Content area
Full Text
Sunds Defibrator and VAI (Voest Alpine Industrieanlagenbau) have recently joined Beloit Fiber Systems in the installation of a new generation of batch digester pulping systems that extend and maximize delignification in the cooking vessels.
VAI's new process, Enerbatch, entered the batch pulping arena with a March startup at the Nettingsdorf integrated kraft-liner and semichemical fluting mill in upper Austria, close to Linz. Sunds' SuperBatch process was inaugurated last December by Europe's newest pulp producer, Enocell's bleached kraft market pulp mill on Enso-Gutzeit's old Uimaharju mill site in Finnish Karelia. Finland is where extended batch delignification technology began, when Beloit initiated its Rapid Displacement Heating (RDH) system at Jutseno Pulp's mill in 1985.
NETTINGSDORF ENERBATCH SYSTEM. The Nettingsdorf startup is the culmination of an OS 1,800-million ($158-million) investment program called Nettingsdorf 2000, begun in 1987-88 (PPI, Mar. 1993, p. 32). Nettingsdorf director Gerhard Puschmann says that environmental protection was the decisive factor in the investment decision, anticipating future legislation as well as meeting existing limits.
The fiberline is one of the last steps in the remodeling program. Until this year, the mill operated with two lines before one was shut down. Pulp mill and energy manager Ferdinand Fuhrmann says that Nettingsdorf spent approximately three years investigating process alternatives for the new line, visiting reference mills and suppliers throughout the world.
With existing boilers limiting steam capacity, continuous pulping was the least favored option, so a choice was made among the new batch processes. Impregnation with an excess of chemicals, quick heating and cooling by liquor exchange, and cold blowing by pumping are the essential steps of this kraft pulping technology.
Fiberline layout includes a tank farm consisting of three black liquor tanks at different temperatures (170deg, 150deg, and 120degC), a white-liquor...