GE Merlin Application Manual

Also see for Merlin: Installation and maintenance manual Installation and maintenance manual Installation and maintenance manual

Contents

SALT DIFFUSION 23Rev CFigure 15 Option 3 with Pressurized TankSALT DIFFUSIONLike all reverse osmosis systems, the Merlin uses semi-permeablemembrane elements to filter contaminants. When pressurized, thismembrane element allows water with low salt concentrations to passthrough, leaving higher concentrations of salt on the opposite side of theelement. Unpressurized, naturally occurring diffusion takes place betweenthe low salt permeate water and higher salt concentrate water. Thisprocess, which happens in all RO systems when not in operation, begins toequalize salt concentrations on each side of the element. After periods ofinactivity, measured TDS rejection of the permeate water held within theRO membrane elements and manifold will have dropped below steady-state rejection levels.Salt Diffusion in Traditional RO SystemsIn a typical home RO system, the salt-diffused permeate water createdthrough periods of inactivity is mixed into the storage tank. Over time, thesalt concentration within the storage tank slightly increases. The endusers are eventually forced to use salt-diffused water. This is one reasonwhy most RO manufacturers recommend flushing holding tanks on aweekly basis — it minimizes, but does not eliminate, salt diffusion effects.Salt Diffusion in the MerlinAfter extended periods of inactivity in the Merlin system, any salt-diffusedwater will be exhausted through the faucet when the system is operated.After this water is flushed from the system, the RO continues producingwater at typical steady-state high rejection levels. The Merlin, therefore,allows users to eliminate the effects of salt diffusion by simply runningtheir system for 1 to 4 minutes after extended periods of inactivity. Formost end users, the salt diffusion will be undetectable. For those usersMerlin RO AssemblyInletPressurePumpIf a pressurized tank must beused, install a diaphragm-stylepressure pump between theMerlin and the pressurized tank.Size the pressure pump for Merlinpermeate flow (~ 0.5 gpm).Pressure pump must have apressure switch to control thepressure in the tank.To Point of UsePressureTank