Pressure exchangers

Claim 1

PRESSURE EXCHANGER APPARATUS COMPRISING A SERIES OF CELLS FOR THE COMPRESSION AND EXPANSION OF A FLUID, THE CELLS BEING ARRANGED IN A RING AND HAVING OPEN ENDS, MEANS DEFINING END WALLS FOR THE RING OF CELLS AND HIGH AND LOW PRESSURE PAIRS OF SCAVENGING DUCTS COMMUNICATING WITH THE CELLS AT INLET AND OUTLET PRESSURE FLUID PORTS DISPOSED IN OPPOSITE END WALLS ON ADJACENT BUT CIRCUMFERENTIALLY OFFSET AXES, THE HIGH PRESSURE SCAVENGING OUTLET PORT BEING LOCATED BEFORE THE HIGH PRESSURE SCAVENGING INLET PORT IN RELATION TO THE DIRECTION OF ROTATION OF THE RING, AND MEANS DEFINING AT LEAST ONE DUCT COMMUNICATING WITH THE CELLS AT ITS END THROUGH BUFFER FLUID PORTS DISPOSED IN OPPOSITE END WALLS AND CIRCUMFERENTIALLY OFFSET AXES, THE INLET BUFFER FLUID PORT HAVING A PROJECTED PERIPHERAL SPAN ALONG LINES PARALLEL TO THE SIDE WALLS OF THE CELLS OVERLAPPING AT LEAST A PORTION OF THE HIGH PRESSURE SCAVENGING OUTLET PORT TO INTRODUCE BUFFER FLUID TO THE CELLS IN THE REGION THEREOF, THE LEADING EDGE OF THE INLET BUFFER FLUID PORT BEING LOCATED BEFORE THE LEADING EDGE OF THE HIGH PRESSURE SCAVENGING OUTLET PORT IN RELATION TO THE DIRECTION OF ROTATION OF THE RING TO EFFECT AN ENERGY TRANSFER BETWEEN THE FLUID OF THE BUFFER INLET PORT AND THE FLUID OF THE HIGH PRESSURE SCAVENGING OUTLET PORT, AND THE OUTLET BUFFER FLUID PORT HAVING A PROJECTED PERIPHERAL SPAN ALONG LINES PARALLEL TO THE SIDE WALLS OF THE CELLS OVERLAPPING AT LEAST A PORTION OF THE HIGH PRESSURE SCAVENGING INLET PORT TO WITHDRAW BUFFER FLUID FROM THE CELLS IN THE REGION THEREOF AND BEING SO LOCATED THAT AN ENERGY TRANSFER IS EFFECTED BETWEEN THE FLUID OF THE HIGH PRESSURE SCAVENGING INLET PORT AND THE FLUID OF THE BUFFER OUTLET PORT WHEREBY A LAYER OF BUFFER FLUID IS SET UP BETWEEN FLUID FLOWS THROUGH SAID INLET AND OUTLET HIGH PRESSURE FLUID PORTS.