| 摘要 |
<p>A pneumatic sewage system has a long main conduit for conducting waste liquid to a receiving tank at a partial vacuum. Waste liquid from sanitary conveniences flows through branch conduits to the main conduit, intermittently a flow control valve in each branch conduit opening when waste liquid starts to flow and closing when flow of liquid stops. When all of the valves close at the same time a long column of liquid being propelled at a high velocity in the main conduit to the receiving tank will suddenly stop. When this occurs forces are developed which adversely affect the main conduit and equipment connected thereto. In accordance with my invention ambient air is mixed with waste liquid in each branch only during the intervals of time waste liquid is flowing therethrough and while it is open. The ambient air mixed with the waste liquid functions as a resilient damper that effectively absorbs the forces developed when the long column of liquid moving through the main conduit suddenly stops.</p> |
