Membrane based in-line fouling monitor for performance tracking in reverse osmosis and Nano-filtration systems

A desalination system with spiral-wound membrane elements housed in pressure vessels comprising:

• a main feed-stream for treatment, a main permeate-stream where permeates from the entire system is collected for use, and a final concentrate-stream;
• one or more stages with each stage having one or more pressure vessel(s) and a common feed inlet-header, a common concentrate outlet-header, and one or more permeate outlet-header(s) that eventually combine to form the main permeate-stream;
• wherein the inlet stream for first stage comprises of main feed-stream and inlet stream for subsequent stages comprises of either preceding stage-concentrate stream or a blend of preceding stage-concentrate stream and a portion of the main feed-stream;
• wherein each pressure vessel has one or more spiral wound membrane element(s) and a central permeate channel with hollow interconnectors to collect and transfer membrane permeates through one or both ends of the pressure vessel to form the main permeate-stream;
• wherein within any stage, one or more pressure vessel(s) have blanked-off interconnectors to isolate and divert permeate of either the lead or the tail membrane element from the remaining membrane elements within the pressure vessel to allow for specific membrane element permeate quality and quantity measurements;
• wherein the diverted permeate(s) of the isolated one or more membrane element(s) within a stage for either lead or tail membrane element(s) is collected through their own ends of the pressure vessels and combined as “diverted-permeate” and the permeates of all other membrane elements are collected through the opposite end of the isolated membrane elements;
• wherein the quality and quantity of the said “diverted-permeate” flows through one or more measurement apparatus for temperature, pressure, conductivity, composition, flow-rate, pH, or oxidation potential for real-time diverted-permeate data for inline monitoring and diverted-permeate subsequently merges with the main permeate-stream;
• wherein the diverted-permeate data, termed as “membrane element monitor” is used for real-time membrane performance measurements of either lead or tail ends of a stage within the system;
• wherein the membrane element monitor data is tracked and analyzed for quality, quantity, rates-of-change, limits, look-up-tables, and correlations to feed-water compositions to rapidly detect membrane fouling and perform either automated or operator assisted actions resulting in—a) slowing-down fouling, b) stopping fouling, c) recovering from fouling, d) predicting, planning, and scheduling steps for system recovery and improved system performance.