PM White Water treatment at Metsa-Serla Kirkniemi Mill in Finland

摘要

During 1996 an ultrafiltration system was installed at a pulp and paper mill in Finland. The purpose was to recycle a larger amount of PM-water and thereby reduce the eater consumption in papermaking. The paper machine produces fine paper with a capacity fo approx.300 000 ton/year. The installation consists of 9 ultrafilter units which prodcues 200-250 m sup 3/h water free of colloidal matter. The treated water is used in different positions around the paper machine, such as dilution waters and shower waters. A continuous volume flow of the PM water is cleaned by ultrafiltration in order to reduce the colloidal disturbing matter in the water loops. WIth these means the consumption of water has been brought down to 8-10 m sup 3/ton uncoated paper. The operational experinnece of the ultrafilter system has been very good. A high oeprability conbined with long membrane lifetime and low fouling efects have together resulted in low oeprational costs. Expressed in relation to capacity the operational costs for the system is below USD 0.2/m sup 3. During 1999 steps and research towards further closure of hte Metsa-Serta, Kirkniemi mill will be taken.