Improvements in Paper Pulp Strainers or Knotters.
Year: 1892

page_text: Date of Application, 15th July, 1892
Complete Specification Left, 15th Dec., 1892-Accepted, 11th Feb., 1893
PROVISIONAL SPECIFICATION.
Improvements in Paper Pulp Strainers or Knotters.
I, WILLIAM UMPHERSTON of 83 Bonnington Road, Leith, in the County of
Midlothian, Engineer, (a communication to me from abroad by Edward W. Goodrich
of Appleton, Wisconsin, U.S.A. Engineer), do hereby declare the nature of this
invention to be as follows:-
This invention relates to improvements in paper pulp strainers or knotters.
The machine is preferably supported upon suitable legs rigidly bolted down to
the floor. A vat having a curved bottom and lateral wings is mounted upon the
legs and a stock hopper is secured to the wings and edges of the vat by any suitable
fastenings, such as bolts.
A series of rotary disks are located within and are fixed
to a horizontal drive shaft which passes through packing boxes in the sides of the
vat and rotates in bearings. The vat is divided into several compartments of equal
size, formed by the longitudinal partitions which extends transversely to the axis
of the disks and also by a transverse vertical partition extending parallel with the
drive shaft, and hence the axis of the disks. This vertical partition is provided
with openings in which the disks revolve, as little space as possible being left
between the edges of the partition and the disks in order to insure tightness and
cut off as much communication as possible between the compartments. Four disks
and eight compartments (or other numbers of disks and compartments may be used)
the disks being so arranged relative to the compartment that each compartment
will contain half a disk for the purpose which will be presently described.
The hopper is provided with the usual horizontal screen. A vertical partition
is placed within the hopper at a point between the outlet pipe and vat. and the
lower part of this partition is provided with a recess. Interposed between this
partition and the outlet is a low inclined partition, against which the out-flowing
material strikes before descending into the pipe.
All of the disks are constructed alike and each are provided with a curved or
arc-shaped internal passage, one end of which commences at the vertical side of
the disk between the axis of the disk and its periphery and at a point nearer to the
axis than the periphery, while the opposite end of the passage terminates at the
periphery and diametrically opposite the axis of the disk. This outlet slopes
gradually into the periphery of the disk; and it will be seen that the receiving end
of the passage will be within one compartment, while the discharge-opening is
within another compartment, for the purpose of drawing the fluid from one com-
partment and discharging it in the other when the disks are rotating.
The disks are so arranged on the drive-shaft that one half the number will be
discharging upon one side of the vertical partition, while the other half of the
number are discharging upon the opposite side. The purpose of these rotary disks
and their curved passages is to set up active currents in the fluid in the vat, thereby
agitating the stock or material as it lands upon the strainer and keeping the latter
clear and free from clogging.
When in operation the disks revolve rapidly and the fluid mass of material in the
vat is made to enter the receiving end of the passage and by centrifugal force is
discharged with great force at the periphery of the wheel through the openings.
In this operation each disk acts independently of the other and, as previously
stated, the fluid enters the disk from one compartment and is discharged into the
opposite compartment, this action taking place alternately as the receiving end of
the passage moves from one side of the vertical partition to the other side.
When the disks are revolving at the rate of 500 revolutions a minute the fluid
lischarges from their peripheries with great force, thereby causing such a pulsation

page_text: of internal currents that the paper stock is violently agitated and drawn through
the strainer, and discharged at one end of the hopper, through the recess over the
sloping partition and out of the pipe. By this all knots, dirt and extraneous
matter are caught on the top of the strainer, from which it can be readily removed
from time to time by an attendent.
Dated this 11th day of Jul 1805
JOHNSONS,
115, St. Vincent, Street, Glasgow, Petitioner's Agents.
COMPLETE SPECIFICATION.
Improvements in Paper Pulp Strainers or Knotters.
I, WILLIAM UMPHERSTON of 83, Bonnington Road, Leith in the County of
Midlothian, North Britain, Engineer, (a communication to me from abroad by
Edward W. Goodrich of Appleton, Wisconsin, United States of America,
Engineer), do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement:-
This invention which relates to improvements in paper pulp strainers or knotters
consists as follows, and as is illustrated in the accompanying drawings.
Figure 1 is a longitudinal section.
