The inventor provides for injecting pulverised fuel, such as coal dust, into the engine through a fuel valve, or nozzle similarly to the usual injection of fuel oil alone, that is to say, under pressure with or without the assistance of compressed air, and the liquid fuel is injected separately at or slightly before the moment of injection of the stream of combustible into the engine.
The invention is said to consist in the means to separately inject a stream of coal dust in a finely divided state, and a spray of fuel oil, preferably by means of a stream of compressed air.
The invention is said to be applicable both to engines wherein the ignition temperature is secured by the heat generated in the compression and also to those of the "Hot Bulb" type.