| 摘要 |
PURPOSE:To avoid the adhesion of dust to a transparent plate and permit the correct detection of a flame detector, by a method wherein the transparent plate is arranged at a position whereat the parallel component of the stream of combustion air, sent by a fan, is as large as possible. CONSTITUTION:A transparent plate 31 is attached to a flame detecting window 32, bored at the left and upper position of the front surface of the end of a blow tube 27, so as to close the window 32, while a flame detector 13 detects the flame of a combustion unit 29 through the transparent plate 11, attached so as to close the window 12. The flame detector 13 detects light emitted by the flame in a combustion unit 29, and converts the brightness of the flame into a voltage to transmit it to a controller. The controller decides by the value of the voltage, sent by the flame detector 13, whether the combustion is effected normally or not. Flow speed (speed component on a surface parallel to the transparent plate 31) is highest on the left and upper part of the front surface of the end of the blow tube 27. Dust is readily accumulated in places whereat the flow speed is low, the air is whirled and the like; therefore, the transparent plate 31 is arranged at a position whereat the dust is hardly accumulated. |
