Patent ID: 6238206
Filing Date: 2001-05-29
Classification: F23D,F23G,F23M

Abstract:
A burner comprisingan outer tube defining a flow passage and including a large-diameter inlet portion having a large diameter, a small-diameter outlet portion having a small diameter being smaller than the large diameter of the large-diameter inlet portion, and a nozzle portion interconnecting an outlet end of the inlet portion and an inlet end of the outlet portion and converging toward the outlet portion to establish the flow passage, an inlet end of the large-diameter inlet portion being adapted to be coupled to an air supply to conduct air flowing through the flow passage to an outlet end of the outer tube anda small-diameter inner tube being positioned to lie in the flow passage of the outer tube, the inner tube having an inlet end positioned to lie in the flow passage outside of the small-diameter outlet portion and adapted to be coupled to a fuel supply, the inner tube having a diameter that is smaller than the small diameter of the outer tube, and the inner tube being formed to include a downstream end opposite to the inlet end and a fuel-injection hole positioned to lie in spaced-apart relation to the downstream end to conduct fuel flowing from the inlet end of the inner tube through the inner tube into the air flowing through the flow passage to establish a combustible air-and-fuel mixture within the flow passage, anda flame holder coupled to the downstream end of the inner tube and positioned to extend beyond an exit end of the small-diameter outlet portion of the outer tube and lie outside the flow passage defined by the outer tube to complete the mixing of the fuel with the air as the combustible air-and-fuel mixture exits the flow passage of the outlet end of the outer tube to produce a low-emission flame attached to the flame holder upon ignition of the combustible air-and-fuel mixture.