The present invention relates to an internal expansion heat engine, and more particularly to a flash plug for such an engine.
Internal expansion heat engines are known, and are of either the piston type or the vane type, which pistons of vanes are provided as movable elements within an expansion chamber or chambers. Steam is applied to the expansion chamber or chambers, in order to move the movable elements to cause a shaft to rotate.
To supply steam to the expansion chamber or chambers, steam plugs may be utilized, which are of hollow construction, and which are heated from the outside, and are provided with a spray of water on the inside, the water particles which are sprayed engaging the interior surface of the hollow steam plug, and being convereted thereby to steam. The hollow steam plug is connected to the expansion chamber or chambers, and thereby provides steam thereto. The steam plugs are heated by being placed in a fire chamber, where they are exposed to heated gasses and/or flames, which may be generated by a suitable burner, such as an oil burner or a burner for pulverized coal. The hot gasses of combustion are conducted through the fire chamber, where they engage and heat the steam plugs.
A number of proposals in connection with such internal expansion engines have been made. Bailey U.S. Pat. No. 3,990,238 discloses an engine of this type which is provided with a "steam head" which comprises a plurality of heat plates which are in spaced apart relationship, passages between the plates defining steam passages which lead to the expansion chamber of the engine. The plates themselves are heated by electrical resistance coils. Vorel U.S. Pat. No. 1,744,288 discloses a steam engine of the piston type wherein water is supplied through a pipe, and is converted to steam, which is conducted to the pistons, heating of the water being effected by electrical resistance coils. Garland U.S. Pat. No. 1,290,966 is a disclosure of a steam engine in which the piston is provided with electric resistance coils, to cause water sprayed into the cylinder in which the piston moves to be heated into steam. Of general interest is Michelson U.S. Pat. No. 3,400,534 which provides the disclosure of a steam engine which includes spark discharge chambers in which high voltage sparks are discharged between spaced electrodes to heat the water and produce a shock wave. In general, these prior art proposals have been deficient in not providing a satisfactory heated steam generator, and in utilizing no electric heating, or utilizing only electric heating from resistance heaters or spark discharge.