| 摘要 |
<p>A system for pumping liquids that may be subject to solidification in the line, uses a compressed gas as an expulsion medium for the liquid. A compound hose pipeline is used, having a variable volume gas chamber adjacent a compressible transfer passage, both of which extend the length of the line. The line may comprise an outer hose that provides a gas annulus about a collapsible inner hose, through which inner hose the pumped liquid can flow. Air or other gas within the annulus operates to expel the liquid by compressing the inner hose. A compartmented hose embodiment has a separating diaphragm running the length of the hose, dividing the hose into expansible gas and liquid portions. The system may be self priming, using a source of vacuum to remove the air and expand the volume of the liquid transfer hose portion, to thereby induce filling of the transfer flow portion of the hose or pipeline, followed by an emptying phase, by re-applying air pressure. A Shrader-type valve or a needle inflator valve in the line outer wall may provide convenient access for inflation air. The delivery system can use piston or centrifugal type pumps; or a gas compressor can serve as the sole pumping medium. An immersed intake for use with the system in fresh water can incorporate a fine filter cloth against zebra larvae or other contaminants, which filter is back-flushed at the end of each pumping cycle. The line, when being operated to serve as a pump may be duplexed, so as to provide more continuous flow. An inner hose may be used that is normally in a flattened condition, thereby incorporating an initial charge of atmospheric air upon sealing the line ends, while its "memory" assists in dewatering. A discovered air pressure "bump" when dewatering further contributes to system effectiveness. The co-extensive hose may be manufactured by co-extrusion, in endless length, thus removing the limitation of having to thread the inner hose within the outer hose.</p> |
