Solves the steady-state binary mass balance for a single-effect evaporator with a non-volatile solute. Three inputs — feed flow, feed concentration, target concentration — return water removal rate, concentrate flow, and concentration ratio. The answer is independent of evaporator type, temperature, or pressure; it is the upstream input to every downstream tool on this site.
TOOL VISUAL
Given feed flow rate, feed solute concentration, and target concentration, this tool solves the binary mass balance (overall + solute) to return three values:
(1) Water removal rate W — tons of water per hour that must be boiled off.
(2) Concentrate flow P — tons of concentrated product per hour leaving the evaporator.
(3) Concentration ratio CR — the factor by which the solute has been concentrated (XT / XF).
Evaporation capacity is the single most important specification of an evaporator train — it sets heat-transfer area, energy consumption, CAPEX, and OPEX. Every downstream engineering question (which energy strategy? which crystallizer? what is the payback period?) depends on this number.
Before comparing MVR vs. multi-effect, before talking to vendors, before budgeting: you need to know how much water you must remove per hour. This tool gives you that number in 30 seconds, without a process simulator.
Enter three inputs and click Calculate. Default values reflect a 10 t/h feed of 5 wt% NaCl wastewater concentrated to 25 wt% — a typical mid-size ZLD concentrator duty.
[ Calculation results will display here ]
Preliminary estimate only — actual values require detailed engineering.
W = F × (1 − XF / XT)P = F − W = F × XF / XTCR = XT / XF
Understanding the mass balance behind the number — and where it stops being accurate.
Industrial evaporation is a separation process: a feed stream containing a volatile solvent (almost always water) and a non-volatile solute enters a heat exchanger, boils, and leaves as two streams — a vapor stream of near-pure water and a concentrated liquid stream containing the solute. The evaporation capacity reported by this calculator answers a single, deceptively simple question: how much water per hour must that evaporator boil off to take your feed from its initial concentration to your target concentration?
For a single-effect evaporator with no solute in the vapor (which is valid for non-volatile solutes such as salts, sugars, and most inorganic compounds), the overall and solute mass balances reduce to three equations. The water removal rate W equals the feed F multiplied by (1 − XF/XT). The concentrate flow P equals the feed minus the evaporated water. The concentration ratio CR equals XT/XF. These three equations are what this tool solves.
The result is independent of temperature, pressure, heating surface, energy source, or evaporator type. The mass balance is the same whether you are running a single-effect falling-film, a five-effect forward-feed, or an MVR unit. The energy balance and equipment sizing come later — this is the upstream question.
The three inputs above cover most screening cases, but several real-world effects will shift the actual evaporation requirement away from the calculated value:
The evaporation number feeds directly into the next questions: which energy strategy (MVR, TVR, multi-effect) is appropriate? What is the heating steam or electrical energy demand? What is the required heat-transfer area? Once you have the mass balance, our other tools — the Energy Comparison and ROI Calculator — can take this number forward.
This calculator performs a binary mass balance assuming a non-volatile solute, zero solute in the vapor phase, steady-state operation, and no purge or side streams. It is suitable for preliminary screening of industrial evaporation projects — wastewater concentration (NaCl, Na₂SO₄, mixed salts), inorganic salt recovery, food and fermentation broth concentration, and similar non-volatile-solute duties.
Results are preliminary screening estimates only and do not account for boiling point elevation, vapor-liquid equilibrium of volatile species, feed enthalpy, heat losses, fouling and scaling margins, purge/recycle streams, hydrate water of crystallization, or non-ideal mixing. They do not constitute a process guarantee. For volatile feeds (ethanol, ammonia, VOC), high-purity separations, or any application where vapor composition matters, a detailed process simulation with feed-specific VLE data is required.
Always validate results with bench-scale testing and consult a qualified process engineer before making equipment decisions. Contact our engineering team for a feed-specific assessment.
Send us your feed analysis (TDS, density, solute composition, fouling tendency) and target throughput. We will return a process design package with heat-transfer-area sizing, energy balance, and guaranteed performance — typically within two weeks.
Send your feed characterization (TDS, COD, main salts, viscosity), throughput and product targets — we respond with a preliminary process route within two business days.