Commercial Reverse Osmosis Systems
Commercial reverse osmosis systems, in their most basic form, consist of a pressure pump, housing, and membrane. Water is forced into the housing under pressure and the pure water (or permeate) is collected and passed to service. Reject water (or concentrate) is collected from another outlet and routed to drain, with a portion of the concentrate water recycled back to the inlet of the pump. This means that the portion of water sent to the drain is
kept to a minimum, allowing a recovery ratio of approx 75% to be achieved without significant fouling of the membrane. The recirculation allows a higher flow of water through the pump, reducing the load on its bearings and keeping the pump running cooler. The recirculation on all units is adjustable. The controller used on commercial reverse osmosis systems constantly monitors the quality of the permeate water and is also linked with safety controls on the system, to ensure the unit cuts out on low & high pressure, high & low conductivity, and
full permeate tank signal. It will also run various pre and post-flush cycles to maximize the life of the membranes. The constant monitoring is automatic and the programming is all pre-set to ensure the protection of the system at all times and to maximize the quality of the pure water.
Commercial reverse osmosis systems must be supplied with softened and de-chlorinated water. A duplex softener is recommended for continuous operation. Utilizing softened water for the feed to the RO plant will reduce the scaling potential on the membrane and therefore lengthen its working life. De-chlorination of the feed will reduce oxidation damage to the surface of the membrane. Membranes can also be fouled by Iron, Manganese, organics, and microorganisms.
For boreholes and other private supplies, a full water analysis is advised before installing an RO plant, Once the water analysis is provided the pre-treatment system requirements can be specified.
Here is a great video on how a commercial reverse osmosis system works.