GB429923A - Improvements in or relating to combined gas and solid fuel stoves and furnaces for boilers - Google Patents

Abstract

429,923. Combined gas and solid-fuel furnaces. HELPS, G., Manor Court, Nuneaton, Warwickshire. Sept. 5, 1933, No. 24578. [Class 51 (i)] A furnace or stove for water heating or steam raising is provided with a grate for the combustion of solid fuel and one or more chambers extending into the interior of the furnace and providing additional grate area, gas burners being positioned within or at the entrance to the chamber or chambers so that the combustion products from the burners pass entirely or partially through the solid fuel. In one form, Fig. 1, the boiler comprises two rectangular chambers 1, 2 below which is a combustion chamber bounded by walls of spaced water tubes 7 and a grate 8. Extending into the furnace is a chamber 41 bounded by two grids or grates formed by water tubes 5. Within the chamber are gas burners 6. The top of the chamber is covered by a refractory bridge piece 8<1>. The air supply is regulated by means of louvres 11 outside the tubes 7 and by a hit-and-miss regulator, (not shown), associated with the grate 8. Alternatively the lower grate may comprise tooth-like members mounted on a spindle which may be rotated or joggled to discharge ash. The solid fuel may be fed from a hopper 9 by gravity or by means such as a screw feeder. In a modification, Fig. 11, there are two fuel supply hoppers 31 and 29 one feeding fuel to a V-shaped grate formed by water tubes 27 and 30 and the other to a grate formed by water tubes 28, the space between the sets of tubes 27 and 28 forming the chamber 4<1> having at its base a gas burner 6. In other forms the grate is of W form in section. In a further modification, Fig. 7, the chambers 4<1> are formed by superposed inclined rows of water tubes 22, part of the solid fuel entering the lower portion of these chambers and burning on the water tubes. If desired, radiants or artificial cobble fuel may also be used in association with the gas burners, such fuel being positioned within the chambers 41 and supported in proximity to the water tubes. Specification 407,923, [Group XI], is referred to.