This invention relates to an apparatus for cooling skid pipes in a continuous slab reheating furnace. The conventional method for cooling the said skid pipes was such that coolant such as cooling water was passed inside refractory insulating material covering the skid pipes. But evaporative cooling or the method of recirculating coolant requires large-size equipment of complicated structure partly because of necessity of a countermeasure for leakage and safety aid.
In another method of passing water as coolant, thermal energy of cooling water is not utilized at all and there is great heat loss from the furnace as the skid pipes are cooling to 30.degree. to 50.degree. C. with cooling water. In addition to these thermal problems, there is a disadvantage that the cooling effect drops due to the precipitation of such salts as calcium and silica, and formation of scale inside the skid pipes during a long period of use.
This invention, intended to eliminate defects of the said conventional cooling methods, provides an apparatus for cooling skid pipes in a continuous slab reheating furnace, in which hot water made high in temperature in the skid pipes is cooling by heating other fluid through heat exchangers provided in a closed circuit formed with a passage inside the skid pipes made part of a hot water circulating passage so that the skid pipes may be protected, without reducing the temperature of the circulating hot water too much and with effective utilization of heat and minimized furnace heat loss, and the precipitation of calcium and silica in the piping may be minimized by circulating processing water in the closed circuit.