Improvements in Pulp Strainers of Paper Making Machines and the like,
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in Pulp Strainers of Paper Making Machines
and the like,
I, ALEXANDER LAWRENCE WESTWOOD, 5, Easter Road, Edinburgh, N.B., Consulting
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in pulp strainers of paper making machines
and the like and consists essentially in imparting a rotary or a two and fro motion to
the strainer plates of the class of strainers in which the plates are ordinarily fixed in a
horizontal position, whereby the working surface of the plates is moved under the
wash of the pulp flowing on to be strained and thereby kept clear of refuse matter
which is discharged to the edges of the plates and into a channel.
In carrying out the invention the strainer is preferably circular and the plates are
fixed in a frame which rotates about a vertical or inclined axis in a vat and is formed
with a refuse channel at the periphery of the plates, the vat being supported by
upright standards. The said plate carrying frame is supported by a vertical spindle
which is rotated by any convenient gearing from below such as by the same
horizontal shaft which operates the pulsated diaphragm which diaphragm may be of
the ordinary kind but made to suit the particular formation of my strainer. The
said shaft has a small pulley keyed upon it which pulley drives a larger pulley
immediately above it by means of a driving belt. The said pulley operating a worm
which is engaged with a worm wheel keyed upon the spindle. The said gearing
being for the purpose of reducing the speed from the diaphragm shaft. I may
employ two diaphragm acting rods one at each side of the rotating spindle. The
refuse from the channel at the periphery of the plate frame may be discharged in
any convenient manner for example may have a series of discharge pipes under-
neath the strainer plates the said pipes leading from the channel to a hollow in the
rotating spindle; the refuse being discharged through openings in the rotating
spindle at a point below the vat. The strainer plate may be conveniently divided
into say six segmental portions and there may be a corresponding number of refuse
discharging pipes.
The strained pulp may be led away in any convenient manner such as from a
cupped portion of the discharge pipe, formed around the rotating spindle, the
stuffing box for the rotating spindle being made at the bottom of the said discharge
recess. The diaphragm forming the bottom of the vat may be somewhat dish shaped
in order to induce the strained pulp towards the discharge orifice and similarly the
discharge pipes for the refuse may be correspondingly inclined towards the hollow of
the rotating spindle.
The diaphragm may extend over the whole of the bottom of the vat and.the said.
diaphragm may consist of a metallic ring, the inner periphery of which is connected
to the cupped shaped portion of the strained pulp discharge pipe through the medium
of an india-rubber or other ring; the outer periphery of the diaphragm ring being
elastically connected to the inner periphery of the vat in assimilar manner.
* "

page_text: As a modification the discharge for the strained pulp may be at the periphery or
side of the vat.
The mouth of the in-flowing pipe of the pulp to be strained, may be of such a
width as to cause a wide flow of pulp on to the strainer plates or the said discharge
mouth may be divided into two, three or more contracted mouths.
As the pulp rushes on to the plates between the centre of their rotating axis and
their periphery and against the direction of the rotation of the plates, the refuse
already on the plates is arrested by the flow and diverted to the periphery of the
plates and into the discharge channel.
In lieu of a continuous rotation of the plates, the motion may be intermittent that
is to say I may give the plates a motion say in one direction and then a motion in say
an opposite direction.
In lieu of the pulp shute or shutes being stationary they may be made to move by
any convenient mechanism for example they may be made to rotate directly or
indirectly from the same spindle which rotates the plates; or any other motion may
be given to the shute or shutes, for example a. to and fro motion may be given to
them for the purpose of causing the flow of pulp to more or less completely wash or
cleanse the whole surface of the plates whereby the refuse is caused to move from off
the working surface.
Or the plates may be stationary whilst the shute or shutes are moved over the
plates such as by causing the shute or shutes to revolve by means of a similar spindle
to that described for revolving the plates. In this case the pulp may be supplied
from overhead into a basin or cup which forms the centre of the shute with radiating
channelled arms for the delivery of the pulp; the pulp being delivered from the ends
of the arms of the shute or it may be delivered out from the side of the arm or arms,
so that the rush of the pulp more or less completely washes or cleanses the whole
surface of the plates.
Under all the various modifications of my said invention the essential feature is
the same namely to produce a machine which both strains the pulp and washes or
cleanses the plates in a continuous action so as to at once get rid of the impurities.
and give a cleaner pulp as well as a more regular discharge from the machine.
Dotad this 4th day of March 1807
Improvements in Pulp Strainers of Paper Making Machines
and the like.
I, ALEXANDER LAWRENCE WESTWOOD, 5, Easter Road, Edinburgh, N.B., Consulting
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 relates to improvements in pulp strainers of paper making machines
and the like and consists essentially in imparting a rotary or a to and fro motion to
the strainer plates of the class of strainers in which the plates are ordinarily fixed in-
a horizontal position whereby the working surface of the plates is moved under the.
wash of the pulp flowing on to be strained and thereby kept clear of refuse matter
which is dicharged to the edges of the plates and into a channel.
And in order that my said invention and the manner of performing same may be
properly understood I have hereunto appended a sheet of explanatory drawings in
which the same reference letters are used to indicate like parts in the several figures
where shewn.
°

