초록 ▼

The present invention relates to a fuel-fired heating element of the tubular kind particularly though not exclusively for use as an immersed heating tube in molten metals, salts or fluidized beds of solid particles for conductive heating or for use in an enclosed or partially enclosed chamber to pro

The present invention relates to a fuel-fired heating element of the tubular kind particularly though not exclusively for use as an immersed heating tube in molten metals, salts or fluidized beds of solid particles for conductive heating or for use in an enclosed or partially enclosed chamber to provide radiant and convective heating. The element includes a tubular housing 1 having one end 2 closed and an opening to provide an outlet 4 for combustion products. A burner assembly 6 is received with an annular clearance 51 within the housing between the outlet 4 and the closed end 2 and is arranged to direct its combustion products as a stream towards the closed end 2. The tube 7 encloses with clearance three axially aligned tubes 60, 61 and 62 whose external and internal diameters decrease sequentially from the burner 6 to the end 2. The combustion products are conveyed by the ducts from the burner 6 to the closed end 2 and back again with some re-conveyed products re-entering the duct 60 while the remainder leave by way of the clearance between the burner 6 and the tube 7. Some of the products conveyed from the burner 6 to the closed end 2 are drawn into the returning stream by way of the gap between the ducts.

대표청구항 ▼

A fuel-fired heating element including a tubular housing having one end closed and an opening to provide an outlet for combustion products, a burner assembly received with clearance within the housing between the outlet and the closed end and arranged to direct its combustion products towards the cl

A fuel-fired heating element including a tubular housing having one end closed and an opening to provide an outlet for combustion products, a burner assembly received with clearance within the housing between the outlet and the closed end and arranged to direct its combustion products towards the closed end of the housing and a duct received with clearance within the housing to convey the combustion products leaving the burner as a central stream towards the closed end of the housing and as contiguous outer stream within the clearance between the duct and the housing in the opposite direction towards the burner assembly, the duct comprising a plurality of axially aligned tubes, each tube being spaced from the tube adjacent thereto and the tubes being so dimensioned that in a direction downstream of the burner assembly, the upstream tube has an internal diameter greater than the external diameter of the adjacent downstream tube to permit a part of the central stream to discharge into and directly against the flow of the outer stream through the space between corresponding tube pairs.