The invention relates to a fuel vaporizing device suitable for vaporizing the liquid fuel charge in the inlet system of an internal combustion engine, and to an internal combustion engine which comprises such a device.
The invention also relates to a heat pipe.
The conventional spark-ignition gasoline engine relies on a carburetter to mix a desired proportion of a volatile fuel with the inlet air. For complete combustion of the fuel-air mixture the fuel needs to be uniformly dispersed in the air. Such a uniform mixture is seldom if ever obtained in practice with a conventional carburetter, and manifold fuel injection offers only marginal improvement.
In the fuel-air mixtures obtained with these conventional techniques the fuel is at least partly present in the form of small liquid droplets, and as a film of liquid on the walls of the manifold.
It has been proposed to supply, with the aid of a heat pipe, at a substantially constant temperature sufficient heat to vaporize the entire liquid fuel charge prior to mixing it with the major part of the combustion air, in order to obtain a uniform mixture of fuel and air. Backflowing of evaporated fuel in the air supply ducts, and condensation of the evaporated fuel in the air supply ducts was experienced in a number of cases. This is considered to be a drawback of the said method, because in the said cases no uniform air-fuel mixture will be achieved.
The invention provides a device in which the said drawback has been overcome.