Membrane condition: normalised flow, salt passage and pressure drop
ASTM D4516 normalisation to 25 °C and the reference net driving pressure, as % of the clean-membrane baseline at the same seawater temperature. Dashed lines: cleaning triggers (flow −10 %, salt passage +10 %, pressure drop +15 %). Last 2 hours.
Membrane water flux vs. net driving pressure
Average flux of the 280 SW30HRLE-440i elements (11,480 m²) against the train NDP. Solid: clean membranes at the live seawater temperature (solution-diffusion, A fitted to the DuPont test point, TCF exp(2640(1/298 − 1/T))). Dashed: 20 °C and 35 °C. Grey band: 10 % flux loss, where a clean is due. Dot: live, with trail.
Reverse osmosis train
Cartridge filters, HP pump in parallel with the PX energy recovery and booster, the 40-vessel rack in 4 banks, permeate and brine, with live sensor values. Red = beyond the twin's alarm limit.
Condition sensors
Bars against the alarm limits in the twin file (red line).