| abstract |
A closed water recycling system produces portable drinking water from total domestic waste-water, including household sewage. A microprocessor monitors the operation of the system and automatically back-flushes the ultra-filter assembly, regenerates the ion exchange bed when the monitored variables indicate this is necessary, and acts as a failsafe monitor to insure water quality by shutting down the system in case of a malfunction. For example, the bed includes acid and base regenerated resins having different specific gravities. When a monitor indicates that the bed requires regeneration, a water flush separates resins by specific gravity. Acid and bas regenerating solutions are supplied to opposite sides of the bed. The flow of regenerating solution is stopped when the salt band produced during regeneration approaches an outlet at the middle of the bed. By stopping regeneration before excess regenerative has entered the bed, a saving in regenerating solution is effected and reduction in rinse water is effected, keeping the water losses from regeneration to a minimum. (It is desireable to have only a small amount of by-product water of high salt content to dispose of.) In a preferred embodiment, a rotational digestor has a wheel which evaporates the waste-water solution. |