GB926490A - Improvements in shell type boilers - Google Patents

Abstract

926,490. Feeding steam boiler furnaces. G.W.B. FURNACES Ltd. Feb. 13, 1962 [Feb. 17, 1961; Aug. 30, 1961], Nos. 6028/61 and 31245/61. Class 51 (1). [Also in Group XIII] In a shell type boiler solid fuel is fed to the furnace through a tube passing down through the steam and/or water spaces of the shell. In the form shown the boiler consists of an enveloping shell 1, a steam drum 2, furnace 6, combustion tube 15 and front and rear plenum spaces 5, 16, respectively. A solid fuel delivery tube 12 passes vertically down through the steam drum 2 and includes solid fuel delivery apparatus as described in Specification 816,745. Primary air is supplied through an air box 13 and the secondary air is that used to spread the fuel butwardly from the mouth of the delivery tube whilst tertiary air is fed through conduits 14 beneath the rear end of the grate. The combustion gas flows in through the combustion tube 15 to the rear plenum space 16 which is lined with water tubes 17 connected to the boiler shell by headers. The rear plenum chamber is baffled to pass the combustion gases forwards through a set of fire tubes to a front plenum chamber 5, whence they pass into another set of fire tubes to the rear plenum chamber and thence to a flue outlet 23. The arrangement enables a change-over from solid fuel to oil or gas firing to be made easily, a clean out door 9 being removed and the appropriate burner fitted in its place.