Crucible push – out – device

is a device for removing the wear crucible from the crucible furnace. Due to the contraction of the crucible in the cold condition and the conicity of approx. 0.8%, this can be done with hydraulic cylinders with different pressure surfaces and strokes. In order to prevent possible difficulties, the crucible should be “loosened by hand” in the area of the casting spout. If the crucible cannot be removed due to too little contraction, the crucible must be slit from bottom to top to a width of about 100 mm. Slitting from bottom to top has 2 advantages over working from top to bottom: 1. when starting in the lower cone area, the work is not carried out directly against the coil, and 2. during further caulking toward the top the work is carried out against the existing hole and later against the slit. This minimises the risk of damage to the coil. The position is opposite to the casting spout. The crucible is started out at a force of up to 200 kp/cm2 and the further removal at 30 – 60 kp/cm2, depending on the crucible size, without damage to the coil.