Impulse Drying

Impulse drying involves pressing the paper between one very hot rotating roll (150-500°C) and a static concave press with a very short contact time. The pressure is about 10 times higher than that in press and CondeBelt drying. Impulse drying may lower the moisture content of the paper web entering the drying section by upto 38%, pointing at significant reductions in energy demand in the drying stage of the paper machine. However, current results from pilot operations show limited energy efficiency improvements when compared to state-of-the-art efficient paper machines. Hence, further research is needed to realize the promises of impulse drying.

Other reported benefits of this technology include reduced capital costs, increased machine productivity, improved strength, reduced fiber use, and increased recycled fiber content allowed for any given paper strength (Kramer et al., 2009. p.112).

Development Status Products
Demonstration

Impulse DryingCosts & Benefits

Parent Process: Papermaking
Energy Savings Potential

An estimate has put the possible savings in dry steam utilization at 50 to 75%. Another study reports the energy savings of around 18 to 20% or 2.1 GJ/ton of paper. Electricity requirements increase by 5 to 10% (Kramer et al., 2009. p.112).
By allowing 5 to 10 percent points of increased drying, impulse drying can reduce heat energy consumption by 0.44 to 0.9 GJ/t-paper (assuming 2.5 MJ/kg of steam) (BREF, 2010. p 665)

CO2 Emission Reduction Potential
Costs

Not available

Impulse Drying Publications

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112