Liquid supply system

Abstract

A liquid transfer system for liquids that are subject to solidification uses a pipeline, with compressed gas as the liquid displacement medium. The pipeline comprises a substantially rigid outer line and a flexible inner hose, forming with the outer line an intermediate interstitial zone along the inner hose; a check valve located adjacent each end of the inner hose provides uni-directional flow within the system. A gas compressor connected with the interstitial zone by way of a flow control selectively applies pressurized gas or vacuum to the zone. The three possible phases of operation comprise; a first phase, when vacuum is applied to the interstitial zone, to expand the inner hose and induce liquid from the source to substantially fill the inner hose; a second phase when gas pressure is applied to the interstitial zone, to compress the inner hose and expel the liquid toward the point of delivery. The first and second phases are repeatable, to provide cumulative delivery of the liquid. In the third phase, gas pressure is maintained within the interstitial zone to maintain the inner hose collapsed and substantially 'dry' so as to prevent 'freezing' within the inner hose. A second such pipeline adjoining the first pipeline, working in opposite phased relation, enables substantially continuous flow. The third, purging phase of operation is applied co-extensively to both the pipe-lines. The system can utilize interstitial gas to assist the prime mover on start-up. Liquids other than water can be pumped.