Central core element for a spirally wound separator assembly

The present invention provides a central core element for separator assemblies useful in the purification of fluids, for example separator assemblies useful for the desalination of seawater. The central core element provided by the present invention comprises at least two porous exhaust conduits wherein each porous exhaust conduit comprises an exhaust channel and one or more openings which allow fluid communication between an exterior surface of the porous exhaust conduit and the exhaust channel. The central core element defines a cavity into which may be disposed a first portion of a membrane stack assembly. In the preparation of a separator assembly comprising the central core element provided by the present invention, a second portion of the membrane stack assembly forms a multilayer membrane assembly disposed around the central core element. Also provided are central core elements for salt separator assemblies and spiral flow reverse osmosis devices.