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Membrane process calculator

Membrane Flux, Area & Train Sizing Calculator

Screen membrane area, modules, train arrangement, N+1 availability, and a configurable flux regulator that dispatches only the required number of trains while holding the selected flux ceiling.

Preliminary membrane design screen: Enter a net flux supported by membrane supplier data, pilot testing, or proven comparable operation. This calculator does not select a membrane product or certify a sustainable flux. It makes the assumed flux, cleaning availability, module area, and train-resilience checks explicit.

Input parameters
Define flow, net-flux basis, modules, redundancy, and optional flux regulation.
Design flow envelope
m³/day
peak flow = average flow × peak-flow factor
Net flux and cleaning basis
Use direct net flux when downtime and backwash have already been included in the supplier or pilot basis.
LMH; site- and membrane-specific design assumption
percent; keep at 100% where your net flux already includes long-cleaning downtime
Module, train, and redundancy arrangement
m²/module; supplier-certified effective area
physical train constraint
trains filtering in normal operation
installed but not normally filtering
trains unavailable for the selected N+1 review
percent; explicit capacity allowance before module rounding
Flux regulation and membrane air-scour hand-off
LMH; normally equal to or below the selected effective net design flux
Nm³/(m²·h); optional supplier or pilot input
percent of time the membrane scour air is active
trains used for the stated scour-air case
Calculated results
Area, physical train arrangement, duty flux, and regulation response.

Enter values and select Calculate to view the membrane area and train-sizing screen.

Governing equations

The primary input is a transparent, effective net design flux. The calculator converts the selected flow into area, applies the explicit margin, rounds the arrangement to equal modules per train, and then checks actual fluxes against the selected design criterion.

Qpeak = Qavg × peak-flow factor
Jnet,protocol = (Jf × tf − Jb × tb) ÷ (tf + tr + tb)
Jnet,effective = Jnet × cleaning availability
Abase = Qsize × 1,000 ÷ (24 × Jnet,effective)
Atarget = Abase × (1 + area margin)
Modules/train = ceil[Atarget ÷ (duty trains × area/module)]
Jcase = Qcase × 1,000 ÷ (24 × available membrane area)
Required regulated trains = ceil[Qcase × 1,000 ÷ (24 × Jceiling × area/train)]

Interpretation

Flux is permeate flow per unit membrane area. The sustainable value depends on membrane configuration, wastewater characteristics, mixed-liquor conditions, temperature, cleaning strategy, and proven supplier or pilot performance. This page is intended for preliminary screening and not final OEM selection. MBR flux, TMP, permeability, and shear reference [1]