Figure 2 a plan with the cut plates or screen removed, and
Figure 3 a cross section of a pulp strainer or knotter constructed in accordance
with my said invention.
Referring to the said drawings I support the whole machine on legs or
standards a which are rigidly bolted at their lower ends to the floor. The machine
itself consisting of the vat A which is divided into two compartments (au upper
and a lower) by means of the cut plates B through which the pulp is strained;
the said plates B thus forming the screen upon the surface of which the pulp
kept in a state of tremulous agitation so as to enable it to pass through as herein-
after described.
The lower compartments of the vat A under the screen B, is divided into a
number of compartments by means of the cross partitions C, and each of these
compartments is again subdivided by the longitudinal central partitions D. In
each of these central partitions D, there is an oblong opening d corresponding to
the diameter and breadth of the drums E but slightly larger so that the drums
may revolve clear of the edges of said openings d. The shaft F upon which the
drums E are mounted passes through and clear of the cross partitions C, and
extends through the stuffing boxes G, provided at each end of the vat A, as shown.
The ends of said shaft F being carried by the outer bearings H; upon one of the
said ends I key or otherwise mount the driving pulley J which is of such a size as
to permit of the drums being driven at a high speed.
The drums E are constructed as hollow drums having an opening L on each side
near the shaft F, and one opening M in the periphery diametrically opposite to the
openings L in the sides. Between the holes L and M is an internal curved
passage N formed within the drum so as to permit of the pulp flowing from the
inlet holes L to the discharge holes M when the drums are revolving. The flow
of the pulp through the said drums E is constant but as the inlet openings L, and
the discharge openings M in each drum are diametrically opposite to each other;
and each of the compartments formed by the partition C being again divided by
the partitions D, the. pulp is caused to flow alternately from the one small
compartment into the other, through the passage N in each drum during each
revolution; thus producing the tremulous agitation of the pulp upon the face of
cut plates or screen B, required to facilitate the passage of the pulp through them,
so as to leave all knots, dirt and extraneous matter on the top of the screen B and
from which it can be readily removed from time to time by the attendant.
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page_text: The drums E are arranged and fixed on the shaft F in such a manner that one
half of them may be discharging the pulp towards one side of the vat, when the
other half are discharging towards the opposite side of the vat, thus balancing the
drums in their work, and so causing the action upon the plates or screen B to be
equally distributed over the whole of the surface, I also provide sufficient room
below each drum E as to allow of the pulp to pass from the one compartment into
the adjacent compartment, from whence it passes from both compartments through
the outlet openings P into an outside collecting box Q and from said box Q to the
paper making machine or otherwise.
"Per
may if desired use any number of druins and compartments in lieu of six as
shown.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
(1) In a pulp screen, a vat provided with one or more rotary disks, each disk
being provided with an internal passage receiving at the vertical sides of the disk
and discharging at its periphery in the manner and for the purpose specified.
(2) In a pulp screen, a vat provided with a rotary disk having an internal arc-
shaped passage eccentric to receive at the side and discharge at the periphery of
the disk in the manner and for the purpose set forth.
(3) In a pulp screen a disk provided with an open internal eccentric passage
discharging at the periphery as and for the purpose set forth.
(4) In a pulp screen a rotary disk located in a vat and provided with an internal
passage in combination with a vertical partition fitting around the disk and forming
separate compartments upon opposite sides thereof, said passages being adapted to
extend from one compartment to the other as and for the purpose specified.
(5) The combination with a screen and vat containing compartments, of a rotary
disk having its opposite sides revolving in the compartments and provided with a
fluid passage extending through the disk from one compartment to the other, in the
manner and for the purpose substantially as described.
(6) In a pulp screen, the combination of a vat, hopper, and screen, a horizontal
rotary shaft carrying disks provided with arc-shaped eccentric passages receiving
at. the sides of the disks and discharging at the periphery, and one or more
vertical partitions dividing the vat into compartments in the manner and for
purpose substantially as set forth.
(7) In a pulp screen the combination of the vat, a screen and hopper above the
vat, a horizontal shaft extending through the vat, a vertical partition, and a series
of disks diametrically embraced by the partition, said disks being provided with
arc-shaped open passages extending from one compartment to the other, as and for
the purposes described.
Dated this 14th day of December 1800
JOHNSONS,
115, St. Vincent Street, Glasgow, Applicant's Agents.