PURPOSE: To provide a fan heater adapted to burn a fuel stably with the emission of CO being suppressed, while at the same time reducing the formation of NOx over an extremely wide range from a total primary combustion to a diffusion combustion zones.
CONSTITUTION: A primary combustion chamber 4 is formed in a casing 6 which is in turn formed by raising vertically from the end of primary flame port 2 towards the downstream side of combustion exhaust gas and by inclining inwardly from a suitable position. A secondary flame port 7 is formed through the end of inclined surface. A secondary combustion chamber 10 is formed by guides 8a, 8b at a position above the secondary flame port 7. A flow-uniforming plate 11 is provided above the secondary combustion chamber 10. Flame rods A12 and B13 are provided above the primary and the secondary flame ports respectively as flame detecting elements. Besides, a solenoid valve 14 controlling a fuel supply, a comparison circuit section 15 and a drive circuit 16 are provided. Unburnt fuel which is unable to be burnt completely due to an oxygen starvation or a clogged damper etc., even if an equivalent ratio is ≥1 can form a stable secondary flame owing to a secondary air flow uniformed as a parallel flow along an air passage. As a result, a fuel can be burnt with a lowered NOx emission under such a condition.
KANEKO HIDEKI
INDOU MASAHIRO
Next Patent: SAFETY COMBUSTION DEVICE