Combustion apparatus for granular solid fuel

DETAILED DESCRIPTION An object of this invention is to provide a combustion apparatus which has a simple construction and provides complete combustion of a pulverized or granulated solid fuel with high efficiency.
To accomplish the object described above according to the present invention, there is provided a combustion apparatus comprising a plurality of cylindrical combustion chambers serially disposed with their respective axes running horizontally.
First in the upstream combustion chamber, the pulverized or granulated solid fuel (hereinafter referred to briefly as "granular fuel") supplied as carried on a current of air is fluidized by agitation and burnt in the fluidized state.
The combustion gas thus produced is blown out into the peripheral portion of the next combustion chamber, there to be swirled in a spiral with secondary air and burnt the second time in the swirled state.
In either of the combustion chambers mentioned above, the granular fuel is burnt as kept in a swirled state with the forced current of air.
Into the downstream combustion chamber, one end of a combustion gas outlet tube is opened to permit removal of the combustion gas to the outside.
As described above, the combustion apparatus according to the present invention comprises a plurality of cylindrical combustion chambers, in each of which the granular fuel is fluidized and swirled and burnt in the fluidized and swirled state.
The combustion gas produced in one combustion chamber is forwarded to the immediately next combustion chamber.
Thus, the combustion apparatus of the present invention provides complete combustion of the solid fuel and derives high thermal power from the fuel.
The other objects and characteristics of the present invention will become apparent from the further disclosure of the invention to be made hereinafter with reference to the accompanying drawings.