GB784595A - Improvements in vapour, e.g. steam generation - Google Patents

Abstract

784,595. Combustion apparatus. COMBUSTION ENGINEERING, Inc. July 22, 1955 [Aug. 5, 1954], No. 21265/55. Class 51 (1). [Also in Group XIII] Superheated steam, or other vapour, is generated by combusting fuel within a fluidized mass of discrete material which is caused to impart heat to, at least, an evaporator and a superheater, the fuel being supplied to the discrete mass through burners near the locations of said evaporator and superheater in quantities controlled in accordance with the desired steam output and temperature. The boiler may comprise a cylindrical casing 10 housing coaxial cylindrical members 16, the latter constituting an annular air chamber 18, so as to provide a central passage 12 and an annular passage 14 through which the fluidized mass is continuously circulated by the combustion gases, downwardly through the passage 12 and upwardly through the passage 14. The evaporator and superheater 54, 58 are disposed immediately above burners 24, 20 and comprise banks of sinuously-bent tubes having their inlets and outlets connected to ring headers 60, 62; an economizer 52 and steam reheater 56, with associated burner 22, may also be provided. The burners 20, 22, 24 are connected to a common supply conduit 32 and each is controlled by a valve 34, 36, 38, and combustion air conduits 39 extend radially from the chamber 18 across the passage 14 immediately below the said burners, air being supplied to the chamber 18 and conduits 39 through a conduit 40. Combustion gases leave the boiler through a separator 72 and are led to an air heater 76 and exhaust stack, not shown. The rate of circulation of the fluidized mass, which is preferably a highly active oxidizing catalyst, may be controlled by semi-circular valve members 88, 88 which are adapted to be moved towards or away from a perforate spider 82, fixed within the passage 12, by an actuating rod 84.