page_text: Figure 1, is a side elevation and Fig. 2 a sectional elevation at right angles to
Fig. 1 and Fig. 3 is a plan of my invention. Figure 4 is a sectional elevation and
Fig. 5 is a part plan, of a modification of my invention.
In carrying out the invention the strainer is preferably circular Figs. 1, 2 and 3
and the plates A are fixed in a frame B which rotates about a vertical or slightly
inclined axis in a vat C and is formed with a refuse channel D at the periphery of the
plates: The vat C being supported by upright standards E from the sole platė F.
The said plate carrying frame B is supported on the conical head of a vertical
spindle G [which admits of its being raised out of the vat for cleaning] and is rotated
by any convenient gearing from below such as by the horizontal shaft H which
operates the pulsating diaphragm. The said shaft H has a small pulley I keyed upon
it which drives a larger pulley J immediately above it by means of a driving belt K.
The pulley J operates a worm L which is engaged with a worm wheel M keyed upon
the spindle G. The plate frame B is fitted with pipes N which drain the refuse from
the channel D into the cup O at centre from which it is discharged by the pipe P
to the auxiliary strainer in the usual manner. The pulsating diaphragm Q is of cast
iron or other metal and its inner periphery is connected to the cup shaped portion of
the, strained pulp discharge pipe R through the medium of an indiarubber or other
ring, the outer periphery being elastically connected to the inner periphery of the
vat C in a similar manner. The diaphragin is supported by springs S and made to
pulsate by means of rods T fixed to it and jointed upon small-throw cranks on the
rotating shaft H in the usual manner or by cams or eccentrics as may be found most
convenient in practice. The mouth of the onflowing pipe of the pulp to be strained
(not shewn) may be of such a width as to cause a wide flow of pulp on to the strainer
plates or the said discharge mouth may be divided into two, three or more contracted
mouths. As the pulp rushes from this pipe on to the plates between the centre of their
rotating axis and their periphery and against the direction of the rotation of the
plates, the refuse already on the plates is arrested by the flow and diverted to the
periphery of the plates and into the discharge channel and pipes to auxiliary strainer.
The strained pulp is led away by the pipe R which is attached to the port in vat and
is formed with the cup shaped centre ①fitted with stuffing boxes and glands. A
regulating hox is fixed to pipe outlet as usual to regulate the level of pulp.
In lieu of a continuous rotation of the plates the motion may be intermittent,
that is to say I may give the plates a motion say in one direction and then a motion
in say an opposite direction by any convenient mechanism such as by a lever arm
attached to spindle G and actuated by a rod jointed to it and to a crank or cam on a
separate vertical spindle which spindle would be geared from H by similar gearing
to I, J, K, L, M. Or the plates A may be stationary as in Figs. 4 and 5 whilst the
shute or shutes V are moved over the plates either in continuous rotation; or any
motion may be given such as a to and fro motion as already described. In this
modification the clean pulp is discharged by the pipe R as already described and the
refuse pulp by a branch pipe (not shewn) from refuse channel in vat to auxiliary
strainer in the usual manner. In this modification the pulp is supplied from over-
head into a basin or cup U which forms the centre of the shutes and delivered from
the sides or ends or bottom of the shutes V on to the plates as may be found best in
practice, so that the rush of the pulp more or less completely washes or cleanses the
whole surface of the plates A. Under all the various modifications of my said
invention the essential feature is the same namely to both strain the pulp and wash
or cleanse the plates in a continuous action so as to at once get rid of the
impurities and give a cleaner pulp as well as a more regular discharge from the
machine.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is :-
1. In pulp strainers of paper making machines, imparting a rotary or to and fro

page_text: motion to the strainer plates, substantially in the manner as and for the purpose
herein before described and shewn in the accompanying drawings.
2. The mode of mounting the strainer plates in the vat whereby a rotary or to
and fro motion can be imparted thereto substantially as and for the purpose herein-
before described and shewn in the accompanying drawings.
3. In pulp strainers of paper making machines, the arrangement of the refuse
channel D with the pipes N whereby the refuse matter after being washed over the
edges of the strainer plates is drawn to the centre of the vat to be discharged to
the auxiliary, substantially as hereinbefore described and shewn in the accompanying
drawings.
4. In pulp strainers of paper making machines having stationary strainer plates,
mounting the pulp supply shutes over the plates and imparting a rotary or to and
fro motion to same, substantially in the manner as and for the purpose hereinbefore
described and shewn in the accompanying drawings.
5. The construction and mode of operating of the pulp supply shutes arranged in
the manner set forth, substantially as herein before described and shewn in the
accompanying drawings.
6. The general arrangement, construction and combination of parts constituting
my improvements in pulp strainers of paper making machines, substantially as
herein before described and shewn in the accompanying drawings.
Dated HIS U day of December 1891.
JOHNSONS,
Applicant's Agents, 115, St. Vincent Street, Glasgow.