Risk factors:

The defects of the molten iron tank, molten steel tank, tundish (tank), slag tank equipment in electric arc furnace, improper operation, prone to explosion, burning.

 

Precautions:

The shell of molten iron tank, molten steel tank and tundish shall be provided with vent holes.

 

After the molten iron tank, molten steel tank, tundish are built, they shall be kept dry and baked to the required temperature before use.

 

The trunnion of the tank body shall be located at the symmetrical center of 0.2-0.4m above the synthetic center of gravity of the tank body, and its safety factor shall not be less than 8. It can only be used after passing the heavy load test at 1.25 times of the load.

 

For the arc furnace in use, the trunnion part shall be inspected regularly. If the trunnion has internal crack, shell weld crack, obvious deformation, trunnion wear is more than 10% of the diameter, mechanical failure, lining brick damage exceeds the requirements, it shall be reported for repair or scrapped.

 

When lifting the tank containing molten iron, molten steel and liquid slag, the clearance distance of more than 1.5m shall be kept between the tank and adjacent equipment, buildings and structures.

 

When there is a condensation cover for the molten iron and steel in the molten iron tank or the molten steel tank, the pressure condensation cover of other molten iron tank or the molten steel tank shall not be used, and the tubular object shall not be used to impact the condensation cover manually. For molten iron with non condensing residues, the steel tank shall not be placed horizontally.

 

The sliding nozzle of the steel tank shall be cleaned, inspected and debugged to be qualified before each use.

 

The slag tank shall be inspected before use, and there shall be no water or wet materials in the tank.

 

Risk factors:

The baking system of hot metal tank, molten steel tank and intermediate tank leaks gas or natural gas, which is prone to poisoning, suffocation and scalding.

 

Precautions:

Special personnel with crane command certificate shall lift the molten iron tank command to the position of the toaster to avoid damaging the toaster and causing gas leakage.

 

After baking, the cover of the toaster shall be raised to the original parking place to avoid damaging the toaster by crane crane and causing gas leakage.

 

Check the long open fire and burner of the gas roaster to prevent the gas fire from being extinguished due to the low pressure of the network management system and the leakage after the gas is supplied; if it is extinguished, close the valve immediately.

 

Check whether all parameters of baking medium, quick cut-off valve and flameout detection device of the toaster are normal, ensure that the open fire is not flameout and normal baking is carried out.

 

Fixed gas detection alarm shall be installed in the area.

 

More than two people are required to enter the area, and portable gas detection and alarm device shall be carried.

Long distance automatic ignition facility should be applied. During ignition and baking, it is necessary to "ignite first, then supply air". During air combustion, it is necessary to "ignite first, then supply air". Before normal combustion, the baking cover shall not be lowered to the tank mouth.

 

TAG:  steelmaking   electric arc furnace   arc furnace