Solid material comminution or disintegration – Apparatus – With separation or classification of material
Patent
1989-01-23
1990-09-11
Rosenbaum, Mark
Solid material comminution or disintegration
Apparatus
With separation or classification of material
241 893, 2412591, 2412611, B02C 1900
Patent
active
049555499
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
This invention relates to an apparatus for treating fibre suspensions by screening (centrifugal screening) and fibre-separating mechanical working (refining), for example in water, air or steam, for the manufacture of papermaking pulp. The treatment has the object to clean the suspension by screening of enclosed coarse particles, as for example fibres not sufficiently separated, fibre bundles (shives), and to subject the coarse fraction to a fibre-separating mechanical treatment, by which this fraction is converted to dimensions acceptable in the cleaned fraction.
The present state of art has solved the screening problem by using separate screening devices and connected thereto separate devices for the treatment of the separated coarse reject fraction. This combination, however, involves the problem that available screening devices require for optimum function a very low fibre/water concentration (normally 1-4%), while the beating devices require for optimum development of strength and quality a much higher concentration (normally 10-30%). This necessitates expensive dewatering devices between screening and reject treatment and consequently much space-requiring storage containers and extensive pump work.
SUMMARY OF THE INVENTION
The present invention eliminates these problems by combining the screening device with the refining device, which during the passage of the fibre suspension over the screen surface continuously carries out an adjustable selective refining work on the coarse fibre fraction thereby separated.
The invention, thus, renders it possible that the fibre suspension can be processed further without fibres already sufficiently treated being subjected to additional undesirable energy-requiring treatment, and that at the same time the fibre concentration in the refining/screening device can be maintained at a high level and thereby permits optimum strength-increasing treatment of separated coarse fibre bundles (reject).
By carrying out the mechanical treatment on the inside of a cylindric or conic rotation body at relatively high rotation speed and by utilizing the intensive fluidization resulting from the refining of the reject, while at the same time the centrifugal force generated at the rotation acts substantially in perpendicular direction to apertures or slits in the screen/refining surface, the screening can be performed effectively at the higher concentration required for optimum effective treatment of the separated fraction (reject).
By using an apparatus according to the invention, the treatment can be carried out in direct connection to a so-called thermomechanical pulp manufacture where the fibre pulp produced is obtained in steam suspension. The fibre suspension can be screened and processed in steam phase at concentrations up to those resulting from the pulp manufacturing process (50% or higher).
This processing can also suitably be combined with an additional final treatment of the entire pulp flow for increasing the strength and quality, whereby fibres completely worked during the refining continuously are discharged as accept. According to the invention, the requirement of separate screening systems and separate reject treatment, including dewatering devices, storage containers with pumps and piping etc., is entirely eliminated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following, some embodiments of the invention are described in greater detail, with reference to the accompanying drawings, in which
FIG. 1 is an axial cross-section of the apparatus,
FIG. 2 is a radial cross-section of the apparatus,
FIGS. 3-6 show different embodiments and combination of refining/screening surface and rotor device,
FIG. 7 is an axial cross-section of a different embodiment.
DETAILED DESCRIPTION
A refining/screening device according to the invention comprises a rotor 10 supported on a shaft 12, which is mounted rotatably in a bearing housing 14. Said bearing housing is axially displaceable by means of a piston 16 attached thereon, which piston is enclosed by
REFERENCES:
patent: 1939747 (1933-12-01), Wiener
patent: 2741954 (1956-04-01), Allibe
patent: 2980350 (1961-04-01), Lejeune
patent: 3790092 (1974-02-01), Reinhall
patent: 4283016 (1981-08-01), Reinhall
Rosenbaum Mark
Sunds Defibrator Aktiebolag
LandOfFree
Apparatus for treatment of fibre suspensions does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus for treatment of fibre suspensions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus for treatment of fibre suspensions will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1179175