A Portable Hand-Operated Reverse Osmosis Desalination Device with Integrated Hydraulic Brine Energy Recovery

Securing a freshwater supply for personnel engaged in remote maritime operations remains a persistent logistical challenge. This paper presents the design, hydraulic simulation, and experimental validation of a compact, manually operated seawater desalination device based on reverse osmosis (RO) coupled with an integrated hydraulic energy recovery system. The device employs a valve-commutated piston pump (cylinder bore 6 mm, rod diameter 3.7 mm, stroke 70 mm) driven by a lever-type handle mechanism. High-pressure brine rejected by the RO membrane is redirected via a two-position, three-way directional valve into the rod-end cavity of the pump cylinder, partially offsetting the filtration resistance and achieving an energy recovery ratio of 49.5%. Hydraulic circuit dynamics were analyzed using AMESim software, yielding a simulated freshwater output of approximately 0.02 L/min (1.2 L/h). A functional prototype with overall dimensions of 200 × 128 × 63 mm was fabricated and tested under 3.57% salinity conditions. Five consecutive trials produced a mean freshwater flow rate of approximately 1.15 L/h (desalination rate exceeding 95%), confirming consistency with the simulation predictions and satisfying the design requirements for individual field use in remote maritime settings.