1. Modernization of the Ground Wood Mill with a New GW Reject Refining Line
Year of Rebuild: 2006
- increase the mechanical strength of pulp;
- enable reduced consumption of market chemical pulp by 3% in the furnish;
- improve the quality of GW and TMP; and
- enhance the newsprint strength and printability: i.e. higher breaking length, CD strength and density, reduced dusting and shive content.
The project includes new equipment for GW screening and reject refining, as well as for chemical pulp (kraft) refining. Three FS-503E Optiscreens are installed to ensure fine screening of groundwood. Accept pulp goes to the process, while screen rejects are sent to a reject refining line.
The screen rejects go first to the CleanPac-700 cleaner plant (centricleaner system) to remove mineral impurities (sand, abrasive materials, etc) and then to TS-3 bow screens and SP70SL screw press for thickening. The pulp is then transported by screw conveyors to RGP-268 reject refiner. The refining chamber is sprayed with water and the resulted air-steam mixture is blown into the cyclone to separate the pulp from steam. In the end, after diluting and mixing, the refined pulp goes through FS-503 fine screen.
In addition, three FR-4 Optifiners are included to improve kraft refining.
Volga's Design & Development Department took an active part in designing the project. The equipment is supplied by Metso (Finland).
2. Wood-Fired Boiler Plant
Year of Commissioning: 2008
The boiler plant includes:
- bark handling line;
- dispose of all wood residuals and sludge from the waste water treatment facilities;
- improve cost-effective use of resources and energy efficiency in the industrial process; and
- reduce greenhouse gas emissions in the waste incineration process.
The project presents a unique combination of recycling technologies and equipment from the three companies: Wellons Incorporated (USA) for the boiler plant, MCE Stahl-und Maschinenbau GmbH & Co (Austria) for the sludge dewatering/handling area, and Saalasti Oy (Finland) for the wood rejects dewatering/handling area.
A distinguishing feature is that the wood-fired boiler does not need any additional fuel sources. The plant includes an advanced flue gas treatment system, with a total treatment effect of 98.5%.
The Mill's wood residuals and sludge from the waste water treatment facilities, which receives sewage water from the whole Balakhna community, are disposed of in the most ecologically and cost- effective way. The heat recovery boiler generates more than 50 tonnes steam per hour for the Mill's processes, enhances the energy efficiency and creates new jobs.
3. PM6 Rebuild
Year of Rebuild: 2011
- improve the quality of PM6 newsprint; and
- enhance PM6 performance.
The main features of the project are the replacement of the headbox and the reel and the installation of a new quality control system.
The PM6 rebuild project has resulted in less deviation in basis weight, caliper and moisture profiles in the paper sheet, increased paper machine productivity and better (tighter) winding of finished paper rolls.
PM6 newsprint has been successfully tested to comply with stringent demands for paper quality from the printing market.
4. Water-Filled Ash Conveyor
Year of Commissioning: 2014
- minimize dust hazards during ash removal, transportation and storage;
- cool down the temperature and reduce the amount of disposed ash; and
- improve the energy efficiency of the process.
A new ash conveyor collects both bottom ash (from cells) and fly ash (from ESP) to discharge it in one concrete platform instead of two cart-loading points previously employed.
Ash disposal has become easy and safe: The new water-filled conveyor quenches the ash, so it does not present a hazard during transportation or storage. In addition, wet ash volume is about 30-35% less.
Ash handling system is fully automated.
In addition, the energy consumption and efficiency after the retrofit were improved by eliminating three ash valves, power 0.75 kW each, and two augers, power 5.5 kW each, while the new conveyor drive consumes only 1.1 kW.