Combustible particulate fuel heater

Abstract

A heater is disclosed for burning combustible particulate fuels. The fuels are delivered to an internal retort at a constant rate. They are burned at an open end of the retort with the aid of a primary air supply manifold that surrounds the open end of the retort and directs primary combustion air into the particulates at the open retort end. Secondary combustion air is directed through an annular air supply manifold situated above the open retort end. The hot exhaust gases pass upwardly through a combustion chamber and subsequently downwardly through an exhaust gas plenum to an exhaust gas discharge. Flow of the combustion air and exhaust gases is induced by a vacuum blower mechanism by which a reduced pressure is produced within the combustion chamber to draw air through the primary and secondary air supply manifolds. The exhaust gases drawn off by the vacuum mechanism are pressurized on a discharge side of the vacuum mechanism. A heat exchanger can be provided in close proximity to the combustion chamber and exhaust gas plenum to receive heat generated thereby and to transmit it to useful areas within the surrounding structure. The heat exchanger may also be utilized as an insulator between the hot surfaces of the exhaust plenum and a fuel hopper which may be supplied as an integral part of the heater.