GB717782A - Improvements in or relating to systems for preheating and humidifying air - Google Patents

Abstract

717,782. Heating air supply for combustion. SVENSKA ROTOR MASKINER AKTIEBOLAG. March 28, 1952 [April 24, 1951], No. 7970/52. Class 51 (1). [Also in Group XIII) Air for combustion in a boiler furnace is heated in two stages between which it is humidified, the air in the two heating stages receiving heat either from a single stream of combustion products or from two streams of combustion products flowing in parallel. In one construction, Fig. 1, the air flows successively from an inlet passage 31 through two rotary generators 10, 12, and is humidified by a water spray 36 in the passage 34, between the regenerators. The latter are heated by gases in flue 18. The water supplied to the spray 36 may be pre-heated in a finned pipe 35, extending through the flue 18. The air may be heated before entering the regenerator 10 by mixing with it hot gases drawn from the flue 18 by a fan 24. Part of the air leaving the first regenerator 10 may flow through a pipe 33 to the furnace for use as primary air. In another form, a single rotary regenerator is provided with one hot gas passage and two air passages through which the air flows in series and between which it is humidified. In a plate or tubular recuperator, Fig. 4, of the indirect contact type, the air is moistened by a spray 56 is a passage 54 connecting the air passages of two main recuperator sections 50, 52, in series. To prevent corrosion by excessive cooling of the hot gases, the air before entering each section 50, 52, is heated by the hottest gases in a preliminary section 51 or 53 respectively.