Patent ID: 6447259
Filing Date: 2002-09-10
Classification: B01D,F04B,Y02A

Abstract:
An energy recovery device comprising:at least one pair of cylinders; a piston slidable in each of the at least one pair of cylinders; a spool valve having a valve housing and a slidable valve element for controlling the flow of waste liquid to and from the at least one pair of cylinders, said spool valve selectively connecting one end of one of the at least one pair of cylinders to waste liquid at a first relatively high pressure and connecting another one of the at least one pair of cylinders to drain and vice versa; first and second valves for allowing feed liquid to enter the other end of said one of the at least one pair of cylinders at a second lower pressure via a feed liquid entry port and to be discharged via a feed liquid discharge port from said other end of said one of the at least one pair of cylinders in response to movement of the piston caused by waste liquid entering said one end of said one of the at least one pair of cylinders; and means ensuring that the area of the piston acting, in use, on the feed liquid is less than the area of the piston, in use, acted upon by the waste liquid so that the piston acts as a pressure intensifier to discharge feed liquid through the feed liquid discharge port at a higher pressure than the pressure of waste liquid entering said one end of said one of the at least one pair of cylinders, wherein said one of the at least one pair of cylinders extends from the spool valve in a first direction transverse to the axis of movement of the valve element and the other one of the at least one pair of cylinders extends from the valve housing in a second direction transverse to the axis of movement of the valve element.