Scrubber Water Requirement Calculator

Work out scrubber water requirement instantly with clear inputs, formula shown and shareable results.

About Scrubber Water Requirement Calculator

Wet scrubbers circulate liquid at a liquid-to-gas ratio of 0.7-2.7 litres per cubic metre for packed towers and up to 4 for venturi units. Most of it recirculates; make-up replaces evaporation and blowdown. Blowdown carries the absorbed pollutants and is usually the effluent stream that needs treatment and consent.

Formulas

Circulation rate

Circulation (L/h) = gas flow (m3/h) x liquid to gas ratio

Make-up and blowdown

Make-up = circulation x (1 - recycle fraction)

Worked example

With the default values below, Scrubber Water Requirement Calculator returns Scrubbing Liquid Circulation of 30,000.0. Change any input above and every figure here is recalculated in your browser.

Inputs used

Gas Flowminimum 0 m3/hour: 20,000 m3/hour
Liquid To Gas Ratiominimum 0 L per m3 gas: 1.5 L per m3 gas
Recycle Fractionaccepts 0–99.9 %: 90 %
Pollutant Absorbedminimum 0 kg/hour: 20 kg/hour

Results

Scrubbing Liquid Circulation: 30,000.0
Make-Up Water Required: 3,000.00
Blowdown Rate: 2,400.00
Pollutant Concentration In Blowdown: 8,333.3

Step by step

1Values used
2Circulation rate
3Make-up and blowdown
4Scrubbing Liquid Circulation= 30,000.0
5Make-Up Water Required= 3,000.00
6Blowdown Rate= 2,400.00
7Pollutant Concentration In Blowdown= 8,333.3

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax or compounding frequency into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
Scrubber blowdown is an effluent requiring treatment and discharge consent. Its composition depends on the pollutants absorbed and may be classified as hazardous.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Scrubber blowdown is an effluent requiring treatment and discharge consent. Its composition depends on the pollutants absorbed and may be classified as hazardous.

Frequently Asked Questions

Why is the liquid-to-gas ratio critical?

It determines the interfacial area and the driving force for absorption. Too low and the gas is not scrubbed; too high and pumping energy and effluent volume rise without further removal.

What limits recycle?

Dissolved solids concentration. Beyond saturation, scaling blocks packing and nozzles, and pollutant partial pressure in the liquid rises enough to reduce absorption driving force.