Recovered paper is mixed in the TwinDrum with water at a stock consistency of 25%, which is gently pulped and then separated from the reject. The TwinDrum consists of a pulping drum and a sorting drum, which provide the ideal conditions for both processing steps. As a result, compared with conventional, single-section drum pulping systems, it is possible to reduce the use of chemicals by 20% - 40% in addition to reducing the energy used by about 20%.
The TwinDrum for King's Lynn is the largest drum pulping unit that Voith Paper has ever delivered. The second of these giants, Voith reports, is already in the construction phase.
TAPPI
http://www.tappi.org/