Pulp and paper
Multi-effect evaporator
Also known as multiple-effect evaporator, evaporator train, kraft evaporator.
A multi-effect evaporator train concentrates kraft black liquor from ~15% solids (as it exits pulping) to 70–75% solids before it can be burned in the recovery boiler. The train consists of 5–7 evaporator effects operating at descending pressure and temperature, each one driven by the vapour from the effect upstream — a counter-flow design that minimises live-steam consumption.
Scaling and fouling
Black-liquor evaporators scale heavily with sodium-rich inorganic deposits, particularly in the high-solids final effects. Periodic water-washing of the evaporator tube bundles is part of routine mill maintenance.
Sonic-horn relevance
The evaporators themselves are mostly liquid-side equipment and rarely benefit from gas-side acoustic cleaning. The downstream recovery boiler is where Sylio's products engage with the kraft chemical-recovery cycle most directly.
Related terms
Related terms
- Black liquorBlack liquor is the concentrated spent cooking liquor from kraft pulping. It is burned in the recovery boiler to generate steam, power and to recover the pulping chemicals.
- Recovery boilerA recovery boiler burns kraft black liquor to generate steam, electrical power and recovered pulping chemicals. Iconic application for sonic horns on superheater cleaning.