Burner system

Abstract

A burner system adapted to vaporize liquid fuel, generally kerosene, and burn gaseous fuel in blue flames includes an evaporator heated by a heater to about 250.degree.-300.degree. C. to vaporize the kerosene. The evaporator is thermally insulated from a premix passage and a burner, to reduce the time required for preheating the evaporator. At the time of ignition, the volume of a portion of primary air supplied to the evaporator is reduced below the corresponding volume supplied in maximum combustion condition and the volume of the kerosene supplied to the evaporator is substantially equal to the corresponding volume supplied in maximum combustion condition. This enables a premix of liquid and air within a combustible limit to be supplied to flame ports even if part of the premixture forms dew in the premix passage, and allows an enriched premixture to flow out of the flame ports at low velocity to facilitate ignition. The evaporator includes an air inlet in the form of a venturi having a throat in which a liquid fuel supply port opens, and an outlet opening in a throat of a venturi mounted in a passage for the rest of the primary air, to supply air at high flow velocity with a low air pressure developed by a blower. The air volume supplied to the evaporator is selected such that the ratio in weight of the air flow rate Ga to the kerosene flow rate Gl or Ga/Gl is between 0.3 and 5.0, to minimize the particle size of atomized kerosene and reduce the capacity of the heater.

Dependencies are inferred from the claim text.