Water treatment system with purge valve responsive to fluid signals

Abstract

A water treatment system including a pair of water treatment tanks, each tank defining a flow path extending from a tank inlet to a tank outlet and containing a water treatment material disposed along the flow path for treating water as it travels from the inlet to the outlet. A system controller controls which of the tanks is on-line and which of the tanks is off-line and controls the regeneration of an exhausted tank. The system controller is operative to provide a final rinse in the service direction. This is accomplished by a purge valve which communicates the outlet of a tank being regenerated to a drain under predetermined operating conditions. The operation of the purge valve is responsive to fluid signals applied to an inlet valve and an outlet valve associated with the tank being regenerated. More specifically, the fluid signals that close the outlet valve and open the inlet valve, are utilized to cause the opening of the purge valve in order to communicate the tank outlet with the drain. The invention obviates the need for separate fluid pressure signals for the purge valve. The system controller also includes an improved regeneration control turbine which includes a plurality of vanes extending from a hub and positioned between disc-like members that overlie the edges of the vanes in order to create cavities for receiving fluid emitted by a regeneration control nozzle. The improved turbine reduces water consumption of the system.