Description
Class F23B : METHODS OR APPARATUS FOR COMBUSTION USING ONLY SOLID FUEL
Subclass 50/10: Combustion apparatus in which the fuel is fed into or through the combustion zone by gravity, e.g. from a fuel storage situated above the combustion zone the fuel forming a column, stack or thick layer with the combustion zone at its bottom with the combustion zone at the bottom of fuel-filled conduits ending at the surface of a fuel bed