Patent ID: 6234164
Filing Date: 2001-05-22
Classification: F23N

Abstract:
A forced intake and discharge combustion device, comprising:an intake tube;a discharge tube;a burner;a fan for introducing combustion air into the burner through the intake tube and for discharging combustion gases from the burner through the discharge tube;a closure detector for detecting an undesirable closure of the intake tube or the discharge tube; andcombustion stopping means for at least initiating a suspension of combustion by said burner if the closure detector detects the undesirable closure;said closure detector comprises:an orifice plate in the intake tube or the discharge tube;a pressure detector for detecting pressure difference values between a pressure upstream of said orifice plate and a pressure downstream of said orifice plate;memory means for storing a first pressure difference value in a condition prior to operation of said fan;change detecting means for comparing a second pressure difference value detected by said pressure detector in a condition while said fan is in operation with said first pressure difference value, in order to detect a pressure variation between said first pressure difference value and said second pressure difference value; anddetermining means for detecting said undesirable closure if the absolute value of said pressure variation detected by said change detecting means is smaller than a predetermined threshold value.