pipelines. The discharge port at the bottom of the primary liquid caustic soda absorption tower is connected to the inlet at the top of the primary liquid caustic soda circulation tank via a sight glass and pipelines.

5. The sodium hypochlorite production apparatus for chlorine-containing tail gas byproducts according to claim 1, characterized in that, The cooling water inlet is connected to the cooling water inlet of the first-stage liquid alkali condenser through a pipe and an automatic valve, and the cooling water outlet of the first-stage liquid alkali condenser is connected to the cooling water return pipe through a pipe.

6. The sodium hypochlorite production apparatus for chlorine-containing tail gas byproducts according to claim 1, characterized in that, The process water is connected to the purification tower circulation tank through pipelines, automatic valves, and flow meters. The purification tower circulation tank is connected to the purification tower circulation pump inlet through valves, pipelines, and filters. One outlet of the purification tower circulation pump is connected to the top spray port of the tail gas purification tower through valves and pipelines, and the other outlet of the purification tower circulation pump is connected to the previous stage absorption device through valves, flow meters, and pipelines.

7. The sodium hypochlorite production apparatus for chlorine-containing tail gas byproducts according to claim 1, characterized in that, The tail gas outlet at the top of the secondary liquid alkali absorption tower is connected to the vent pipe via a pipeline; fresh liquid alkali is connected to the secondary liquid alkali circulation tank via a pipeline, automatic valve, and flow meter; process water is connected to the secondary liquid alkali circulation tank via a pipeline, automatic valve, and flow meter.

8. The sodium hypochlorite production apparatus for chlorine-containing tail gas byproducts according to claim 1, characterized in that, The bottom outlet of the exhaust gas purification tower is connected to the top inlet of the purification tower circulation tank via a sight glass and a pipe.

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