Fuel-air mixing device

Apparatus for mixing a vaporizable fuel and a gaseous oxidizer, comprising:

• a housing defining a mixing chamber;
• fuel inlet means formed in the housing for feeding fuel into the chamber;
• a shroud mounted within the mixing chamber, the fuel inlet means directing fuel onto upper and outer surfaces of the shroud to facilitate vaporization of the fuel;
• air feed means carried by the housing for feeding gaseous oxidizer into the chamber and into mixing relation with the fuel vaporizing within the chamber, the air feed means comprising a mixing tube extending through the housing and disposed within the confines of the shroud, that portion of the tube disposed internally of the housing having apertures formed therein to communicate the interior of the tube with the chamber, one end portion of the tube extending externally of the housing and being in free communication with a source of gaseous oxidizer, and the opposite end portion of the tube extending through an opposite portion of the housing, the air feed means further comprising a control tube concentric with and movable relative to the mixing tube and having apertures formed therein which are alignable with the apertures formed in the mixing tube to vary the degree of communication between the interior of the mixing tube and chamber, and means connected to the control tube for displacing said control tube to control the alignment between the respective apertures formed in the tubes, thereby to vary the degree of communication between the interior of the mixing tube and the chamber;
• and
• means communicating with the interior of the chamber and carried by the housing for ducting mixed fuel vapors and gaseous oxidizer from the chamber, the said opposite end portion of the mixing tube communicating with said ducting means.

Apparatus for mixing a vaporizable fuel and a gaseous oxidizer, comprising:

• a housing defining a mixing chamber;
• a shroud mounted within the mixing chamber, the shroud comprising an inverted, U-shaped structural element having opposed leg portions and an arcuate bight portion connecting upper edge portions of the leg portions, lower edge portions of the leg portions extending downwardly into spaced relation with lower floor portions of the chamber, the shroud extending throughout the chamber to separate the chamber into a first volumetric portion lying above and along outer surfaces of the shroud and a second volumetric portion lying within the confines of the shroud and bounded by inner surfaces of the shroud, the first and second volumetric portions communicating through openings formed between said lower edge portions of the leg portion and the lower floor portions of the chamber;
• fuel inlet means formed in the housing for feeding fuel into the chamber directly over surfaces of the shroud to form a thin layer of fuel over the surfaces of said shroud to facilitate vaporization of the fuel, the fuel inlet means directing liquid fuel onto upper and outer portions of the shroud, the thin layer of fuel moving downwardly over outer surfaces of said shroud and vaporizing on such movement, the vaporized fuel mixing with air present in the first volumetric portion of the chamber and moving downwardly within a chamber through the openings and into the second volumetric portion;
• air feed means carried by the housing for feeding gaseous oxidizer into the chamber and into mixing relation with the fuel vaporizing within the chamber, the fuel being vaporized by a mixing with the gaseous oxidizer delivered into the chamber through the air feed means;
• and,
• means communicating with the interior of the chamber and carried by the housing for ducting mixed fuel vapors and gaseous oxidizer from the chamber.