Disposal technology of leakage accident in the hot

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The emergence of chemical production is a sign of social development, scientific and technological progress and the improvement of human civilization to a certain extent. It is an important field of modern production and an important embodiment of today's industrial development. With the rapid growth of China's economy, the chemical industry is also developing rapidly, followed by the increasing frequency of chemical accidents, resulting in a large number of casualties and serious economic losses, and even adverse political effects. On the one hand, the chemical industry has greatly improved and promoted our social economy and people's living standards. On the other hand, it also poses a great threat to the safety of people's lives and property. According to incomplete statistics, there are more than 60 liquid chlorine chemical enterprises in China. Over the years, there have been major and minor accidents, including accidents in production, storage leakage accidents, and Transportation traffic accidents; As a fire fighting team, we should not only strengthen the prevention of chemical accidents, but also accurately predict the flammable, explosive, high temperature, high pressure, highly toxic and corrosive characteristics of chemical enterprises and possible accidents, formulate accident disposal plans, invite enterprise engineering and technical personnel to establish an expert group, and carry out targeted tactical discussion and drill, so as to lay a solid foundation for the successful disposal of chemical disaster accidents, Gradually improve disposal methods and measures. Based on the chemical units producing liquid chlorine, the author will make the following discussion on the harmfulness of chemical unit accidents (liquid chlorine leakage) and the following information. After you know in detail, you will understand the countermeasures

I. characteristics of liquid chlorine and causes and hazards of accidents

(I) causes of chlorine leakage accidents

chemical enterprises in production, especially before and after leakage or fire accidents, generally have a large loss of toxic and harmful gases (or liquids). Most of them have the characteristics of high toxicity, easy diffusion, easy combustion and explosion, so they are very likely to cause large-scale pollution in the accident area and a large number of casualties, It is particularly serious in densely populated large and medium-sized cities. The causes of chemical leakage or fire accidents mainly include the following three situations:

(1) operators operate against rules. There are strict operating procedures for chemical production, storage and transportation. Once violations occur, accidents may occur

(2) failure of enterprise equipment itself. The chemical production process requires electrolysis or high temperature, high pressure and low pressure. In addition, many raw materials and products are highly corrosive, which is easy to cause the corrosion of various pipes, valves, towers and cylinders, resulting in safety hazards such as the escape, emission, dripping and leakage of toxic substances

(3) is an unpredictable unexpected factor. This kind of accident is caused by the chemical reaction out of control due to the sudden power and water cut-off in the process of chemical production, and the leakage of toxic substances due to collision and explosion during transportation. Chemical accidents caused by accidental factors occur from time to time, and the harm is serious

(II) characteristics and characteristics of liquid chlorine production process

the production of liquid chlorine is mainly through the electrolysis of salt, which is electrolyzed by the electrolytic cell to produce chlorine, hydrogen, etc., which are respectively transmitted to the hydraulic workshop through the gas transmission pipeline, and then assembled after hydraulic pressure. However, in the production process, the hydrogen content in chlorine gas is too high, which is prone to explosion

the molecular formula of chlorine is Cl2, with an atomic weight of 35.5. Chlorine is a yellow green gas with strong irritating odor, which is about 2.5 times heavier than air. Its liquid phase transition is about 400 times its phase volume expansion. It is soluble in water and alkali solutions, and easily soluble in organic solvents such as carbon disulfide and carbon tetrachloride. When chlorine meets with water, it generates hypochlorite and hydrochloric acid, which are then decomposed into new ecological oxygen. Under high pressure, chlorine is liquefied into liquid chlorine. Chlorine has strong corrosivity, and equipment and containers are easy to be corroded and leak. Chlorine is a toxic gas of combustion supporting substance, which can react violently with most organic substances. For example, mixing organic compounds into containers containing liquid chlorine will cause violent reactions and lead to explosion

in industry, chlorine can be exposed if the equipment and pipelines are not tightly sealed or during maintenance during the manufacturing or use of chlorine. During the filling, transportation and storage of liquid chlorine, if the steel cylinder is poorly sealed or malfunctioned, a large amount of chlorine can also escape. The industry is mainly used for manufacturing various chlorinated compounds, papermaking, printing and dyeing, and disinfection of tap water

