Plant configurations

Continuous plant design with spiral-wound modules

The graphic illustrates the flow paths in a continuous, feed and bleed membrane filtration plant configuration in spiral-wound membrane format. The feed product typically enters into a feed balance tank. The product is picked up by a feed pump and transferred from the feed balance tank into the first recirculation stage. The stage recirculation pump is responsible for providing adequate flow and pressure conditions for optimal membrane performance. Product is pumped through the vessel, or through multiple vessels in parallel, and across the membrane surface. The permeate is withdrawn from the vessel while simultaneously retentate exits the opposite end of the vessel in a more concentrated state. The retentate flow is split between that which is needed to satisfy the stage recirculation requirements while the remainder progresses forward to the next stage in series. This step-wise concentration progresses throughout a number of stages in series until the final retentate is eventually withdrawn from the plant at the desired concentration and composition.

Batch plant design with tubular modules

The graphic illustrates the flow path of a batch membrane filtration plant configuration in tubular membrane format. The batch tank is first filled with feed product. The product is picked up by a feed pump and transferred from the batch tank into a series of membrane modules. Permeate is withdrawn from the module while simultaneously retentate exits the opposite end of the module in a more concentrated state and proceeds to the next module in series where more permeate is removed. This progresses within certain flow and/or pressure-drop constraints until the retentate exits the last module and is directed back to the batch tank. This cycle continues and, as permeate is continuously withdrawn, the batch tank volume gradually diminishes to some viscosity limited end point.