Apparatus for washing fibrous material

Abstract

Abstract APPARATUS FOR WASHING A FIBROUS, CELLULOSIC MATERIAL SUSPENDED IN A LIQUID COMPRISES A DRUM HAVING A SHELL PERVIOUS TO THE SUSPENSION LIQUID AND SUBSTANTIALLY NONPERVIOUS TO THE FIBROUS MATERIAL, A MEMBER DEFINING A WEBFORMING ZONE ALONG THE PORTION OF THE DRUM, A LIQUID PERVIOUS MEMBER DEFINING A WASHING ZONE ALONG A SECOND PORTION OF THE SHELL AND A FLEXIBLE FORAMINOUS BELT TRAINED AROUND THE DRUM WITHIN THE MEMBERS AND MOUNTED FOR MOVEMENT WITH THE DUM SURFACE. THE SUSPENSION LIQUID IS INTRODUCED AT THE UPSTREAM END OF THE WEB-FORMING ZONE BETWEEN THE FORAMINOUS BELT AND THE DRUM SURFACE. THE MEMBER DEFINING THE WEB-FORMING ZONE IS FORMED AND POSITIONED SUCH THAT THE WEB-FORMING ZONE IS TAPERED IN THE DIRECTION OF ROTATION OF THE DRUM, AND THUS UNDER THE INFLUENCE OF THE PRESSURE SUPPLY OF THE SUSPENSION, THE FIBROUS MATERIAL IS DRAINED INWARDLY THROUGH THE SHELL AND A WEB IS FORMED ON THE DRUM SURFACE. WASH LIQUID IS SUPPLIED UNDER PRESSURE FROM OUTSIDE THE LIQUID PERVIOUS MEMBER DEFINING THE WASHING ZONE AND DISPLACES SUSPENSION LIQUID FROM THE WEB. THE LIQUIDS EXPRESSED AND DISPLACED FROM THE WEB ARE CONDUCTED AWAY FROM INSIDE THE DRUM. THE LIQUID PERVIOUS MEMBER DEFINING THE WASHING ZONE IS SO FORMED AND POSITIONED RELATIVE TO THE DRUM SURFACE THAT THE THICKNESS OF THE WEB IS MAINTAINED AT ALL POINTS THROUGHOUT THE WASHING ZONE AT A VALUE NOT GREATER THAN THE THICKNESS OF THE WEB AT ANY POINT IN THE WEB FORMING ZONE. CONSEQUENTLY, THE FIBROUS MATERIAL IS NOT ALLOWED TO EXPAND IN THE WASHING ZONE. THE APPARATUS ALSO COMPRISES A PRESS ROLL DOWNSTREAM OF THE WASHING ZONE FOR DEWATERING THE WEB AND A DEVICE FOR REMOVING THE WEB FROM THE APPARATUS.

Inventors

• 👤 Gosta Ingemar Ingermarsson

Bibliographic Details