522,080. Powdered-fuel engines. HANNOVERSCHE MASCHINENBAU AKT.-GES. VORM. EGESTORFF, G. HANOMAG. March 8, 1939, No. 7502. Convention date, May 2, 1938. [Class 7 (ii)] An apparatus for forming a mixture of fuel dust and air comprises a storage vessel 1 feeding dust fuel to a worm conveyor 3, which is intersected by an air conduit 4, the mixture thus formed being conveyed by a continuation of the' conduit 4, which is provided with valves 5 for admitting the mixture to the engine cylinders. Excess mixture returns through a pipe 6 to the end of the worm 3, and carries back the excess fuel by means of a pipe 8 to the vessel 1.