Domestic combustion appliances

Claim 1

A fluidized bed domestic combustion appliance comprising an upstanding body, an air permeable support horizontally within the body defining a plenum chamber below the support and a compartmented combustion zone above the support; said support having a plurality of apertures with standpipes located in the apertures and perforations in the standpipes leading toward said combustion zone; said combustion zone having a fluidized bed of particulate material immediately above said support and standpipe, an electric heater centrally positioned and immersed in a front portion of said fluidized bed; a primary boiler located adjacent a rear portion of said fluidized bed; means for introducing air into the combustion zone above the support; flue passages downstream of the combustion zone comprising a generally vertical downwardly extending open passage connected to the top of the combustion zone, a particulate matter drop-out zone at the base of said vertical passage, a further flue opening outwardly therefrom, and a secondary boiler in one of the walls of said flue passages; said plenum chamber having fan means for inducing an air flow through the air permeable support, closure means for blocking off air flow to said rear portion of the fluidized bed, means to simultaneously actuate the electric heater and to close the closure means so that during start-up when the electric heater is bringing the front portion of the fluidized bed up to operating temperature, the rear portion of the fluidized bed can be kept at a lower temperature to avoid heat loss to the primary boiler.