| 摘要 |
PURPOSE:To improve heat recoveries of waste gases when preheating a combustion air and a fuel gas with a high temperature waste gas from a box type annealing furnace, by supplying the waste gas to each heat exchanger proportionally to the thermal capacity of the air and gas to be preheated. CONSTITUTION:When batch annealings are performed on a strip coil 2, etc., with a box type annealing furnace, heat exchangers 6 for preheating a combustion air for heating the annealing furnace and another type heat exchangers 6a for preheating a fuel gas for heating the annealing furnace are respectively installed in parallel along the outer circumference of a heating cover 1 with 120 deg. angle interval by waste gas ports 5, 5. The coil 2 is heated and annealed through an inner cover 3 with a high temperature gas burnt by a burner 4 and the high temperature waste gas is supplied to each heat exchanger 6 and 6a after it is divided in accordance with the thermal capacity of the fuel gas and the combustion air to be supplied to the burner 4. In this way, the waste heat of the waste gas is effectively absorbed into the combustion air and fuel gas, and thus, the waste heat is recovered. |
