| 摘要 |
PURPOSE: To smoothly ignite a hot-air heater without complicating air-sending control system and fuel control system. CONSTITUTION: A damper 9 for opening and closing part of a warm-air outlet 5 is provided. A controller 30 changes the amount of fuel to be supplied to a burner 10, to the amount of ignition supply by a proportional control valve 18, during the igniting action of the burner 10, controls the number of revolutions of a circulating fan 8 corresponding to the amount of the fuel supplied, and controls the damper 9 in the closed state thereof. Since the damper 9 is in the closed state, an air-fuel mixture supplied to the burner 10 during the igniting action becomes in the condition that fuel gas is rich and is easy to ignite. During the igniting action, the damper 9 is effected enough with closed control only and an air-sending control system corresponding to fuel supply is enough in that state and has no need of change. After combustion is stopped, the damper 9 is opened and a postpurge is done, following which the damper 9 is closed. After the combustion is stopped, the burner 10 quickly cooled, is already in the closed state during the igniting action, and the igniting action can be immediately started. |
