IMPROVEMENTS IN PULP STRAINERS
Year: 1874

page_text: LETTERS PATENT to William Edward Newton, of the Office for
Patents, 66, Chancery Lane, in the County of Middlesex, Civil
Engineer, for the Invention of "IMPROVEMENTS IN PULP STRAINERS."-
-
A communication from abroad by Alfred Andouard, of Paris, in
the Republic of France.

page_text: to remove from the useful pulp before the latter can be made into paper.
Various mechanical devices have been proposed from time to time, and
have been used for this purpose, but it is found in practice that the
straining or filtering surfaces soon become clogged up and the straining
operation therefore proceeds very slowly until the extraneous matters
are removed. This periodical and frequent cleansing of the pulp strainer
occasions a very considerable loss of time.
The object of the present Invention is so to construct and operate the
pulp strainer that its action may be continuous and that the cleansing of
the filtering surface may be effected automatically and while the appa-
ratus is in use.
The improved apparatus consists of a large brass cylinder which may
be made of one casting, or it may be constructed in sections or segments
properly bolted or secured together. The entire surface of this cylinder
is covered with long narrow slits which may run longitudinally or
parallel with the axis of the cylinder, or they may be formed round the
circumference of the cylinder. In whichever way these slits may be
made in the surface of the cylinder it is necessary that they should be
narrow inside the cylinder and be widened out on the outside, so that
the fine pulp when it passes through the narrow slits on the inside may
get away easily from the outside of the cylinder and fall into the tank
or reservoir provided to receive it.
The unstrained pulp is supplied to the cylinder at each end through
openings provided for the purpose, and a slow rotary motion is imparted
to the cylinder by means of any suitable gearing so that the straining
surfaces may be constantly changing. A short, sharp, jerking motion is
also given to the cylinder in order to keep the pulp in agitation and
assist it in passing through the straining or filtering surface. Imme-
diately above the cylinder is placed a perforated metal pipe, to which
water is supplied under pressure, and as it issues from the perforations
in the pipe it is thrown in small jets on to the cylinder and will wash
out from the narrow slits of the straining surface any knots, lumps,
strings, and other extraneous matters which cannot pass through the
narrow slits but will adhere thereto until they are removed by extraneous
means. Inside the cylinder, and immediately below the perforated
water pipe is suspended an inclined trough into which the knots and
other matters which (when they are washed out of the straining slits)

page_text: will fall and will be conducted out of the apparatus. The fine pulp
when it passes through the strainer falls into a tank below, where it is
kept in motion by an agitator, and is conducted from thence to the
paper-making machine. This tank will require to be cleaned out
occasionally, and to facilitate this operation the straining cylinder is
supported in a moveable frame or in a pair of arms or levers which are
mounted on hinges or pins so that the cylinder with its appendages may
be lifted up and turned back out of the way temporarily while the tank
is being cleaned out.
From the above explanation it will be understood that the action of
the strainer is continuous, and that as the cleansing of the filtering
surfaces is effected while the cylinder is in motion there will be no loss
of time arising from the necessity to stop the machine while the
surfaces are being cleansed.
5 SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Edward Newton in the Great Seal Patent
Office on the 12th December 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
EDWARD NEWTON, of the Office for Patents, 60, Chancery Lane, in the
O County of Middlesex, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twelfth day of June, in the year of
our Lord One thousand cight hundred and seventy-four, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors, give
3 and grant unto me, the said William Edward Newton, Her special
licence that I, the said William Edward Newton, my exccutors, admi-
nistrators, and assigns, or such others as I, the said William Edward
Newton, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times there-
after during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Inven-
tion for "IMPROVEMENTS IN PULP STRAINERS," being a communication to
me from abroad by Alfred Andouard, of Paris, in the Republic of

page_text: France, upon the condition (amongst others) that I, the said William
Edward Newton, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and scals, should
particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said William Edward Newton, 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, reference being had to the Drawing here-
unto annexed, and to the letters and figures marked thercon (that is
to say) :-
This Invention relates to an improved construction of pulp strainer
for separating from the pulp (used in the manufacture of paper) the
knots, strings, lumps, and other extraneous matters which it is necessary
to remove from the useful pulp before the latter can be made into paper.
Various mechanical devices have been proposed from time to time and
have been used for this purpose, but it is found in practise that the
straining or filtering surfaces soon become clogged up, and the straining
operation therefore proceeds very slowly until the extraneous matters are
removed. This periodical and frequent cleansing of the pulp strainer
occasions a very considerable loss of time.
The object of the present Invention is so to construct and operate the
pulp strainer that its action may be continuous, and that the cleansing
of the filtering surface may be effected automatically and while the
apparatus is in use.
In the accompanying Drawings Fig. 1 is a sectional elevation of a
rotating cylindrical pulp strainer constructed according to the present
Invention; Fig. 2 is a plan of the same; Fig. 3 is an end view of the
machine; Fig. 4 is a top view of the slits drawn on an enlarged scale
shewing the chamfered or wide side of the slits; and Fig. 5 is a
transverse section of a portion of the cylinder shewing the form of the
grooves in the thickness of the metal.
It will be seen that the apparatus consists principally of a large brass
cylinder A which may be cast in one piece, or may be constructed in

