方法
物料平衡与通量计算采用基于回收率的标准形式（Qp = Qf·Y），净驱动压力由进水压力减去浓水侧压降与进水渗透压得出。
脱盐率相对膜元件台架测试基准条件进行温度与通量归一化处理，并施加浓差极化系数以估算膜壁实际脱盐率。
ATLAS WTS · Process Engineering
RO Membrane Performance Calculator
Reverse osmosis mass-balance, temperature correction, and salt-passage performance for single- or two-pass, up-to-3-stage concentrate-staged array configurations, with membrane-aging projection and product-water blending.
Project Information
Pass 1 — Feed Water & Process Conditions
Pass 1 — Pressure & Membrane Configuration
2- and 3-stage arrays feed each stage from the prior stage's concentrate, raising overall system recovery beyond what a single stage can reach.
Pass 1 — Stage 1
ΔP guidance: ~0.2–0.3 bar (~3–4 psi) friction loss per element in series, ≈1.2–2.4 bar for a standard 6–8-element vessel — independent of how many vessels feed this stage in parallel.
Pass 1 — Stage 2
ΔP guidance: ~0.2–0.3 bar/element in series, ≈1.2–2.4 bar for a standard 6–8-element vessel.
Re-pressurizes Stage 1's concentrate before it enters Stage 2, independent of the main feed pump — useful when this stage would otherwise run short on net driving pressure, especially at high recovery or aged-membrane conditions.
Pass 1 — Stage 3 Optional
ΔP guidance: ~0.2–0.3 bar/element in series, ≈1.2–2.4 bar for a standard 6–8-element vessel.
Re-pressurizes Stage 2's concentrate before it enters Stage 3, independent of the main feed pump.
Pass 1 — Membrane Aging Projection
Defaults follow the selected feed water type; edit for a specific project. The "Aged" condition (toggle top-right) projects permeate TDS and required feed pressure at end of the stated membrane age — the design should stay within spec at BOTH Day-1 and Aged conditions.
Second Pass
Pass 2's feed is Pass 1's blended permeate, re-pressurized by an interstage pump (modeled as Pass 2's own feed pressure). Common for high-purity applications (boiler feed, semiconductor, pharma) and RO+EDI trains.
Pass 2 — Feed & Membrane Configuration
Pass 2 feed is Pass 1's permeate (very low TDS), so this selects the 2nd-pass membrane's own bench baseline and aging defaults, not a feed-water fouling classification.
Fully independent of Pass 1's feed pressure — Pass 1's permeate arrives at Pass 2 already at atmospheric pressure (net of its own permeate back-pressure, effectively an atmospheric break tank), so this is the total pressure Pass 2's own booster pump must supply, not an addition on top of any Pass 1 residual.
Pass 2 — Stage 1
ΔP guidance: ~0.2–0.3 bar/element in series, ≈1.2–2.4 bar for a standard 6–8-element vessel.
Pass 2 — Stage 2
ΔP guidance: ~0.2–0.3 bar/element in series, ≈1.2–2.4 bar for a standard 6–8-element vessel.
Pass 2 — Membrane Aging Projection
Pass 2 Concentrate Recycle
Pass 2's final concentrate is already near permeate quality (it started from Pass 1 permeate), so recycling it into the raw feed instead of wasting it is standard practice and materially improves overall system recovery.
Product Water Blending
Optional raw/pretreated water blended directly into the final product stream to hit a target finished TDS without over-designing rejection. Leave flow at 0 to disable.
Overall System
Final Product Flow
—m³/h
Final Product TDS
—ppm
Overall System Recovery
—%
of raw feed, net of recycle boost
Waste (To Drain)
—m³/h
Pass 1 Performance
System Recovery
—%
Total Permeate Flow
—m³/h
Final Concentrate Flow
—m³/h
Blended Permeate TDS
—ppm
Final Concentrate TDS
—ppm
Overall Rejection
—%
Total Membrane Area
—m²
System Average Flux
—LMH
Pass 1 — Stage-by-Stage Breakdown
| Stage | Elements | Recovery | NDP | Osmotic P. | Flux | Rejection | Perm. Flow | Conc. Flow | Conc. TDS |
|---|
Pass 2 Performance
Pass 2 Recovery
—%
Pass 2 Permeate Flow
—m³/h
Pass 2 Concentrate TDS
—ppm
Pass 2 Permeate TDS
—ppm
Pass 2 Membrane Area
—m²
Pass 2 Average Flux
—LMH
| Stage | Elements | Recovery | NDP | Osmotic P. | Flux | Rejection | Perm. Flow | Conc. Flow | Conc. TDS |
|---|
Technical Warnings
No warnings — all parameters within the modeled envelope.
Inputs changed — click Calculate to refresh results above.
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此工程工具目前仅提供英文版本。
01
工程依据
标准 / 参考依据
范围 / 限制
- 仅用于工艺初步评估，不能替代经过验证的设计软件或持证工艺工程师的审查。
02
工程路径
应用
- 回用、淡化与 ZLD 回收、浓缩与零液体排放逻辑。
场景
- 海水淡化与浓盐水管理 通过能量回收和浓盐水价值化实现可持续海水淡化。
- 通用工艺零排放 通过热法-膜法混合系统实现全水回收和废物最小化。