| 摘要 |
PURPOSE:To prevent a trouble that may be caused by a delay or a failure of ignition, by igniting a burner with a small rate of air without using any air supplier such as a damper. CONSTITUTION:A timer 3 is started at the same time when a fan 2 is operated. The number of revolution of a fan 2 is increased to come up to the rated number, and a prepurging operation is performed by the fan 2 before a burner is ignited. After sufficient prepurging, the contact point 4 of a timer is opened, and the number of revolution is decreased. At this time, the contact point 5 of a timer is closed and an ignition transformer 6 is energized. Then the contact point 7 of a timer is closed to energize a fuel valve 8 which injects fuel to the burner. An ignition detecting cell 9 detects ignition and a flame detecting relay 10 is energized, the contact point 11 is closed and the number of revolution of a fan is increased again to come up to the rated number, so that the flow rate of air is increased to move the burner to complete combustion. With such an arrangement, a trouble caused by a delay or a failure of ignition can be prevented. |
