Abstract: A tubular mold is included in a coolant container there being a tubular guide sheet arranged around the mold at a certain distance therefrom, the coolant flows through the gap between the mold and the guide sheet; as specific improvement the upper portion of the mold has grooves cut into the outside to be flown though by water offering therefore a relatively enlarged cooling surface as compared with the remainder of the configuration of the mold underneath, the guide sheet has a radially inward extension such that water is forced into and through the grooves; these grooves are provided in the area in which the liquid bath level is expected to occur in the mold.

Abstract: In a closed circuit system for circulating cooling water to various parts of a shaft type furnace, particularly a blast furnace, the closed circuit includes a water cooling device and two separate feed lines disposed in parallel and each arranged to cool different parts of the furnace. Two tanks are connected to the closed circuit, one located above and the other below the circuit. An electric pump circulates the cooling water during normal operation. If a power failure occurs, the electric pump is shut down and one feed line is automatically cut out of the closed circuit and receives flow from the upper tank and discharges it into the lower tank. The other feed line continues to receive the cooling water circulated through the closed circuit including the cooling device by an internal combustion driven pump which is started up when the power failure occurs.