GB1000295A - Cooling apparatus for the waste gases of a steel-making converter - Google Patents

Abstract

1,000,295. Heating steam boilers by waste gases; converter chimneys; charging hoppers for converters. WAAGNER-BIRO A.G., and VEREINIGTE OSTERREICHISCHE EISEN-UND STRAHLWERKE A.G. Aug. 3, 1961 [Aug, 11, 1960], No. 28181/61. Headings F4A, F4B and F4J. In a plant for manufacturing steel by a converter process heat is recovered from the converter blow gas by passing it horizontally over tubulous surfaces through which flows a fluid, e.g. water to be evaporated, the tubes forming the surfaces being vertically disposed and the gases transmitting their heat to the tubes firstly by radiation and subsequently by convection as their temperature falls. In the apparatus shown the blow gases discharge from the converter 1 into a double-walled, water-cooled hood 4 which has an insertion opening 5 for the oxygen lance and a feed hopper 6 for flux materials which are delivered from a bin 7 above a weighing and metering device 8, the hood diverting the gases for horizontal flow through a slag screen 9 of suspended Field tubes, a chamber 35 into which secondary air and possibly supplementary fuel is injected at 34 and which may contain a superheater, a radiation chamber 10 and two lateral chambers 11, whence the gases discharge through purifying plants and exhaust fans to a stack. The chamber 10, which is bounded on each side by contacting double tubes 21, 22 of large diameter which serve to support steam and water drums 15, contains rows of widely-spaced radiant evaporating tubes 19, whilst the side chambers 11 contain banks of narrowly-spaced convection heated tubes, the latter and the tubes 19 extending between a grid of distributing and collecting headers 16, 17 which, with the double tubes 21, 22, form a self-supporting framework for the boiler. The inner tubes 22 of the double tubes form downcomers conveying water from the drums to the headers 16, a semi-cylindrical baffle 23 preventing admixture of the water entering the downcomers with the steam-water mixture entering the drum from the outer tubes 21. The outer tubes shield the downcomers from heat. To promote circulation feedwater is injected downwardly into each downcomer, Figs. 9 and 10 (not shown). In a modification, Figs. 6 to 8 (not shown), designed for operation at lower pressure, the central and lateral chambers are each divided by a longitudinal partition and the grids of headers are omitted, the generating tubes extending from a pair of lower headers directly to the drum. The waste gas cooling apparatus may also supply hot water or hot air instead of steam.