US 4,547,150 A · Control system for oxygen enriched air burner

Abstract

A combustion controller (C) controls the relative rates at which a combustion component source (B) supplies fuel, air, and oxygen to nozzles (A). A fuel source (30) supplies fuel to the burners at a rate (50 in FIG. 2) which is appropriate to produce a desired amount of heat. A blower (32) supplies air at a fixed rate (52b) and an oxygen source supplies oxygen gas at a rate (54) in proportion to the fuel supply rate such that stoichiometrically balanced combustion is maintained. To decrease the combustion rate, the air supply rate remains constant (52b) as the fuel and oxygen rich gas supply rates are decreased. After the oxygen rich gas supply rate reaches zero, the combustion rate is further reduced by decreasing the fuel supply rate and the air supply rate (52a) in stoichiometric proportion. In this manner, a relatively high nozzle velocity is maintained over a wide range of combustion rates.

Claims10

Dependent claims

A method of heat treating workpieces comprising:

(a) placing the workpieces to be heat treated in a furnace;
(b) supplying fuel, air, and oxygen rich gas to a burner communicating with the furnace at generally constant fuel, air, and oxygen rich gas supply rates until the furnace reaches a preselected set point temperature;
(c) decreasing the fuel and oxygen rich gas supply rates after the furnace reaches the preselected set point temperature without decreasing the air supply rate such that the relative fuel, oxygen rich gas, and air supply rates maintain a generally stoichiometrically balanced combustion relationship;
and,
(d) continuing decreasing the fuel supply rate and commencing decreasing the air supply rate after decreasing the oxygen rich gas supply rate to a preselected minimum oxygen rich gas supply rate in such a manner that the combustion remains substantially stoichiometrically balanced.

2 more elements

A combustion apparatus comprising:

(a) means for defining a heating chamber;
(b) at least one burner nozzle disposed in communication with the heating chamber for supplying heat thereto;
(c) a fuel source for supplying fuel to the nozzle;
(d) air supplying means for supplying air to the nozzle;
(e) an oxygen rich gas source for supplying oxygen rich gas to the nozzle;
(f) fuel regulating means operatively associated with the fuel source for regulating the rate at which fuel is supplied to the nozzle;
(g) air regulating means operatively associated with the air supplying means for regulating the rate at which air is supplied to the nozzle;
(h) oxygen rich gas regulating means operatively associated with the oxygen rich gas source for regulating the rate at which the oxygen rich gas is supplied to the nozzle;
and,
(i) a combustion component control circuit for controlling the fuel, air, and oxygen regulating means such that above a preselected combustion rate, air is supplied at a generally constant rate, fuel is supplied at an appropriate variable rate to maintain a preselected temperature within the heating chamber, and oxygen rich gas is supplied at an appropriate variable rate to maintain combustion substantially in stoichiometric balance.

7 more elements

Dependencies are inferred from the claim text.

Control system for oxygen enriched air burner

Life of this patent

Control system for oxygen enriched air burner

Life of this patent

Abstract

Claims10