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Show use intermediate-pressure compressed air to operate the four-way selector valve, and low-pressure compressed air to cool the control devices. The increase in power consumption due to these additions is 0.1 x 106 MJ per month. When this is taken into account, the reduction in energy costs amounts to ¥12,000,000 a year. Reduction of unit requirement for refractory material As already mentioned, due to the agitation effect that results from using the regenerative burners alternately, the uniformity of the ladle heating has been improved. This enables the unit requirement for refractory material to be reduced by 1 5 % compared to that in the conventional burner heating system. Conclusions Regenerative burners have already been used in heating furnaces or heat-treatment furnaces for steel. W e introduced a compact regenerative burner into the ladle heating system for an electric furnace, where it was previously considered difficult to install the exhaust-heat recovery system due to problems of heat resistance and limited space. W e achieved a considerable reduction in energy costs by recovering exhaust heat with high efficiency. W e also succeeded in uniformly heating the ladle before it received molten steel, by using two regenerative burners alternately. As a result, the unit requirement for refractory material was reduced significantly. r t ^ |