Improvements in or connected with Apparatus for Straining Paper Pulp and the like.
Year: 1893

page_text: Date of Application, 6th Apr., 1893-Accepted, 17th June, 1893
COMPLETE SPECIFICATION.
Improvements in or connected with Apparatus for Straining Paper
Pulp and the like.
I, ROBERT GIBLE HUTCHISON, of Soho Paper Mills, Wooburn, Bucks, Engineer,
do hereby declare the nature of the said 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 or connected with apparatus for
straining pulp and other similar fibrous materials used in the manufacture of paper
or otherwise; and comprises, as essential features, the formation of the strainer of
a conical shape, its disposition within the vat with its upper surface horizontal so
as to be below and level with the surface of the pulp to be strained, its suspension
within and connection with the vat in such a manner as to allow of pulsating move-
ments being given to it endwise, the various details of construction of the several
parts of the machine and the improved machine as a whole, all as hereinafter more
particularly referred to with reference to the accompanying drawings.
On the drawings ;—
Fig. 1, represents a front elevation of the apparatus, partly in section on the
line a-b, Fig. 2.
Fig. 2, represents an end elevation of the discharge end of the apparatus, partly
in section on the line c-d, Fig. 4.
Fig. 3, represents a sectional elevation of the other end of the apparatus, on the
line ef, Fig. 5.
Fig. 4, represents a plan of the apparatus, taken as at right angles to the axis of
the strainer.
Fig. 5, represents a partial sectional elevation on the line g-h, Fig. 4.
Fig. 6, represents a sectional elevation on the line i-j, Fig. 5. and,-
Fig. 7, represents a sectional plan of the strainer on the line k-1, Fig. 6.
The improved strainer is made of a conical formation, with a tubular centre 8,
having a flat diametrical horizontally-disposed midfeather 9, extending for its
whole length, so as to divide its interior into upper and lower half-parts vide Fig. 6.
At the smaller end of the strainer is cast entire with the tabular centre 8, a closed
conical flange 10, of the inner diameter of this end of the strainer, and at the larger
or outlet end of the strainer are rivetted, as at 11, Fig. 7, to the midfeather 9, two
half-parts of a concentric conical ring 12, of the inner diameter of this end of the
strainer, and at an intermediate part of the strainer are also rivetted, as at 13,
Figs. 6 and 7, to the midfeather, two half-parts of a concentric conical ring 14, of
the inner diameter of such part of the strainer, and to the outer circumferences of
said flange 10, and rings 12, 14, are screwed, as at 15, or otherwise suitably secured,
four semi-conical strainer-plates 16, perforated with closely adjacent fine slits 17,
(not otherwise represented on the drawings than in section in Figs. 5. and 7. on
account of their fineness) running longitudinally of the strainer, the fineness of the
slits being regulated by the class of fibre intended to be dealt with in the
machine.
The conical strainer thus formed is mounted on a through shaft 18, abutting
against a collar 19, at the smaller end and being secured by a cottar 20, at the
outlet end, vide Figs. 5 and 7.
The strainer and its carrying shaft are mounted within a vat 21, at an inclination,
vide Fig. 5, with the upper surface of the strainer horizontally-disposed, being
parallel with and below the surface of the pulp, the level of which latter is
represented by the dotted line m, in Figs. 5, and 6. and in such a manner that both

