| 摘要 |
PURPOSE:To control a ratio of primary air to obtain a substantial constant value by a method wherein a mechanism for varying an inner diameter of float for use in adjusting automatically an inner diameter of a throat is arranged at a venturi pipe mixing part in response to an increasing and decreasing of combustion volume. CONSTITUTION:In case of a maximum combustion volume, a heat value received by a heat sensitive body 17 is high and either liquid or gas 16d is expanded, so that a flexible material 16b such as rubber is deformed as indicated by a broken line A. That is, it acts to reduce a diameter of the throat at the venturi pipe mixing part. As the heat value of combustion is gradually decreased from this condition, the heat value received by the heat sensitive body 17 is also decreased, so that a flexible material 16b such as rubber is deformed gradually from a condition A toward a direction where a diameter of the throat is expanded. With this arrangement, it is made possible to control the ratio of primary air to show substantially constant value, thus, it is made possible to realize a combustion unit having a wide range of adjustment in heat value. |
