Apparatus for modulating the flow of air and fuel to a gas burner
AssigneeHoneywell Inc.
InventorEnno Vrolijk
Life of this patent
Estimating the term…
Abstract
A burner control system for controlling gas flow to a burner in response to a pressure differential indicative of air flow to the burner, the pressure differential being impressed across a diaphragm which actuates a bleed valve controlling the pressure on one side of the diaphragm actuator of a fuel valve. The bleed chamber is connected to the outlet of the gas valve and the low pressure side of a pressure differential through separate flow restrictors.
Claims12
A fuel control system for burner apparatus including a gas nozzle and an air passageway for supplying fuel gas and air to a burner in a combustion chamber, the air flow to the burner being variable in response to heat output required from the burner apparatus, the control system comprising:
- a flow sensor operable to produce a differential pressure signal between high and low pressure ports thereof indicative of the rate of air flow to the burner;
- a gas valve having an inlet for receiving fuel gas from a gas supply and an outlet, the inlet and outlet being connected through a valve seat, said gas valve further having a closure member moveable toward and away from the valve seat by means of a gas valve diaphragm which separates first and second control chambers of which the first control chamber communicates with the outlet so as to be maintained at the outlet gas pressure;
- a first passageway for connecting the outlet of said gas valve to the gas nozzle of the burner apparatus;
- a second passageway containing a flow restrictor connecting the inlet of said gas valve to the second control chamber thereof;
- a control module including a control module diaphragm separating bleed and control chambers communicating with first and second ports respectively, the bleed chamber further communicating with a valve seat through which flow is variably restricted by a moveable closure member carried on the control module diaphragm;
- third and fourth passageways respectively connecting the low and high pressure ports of said flow sensor to the first and second ports of said control module, said third passageway containing a flow restrictor;
- a fifth passageway providing fluid communication between the valve seat of said control module and the second control chamber of said gas valve;
- and
- a sixth passageway containing a flow restrictor connecting the outlet of said gas valve to the first port of said control module.
In a fuel control system of the type in which heat output of a burner is varied by varying air flow to the burner and in which a predetermined fuel to air ratio relationship is maintained by varying fuel gas flow to a gas nozzle at the burner in response to air flow thereto, the air flow rate being indicated by a pressure differential between high and low pressure ports respectively connected to control and bleed chambers on opposite sides of a diaphragm in a control module, of which the bleed chamber is connected through a bleed valve actuated by the diaphragm to a control chamber on one side of a diaphragm in a gas valve, the control chamber being connected through a first flow restrictor to a gas inlet of the gas valve, the other side of the diaphragm in the gas valve being exposed to the pressure of gas supplied through a gas outlet of the gas valve to the gas nozzle, the improvement which comprises:
- a second flow restrictor connecting the bleed chamber of the control module to the gas outlet of the gas valve;
- and
- a third flow restrictor in the passageway connecting the bleed chamber of the control module to the low pressure port.
Dependencies are inferred from the claim text.