GB851750A - Improvements in or relating to recuperators for pre-heating the blast of shaft furnaces - Google Patents

Abstract

851,750. Heat recuperators. FISCHER A.G., G. Oct. 28, 1957 [Oct. 27, 1956], No. 33633/57. Class 64(1) A recuperator for heating the blast of a shaft furnace as a cupola, comprises three concentric tubes radially spaced from each other and from the inner surface of a hollow chamber 2 surrounding and coaxial with the tubes, the annular gap between the innermost and outermost tubes 14, 16 being closed at one end and the end of the intermediate tube stopping short of the said end closure. In the form shown the tubes extend vertically, the intermediate tube comprising heat insulating material 38 and a cylindrical member 35 serving as a heat radiator being arranged within the innermost tube 14. Air to be heated enters a chamber 11 tangentially and hence flows with a helical motion through the annular gap 44 between the intermediate and innermost tubes and then in the opposite direction through the annular gap 45 between the outermost and intermediate tubes to a chamber 17 having a heated air outlet (not shown), arranged tangentially. Furnace exhaust gas enters an annular chamber 29 tangentially and is there mixed with air and burned. The combustion products from the chamber 29 flow with a helical motion downwardly through the annular gap 40 between the outermost tube 16 and the surrounding chamber 2 at the lower end of which there is a hopper 3 to receive dust &c. separated from the gases as they are deflected upwardly through the annulus 42 between the innermost tube 14 and the member 35 'before being withdrawn by a fan 36 through an outlet 46 at the upper end of the recuperator.