| 摘要 |
<p>A system for pumping liquids that are 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 transfer passage, extending the length of the line. The line may comprise an outer hose that provides an air annulus about a collapsible inner hose, through which the pumped liquid can flow. Air or other gas admitted to the annulus operates to expel the liquid from the inner hose, either upon the loss of pressurization of the liquid in the inner hose, or upon the application of adequate pressure within the gas annulus to discharge the liquid from the inner hose. A compartmented hose has a separating disphragm running the length of the hose, where admission of gas to one side of the diaphragm diminishes the adjoining chamber of the hose. When liquid is pumped, the diaphragm is displaced laterally, permitting full flow in the hose. 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 induce filling of the transfer flow portion of the hose or pipeline, followed by an emptying phase, by re-applying air pressure. The system can use piston or centrifugal type pumps. A gas compressor can serve as the sole pumping medium. This "frost-free" water service is suitable for domestic water supply to cottages and the like, and for sprinkler systems.</p> |
