First Valmet-delivered flash dryer started up at Stora Enso
The first-ever flash dryer purely for fiber and delivered under the Valmet brand recently started up at Stora Enso’s biocomposite plant at Hylte mill, Sweden.
Stora Enso decided to invest in full-scale production after seeing strong customer demand for higher volumes of pulp-pellet production for use as a renewable replacement for plastics.
The system included a complete flash dryer with drying stage, scrubber system, supporting and platform, construction, insulation, spare parts, basic engineering, mechanical and electrical erection, erection advice, checkout and startup supervision and training. The dryer will dry from 43 to 93% dryness.
The design of the dryer system was adapted to fit the new equipment into the existing plant and with other machinery in the production line.
According to Valmet, flash drying can be described as almost instantaneous evaporation. Small particles and single fibers with a large exposed surface area meet the hot air stream in the drying stages. Fibers carried by the hot air through the system stay in the drying zone for less than 30 seconds and are never heated higher than the wet bulb temperature. Exhaust gases from the cyclones are cleaned in a gas-washing scrubber tower which minimizes particle emissions into the atmosphere. The system represents a considerably lower investment cost than a conventional sheet dryer, says Valmet.