초록 ▼

A furnace (A) defines a combustion chamber (10) in which a pair of burners (B) are mounted for oxidizing the fuel to heat the combustion chamber. An air blower (12) supplies air to the burners at a rate controlled by a rate control valve (18). A frequency modulated burner control system (C) controls

A furnace (A) defines a combustion chamber (10) in which a pair of burners (B) are mounted for oxidizing the fuel to heat the combustion chamber. An air blower (12) supplies air to the burners at a rate controlled by a rate control valve (18). A frequency modulated burner control system (C) controls the duty cycle of the burners, i.e. cyclically actuates the burner at a fixed burn rate and then deactuates them. The burner control system varies the actuation to deactuation ratio in each cycle to vary the thermal input to the combustion chamber. The burners provide two - stage combustion wherein a fuel rich mixture is partially oxidized in a first stage combustion area (44). Additional air which is thereafter introduced through air passages (50, 52) completes the combustion.

대표청구항 ▼

A combustion apparatus comprising: a combustion chamber; at least a first burner operatively communicating with the combustion chamber; a frequency modulated burner control system for cyclically actuating the burner at a selected, fixed burn rate and deactuating the burner, including: (i) means for

A combustion apparatus comprising: a combustion chamber; at least a first burner operatively communicating with the combustion chamber; a frequency modulated burner control system for cyclically actuating the burner at a selected, fixed burn rate and deactuating the burner, including: (i) means for indicating a selected set point combustion chamber temperature; (ii) means for sensing temperature in the combustion chamber; (iii) error means for determining a deviation between the selected and sensed temperatures, the error means being operatively connected with the set point means and temperature sensing means; and, (iv) duty cycle adjusting means for adjusting the burner actuation/deactuation ratio, the duty cycle means being operatively connected with the error means for adjusting the burner actuation/deactuation ratio in accordance with the deviation such that the frequency modulated burner control system controls thermal input from the burner. A method of combusting fuel comprising: supplying fuel and air to a burner; cyclically actuating the burner to combust the fuel at a preselected burn rate and deactuating the burner; varying a duty cycle at which the burner is actuated at the fixed burn rate to vary the amount of heat produced, whereby the heat is controlled by varying a burner actuation/deactuation ratio of each cycle; sensing a temperature within a combustion chamber; determining a deviation between the sensed temperature and a selected temperature; and, in the duty cycle varying step, adjusting the duty cycle in accordance with the sensed and selected temperature deviation.