| 摘要 |
A heating furnace (1) comprises at least three banks of heated pipes (10) arranged in parallel to a first side wall surface (11a) and a plurality of combustion devices (12, 13) disposed on a second side wall surface (11b). The combustion devices introduce a combustion gas into intermediate areas between the banks of heated pipes. The combustion devices comprise heat accumulating bodies for accumulating sensible heat contained in a combustion exhaust gas, and burners capable of supplying a fuel fluid for combustion to an air supply flow for combustion. The heat accumulating bodies come into heat exchanging contact with the air supply flow for combustion to thereby preheat the air supply flow to high temperatures, and perform heat exchanging with the combustion exhaust gases in the furnace to receive heat. The heating furnace is provided with combustion exhaust gas leading means (40) for leading a fluid portion of a predetermined proportion of combustion exhaust gas generated in a furnace area to outside the heating furnace, and a heat exchanging device capable of introducing the combustion exhaust gas led from the heating furnace. Thus it is possible to realize a heating furnace which has a function of preheating a combustion air to high temperatures, makes effective use of a property or characteristic of high cyclic or high speed switching type heat accumulating combustion system, can exhibit a high overall thermal efficiency and is economical and compact. |
