A CONTINUOUS PRODUCTION MEMBRANE WATER TREATMENT PLANT AND METHOD FOR OPERATING SAME

摘要

A method is provided for the continuous production of treated waters using a staged, tapered array membrane plant by a process of process-logic-controlled (PLC) stage or stage increment isolation and removal from service, washing and return-toservice concurrent with the continued operation of all other stages and/or stage increments of the plant. Specifically, there are plant mounted input/output sensors that supply the PLC with the data required to identify the location and degree of "fouling" of the individual stages or stage increments of a tapered array membranevater treatment plant, where fouling is defined as a loss of water flow through a membrane surface at a given pressure when compared to a water flow standard for the surface. When a stage or stage increment of a plant is defined by this process to be "fouled," the PLC commands the initiation of a sequence of automated valve openings and closings to a) remove the fouled stage or stage increment from feed water treatment service, b) to flush and wash the stage or stage increment, and c) to return the stage or stage increment to feed water treatment service. Optionally the PLC function can be extended to include the monitoring and control of ancillary valves and a variable­frequency-drive feed water pump to command the parts of a plant that remain on-line during the process of a stage or stage increment wash to continue to produce more, or less, or volumetrically identical amounts of membrane water treatment process permeate by combinations of valve re­settings, pump speed adjustments, and stage-to-stage intermediate water diversion.