Rajshree Group manufactures and supplies complete Multi-Effect Evaporator (MEE) systems — also known as multiple effect evaporators — for black liquor concentration in kraft pulp mills. A pulp mill multiple effect evaporator is essential for recovering cooking chemicals and cutting steam consumption.
Our 2021 project in Baroda, Gujarat included a multi-effect evaporator and recovery boiler that raised plant efficiency by 30%. Since 2003, Rajshree Group has delivered 22+ pulp and paper projects across three continents — India, Africa and the Middle East — totalling over 2,000 TPD of installed capacity.
Product Overview
Our evaporators concentrate the weak black liquor (15–18% DS) from the brown stock washer to heavy black liquor (65–80% DS) suitable for firing in the recovery boiler. Multi-effect design maximises steam economy and energy efficiency.
Key Features
- ✓Falling film or forced circulation evaporators
- ✓Surface condenser with vacuum system
Applications
- Kraft mill black liquor concentration
- Chemical recovery loop integration
- Steam generation optimisation
- Tall oil soap skimming
- Turpentine recovery
Our Turnkey Project Process
We understand your requirements, site conditions, and budget to prepare a detailed feasibility report.
Complete process design, P&IDs, civil layout, electrical single lines, and equipment specifications.
In-house and vendor-sourced equipment manufactured, quality-inspected, and dispatched on schedule.
Our engineers supervise erection, electrical, instrumentation, and commission the plant to design parameters.
Hands-on operator training, performance guarantee trial, and ongoing technical support for the life of the plant.
Get a Free Quote
Tell us your capacity requirement and we'll send a detailed technical and commercial proposal within 48 hours.
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📍 Branch Office: 1913 Gunbarrel Road, Suite 105 Chattanooga, TN 37421, USA |
📍 Branch Office: D7, Varsity Chateau, Uniport Road Aluu, Port Harcourt, Rivers State, Nigeria |
Why Choose Rajshree?
- ✅ 20+ years industry experience
- ✅ 22+ successful projects delivered
- ✅ Serving India, Africa & Middle East
- ✅ Complete turnkey — single point responsibility
- ✅ After-sales support and spare parts
- ✅ Competitive pricing and financing options
Multi-Effect Evaporation: Concentrating Black Liquor with Maximum Steam Economy
Black liquor — the spent cooking liquor leaving the brown stock washer — is a dilute solution of dissolved lignin, hemicellulose, and cooking chemicals at 15–18% dry solids. To fire it in the recovery boiler, it must first be concentrated to 65–80% dry solids. This concentration step — performed in the multi-effect evaporator — is one of the most energy-intensive steps in kraft pulping, which is precisely why Rajshree engineers multi-effect systems that maximise steam reuse across each evaporator body.
In a multi-effect evaporator, steam from the first effect heats and evaporates water from the black liquor. The vapour generated in the first effect is used as the heating steam for the second effect — and so on, down the chain. A six-effect evaporator therefore uses roughly one tonne of steam to evaporate six tonnes of water from the black liquor — a dramatic improvement over single-stage evaporation. Rajshree designs five-effect and six-effect systems matched to each mill's black liquor volume and available steam pressure.
Fouling from silica, calcium compounds, and lignin precipitates is the primary operational challenge in black liquor evaporators. Rajshree addresses this through optimised liquor flow sequences (forward feed for low-silica liquors, backward feed for high-silica agro-based black liquors), and through supply of proprietary scale inhibitor dosing systems that extend cleaning intervals by 40–60%.
Rajshree's 6-effect falling film evaporators achieve steam economy ratios of 5.0–5.8 kg water evaporated per kg of live steam consumed — exceeding the industry standard of 4.5 for comparable systems. This steam saving is directly recoverable to the paper machine dryer section, reducing fresh steam consumption.
Frequently Asked Questions
Countries We Serve
Rajshree Group supplies and installs our Multi-Effect Evaporator — and complete pulp & paper mill machinery — for mills across India, Africa and the Middle East, with sea-freight delivery, on-site erection, commissioning and after-sales support in every market we serve.