Description
Return permeateFlow = feedFlow*recovery, concentrateFlow = feedFlow*(1-recovery), permeateConcentration = feedConcentration*(1-rejection) and concentrateConcentration = feedConcentration*(1-recovery*(1-rejection))/(1-recovery).
Membrane calculations distinguish feed, permeate and reject streams, gross recovery and recycle, and hydraulic from osmotic pressure. A local mass balance or pressure difference is only one part of membrane transport and operating performance.
Return permeateFlow = feedFlow*recovery, concentrateFlow = feedFlow*(1-recovery), permeateConcentration = feedConcentration*(1-rejection) and concentrateConcentration = feedConcentration*(1-recovery*(1-rejection))/(1-recovery).
When to use this tool
Use Reverse Osmosis Permeate Recovery Salt Factor when checking a supplied membrane stream balance or driving-pressure term.
How to use the tool and how it works
- Enter feedFlow, recovery, feedConcentration, rejection. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read permeateFlow, concentrateFlow, permeateConcentration, concentrateConcentration. Use the output convention below.
Require nonnegative feedFlow and feedConcentration, recovery in [0,1) and rejection in [0,1]. Return permeateFlow = feedFlow*recovery, concentrateFlow = feedFlow*(1-recovery), permeateConcentration = feedConcentration*(1-rejection) and concentrateConcentration = feedConcentration*(1-recovery*(1-rejection))/(1-recovery).1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| feedFlow | Feed Flow | Required. Finite number; minimum 0. |
| recovery | Recovery | Required. Finite number; minimum 0; strictly below 1. |
| feedConcentration | Feed Concentration | Required. Finite number; minimum 0. |
| rejection | Rejection | Required. Finite number; minimum 0; maximum 1. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| permeateFlow | Permeate Flow | Required. Finite number. |
| concentrateFlow | Concentrate Flow | Required. Finite number. |
| permeateConcentration | Permeate Concentration | Required. Finite number. |
| concentrateConcentration | Concentrate Concentration | Required. Finite number. |
{
"input": {
"feedFlow": 100,
"recovery": 0.5,
"feedConcentration": 1000,
"rejection": 0.9
},
"output": {
"permeateFlow": 50,
"concentrateFlow": 50,
"permeateConcentration": 99.99999999999997,
"concentrateConcentration": 1900
}
}Limitations and assumptions
- This is a steady, additive-volume solute balance with rejection defined relative to feed concentration. At zero feed flow the algebraic concentrations are still returned. No osmotic pressure, scaling, membrane kinetics or drinking-water quality is established.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use a complete process and membrane model for recirculation, concentration polarization, fouling, energy use and operating constraints.
References
Similar or alternative tools
- Membrane Recovery Reject Base
Return grossReject = feed-permeate, netReject = grossReject-recycleReject and recovery = permeate/feed.
- Membrane Transmembrane Pressure One Module
Return tmp = (feedPressure+retentatePressure)/2-permeatePressure and netDrivingPressure = tmp-osmoticDifference.