Method for regeneration of a water softener

Abstract

A method and apparatus for selecting the quantity of salt to be used during each regeneration of a water softener system. The quantity of salt used during each regeneration is approximately equal to the quantity of salt needed to regenerate the resin bed to a preselected design capacity, which is less than the maximum capacity of the resin bed. The design exchange capacity is approximately equal to the exchange capacity of the resin bed at a particular salt dosage, wherein the exchange capacity of the bed at the particular salt dosage divided by the particular salt dosage is generally equal to or greater than 2850. The system is regenerated when at the end of any preselected time period, the percentage of the design capacity of the resin bed used since the last regeneration cycle exceeds a predetermined percentage. In determining the salt dosage used during each regeneration cycle, the exchange capacity of the resin bed is determined for various salt dosages. The available exchange capacity of the resin bed is determined by subtracting the exchange capacity of the resin bed used since the last regeneration from the selected design capacity of the resin bed. The salt dosage used during each regeneration is approximately equal to the salt dosage of the resin bed at the design exchange capacity less the salt dosage of the resin bed at the available exchange capacity of the resin bed. The apparatus of the present invention utilizes a micro-computer to automatically make the necessary calculations to determine when to regenerate the resin bed and to determined the proper salt dosage fill time to the brine tank prior to each regeneration. A turbine water meter located in the soft water outlet line measures the water usage since the last regeneration.