Siemen's process

A process for making steel by using a regenerative gas furnace which utilizes the heat of the escaping gases in reheating firebricks placed in the passageways for air and gas leading to the furnace. Two sets of passageways are required, being used alternately. While one is conveying the gas and air to the metal, the other is being reheated by the escaping gas from the hearth. Every twenty or thirty minutes a valve is moved, so as to alternate the flow.