| 摘要 |
<p>A device for the continual release of batches of liquid from a reservoir which is itself continuously filled at a slow rate, and particularly for the periodical release of liquid effluent from the rotary arm assembly of a sewage trickle filter bed. The device comprises a "U"-tube 21 with one limb taller than the other. The free ends of the taller and shorter limbs are respectively connected to the reservoir outlet and open to atmosphere, so that atmospheric pressure can support a head of liquid within the tube when the latter is full and the reservoir outlet is closed by a seal 25. That seal 25 is buoyant, located within the reservoir and restrained from lateral movement so that it tends always to approach and close the outlet as the reservoir level falls. <IMAGE></p> |
