Day 3-4 Newsletter, 26-27th October 2013
Andritz Pulp & Paper has developed a new technology in the area of optimised rejects treatment. The waste from paper mills is normally sent to landfill. This can be a costly and environmentally sensitive operation. A proper water, sludge and rejects treatment system is now a must for every recycled fibre line. Andritz focuses on analysing and optimising individual process steps for careful rejects handling. The major operations in this process are shredding, metal and heavy particle separation, sludge dewatering, compacting, drying and either pelleting and combustion or gasification.
A new development has also taken place in the form of PrimeCal Y belt calendar. The new PrimeCal Y belt calendar has a dwell time in the pre-heating zone more than 50 times longer than in a typical hard nip calendar. Because of this, the temperature of the heated roll needs to be only 20-30° C above the glass transition temperature of the sheet. This allows the calendar to properly soften the paper at a thin surface layer of the sheet, preserving bulk and reducing energy consumption. Compared to conventional soft or hard nip calendars, lower roll temperatures and lower line loads in the PrimeCal Y achieve the same, or better, calendaring effects.
New improvements in the Andritz vacuum washer have resulted in increased and adjustable vacuum, which leads to improved washing efficiency and throughput. The washer has lower losses and better runability, which also lowers the chemical consumption in the pulping line.
The addition of Andritz lifters in the lime kiln improves the mixing of lime during the lime-reburning process. This gives better heat exchange within the lime, leading to a more stable operation, less ring formation and improved energy efficiency. The economics (reduction in fuel consumption) are impressive.
Andritz has also developed a series of EWR (extreme wear resistant) products for the wood yard and wood room. One such product is the chipper bed knife, which has a much longer life than a conventional bed knife.
