GAS FLOW CIRCULATION TYPE TUBULAR HEATING EQUIPMENT

摘要

The present invention relates to a gas recirculating tubular heating equipment which improves the heat transfer performance, reduces a heat transfer area to approximately 1/2 or under of that of a prior art and is not limited to a certain type of available fuel. This equipment comprises: a furnace 1 having a plurality of tubes 19; heating chambers 2 provided with heat sources 3A and 3B for heating a recirculating gas current outside the furnace; and an out-of-furnace circulating path 4 for taking out a part of the recirculating gas current passing through the inside of the furnace 18 to the outside of the furnace and flowing it back from another position to the inside of the furnace 18. The out-of-furnace circulating path 4 is provided with: regenerative beds 5A and 5B at outlet and inlet openings 9A and 9B communicating with the heating chambers 2; a circulating fan 6; a passage switching device 7 for selectively and alternately connecting an intake opening side and a discharge opening side of the circulating fan 6 with one of the regenerative beds 5A and 5B to switch a direction of the gas current flowing to the regenerative beds 5A and 5B; and a heat removing means 8 for performing heat removal or dilution in the both regenerative beds 5A and 5B, in order that inside the furnace 18 is formed a high-temperature strong recirculating current 10 for periodically inverting a direction of the gas current by the passage switching device 7.