Scrap steel recycling and safe welding and cutting

One of the most important uses for the recycling of waste steel drums is the restructuring of steel drums. There are several forms of restructuring, summed up in the following categories:

1, the use of old steel barrels to make other products.

The old steel drums were dismantled into three components by gas cutting, namely the top of the drum, the bottom of the drum, and the barrel, and the hard-to-use parts were cut off, and the available parts were cleaned and flattened. Flattening materials can be used as blanks for the processing of other products.

2. Refitted into smaller-capacity steel drums.

In the old steel barrels, due to bumps in the course of transportation and the like, the barrels are often pitted and deformed, and the barrels and the top and bottom of the barrels are also deformed, making it more difficult to round. In order to use it to remanufacture new steel drums, one method is to cut the top of the drum and the bottom of the drum along the curling edge, clean the bucket and turn it over again, add a new top of the drum and the bottom of the bucket, and then perform roll closure. , The steel drums manufactured in this way are lower in height than the old ones and the capacity is smaller. The top and bottom of the old barrel can be used to make the top and bottom of the steel barrel with smaller diameter, and other products can also be made.

3, a little restructuring can be made of daily necessities.

Put the old steel drum on the roof as a storage tank, add welded water pipes and outlet pipes, and can make simple tap water; cut the steel drum from the barrel body along the diameter to make the laundry tub; cut the steel drum along the axis Open a trough that can be used as livestock, in rural areas there are people using it as a bathtub; open a large mouth above the barrel, and then welding the valve on the bottom of the barrel, you can put on the tricycle for water and water storage tools; There are also people using it as a solar water heater or a shower tank, etc...

The recycling of waste steel drums is of high value, but the restructuring process is sometimes complicated and often involves risks. In China, accidents occur when steel drums are reformed, mainly due to burning and explosion accidents.

Because the steel drums are generally inseparable from the welding and cutting operations, welding and cutting steel drums often result in explosion accidents due to contact with welding and cutting flames due to residual gasoline and flammable gas in the drums. Because of the welding and cutting operations on steel drums, measures such as demolition, cleaning, and replacement must be taken to perform welding and cutting operations.

(I) Scrap steel welding and cutting

First, pour the remaining flammable liquid in the barrel, then pour it into the barrel with a pyrogenic alkali (sodium hydroxide) aqueous solution for cleaning. The amount of fire caustic soda is generally 0.5 kg for each 200-liter gasoline tank. When cleaning, 0.5 kg of fire alkali is used three times. First, pour half of the boiling water into the drum, place a third of alkali, cover the mouth, shake the bucket for half an hour, then pour out the water, and clean it three times in a row. Only after washing for one or two times with clean water can the welding be cut. If it has not been welded or cut immediately after cleaning and it has been stored for a period of time, it must be rinsed with clean water for one or two times before welding and cutting. Otherwise, a small amount of gasoline that has not been cleaned will evaporate flammable vapors and an explosion will occur because the explosion limit of gasoline is very low (0.76% to 7%).

(II) Waste steel drum replacement welding method

First, the residual gasoline in the barrel is decanted, filled with inert gas such as nitrogen, and then flushed with air, followed by replacement of two or three times, and then filled with inert gas, then the hot welding can be performed. If there is no inert gas, steam can be used instead, but the number of replacements should be increased appropriately.

(III) Waste steel drums and water welding method

If the welding point of the gasoline tank is only at the top of the barrel above the steel drum, the gasoline can be drained and rinsed once or twice with clean water. Then the bucket is filled with clean water so that no flammable vapor can accumulate in the container. This method is relatively simple, but it has its limitations.

When welding any other component beside the steel drum, the inside of the steel drum must be cleaned or filled with water, because not only welding Mars will endanger the safety of the steel drum, but also the steel drum will be in a live state during welding. Sparks may occur at the connection of the wire when it is energized.

If it is for repair welding, after the steel drums are welded well, check whether there is any leakage of the welds in time with clean water, and if leakage is found, welds shall be made immediately. Otherwise, if the leakage is discovered after a period of time, the welding must be performed again and the cleaning must be performed again.

It is worth noting that some people use old steel drums as boilers. This is extremely dangerous and there have been many accidents in the country. Steel drums are non-pressure vessels and are just ordinary metal packaging materials. Therefore, when the old drums are regenerated, care must be taken not to violate the characteristics of the steel drums for restructuring and use.

Although equipment and energy used in welding and cutting have certain fire hazards, the main cause of fire and explosion accidents is not the equipment and energy itself, but the vast majority are caused by paralysis in welding and cutting operations. Improper operation, lax system, and lack of implementation of safety measures. Therefore, the key is to pay attention and prevention. Prepare the safety preparations before the operation, and strictly follow the procedures during the operation. After the operation, conduct a detailed safety inspection.

(author/Yang Wenliang)

Chinese drum packaging network