Rajshree Group supplies complete Digester and Cooking Systems for chemical pulp mills.
In 2021 we supplied and commissioned a complete 100 TPD kraft pulp mill in Gorakhpur, Uttar Pradesh — wood yard, digester, brown-stock washing, bleaching and pulp dryer. 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 digesters — available in batch and continuous configurations — cook wood chips with white liquor under controlled temperature and pressure to selectively dissolve lignin while preserving cellulose fibre integrity. The result is strong, high-quality unbleached kraft pulp.
Key Features
- ✓Cold blow or hot blow batch digesters
- ✓Continuous digester with chip level sensors
- ✓White liquor impregnation vessel
- ✓Blow tank with heat recovery
- ✓Black liquor displacement heating
- ✓Automatic cooking sequence control
- ✓Safety interlocks and pressure relief
- ✓Integration with chemical recovery system
Applications
- Softwood kraft pulping
- Hardwood kraft pulping
- Agro-residue pulping
- Dissolving pulp production
- Pre-hydrolysis kraft process
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.
Request a Quote →Contact Our Experts
📍 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
Digester Technology: The Heart of Chemical Pulp Quality
The cooking stage is where wood chips are transformed into cellulose pulp. Every variable in the digester — cooking temperature, time at temperature (H-factor), liquor-to-wood ratio, active alkali charge, and impregnation quality — directly determines the kappa number, viscosity, and fibre strength of the resulting pulp. Rajshree Group's digester engineering team applies over two decades of real-world cooking experience to design systems that hit these parameters with precision, run-after-run.
Our batch digesters feature advanced liquor circulation systems that maintain temperature uniformity within ±2°C throughout the digester volume — eliminating hot spots that cause over-cooking and cold zones that lead to under-delignified rejects. Our displacement heating (DH) batch digester systems achieve chip heating rates matched to the specific raw material, reducing cooking time while improving pulp uniformity compared to conventional indirect steam injection.
For mills requiring continuous output above 100 TPD, Rajshree engineers upflow or downflow continuous digesters with multiple cooking and washing zones. These systems maintain steady pulp quality without the peak-trough quality variation inherent in multi-digester batch operations — critical for paper machine runnability.
Rajshree's digester control systems calculate and track H-factor in real time — integrating temperature versus time to predict kappa number at blow. This allows operators to adjust cooking duration dynamically when liquor strength or chip quality varies, maintaining consistent kappa within ±1.5 units — essential for stable bleaching performance downstream.
Frequently Asked Questions
Countries We Serve
Rajshree Group supplies and installs our Cooking System (Digester) — 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.