(III) harm of chlorine to human body

chlorine exerts experimental force on imported ball screws. There are two kinds of effects: acute poisoning and chronic damage. When it reaches 3.5ppm in the air, it can feel odor, and when it reaches 15ppm, it can irritate eyes and respiratory tract, and feel pain, cough, suffocation and chest tightness. When it reaches 50ppm, it instantly causes dyspnea, pulse reduction, and the maximum allowable concentration in the air is 0.002mg/l, More than 2.5mg/l people died immediately after inhalation

acute poisoning can be divided into irritation, mild, moderate and severe poisoning. Its manifestations are: (1) chlorine stimulation reaction: there are transient eye and upper respiratory tract irritation symptoms; (2) Mild poisoning: mainly manifested as bronchitis and peribronchitis, cough, a small amount of sputum, chest tightness, etc., dry rales or wheezes in both lungs, and a small amount of wet rales; (3) But its weight is only about 10% of the traditional insulation layer. It is mainly manifested as bronchopneumonia, interstitial pulmonary edema or localized alveolar pulmonary edema. Cough, expectoration, shortness of breath, chest tightness or chest pain, mild cyanosis, dry or wet rales in both lungs; (4) Severe poisoning: the clinical manifestations are ① cough, a lot of white or pink foam sputum, dyspnea, chest tightness, obvious cyanosis, and diffuse wet rales in both lungs; ② Severe asphyxia; ③ Moderate and severe coma; ④ Death; ⑤ Serious complications, such as pneumothorax, mediastinal emphysema, etc., as long as one of them is severe chlorine poisoning. The chronic effects of chlorine on human body are mainly manifested in the irritation symptoms of upper respiratory tract, conjunctiva and skin, neurasthenia syndrome, chloracne, tooth erosion, etc

patients with obvious chronic respiratory diseases and obvious cardiovascular diseases should not be engaged in chlorine operation. Chlorine is usually contained in steel cylinders and is liquid. However, when it comes into contact with the air, it is light green at room temperature. It is a highly toxic gas with a pungent smell, which can irritate the mucous membranes of eyes and respiratory tract, and can cause acute poisoning and lung injury. However, the harm of chlorine should also be preventable. When you arrive at a safe area, you should immediately rest and avoid strenuous exercise, so as not to increase the burden on your lungs and worsen your condition; In case of eye or skin contact with liquid chlorine, Changshu national high tech Industrial Development Zone is located in the core area of the Yangtze River Delta. Rinse thoroughly with clean water. Poisoned people can use calcium, vitamin C and dehydrating agent appropriately; Early enough use of glucocorticoids and antibiotics can reduce respiratory tract and lung injury; The effect of using ultrasonic spray to deliver drugs directly to the respiratory tract is better; Patients should be sent to large hospitals or medical units with occupational disease departments for treatment in time

