Military Reverse Osmosis

Aqua-Chem offers a range of reverse osmosis systems for naval ships, and has more than 40 years of experience supplying watermakers to naval forces. Our current watermakers provide reliable potable water production, including the 6,800 gpd seawater reverse osmosis system which was retrofitted on the FFG-7 Oliver Hazard Perry-class frigates as a replacement for their distillation watermakers.

Design Features

Pumps – Our units feature a reliable positive displacement pump.

Motors – Totally Enclosed Fan Cooled (TEFC) motors.

Materials of Construction – We use corrosion-resistant copper-nickel for piping and filter housings.

Pressure Vessels – We use high-pressure, fiberglass-reinforced plastic (FRP), noncorrosive pressure vessels.

Frame – We use heavy-duty, carbon steel frames with resilient mounts.

Pretreatment – This includes a strainer, centrifugal separator, 20 micron filters, 3 micron filters and a separately mounted carbon filter for use when feedwater contains bromine or chlorine.

Controls – The control panel is independently mounted and uses an Allen-Bradley® PLC control with touchscreen interface.

Benefits

• 13,600 gpd of potable water from seawater is produced with our standard design, consisting of two independent 6,800 gpd potable water units working together.
• Local start and automatic operation with automatic safety shutdowns. Product water is continuously monitored with automatic diversion if salinity exceeds programmed limits.
• Designed for disassembly and easy insertion through the munitions hatch of an FFG-7.
• Tested to meet U.S. Navy standards for shock and vibration.
• Vibration and noise meet U.S. Navy airborne and structure-borne acoustic requirements.
• Electromagnetic interference meets current EMI test requirements.

How Reverse Osmosis Works

Desalination by Reverse Osmosis (RO) is a process whereby fresh water is extracted from seawater through the use of a semipermeable membrane. An RO watermaker consists of several key components:

• Prefiltration removes particulate matter from the seawater.
• A high-pressure pump increases the seawater pressure to approximately 700-1,000 psi.
• Pressure vessels house the RO membranes, where separation of fresh water from salt water occurs. Approximately 19 percent of the input water is extracted as potable water.
• The potable water (permeate) is sent to storage and the balance of the water (brine) is discharged.

Equipment Characteristics