Summer is a thunderstorm season, and chemical enterprises are prone to damage to electromechanical, electric power, instrument, communication, metering, electronic control and other systems due to lightning, resulting in equipment failures, trips, shutdowns, false starts and other accidents. Lightning strike often leads to the fire of flammable gas vent nozzle, and even directly leads to accidents. Summer is also a season of frequent electrical accidents. Chemical enterprises should pay special attention to the following points in lightning protection and prevention of electrical accidents.
(1) Lightning protection and grounding of all buildings, equipment, electricity and instruments before the thunderstorm season comes every year. A thorough and detailed inspection should be conducted in advance to comprehensively detect the impulse grounding resistance value of lightning protection grounding. If there is any problem, it should be rectified in time to ensure that it is not missed.
(2) Install lightning rods for key instrument circuits, prepare the walls and roofs of the instrument room in the main control room for rain protection, and timely dredge the rainwater pipes and rainwater ditches at the top of the building to ensure smooth flow.
(3) In terms of electricity, the temperature of contact points of transformers, cables, cable joints, motors (including fuselage and bearings) and electrical components should be detected to prevent overheating; Some electrical equipment should be rain-proof and waterproof, and should be checked after rain.
(4) The safety valve, vent and other parts of the storage tank are the key points for lightning protection of the storage tank, which are vulnerable to lightning strike and fire, especially the towering equipment such as distillation tower. Daily inspection and regular inspection must be combined to rectify the existing problems in time.
(5) Check lightning protection facilities such as grounding wires and jumpers to ensure no looseness or serious corrosion; After the pipeline and equipment are dismantled and repaired, lightning protection grounding wires and jumpers should be restored immediately to ensure normal work.
(6) Check whether there is any leakage at the pipeline joint, and prevent the leaked combustible gas from catching fire due to lightning, especially in hydrogen production enterprises by hydrogenation.
(7) Thunderstorm weather is easy to cause electrical accidents, resulting in power failure or power failure of equipment. Chemical enterprises must constantly improve emergency plans and conduct drills to ensure that power failure accidents can be handled correctly and the impact will be minimized.
(8) During a thunderstorm, self-protection measures should be taken to prevent the human body from being struck by lightning.
(9) In summer, the weather is hot, humid and rainy, which reduces the insulation performance of electrical lines and facilities and is prone to leakage. Non-professionals should stay away from live facilities and disconnect the power supply before moving electrical equipment.
(10) For the ongoing thunderstorm, stop production if possible; If it is impossible to stop production, avoid emptying and feeding operations, and pay attention to the safety of personnel.
2, flood control and typhoon prevention measures
The necessary condition to prevent floods is to ensure smooth drainage system. Chemical enterprises should ensure that light rain can drain water, without water accumulation, and have plans to deal with catastrophic floods. In case of catastrophic flood, they can arrange production in an orderly manner or stop production in an emergency according to the plan. In the rainy season to do the following work:
(1) Check the sewer system, rainwater drainage system, drain outlet, etc. regularly. In the production area, and clean up the uneven ditch bottom standards, ditch cover plate is complete and covered, and guardrails should be intact and firm.
(2) The doors and windows of underground and semi-underground facilities, key production parts, key equipment, water supply and power supply projects and various material warehouses should be heightened or reinforced.
(3) Take measures to prevent rainwater from entering the sewage treatment system, and timely handle the accumulated water in the low-lying areas of the plant area and device area to ensure the normal operation of the sewage treatment system and avoid environmental pollution accidents.
(4) Check the houses, sheds (steel houses) and fences of the factory building to prevent typhoons and landslides.
(5) Pay attention to the rainproof, waterproof and moistureproof of production equipment during flood season or flood period.
(6) Equipped with shovel, woven bag, drainage pump, flood control sand, communication equipment and other necessary emergency tools and articles. Management should be strengthened and responsibility should be implemented to people. The management of emergency relief materials reserve and emergency alarm system should be checked regularly, and necessary relief materials should be replenished in time as needed.