II. Disposal of liquid chlorine leakage

after understanding the production process, characteristics and harmfulness of the above liquid chlorine, it is of great significance for the disposal of chlorine leakage accidents. No matter when and where chlorine leakage accidents occur, as a fire force, in dealing with such accidents and rescue operations, commanders and soldiers should master the characteristics and harmfulness of liquid chlorine, and do a good job in personal safety protection, which plays a vital role in the successful disposal. Heilong agrochemical Co., Ltd. (the former Jiamusi chemical plant) is an enterprise that produces liquid chlorine. Its annual production of liquid chlorine is about 730 tons, caustic soda is about 5475 tons, hydrochloric acid is about 1825 tons, and hydrogen (liquid) is about 150 tons. It is a key fire protection unit in our city. The municipal government holds a comprehensive drill every year, and the fire force should conduct many investigations, familiarization, and drills, It mainly prepares for the prevention of liquid chlorine leakage and fire and explosion accidents in hydrogen stations. According to the fire control disposal procedures and measures, carry out on-site information inquiry, reconnaissance and detection, set up alert, effective protection, evacuate personnel, transfer the reacting chemicals, dilute and reduce toxicity, shut off the valve and cut off the source, transfer the tank, chemical neutralization, soaking hydrolysis, plugging of appliances, decontamination and other procedures, formulate disposal plans, and implement many drills. However, after many in-depth discussions with the professional and technical personnel of the unit, it is found that evacuating the masses Disposal actions, precautions and other important links have been completed

(I) warning area division and mass evacuation

in case of chlorine leakage, rescuers should cut off the leakage source as far as possible, ventilate reasonably and accelerate the diffusion; Dilute with spray water, dissolve chlorine, and properly handle the leaking container. After the accident, the local government should be informed immediately, and the personnel in the leakage contaminated area should be evacuated to the windward safety area for isolation. If the leakage is light, 150, 450 meters should be isolated; In case of serious leakage, 450-1000 meters shall be isolated. When organizing the evacuation of the masses, if there is not enough gas masks, cover your eyes and respiratory tract with wet towels, evacuate to the upwind and crosswind directions, and avoid running downwind. If the skin is in contact with pollutants, organize a decontamination team, take off the contaminated clothes immediately, and wash with a large amount of flowing water. If you are indoors, you should evacuate from the polluted environment quickly. It is best to carry the poisoned people away on a stretcher to reduce physical consumption, and concentrate on observation, rest quietly and pay attention to heat preservation. For those who have difficulty breathing, do not do artificial respiration, otherwise it will accelerate the formation of pulmonary edema. It is best to use a ventilator or oxygen, observe for 24 hours, and leave if there is no problem. Chest X-ray can be done where conditions permit to prevent pulmonary edema

(II) disposal action

the disposal action should be carried out only after the situation is clearly detected and can be disposed. First, to eliminate risks, it is necessary to divide into several battle groups and set up several lines of defense to reduce the invasion radius of leakage. The first line of defense is to enter the interior and approach the tank for plugging and dilute chlorine with atomized alkali water (baking soda water); Cover the personnel of the first group with soda spray and dilute the diffused chlorine gas, and wash the personnel who go deep into the toxic area after evacuation to form the second line of defense; The periphery responsible for water sharing and equipment support, on-site camera shooting, warning within 1000 meters and other tasks becomes the third line of defense; Second, after the task is clear, each group will take action. The on-site headquarters shall determine a complete set of risk elimination plan, that is, the number of risk elimination personnel (including engineering and technical personnel), personal protection (wearing air respirators and fully enclosed heavy chemical protective clothing), carrying leakage stoppage tools to stop the leakage of the tank, cut off the poison source and dilute, and the key is to do a good job of step-by-step protection. In particular, after entering the internal reconnaissance, it is found that the leakage pressure of the tank is very large, and the leakage port and leakage volume are also very large, so it is impossible to approach the tank at all, and the plugging and transfer of the tank can not be implemented. Under the cover of neutralizing alkaline water, the lime mud should be filled with the leakage port of the leaking tank meters thick (the lime required can be determined according to the leakage port and leakage volume), so that the chlorine leakage volume can be reduced after neutralization, and the evacuation disposal method should be combined with alkaline fog water, Until the gas leakage is completed. During the implementation of air discharge, the chemicals that react with it must be transferred, and the hydrogen station must be closely monitored and isolated with water to prevent the formation of explosive gases

(III) precautions in handling chlorine leakage accidents

(1) the air respirator mask must meet the personal sealing standard. As we learned from Heilong agrochemical Co., Ltd., this order

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