Patent ID: 7828972

Claim:
A self-reciprocating energy recovery device including a pair of power recovery chambers having pistons therein respectively, a high-pressure concentrated supply pipe, a low-pressure concentrated discharge pipe, and a high-pressure seawater discharge pipe to enable the power recovery chambers to recover hydraulic power supplied through the high-pressure concentrated water supply pipe and utilize the hydraulic power in driving of a seawater pump, the energy recovery device comprising: a concentrated water control valve block selectively interrupting introduction and discharge of concentrated water to and from the power recovery chambers through fluctuation of a fluctuating plate-like concentrated water valve having pinion gear teeth on the outer peripheral surface thereof; a rack gear having rack gear teeth enmeshed with the pinion gear teeth and inserted into opposite spools; first and second high-pressure concentrated water pilots branched out from the high-pressure concentrated water supply pipe to pilots and connected to sides of the spools to alternately supply high-pressure concentrated water; first and second high-pressure concentrated water pilot valve interrupting supply of high-pressure concentrated water to the first and second high-pressure concentrated water pilots respectively; first and second low-pressure concentrated water pilots connected to opposite sides of the spools to discharge low-pressure concentrated water; and first and second low-pressure concentrated water pilot valves interrupting discharge of low-pressure concentrated water through the first and second low-pressure concentrated water pilots.