A rapid start fuel vaporizer for internal combustion engines employing a very rapid-acting heat exchanger that is heated either electrically or by exhaust gases or both to selectively vaporize the heavier fuel droplets which drop into the intake manifold from the engine carburetor without increasing intake air temperature. This vaporizer assembly is attached to the underside of the intake manifold directly below the downdraft carburetor and it is provided with a membrane of thin stainless steel or other material that resists oxidation caused by heating. A honeycomb, grid pattern, or closed convolutions between membrane and carburetor stagnates the intake air directly above the membrane, thus reducing heat transfer from the membrane surface to the intake air.
A quick heat manifold having a vertical riser bore adapted to be connected to a carburetor for supplying air-fuel mixture to engine cylinders includes an improved heat exchanger including a thin sheet metal heat transfer plate of thermally conductive material closing an opening in the floor of the induction plenum of the manifold above an exhaust heat crossover passage. A plurality of corrugated fin segments define a plurality of separate exhaust flow passes in communication with the exhaust crossover passage for quickly heating the plate during a cold engine start phase of operation. A fuel retainer on the inlet face of the plate includes a plurality of deformed segments thereon defining a plurality of separate cells that prevent blow-off of fuel droplets impinged thereagainst. The retainer is bonded to the plate and is configured to allow the temperature increases of the plate so that fuel droplets impinged thereagainst will vaporize upon contact with the retainer or plate to prevent fuel droplet accumulation on the plate.
A liquid fuel vaporizing device for an internal combustion engine wherein a heat pipe containing a heat transfer fluid having a boiling point up to 400.degree.C is disposed so that the heat transfer fluid transfers heat from a heat-receiving zone to a heat discharging zone which heat discharging zone is disposed to vaporize a mixture of said liquid fuel in the main portion or all of the combustion air.
A fuel economizer device adapted to be interposed between the usual carburetor and manifold of an internal combustion engine, or the like, for substantially vaporizing the fuel prior to discharge thereof into the manifold and comprising a plate member having a plurality of spaced apertures for passing the fuel therethrough, said plate being disposed in relation to the manifold for being heated thereby during operation of the engine whereby fuel impinging thereon is substantially vaporized. In addition, a plurality of spaced detents or indentations are provided on the leading face of the plate for an accumulation of liquid fuel therein which has not been vaporized. The fuel trapped in the indentations is heated to the boiling point thereof which results in a substantially complete vaporization of the fuel stream prior to discharge thereof into the manifold for distribution to the combustion chamber.
This invention relates to a fuel evaporation device including a thermally-conductive plate defining a heat transfer surface adapted to be heated by the exhaust from an internal combustion engine and an evaporation surface, the evaporation surface including a thin layer of porous material, such as aluminum oxide, for defining a network of interconnecting cavities for entrapping, by capillary action, liquid fuel entering the manifold of the engine from the carburetor and for providing a multiplicity of sites for vapor nucleation to reduce the amount of thermal energy required to promote the evaporation process.
