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 Permeate is withdrawn from the module while simultaneously retentate exits the opposite end of the module in a more concentrated state and proceeds to the next module in series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 This cycle continues and, as permeate is continuously withdrawn, the batch tank volume gradually diminishes to some viscosity limited end point.