Method of operating an air pump for a boosted gas burner assembly

Abstract

A gas burner assembly and a method of operating the same are provided. The gas burner assembly includes fuel regulating device for providing a flow of fuel and an air pump for providing a flow of air to a boost burner for combustion. The method includes stopping the flow of fuel using the fuel regulating device and ramping down the operation of the air pump to slowly stop the flow of air. For example, the flow rate of the flow of air may decrease linearly over a predetermined time period to ensure a lean fuel/air mixture is not provided to the boost burner which may result in undesirable flame characteristics.

What is claimed is: 
     
         1 . A method of operating a gas burner assembly, the gas burner assembly comprising a boost burner, a fuel regulating device for providing a flow of fuel to the boost burner, and an air pump for providing a flow of air to the boost burner, the method comprising:
 stopping the flow of fuel using the fuel regulating device; and   ramping down the operation of the air pump to slowly stop the flow of air.   
     
     
         2 . The method of  claim 1 , wherein stopping the flow of fuel using the fuel regulating device comprises:
 instantaneously changing a voltage or a valve control signal supplied to the fuel regulating device to close the fuel regulating device.   
     
     
         3 . The method of  claim 1 , wherein stopping the flow of fuel using the fuel regulating device comprises:
 manipulating a control knob to close the fuel regulating device.   
     
     
         4 . The method of  claim 1 , wherein ramping down the operation of the air pump comprises:
 decreasing a voltage to the air pump at a constant rate.   
     
     
         5 . The method of  claim 1 , wherein ramping down the operation of the air pump comprises:
 decreasing an output of the air pump according to a time-varying rate.   
     
     
         6 . The method of  claim 1 , wherein ramping down the operation of the air pump comprises:
 decreasing an output of the air pump from a steady state output to zero over a predetermined time period.   
     
     
         7 . The method of  claim 6 , wherein the predetermined time period is between about 0.1 and 5 seconds. 
     
     
         8 . The method of  claim 6 , wherein the predetermined time period is between about 0.5 and 3 seconds. 
     
     
         9 . The method of  claim 1 , wherein ramping down the operation of the air pump comprises:
 obtaining a fuel type of the flow of fuel; and   selecting an output control signal for slowing down the air pump that corresponds to the fuel type.   
     
     
         10 . The method of  claim 9 , wherein the output control signal comprises a time-varying voltage signal. 
     
     
         11 . The method of  claim 9 , wherein the output control signal comprises a time-varying frequency control signal. 
     
     
         12 . A method of operating a gas burner assembly, the gas burner assembly comprising a boost burner, a fuel regulating device for providing a flow of fuel to the boost burner, an air pump for providing a flow of air to the boost burner, and a pneumatically controlled valve for stopping the flow of fuel when a pressure of the flow of air drops below a predetermined threshold pressure, the method comprising:
 ramping down the operation of the air pump to slowly stop the flow of air until a pressure of the flow of air drops below the predetermined threshold to close the pneumatically controlled valve and stop the flow of fuel; and   continuing to ramp down the operation of the air pump until the flow of air stops.   
     
     
         13 . The method of  claim 12 , wherein ramping down the operation of the air pump comprises:
 decreasing a voltage to the air pump at a constant rate.   
     
     
         14 . The method of  claim 12 , wherein ramping down the operation of the air pump comprises:
 decreasing an output of the air pump according to a time-varying rate.   
     
     
         15 . The method of  claim 12 , wherein ramping down the operation of the air pump comprises:
 decreasing an output of the air pump from a steady state output to zero over a predetermined time period.   
     
     
         16 . A gas burner assembly for a cooktop appliance, the gas burner assembly comprising:
 a boost burner comprising a plurality of boost flame ports in fluid communication with a boost fuel chamber;   a fuel regulating device fluidly coupled to the boost fuel chamber for providing a flow of fuel to the boost fuel chamber;   an air pump for selectively urging a flow of air into the boost fuel chamber; and   a controller operably coupled to the fuel regulating device and the air pump, the controller being configured for:
 stopping the flow of fuel using the fuel regulating device; and 
 ramping down the operation of the air pump to slowly stop the flow of air. 
   
     
     
         17 . The gas burner assembly of  claim 16 , wherein stopping the flow of fuel using the fuel regulating device comprises:
 instantaneously changing a voltage or a valve control signal supplied to the fuel regulating device to close the fuel regulating device.   
     
     
         18 . The gas burner assembly of  claim 16 , wherein ramping down the operation of the air pump comprises:
 decreasing a voltage to the air pump at a constant rate or a time-varying rate.   
     
     
         19 . The gas burner assembly of  claim 16 , wherein ramping down the operation of the air pump comprises:
 decreasing an output the air pump from a steady state output to zero over a predetermined time period.   
     
     
         20 . The gas burner assembly of  claim 16 , further comprising:
 a boost valve for regulating the flow of fuel to the boost fuel chamber, wherein the boost valve is a pneumatically controlled valve configured for closing when the air pump is stopped.