F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
F02M31/00—Apparatus for thermally treating combustion-air, fuel, or fuel-air mixture
F02M31/02—Apparatus for thermally treating combustion-air, fuel, or fuel-air mixture for heating
F02M31/04—Apparatus for thermally treating combustion-air, fuel, or fuel-air mixture for heating combustion-air or fuel-air mixture
F02M31/06—Apparatus for thermally treating combustion-air, fuel, or fuel-air mixture for heating combustion-air or fuel-air mixture by hot gases, e.g. by mixing cold and hot air
F02M31/08—Apparatus for thermally treating combustion-air, fuel, or fuel-air mixture for heating combustion-air or fuel-air mixture by hot gases, e.g. by mixing cold and hot air the gases being exhaust gases