Patent ID: 8714460
Filing Date: 2014-05-06
Classification: F23N,Y10T

Abstract:
1. A valve unit for adjusting gas flow to a two-stage combustion apparatus, the valve comprising: a valve member that moves in response to a magnetic field generated by a coil to vary a gas flow rate through the valve unit; a first connector configured to receive a high-stage activation signal; a second connector configured to receive a low-stage activation signal; a valve controller configured to control the coil to establish a high-stage gas flow rate while the high-stage activation signal is present at the first connector, and configured to control the coil to establish a low-stage gas flow rate while the low-stage activation signal is present at the second connector up to a low stage time limit, the valve controller being further configured to establish at least one intermediate gas flow rate between the low-stage and high-stage gas flow rates when the low-stage activation signal is present beyond the low stage time limit, the valve controller being further configured to discontinue the high-stage gas flow rate and establish the at least one intermediate gas flow rate up to the low stage time limit when the high-stage activation signal is no longer detected and establish the low-stage gas flow rate after the low stage time limit.