GB384573A - Improvements in or relating to furnaces for superheating steam and other purposes - Google Patents

Abstract

384,573. Steam superheater &c. furnaces. SUPERHEATER CO., Ltd., Bush House, Aldwych, London.-(Compagnie des Surchauffeurs Soc. Anon. ; 3, Rue la B÷etie, Paris.) June 7, 1932, No. 16107. Addition to 365,926. [Class 51 (i).] In furnaces having means for returning combustion products to the heating chamber under the control of a thermostat influenced by the heating medium according to the parent Specification, the fuel supply is controlled by a thermostat influenced by the heated medium. The thermostats may also control the air supply to the furnace. As shown applied to an independently fired steam superheater fired by solid fuel a thermostat 14 at the inlet of the heating chamber 4 controls the speed of a fan 8 which withdraws the combustion gases and returns a portion of them through a duct 11 into a mixing chamber 12 where they mix with the gases from the combustion chamber 2. A damper 13 controls the distribution of the gases between the duct 11 and the chimney 10. A thermostat 16 in the superheated steam collector 17 controls through a connection 18 a travelling grate 21 and through a connection 28 a fan 23 supplying the air for combustion. The thermostat 14 also controls through a connection 27 a damper 26 determining the ratio between the primary and secondary air admitted below and above the grate through ducts 24, 25 respectively. In furnaces fired by liquid, gaseous or pulverulent fuel the thermostat 16 controls a valve in the fuel supply duct. The thermostats may be duplicated, one of each pair controlling the fuel supply or return of combustion products while the other controls the air supply.