Recuperative coke oven and process for the operation thereof

Claim 1

In a recuperative coke oven of the type including an oven chamber, heating flues, at least one recuperator chamber arranged below said oven chamber and defined by heating walls formed of fire-resistant brickwork, exhaust gas inlet means for introducing hot undergrate firing exhaust gas into said recuperator chamber, and exhaust gas outlet means for discharging exhaust gas from said recuperator chamber, the improvement comprising: at least one recuperator extending into said recuperator chamber; said recuperator comprising an inner elongated tubular member and an outer elongated tubular member coaxially surrounding said inner tubular member and defining therebetween an elongated annular chamber; said inner tubular member having a first end positioned outside of said recuperator chamber for introducing combustion air to be heated into said inner tubular member, such that said combustion air flows through said inner tubular member in a first direction; said inner tubular member having an open second end positioned within said recuperator chamber for discharging said combustion air from said inner tubular member; said outer tubular member having a closed first end positioned within said recuperator chamber for closing said annular chamber, such that said combustion air discharged from said open second end of said inner tubular member is caused to flow through said annular chamber in a second direction opposite to said first direction, and said that said combustion air flowing through said annular chamber is heated by exhaust gas passing through said recuperator chamber from said exhaust gas inlet means to said exhaust gas outlet means; said outer tubular member having a second end positioned outside of said recuperator chamber; heated combustion air outlet means, connected to said second end of said outer tubular member, for discharging heated combustion air from said annular chamber; and means for regulating the temperature of the heated combustion air discharged from said heated combustion air outlet means by controlling the amount of heat taken from said exhaust gas passing through said recuperator chamber and said exhaust gas outlet means, said regulating means comprising means for mounting said recuperator to slidably extend through a wall of said recuperator chamber, such that the effective length of said recuperator within said recuperator chamber is adjustable.