(7) Seriously organize emergency drills for flood control and wind disaster relief, and do a good job in publicity and education, so that each employee can clearly understand the significance of flood control and wind disaster relief and his responsibilities and obligations in flood control and wind disaster relief.
(8) According to the weather forecast or early warning issued by the Meteorological Observatory, make preparations for flood control in advance, with personnel and materials in place, and start the emergency plan according to the situation when necessary.
3, heatstroke prevention and cooling measures
In summer, the weather is sunny and hot, and the intensity of solar radiation and ultraviolet rays reaches the highest, which has a great impact on human health and is prone to heatstroke, chronic heat stroke and other diseases. In order to ensure the health of employees, chemical enterprises need to do the following work.
(1) Turn on the air conditioner in the power distribution room and other hidden dangers, and keep the indoor temperature at 25 ~ 27℃.
(2) Arrange the time reasonably. Operators should try to avoid high temperature operation, wear protective overalls reasonably, avoid working in high temperature environment for a long time, drink more salty water (salty soda water), pay attention to rest, and prepare heatstroke prevention and cooling drugs.
(3) In summer, people are prone to fatigue due to the hot weather. Enterprises should pay attention to observe the mental state of employees, improve working conditions, reduce labor intensity and strictly control overtime.
(4) Provide necessary nutrients, heat-resistant health drinks and other health care measures to improve the physical fitness of workers, control and eliminate heatstroke, and reduce the long-term impact of high temperature on health. People with poor physical fitness who are not suitable for high-temperature operation can arrange night shifts or change jobs.
(5) If patients with heatstroke symptoms are found, they should immediately rest in the shade, and carry out first aid and necessary treatment.
(6) Strengthen the inspection and management of wearing labor protection articles. It is forbidden to wear spikes, slippers, vests, shorts (skirts) and chemical fiber clothes.
4. Measures to prevent overtemperature, overpressure and explosion
Long illumination time and high temperature in summer will accelerate the decomposition, gasification, heating and expansion of flammable and explosive substances, which will easily lead to over-temperature and over-pressure of equipment, and even lead to explosion accidents in serious cases. In order to prevent overtemperature and overpressure, the following matters should be noted.
(1) Safety facilities such as safety valves, pressure gauges, breathing valves, pressure reducing valves, liquid level gauges, thermometers, quick cut-off valves, water curtains and spraying facilities of boilers and pressure vessels must be kept in good condition, and 100% shall be put into use.
(2) The reserves of atmospheric storage tanks should be strictly controlled within the safety critical range, and overloading is strictly prohibited. Non-open barrels and tanks containing dangerous chemicals should not be filled, and a gap of 10% ~ 15% should be left to avoid explosion and rupture of containers caused by expansion of flammable liquids.
(3) The pressure vessel shall operate smoothly. At the beginning of loading, the speed should not be too fast to avoid a sudden increase in pressure. Heating or cooling should be slow to avoid excessive pressure fluctuation and accidents. Do a good job of pressure relief and purging of all equipment and pipelines that are out of service.
(4) Take measures such as rotating operation or suspending operation for the compressor, nitrogen generator, electrical equipment and other equipment that is prone to overtemperature and overpressure.
(5) Grasp the integrity of the venting and pressure relief system at any time to ensure that it is intact and unblocked, and focus on monitoring and inspecting the areas where there may be leakage points, focusing on controlling the venting points at high altitude and the possible leakage points at high altitude to prevent the leakage from being ignited by lightning.
(6) The indoor temperature and ventilation of the main control room, instrument and electrical equipment operation room should be controlled in a normal state.
(7) Strengthen process management, adjust process indicators in time, and prohibit over-temperature, over-pressure and over-load production. Operators should be careful when working, pay close attention to the working conditions of heat exchange equipment, the operation of cooling water and abnormal changes in temperature, liquid level and pressure, and strengthen inspection to prevent running, running, dripping and leaking.
Summary: Summer is not terrible. As long as preparations are made in advance, necessary inspections are made, training is in place, materials are in place, plans are made, meteorological conditions are always concerned, a clear head is kept, and emergency preparedness is always made, we will certainly be able to spend this summer safely.