EBT electric furnace’s outlet filler and operation

Tapping filler and automatic pouring technology of arc melting furnace

EBT electric furnace realizes the opening and closing of the water outlet through the opening and closing mechanism of the steel outlet, while blocking the steel outlet and automatic pouring are realized through the filler. If the molten steel can’t flow out automatically, the steel can be tapped by gently striking the steel drill or burning oxygen. When burning oxygen, use a special oxygen blowing elbow to blow oxygen at the steel outlet. Generally, it takes only a few seconds to burn the sintered filler at the steel outlet to make the molten steel flow out.

The filler is required to have high melting point, good thermal stability, poor thermal conductivity and good fluidity. At the steel-making temperature, the surface is slightly sintered when contacting molten steel, and the lower part is still loose. This thin sintering layer can protect the lower filler from floating and prevent liquid steel from infiltrating. Furthermore, the strength of the sintering layer is small. When the tapping port is opened, the lower loose material falls, the sintering layer automatically breaks under the static pressure of molten steel, and the molten steel flows into the ladle to realize automatic tapping.

According to the use characteristics of EBT electric furnace filler, the materials used as filler include olivine (tapping hole sand for open hearth furnace), river sand and synthetic sand, mainly MgO (40% ~ 50%), SiO2 (40% ~ 45%), and a small amount of Fe2O3 (about 10%), with a particle size of 0.5 ~ 5.0 mm and no water.

Maintenance of steel outlet of Excentric bottom tapping electric arc furnace

After tapping, the ladle shall be moved to the next process, the tapping port maintenance platform shall be moved below the tapping port, and the slag and steel crust on the end of the tapping port shall be removed with a shovel tool (note that it must be removed immediately after tapping, otherwise the cleaning work is difficult due to low temperature). In serious cases, oxygen blowing can be used for cleaning.

After cleaning, close the steel outlet support plate, align the charging funnel with the steel outlet through the operation port of the steel outlet box, and add the filler into the steel outlet.

The replacement cycle of the tap hole should match the periodic shutdown, so it’s best to use refractory materials matching the periodic shutdown cycle, especially the tap hole seat brick. When the tap hole is seriously damaged or the tap hole is too large and needs to be replaced, the following operations can be adopted:

1. Only replace the steel end brick. Loosen the support ring supporting the end brick of the steel outlet, remove the damaged end brick, remove the sundries on the mating surface, ensure the coordination between the end brick and the pipe brick, install the end brick and the support ring, close the steel outlet mechanism and fill the steel outlet channel with filler.

2. Replace the whole outlet pipe brick. The outlet pipe brick and outlet end brick need to be replaced together.