GB891644A - Heat exchanger - Google Patents

Abstract

891,644. Fluid heaters. BROWN FINTUBE CO. Aug. 23, 1960 [Sept. 11, 1959], No. 29090/60. Class 64(1) Air or other gas or a liquid is heated in flowing through an annular space between an outer tube 10 and an inner tube 20, the latter having longitudinal external fins 21 extending into the annular space, and longitudinal internal fins 40 provided only in a zone adjacent the heating fluid outlet end thereby increasing the rate of heat transfer in this zone between the heated fluid flowing in the annular space and the heating flowing through the inner tube from a heat source such as a fluid fuel burner 30. In the form shown, a cylindrical baffle 41 is provided within the internally finned portion of the inner tube 20 to direct the heating gases between the fins 40, and is centrally positioned by rings 45 which also act as baffles. Lateral ducts 11, 12 are provided to conduct the heated fluid into and Out of the annular space. The heat exchanging fluids may flow in co-current or, as shown, in countercurrent. Studs 33 are welded to the exterior of the inner tube adjacent the burner 30 to increase the rate of heat transfer whilst permitting circumferential flow of the heated fluid at this zone. Either or both of the inner and outer tubes may be of oval, square, rectangular or other non-circular cross-section.