Pumping system with energy recovery and reverse osmosis system

Abstract

A liquid pumping system comprises a plurality of liquid pumps and a hydraulic drive unit. Each liquid pump is driven by a separate hydraulic cylinder. The hydraulic cylinders are powered by a shared hydraulic pump through a valve set. A valve set controller is configured to operate the valve set. A liquid pumping process comprises distributing an initial flow of pressurized hydraulic fluid between the hydraulic cylinders. The hydraulic cylinders move through a cycle in a phased relationship to provide a constant sum of flow rates from the liquid pumps. A membrane filtration system combines the liquid pumping system with a membrane unit. In a water treating process, feed water is pumped through the membrane unit. Brine from the membrane unit is returned to each liquid pump while that liquid pump is feeding water to the membrane unit.

Dependencies are inferred from the claim text.