Risk factors and preventive measures of the hottes

2022-09-20
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Risk factors and preventive measures of coking unit

due to its own technical characteristics, coking unit has both continuous and intermittent production characteristics, both chemical reactions under high temperature conditions and toxic gases, operating conditions change from time to time, and the processed residue is easy to catch fire and coking, so the accident probability is high

(I) risk factors and prevention during start-up and shutdown

1. hazard analysis and preventive measures during start-up

the start-up of the device is an unstable operation process. The device gradually heats up and pressurizes from normal temperature and pressure to reach the normal operation index. The introduction and delivery of materials are relatively frequent, and the impact of each link is large, so accidents are relatively easy to occur. According to incomplete statistics, something happens every time the construction starts. The starting steps of the coking unit are: through pressure test, oven drying, oil receiving, wax oil entering and circulation establishment - temperature rise and dehydration - 350 ℃ constant temperature - start the radiation pump - switch to normal

during the starting process, all links are closely connected, and the accident analysis of each stage is as follows:

(1) oven drying stage

oven drying is to remove water and inspect the equipment, Ignition and temperature rise must be carried out in strict accordance with the regulations and the furnace curve when talking about the differences between domestic and foreign material suppliers, otherwise equipment accidents and explosion accidents are likely to occur

(2) temperature rise stage

to vigorously develop the new energy vehicle industry, we should grasp the speed to prevent the sudden boiling of raw material tanks and the evacuation of convection pumps. Such things happen more in the process of construction

(3) 350 ℃ constant temperature stage

we have an advantage

in the constant temperature stage, we must strengthen the dehydration of all parts, especially the gasoline oil-water separator on the top of the fractionator. If the dehydration is not timely, it is very easy to cause gasoline overflow. The dehydration of the fractionation system is not clean, which will cause difficulty in starting the radiation pump and delay the start-up. Constant temperature stage is the peak period of finding problems, and it is also prone to accidents. Therefore, we must strengthen the inspection of equipment to prevent accidents such as running, emitting, channeling and leakage

(4) 460 ℃ constant temperature stage

the main fault in this stage is that the four-way valve does not contain water, and the acid and other mixture valves are stuck. The key is to use multiple movable four-way valves to timely supply steam seals

(5) switch to normal

switch to normal, establish a normal production material process, and mainly pay attention to material balance and heat balance. At the same time, before venting the first tower, the air in the venting system should be cleaned first to prevent the formation of explosive gases

in the process of commencement, special emphasis should be placed on the standardization of operation methods. At the same time, learning and training before commencement should be strengthened to create conditions for commencement. See table 2-62 for the summary of risk factors and preventive measures during construction

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