Every evaporation or crystallization plant is four engineering decisions, not one. This page puts the options side by side across all four dimensions — energy source, evaporator configuration, supersaturation method and crystallizer configuration — with the numbers that separate them.
Each set compares the options inside one dimension. Jump to the table you need — or read all four and see how they combine at the end of the page.
How vapour gets recompressed or steam gets reused. Decided by electricity price, steam price and annual operating hours — see the energy table.
How liquor moves across the heating surface. Decided by viscosity, fouling tendency and thermal sensitivity of the feed — see the configuration table.
How crystals grow and get classified. Decided by target particle size, purity spec and scaling tolerance — see the crystallizer table.
How supersaturation is generated inside the crystallizer. Decided by the solubility curve of your system — see the method table.
Three ways to drive evaporation: mechanical vapour recompression, multi-effect steam reuse, or thermal vapour recompression. The utility price ratio and annual hours decide — not brand preference.
Hybrid arrangements (MVR + multi-effect trim, TVR boost on an existing train) are routine where utility prices sit between the clean cases. Figures reflect typical industrial ranges from operating references; project-specific selection requires a utility-context heat balance.
Three ways to move liquor across the heating surface. Heat transfer, residence time and fouling tolerance trade off against each other — you cannot maximize all three at once.
Coefficient ranges reflect typical water-like to moderately viscous service; fouling factors and actual cleaning cycles are set by the specific feed chemistry.
Three crystallizer configurations spanning the industrial size range. Target particle size and purity spec elect the winner — the full working principle lives on Crystallization Technologies.
Circulation velocity and supersaturation level move inversely: FC suspends through high supersaturation, Oslo holds supersaturation sub-metastable in the fluidized bed. Selection detail and chemical-system examples on Crystallization Technologies.
Five routes to supersaturation, closed or opened by one variable: the solubility-vs-temperature behavior of your system. Method selection precedes equipment selection, always.
The method is orthogonal to the crystallizer configuration — any documented method pairs with any documented configuration. Full method descriptions on Crystallization Technologies.
The four tables above do not compete with each other. A real plant is one winner from each table — joined by a heat-and-mass balance into one flowsheet.
Pick one option from each dimension. Each choice is justified by its own variable — utility economics, feed rheology, solubility curve, particle-size target — and none of them constrains the others:
MVR + falling film + FC is a documented ZLD pattern — but so are multi-effect + FC, TVR + falling film, and MVR + Oslo. The dimensions combine freely; the heat and mass balance reconciles them.
3 options — decided by electricity price, steam price and annual operating hours.
3 options — decided by viscosity, fouling tendency and thermal sensitivity.
4 options — decided by the solubility curve of the system.
3 options — decided by target particle size, purity spec and scaling tolerance.
Find your situation — each row names the winning dimension and where its table lives on this page.
All figures on this page are indicative ranges from operating references and public literature, not process guarantees. Real selection requires your feed analysis, utility context and a project heat-and-mass balance. Screen against measured data, not catalog figures.
How to read the four tables correctly — and what the numbers do and do not promise.
It means the four decisions do not constrain each other. Your choice of energy source (MVR, multi-effect, TVR) changes nothing about which evaporator configuration suits your feed; your solubility curve changes nothing about which crystallizer delivers your particle size. Each table on this page elects one winner from its own dimension — the plant is the four winners joined by a heat-and-mass balance.
Because boiling-point rise, compression ratio and the motive temperature difference all move the number. High-BPE brines with a small compression ratio land near the top of the range; clean, low-viscosity liquors with an efficient compressor land near the bottom. Note the denominator is per tonne of water evaporated — not per tonne of product.
When steam is cheap or already generated on site and electricity is expensive. Multi-effect converts surplus steam into evaporation duty with modest CAPEX and no compressor; MVR converts electricity into evaporation with the lowest OPEX but the highest upfront cost. The utility price ratio decides — and where it sits between the clean cases, hybrid trains take over.
An FC crystallizer cannot classify — put a battery-grade spec on it and the fine fraction carries the impurities straight through to the centrifuge. An Oslo cements on scaling brines — the fluidized bed becomes a solid block. A DTB trades size ceiling for classification: it will not reach the 5 mm Oslo territory. The failure mode is specific to each mismatch, which is why the configuration table exists.
Freely, within the heat-and-mass balance and materials limits. Documented pairings include MVR + falling film + FC for ZLD, multi-effect + FC for fertilizer salt, reaction + DTB above 90 °C for Li₂CO₃, and MVR-fed Oslo trains for coarse NiSO₄. If a pairing violates no physical constraint, it is an engineering question — not a catalog question.
Operating references, vendor selections and the crystallization literature — Perry’s Chemical Engineers’ Handbook for property ranges, Geertman (2003) on lithium-salt crystallization, Bennett (1993) on DTB practice. They are indicative ranges for screening, not guarantees; every project number is settled by bench data and a project-specific heat-and-mass balance.
Send us the feed analysis, utility context and throughput target. We will return a preliminary selection — dimension by dimension, with indicative energy figures — not a brochure.
Send your feed characterization (TDS, COD, main salts, viscosity), throughput and product targets — we respond with a preliminary process route within two business days.
