Abstract: A vapor generating and vapor superheating installation for marine propulsion purposes, and a method of operating such an installation. The installation including a vapor generating and vapor superheating unit adapted to be fired with fluent fuel including tubulous vapor generating and vapor superheating surface proportioned to give a predetermined superheated vapor output at a maximum firing rate. The installation also including a fluent fuel fired fluidized bed furnace provided with a superheater tube bank connected to receive vapor from the vapor generating and vapor superheating unit and arranged to impart superheat to the vapor at part load operation of the unit.

Abstract: The invention relates to fluidized bed combustors that might tilt in use so that the depth of the bed progressively changes across its width. Air is supplied from two or more sources and means are provided to vary the flow from the sources as the bed tilts so that the air supplied to the portion of the bed of increased depth is increased relatively to the air supplied to the portion of the bed of lesser depth.