Patent ID: 9181110
Filing Date: 2015-11-10
Classification: B01D,C02F

Abstract:
1. Apparatus for regenerating a water softening system said system of the type that removes multivalent ions from water provided by a hard water source, and recovers at least a portion of the regenerating salts used for the regeneration, the water softening system including: a) a softener tank through which the water from the hard water source passes from an upstream end thereof to a downstream end thereof; b) a brine tank for holding a regenerating solution; c) a first diverter valve supplying liquid selectively from either the hard water source or the brine tank to the upstream end of the softener tank; d) a nanofilter having upstream and downstream sides, said upstream side having an inlet and an outlet, and said downstream side having an outlet, said nanofilter passing monovalent ions to the downstream side and retaining multivalent ions on the upstream side; e) a second diverter valve having an inlet connected to receive liquid from the downstream end of the softener tank and to selectively supply liquid at a first outlet to a water distribution system and to a second outlet; f) a connection between the downstream side outlet of the nanofilter and the brine tank; g) a throttling valve connected between the upstream side outlet of the nanofilter and a drain; h) a pump receiving liquid from the second outlet of the second diverter valve and supplying pressurized liquid to the upstream side inlet of the nanofilter; i) a third diverter valve having an inlet and first and second selectable outlets, said inlet thereof connected to receive liquid from the second outlet of the second diverter valve, said first outlet of the third diverter valve connected to the pump, and said second outlet of the third diverter valve connected to the drain; and j) a controller that in response to a regeneration signal, operates the first diverter valve to pass solution from the brine tank through the softener tank of the water softening system, operates the second diverter valve to direct liquid from the downstream end of the softener tank to the second output of the second diverter valve, and operates the third diverter valve during a first phase of a regeneration cycle to supply liquid from the second outlet of the second diverter valve to the first outlet of the third diverter valve and during a second phase of the regeneration cycle which follows the first phase of the regeneration cycle, operating the third diverter valve to direct liquid from the second diverter valve to the second outlet of the third diverter valve.