| 摘要 |
<p>PURPOSE:To have efficient and automatic change-over from main suction operation to dredging work with the aid of a singlebell-mouth by furnishing an actuator control mechanism to adjust the gap of bell-mouth from the bottom surface of tank in accordance with the liquid level in the tank. CONSTITUTION:While liquid level sensor 4 senses the liquid level in a tank which contains sufficient liquid, a bell-mouth 1 is held at its highest position M by an actuator control mechanism 5 and an actuator 2, and when the level sinks, the bell-mouth 1 is put under downward control so as to have an efficient liquid suction in the condition not sucking the air on the basis of signals from the liquid level sensor 4 to be given finally its lowest position N and held there which is suitable for dredging works. Thus the gap of the bell-mouth 1 from the bottom surface of tank is adjusted automatically on the basis of information from sensing of the liquid level in the tank, so that a single bell-mouth 1 can perform efficiently change-over of its operation from main suction work to dredging works automatically.</p> |
