CA1077861A

CA1077861A - Rotary filter for concentrating fibre suspensions

Info

Publication number: CA1077861A
Application number: CA253,456A
Authority: CA
Inventors: Bjarne I. Nilsson
Original assignee: NILSSON HARRY WILHELM
Current assignee: NILSSON HARRY WILHELM
Priority date: 1976-05-27
Filing date: 1976-05-27
Publication date: 1980-05-20

Abstract

ABSTRACT

A rotary filter for concentrating fibre suspensions com-prises annular disks mounted in parallel and spaced from each other on a motor-driven drum having a lattice-shaped cylindrical wall, said drum being journalled in a vessel for liquid to be filtrated. Each filter disk is composed of sector-shaped filter boxes having at least two opposite filter walls and connected to outlet conduits included in said lattice-shaped wall of the drum. Further, a collecting hopper is stationary inserted in the drum to collect concentrated pulp falling down through the lattice--shaped drum wall from the filter surfaces at the moment being in their uppermost positions.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A rotary filter for concentrating fibre suspensions, comprising a plurality of annular disks formed of sector-shaped filter boxes and mounted in parallel to each other and in spaced relationship on a common shaft which is journalled in a vessel for liquid to be filtered, means for rotating the shaft, each of said filter boxes having at least two opposite walls made of filter cloth, and an outlet opening for filtrate at the inner end of each filter box, each said outlet opening communicating with a longitudinal outlet tube in the shaft, characterized in that said shaft is a drum having a cylindrical lattice wall in which said longitudinal outlet tubes are included spaced peripherally, and in that a collecting hopper carried by a stationary support outside the drum is introduced through an open end of the drum in such a way that its inlet opening is turned upwards within the uppermost portion of the cavity of the drum, said inlet opening extending along all filter disks carried by the drum to receive concentrated pulp falling down through the lattice wall of the drum from those filter surfaces at the moment being in their uppermost positions above the liquid level during the rotation of the drum.

2. A rotary filter as claimed in claim 1, in which the collecting hopper has a chute-like bottom portion containing a motor-driven feed screw.

3. A rotary filter as claimed in claim 1, in which each filter box has its inner end connected to a short tube extending peripherally in the cylindrical wall of the drum and having one of its ends in communcation with an adjacent longitudinal outlet tube.

4. A rotary filter as claimed in claim 2, in which, at one end of the drum, the longitudinal outlet tubes are connected to tubes extending radially inwards and having their inner ends in communication with a locking device for locking out filtrate from said filter boxes.

5. A rotary filter as claimed in claim 1, in which the vessel has a semi-cylindrical bottom surrounding the lower parts of the filter disks with only a little clearance scrapers arranged to sweep along said bottom being mounted at the outer peripheray of the filter disks.

6. A rotary filter as claimed in claim 1, in which agitator blades directed radially are present in the spaces between the outer portions of the filter disks.