Fire prevention of the hottest chlorine production

2022-08-21
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Fire prevention of chlorine production process

chlorine is also widely used, which can be used not only as important industrial raw materials, but also as bleach and disinfectant. Chlorine is also a highly toxic gas in the life cycle of vehicles. During preparation, it is necessary to prevent not only its combustion, but also its toxicity

I. fire risk

1. In the process of brine refining, the precipitation of some impurities is easy to cause short circuit of the circuit, even electric leakage and sparks. At the same time, hydrogen leakage during electrolysis will cause explosion

2. In the electrolysis process, sometimes poor contact, poor insulation, hydrogen, oxygen and chlorine released from the electrolysis workshop are mixed, reaching the explosion limit and other reasons are easy to cause explosion

3. if the gas is inadvertently transported and stored, it is easy to cause explosion and fire

4. During the liquefaction and filling of chlorine, because hydrogen is still gaseous under the pressure and temperature during the liquefaction of chlorine, the content of hydrogen in the remaining chlorine will increase relatively with the increase of chlorine liquefaction, which is very easy to form an explosive mixture, and there is a certain fire risk

II. Fire prevention measures

1. The salt electrolysis section belongs to class a production. The plant should be a building with class I and II fire resistance rating, and the explosion-proof and pressure relief area should exceed o.2o square meters/cubic meters. There must be good ventilation in the plant, and folded plate roofs and trough roofs are not allowed to be used to avoid the accumulation of hydrogen. The electrolysis section of the diaphragm electrolysis workshop shall be arranged in a single-layer plant. Each section of mercury electrolysis can be arranged in one or several separate plants, but the hydrogen cooling, purification and pressure delivery sections should be arranged in rooms or plants separated by main walls. Lightning protection facilities shall be installed in the electrolytic plant, and the protection range of the lightning rod of the hydrogen vent pipe shall be more than 3 meters above the top of the pipe. The electrical equipment in the plant must be explosion-proof

2. Electrolysis should be carried out in strict accordance with the requirements of process conditions, and the voltage and current density should be controlled in strict accordance with the specified values. Regularly take samples to analyze the purity of chlorine and hydrogen. The hydrogen content in chlorine should be controlled within 3%. If it exceeds 4%, there is an explosion risk. The nitrogen content of the air in the plant should be controlled within 0.5%. The diaphragm electrolyzer shall prevent rust spots in the diaphragm, and there shall be no iron filings left in the mercury solution chamber of mercury electrolysis. To prevent the hydrogen content from soaring during production. The liquid level of the electrolytic cell shall be relatively stable, and the anode diaphragm shall not be exposed to the liquid level, so as to prevent hydrogen and chlorine from mixing and exploding and hydrogen from escaping and burning in the presence of sparks. The diaphragm on the anode of the electrolytic cell needs regular maintenance to avoid falling off

the water temperature in the mercury dissolving chamber should not be too low, and the vanadium content in the graphite anode should not exceed 1/100000. Electrical insulation measures shall be taken at the salt water inlet and alkali liquor outlet of the electrolytic cell to prevent leakage and sparks. The electrolyzer shall be connected with two independent power supplies to prevent the risk of mixing hydrogen and chlorine when the power supply is interrupted. Under no circumstances shall hydrogen be discharged indoors, and the vent pipe shall extend out of the roof and be equipped with water seal and flame arrester

3. Regularly maintain and check the pipelines and equipment that transport and store chlorine from the perspective of weight to prevent leakage. A water seal shall be installed on the conduit connecting the electrolytic cell and the gas tank to prevent the continuous explosion caused by the spread of fire

4. Chlorine is easy to store and transport after liquefaction and filling. In order to prevent the hydrogen content in the residual chlorine gas from being too high to form an explosive mixture, the liquefaction efficiency should be determined according to the hydrogen content in the chlorine gas. Liquid chlorine metering tank, storage tank and other equipment should be directly exposed to liquid chlorine below - 3O ℃, so it should be made of low temperature resistant alloy steel. In non condensable chlorine gas, the hydrogen content should be less than 4%. Higher than the state's application of dry air dilution before liquefaction. Before filling, the cylinder should be carefully checked. There should be no rust, organic matter, etc. in the cylinder. There must be a residual pressure of not less than 0.05 MPa in the cylinder. Only qualified cylinders can be filled. The content of nitrogen trichloride in chlorine should also be carefully checked. If the content is too high, do not fill it. Strictly control the filling volume, which shall not exceed 1.21 kg/L

5. Other fire prevention requirements

(1) the chlorine plant should be located in the suburbs and in the downwind direction of the perennial dominant wind direction of the place. A chlorine neutralization tank should be set in the plant area, which contains 15 ~ 2O% concentration of calcium hydroxide or 5 ~ 15% of lime water. When the chlorine bottle leaks, it should be pushed into the tank for neutralization

(2) the electrolytic plant should be a building with class I and II fire resistance rating, with good ventilation, and the explosion-proof pressure relief area should be greater than 0.20 square meters/cubic meter. The material manufacturers in the electrolysis section of the diaphragm electrolysis workshop usually use spray plating, which should be a single-layer building; Each section of mercury electrolysis can be arranged in one or several separate plants. Electrolyzer, hydrogen cooling, purification and pressure transmission equipment, evaporation equipment, etc. are best arranged in the open air, but when the electrolyzer is arranged in the open air, an open shed should be added to prevent rain and snow from falling on the conductive equipment and leakage. The electrolytic plant shall be equipped with lightning protection facilities

(3) the plant should be equipped with oxygen respirators, which can be worn for rescue in case of accidents. In case of chlorine leakage, fog water can be used to disperse, rather than direct water, to prevent chlorine and water from generating hypochlorite and hydrochloric acid, which are highly corrosive

(4) the operator shall operate in strict accordance with the regulations. And regularly check and repair pipelines and equipment with chlorine to prevent leakage

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