技术百科

计算器与单位换算

面向水处理工程的浏览器端计算器，覆盖常见单位换算、水化学、流体和膜系统快速校核。关键设计数值仍需结合 OEM 限值、标准和现场测量数据复核。

四阶段工具路线图

这是换算工具的建设路线图。已上线和部分完成的项目对应下方可用计算器；点击条目可以跳转到对应工具。

基础单位

基础线性换算，并统一本页工具的输入联动和显示规则。

压力 — bar、psi、MPa、kPa、kg/cm²、mH₂O已上线
温度 — °C、°F、K已上线
长度与面积 — m、ft、in；m²、ft²（标签切换）已上线

水力计算

多字段联动，修改任一输入后其他结果同步更新。

流量 — m³/h、US/UK GPM、L/s、m³/d已上线
管径与流速 — Q+D→v；Q+v→D；D+v→Q已上线
体积与质量 — m³、L、gal、ft³；kg、lb、t（堆积密度 ρ）已上线

水化学

面向专业化学计算的分子量、药剂浓度和水质参数换算。

硬度 — mg/L CaCO₃、mmol/L、°dH、°fH、gpg、meq/L已上线
浓度 — ppm、ppb、mg/L、μg/L、质量百分比（ρ）已上线
摩尔浓度 — 药剂（NaOH、HCl 等），mol/L ↔ g/L ↔ mg/L已上线
EC → TDS — 可调 k 值（0.4–1.0）已上线

行业工具

面向现场判断和专用场景的工程计算工具。

筛网目数 ↔ 微米 — ASTM E11，单值或滤料范围已上线
SDI — T_i、T_f、T_total（5/10/15 min）+ 75% 堵塞规则已上线
碱度 — P/M → OH⁻、CO₃²⁻、HCO₃⁻ + 比例条已上线

说明：RO 产水通量（GFD）是附加现场工具，不属于编号路线图的四个阶段。

计算器

阶段 1（基础）：压力、温度、长度与面积；阶段 2（水力）：流量、管速/管径、体积与质量；阶段 3（水化学）：硬度、浓度、摩尔浓度、EC→TDS；阶段 4（行业工具）：筛网目数、SDI 和碱度形态。

显示小数位

应用于本页所有换算结果（默认 2 位）。

阶段 1 · 基础单位

Pressure

What this tool does

Convert between bar, psi, MPa, kPa, kg/cm², and mH₂O so you can compare pumps, membranes, vessels, and gauges when datasheets and site instruments use different units.

Base: bar. 1 bar = 14.5038 psi = 0.1 MPa = 100 kPa = 1.0197 kg/cm² = 10.1972 mH₂O.

bar — Bar

psi — PSI

MPa — Megapascal

kPa — Kilopascal

kg/cm² — kg/cm²

mH₂O — Meter water column

Temperature

What this tool does

Switch between °C, °F, and K for process conditions, shipping limits, and client reports without mental math.

Base: °C. °F = °C×9/5+32; K = °C+273.15.

°C — Celsius

°F — Fahrenheit

K — Kelvin

Length & area

What this tool does

Convert lengths and surface areas between metric and US customary units for vessel sizes, piping runs, and membrane or filter areas in quotes and field work.

Length: 1 m = 3.28084 ft = 39.3701 in. Area: 1 m² = 10.7639 ft².

m — Meter

ft — Feet

in — Inch

阶段 2 · 水力计算

Flow rate (super)

What this tool does

Express the same flow as m³/h, US or UK GPM, L/s, or m³/day so you can match pump curves, supplier datasheets, and daily production figures.

Base: m³/h. 1 m³/h = 4.40286 US GPM = 3.66615 UK GPM = 0.27778 L/s = 24 m³/d.

m³/h — Cubic meters per hour

GPM (US) — US gallons per minute

GPM (UK) — UK gallons per minute

L/s — Liters per second

m³/d — Cubic meters per day

Pipe velocity & diameter

What this tool does

Estimate flow velocity from flow rate and pipe ID, or back-calculate diameter or flow from a target velocity—handy for hydraulic checks and pipe sizing. The colored bar highlights typical water-like design bands (not a substitute for full line sizing).

Q in m³/h, D = internal diameter in mm, v in m/s. Formula: v = Q ÷ (3600 × π × (D/2000)²). Edit any two fields to solve the third (when Q and D are set, v is derived first).

Flow Q (m³/h)

Internal diameter D (mm)

Velocity v (m/s)

Safe velocity indicator

Green 1.0–2.0 m/s (recommended) · Yellow 0.5–1.0 or 2.0–2.5 · Red <0.5 (deposition) or >2.5 (noise / surge risk)

Current: 0.35 m/s — Outside typical design band

Volume & mass (bulk density)

What this tool does

Convert bulk volume and mass for filter media (e.g. carbon, resin): enter ρ in kg/L, then align m³, L, gallons, or ft³ with kg, lb, or metric tons for purchasing and logistics.

Weight = volume × bulk density (ρ in kg/L). Default ρ = 0.5 kg/L (activated carbon). Use presets for common media or type a custom ρ.

