| 摘要 |
PURPOSE:To enable the excess rate of a primary air to be maintained at a given value, by a method wherein a flame rod is caused to face on a burner to detect a flame current value. CONSTITUTION:When the excess rate of a primary air, obtained by a terminal 14, becomes different from the set excess rate of the primary air of a comparator 16 resulting from a change in a gas pressure fed to a main burner 2, a voltage proportioning a deviation is generated, and a variation in the number of revolutions of a blower 5 is controlled, and the excess rate of the primary air is maintained at a specified value to provide excellent combustion. As noted above, the number of revolutions of the blower 5 for feeding the air to the burner 2 is varied and controlled according to a flame current produced by a flame rod 12, and even in case an amount of gas fed is changed due to a change in a feed gas pressure, the excess rate of the primary air can be maintained at a specified value, and proper combustion can be controlled. |