page_text: the shaft and strainer can receive continuous rapid pulsating movements end wise
and in a vertical plane communicated by suitable actuating mechanism.
To such end or purpose, each end of the shaft 18, is pivotally connected in a
readily separable manner, as at 22, Figs. 1, 2, 3 and 5, to a link 23, suspended
from an adjustable centre-pin 24, each such pin being supported by a volute
spring 25, and provided with set nuts 26, by which it can be adjusted and set as
may be required, the spring at the smaller end of the strainer being supported by
a bracket 27, cast on the vat, and that at the outlet end of the strainer being
supported by a bracket 27*, projecting from an outlet casting 28, bolted to such
end of the strainer.
The vat is made of a shape conformable as regards its lower part with the shape
and disposition of the strainer and each of its ends is made with an opening 29,
(ride Fig. 5.) somewhat larger than the adjacent end of the strainer so as to permit
of the latter swinging freely therethrough and of its receiving the desired combined
endwise and vertical pulsations, and to the same end or purpose as regards the
corresponding movements of the adjacent projecting end of the shaft 18, the outlet
casting 28, is also made with an opening 30, somewhat larger than such end of the
shaft.
The openings 29, 30, are respectively closed by rubber diaphragms 31, 32,
respectively secured to the adjacent parts by rings 33, holted thereto, as at 34,
Figs. 2, 3 and 5, and by the bolting of the casting 28, to the adjacent end of the
vat, as at 35.
The aforesaid combined end wise and vertical pulsating movements of the strainer
are effected from a driving shaft 36, which is formed or fitted with an eccentric 37,
and is provided with fast and loose pulleys 38, 39, and with a fly-wheel 40, for
ensuring regularity of the motion, and is supported by bearings 41, bolted to a
stool-bracket 42, which also carries the adjacent end of the vat, vide Figs. 1,
3, and 5.
The throw of the eccentric is preferably between about one-eighth to about one
quarter of an inch, and about 700 revolutions are made per minute. By such
means, steady, continuous, rapid, combined end wise and vertical pulsating
movements are imparted to the strainer, the vertical movements being accom-
nodated by the volute springs 25, and also by the give-and-take of the elastic
diaphragms 31, 32, which latter also, together with the linked connections 23, of
the shaft 18, accommodate and permit of the end wise reciprocations of the shaft and
strainer.
The outlet end of the vat is closed by the casting 28, which is made with an
outlet 43, to which all the strained pulp gravitates, as will be seen on reference
being had to Fig. 5. The outlet 43, is connected with a conduit 44, leading to the
service or regulating box 45, and supported on a sole-plate 46.
The casting 28, is also formed with two hand-holes 47, at the end, and with two
others at the top, each thereof being closed by a cover 48, secured by a screw 49,
engaging with a bridge-piece 50, hinged to the casting, as at 51; the arrangement
being such as to permit of the ready removal of the covers when required to
wash out and clean the interior of the strainer, and of the ready replacement
thereof.
The outlet end of the vat is supported by a stool 52, and at its lowest point is
connected with a pipe 53, serving to drain off the refuse and unprepared pulp, fibre
or material that will not pass through the strainer.
The pipe 53, is provided with two cocks 54, 55 the former of which can be used
when washing out the vat, and the latter of which can be used when the strainer is in
operation for leading the discharge to an auxiliary apparatus where it can be again
utilized.
When the apparatus is in operation, the combined endwise and vertical pulsations
imparted to the strainer submerged in the pulp produce a powerful vacuous
tendency within the strainer, effective in causing the pulp to stream through its
straining slits into its interior and into the outlet casting 28, finding its level therein

page_text: according to the height of the regulating sluice 56, of the service-box, and escaping
to the latter in a regular discharge of strained and finished pulp ready for the paper
making machine.
The regulating sluice of the service-box is always kept lower than the level of
the pulp in the vat so as to create the necessary fall and the vat is kept continuously
supplied with pulp so as to keep up the required head.
The inclined disposition of the bottom of the vat tends to produce a natural
gravitation of the pulp to the outlet, and the inclined disposition of the conical
strainer with its top surface horizontal disposes all the taper thereof towards the
lower part where the density of the pulp is the greatest, and the peculiar endwise
motion imparted to the strainer causes it to present an acting surface inclined to and
acting against the flow of the pulp in contra-distinction to the slipping motion of
cylindrical strainers reciprocating in arcs coincident with their radii as hitherto
used. This peculiar motion of the strainer is also effective in automatically keeping
its outside perfectly clean and free from all choking or clogging in the slits,
which is a defect inherent to such cylindrical strainers.
As modifications of the foregoing, I may impart to the inclined conical strainer a
combined endway and lateral motion or simply a reciprocating end way motion; or
I may arrange it with its axis at a greater or less inclination than aforesaid or
horizontally-disposed and may then impart to it any of the motions aforesaid; or I
may arrange it in a surrounding vat with its axis vertically disposed and without its
linked connections and may then impart to it a vertically reciprocating endway
motion or a conical motion about its bottom as a centre.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is ;-
In apparatus for straining pulp and other similar fibrous materials :-
1. The formation of the strainer of a conical shape.
2. The formation of the strainer of a conical shape of the construction herein-
before described.
3. The combination with a vat of an inclined conical strainer.
4. The combination with a vat of an inclined conical strainer of the construction
hereinbefore described.
5. The combination with a vat of an inclined conical strainer so suspended in and
connected with the vat as to allow of pulsating endway or analogous movements
being given thereto.
6. The combination with a vat of an inclined conical strainer suspended in and
connected with the vat as hereinbefore described.
7. The combination with a vat of an inclined conical strainer so suspended in
and connected with the vat as to allow of pulsating endway or analogous
movements being given thereto and of means of imparting such movements.
8. The combination with a vat of an inclined conical strainer suspended in and
counected with the vat as hereinbefore described and of the means herein before
described of imparting end way or analogous movements to the strainer.
9. The combination with an open ended vat of the outlet casting 28, adapted as
hereinbefore described, and of the conduit 44, leading to the service box.
10. The combination with an incline-bottomed vat of the discharge devices 53, 54,
and 55.
11. The improved pulp-straining machine hereinbefore described with reference
to the accompanying drawings.
12. The several modifications hereinbefore set forth.
Dated this 07th dow of Mach 1902
DAY, DAVIES & HUNT,
321, High Holborn, London, W.C., Agents for the Applicant.