Bulk density ρ (kg/L)

Presets

Volume

m³ — Cubic meters

L — Liters

gal (US) — US gallons

ft³ — Cubic feet

Mass

kg — Kilograms

lb — Pounds

t — Metric tons

阶段 3 · 水化学

Water hardness (full)

What this tool does

Convert between hardness scales used in boilers, softening, and international specs. All units are tied to mmol/L as Ca²⁺ using the constants in the project spec.

Base: mmol/L (Ca²⁺). mg/L as CaCO₃ = mmol/L × 100.0869; °dH = mmol/L × 5.6077; °fH = mmol/L × 10.0087; gpg = mmol/L × 5.8411; meq/L = mmol/L × 2.

mmol/L — mmol/L (Ca²⁺)

mg/L — mg/L as CaCO₃

°dH — German hardness

°fH — French hardness

gpg — US grains per gallon

meq/L — Milliequivalents per liter

Concentration matrix

What this tool does

Relate ppm, ppb, mg/L, μg/L, and mass % for solutions. Mass % uses solution density ρ (g/cm³); dilute water-like defaults use ρ = 1.0.

At ρ = 1: 1 ppm ≈ 1 mg/L; 1 ppb ≈ 1 μg/L. Mass % = (mg/L) ÷ (ρ × 10,000).

Solution density ρ (g/cm³)

mg/L — Milligrams per liter

μg/L — Micrograms per liter

ppm — Parts per million (≈ mg/L at ρ = 1)

ppb — Parts per billion (≈ μg/L at ρ = 1)

Mass % — Mass percent (w/w)

Molarity ↔ mass concentration

What this tool does

Convert molarity (mol/L) to mass concentration (g/L, mg/L) using molecular weight—typical for dosing NaOH, HCl, and other reagents.

g/L = (mol/L) × MW; mg/L = g/L × 1000. MW is editable for non-standard grades.

Chemical

Molecular weight (g/mol)

Molarity (mol/L)

Mass concentration (g/L)

Mass concentration (mg/L)

EC → TDS (estimate)

What this tool does

Estimate total dissolved solids from electrical conductivity using a tunable factor k (typical for natural waters and NaCl-like mixtures).

TDS (mg/L) ≈ EC (μS/cm) × k. Default k = 0.67; allowed 0.4–1.

TDS estimation is an approximation based on the selected k-factor; use lab TDS for compliance and design decisions.

k presets:

Electrical conductivity EC (μS/cm)

Factor k (0.4–1)

Estimated TDS: 335.00 mg/L

阶段 4 · 行业工具

Mesh ↔ micron (ASTM E11)

What this tool does

Map standard sieve mesh numbers to nominal opening size in millimetres and micrometres for media specification (e.g. activated carbon 8×30).

Single mesh uses ASTM E11 nominal openings (mm). Range mode reports the span between two mesh openings (e.g. 8 and 30) for typical commercial cuts.

Mode:

Mesh number

Nominal opening

1.70 mm · 1700.00 μm

Micron = mm × 1000.

SDI — silt density index

What this tool does

Field estimate of fouling potential from timed 500 mL filtration intervals. Uses the same time units for T_i and T_f; T_total is the test duration in minutes.

SDI = ((1 − T_i/T_f) × 100) / T_total. If (1 − T_i/T_f) > 75%, the test is invalid (ASTM D4189-style plugging rule).

Use consistent units for T_i and T_f (typically seconds). For design decisions, follow ASTM D4189 and site QA.

T_i — initial 500 mL time

Must be > 0.

T_f — final 500 mL time

Must be ≥ T_i.

T_total — test duration (minutes)

SDI = 2.22Excellent (low fouling)

Alkalinity — species distribution

What this tool does

Split phenolphthalein (P) and total/methyl-orange (M) alkalinity into hydroxide, carbonate, and bicarbonate (as CaCO₃ equivalents) for dosing and scaling insight.

Branches follow standard aqueous-carbonates logic; P cannot exceed M. Displayed species use Math.round per engineering convention. The balance row checks Σ species vs M (exact model vs rounding).

P — phenolphthalein alkalinity (mg/L as CaCO₃)

M — total alkalinity (mg/L as CaCO₃)

OH⁻

mg/L as CaCO₃

CO₃²⁻

mg/L as CaCO₃

HCO₃⁻

120

mg/L as CaCO₃

Mass balance check (CaCO₃ equivalents)

Exact model: Σ(OH⁻ + CO₃²⁻ + HCO₃⁻) = 120.00 mg/L · M = 120.00 mg/Lmatches M
After Math.round per species: Σ = 120 mg/L · Δ = Σ − M = 0.00 mg/L — typical rounding drift

Share of M (approximate)

100%

OH⁻ 0.0% · CO₃²⁻ 0.0% · HCO₃⁻ 100.0%

更多工具

RO 产水通量 — GFD

工具说明

根据产水流量和有效膜面积计算 GFD，并给出近似 L/m²/h 参考值。适合快速校核，不能替代膜厂家通量限制或系统分段规则。

输入：产水流量（m³/h）和有效膜面积（m²）。输出包含可与公制 datasheet 交叉核对的近似 L/m²/h。

产水流量 (m³/h)

有效膜面积 (m²)

通量： 16.83 GFD (≈ 28.57 L/m²/h 参考值)