page_text: sections or segments properly bolted or secured together. This cylinder
is pierced or perforated throughout its entire surface with numerous
narrow slits or grooves a (Fig. 5) which may run longitudinally or
parallel with the axis of the cylinder, or they may be formed round the
circumference of the cylinder. In whichever way these slits may be
made in the surface of the cylinder it is necessary that they should be
made narrow inside the cylinder and be widened out or chamfered as
at b, Fig. 5, on the outside, so that the fine pulp when it passes through
the narrow slits on the inside may get away casily from the outside of the
cylinder and fall into the large wooden vat or reservoir B, B, (Figures 1
and 3) which is placed there to receive it. The slits a should not exceed
one fifth millimetre in width, and are preferably made by means of
very thin saws. The chamfers are made by means of a chamfering
drill, and in order to ensure strength the slits a should have a depth of
not less than one and a half millimetres. The cylinder is provided
above and below its surface with rigid longitudinal battens t, t, to
prevent the water issuing from the pipe C from flowing over the
cylindrical surface and mixing with the pulp. A', A', are strong plates
fixed to the cylinder and supporting hollow trunnions through which the
pulp is supplied to the interior of the cylinder. Immediately above the
cylinder is placed a perforated metal pipe C; to which water is supplied
under pressure, and as the water issues from the perforations in the pipo
it is projected with force but in the form of small jets on to the cylinder,
and will thereby wash out from the narrow slits of the straining surface
any knots, lumps, strings, and other extraneous matters which cannot
pass through the narrow slits but will adhere thereto until they aro
removed by extraneous means. The pipe C is supported by small
uprights c, c¹, fixed on collars which support the cylinder. Inside the
cylinder (and immediately below the perforated water pipe C) is
suspended by stirrup shaped picces x, x, an inclined trough X divided
into two pieces and united by a joint so as to allow it to be passed into
the cylinder through the trunnion. This trough X will catch and
convey out of the apparatus at all the knots and other matters which
are washed out of the straining slits a by the jets of water from the.
pipe C. Troughs Z, Z, are placed at each end of the cylinder for the
purpose of feeding the pulp into the interior of the straining cylinder.
A wide spout or mouth V is placed at the front portion of the vat B to
convey the strained pulp to the paper-making machine.
G is the
driving pulley for communicating motion to the shaft M, which turns

page_text: in bearings m, m³, m², fixed on the brackets M', M², and on which is
keyed the bevil wheel N, and the two ratchets O and O₁. A bevil
wheel P keyed on a shaft Q mounted in bearings 7, 9, gears into the
wheel N and carries on its shaft Q a worm R, which takes into a worm
wheel » firmly fixed to the trunnion of the straining cylinder. Strong
collars or bearings F, F, Fig. 3, support the straining cylinder A, and
are jointed at f, f, to the supports f¹, f¹; arms f², ƒ³, extending from
and forming part of the collars F, F, arc provided at their extremities
with pawls or studs ƒ³, ƒ³, which rest on the ratchets O, O', the rotation
of which will communicate a short jerking motion to the straining
cylinder A. This cylinder may be raised from its place over the vat B
when required to clean the latter or for other purposes, and this is
effected simply by turning the crank handles E, E, and thereby actuating
the pinions c, e, the wheels e', e', and the second pinions e², e². These
latter gear into the teeth of the curved rack H, Fig. 3, which is held in
gear with the toothed pinion e² by. the friction roller in the bearings A².
The curved rack H is connected by the pin K to the arms of the bearings
or collars F, F", as seen best in Fig. 3, and it will be evident that by
actuating the toothed rack H by means of the gearing just described the
cylinder A will be lifted up and turned over on the pin f, Fig. 3. The
pulp is fed into the troughs Z, Z, and the perforated water pipe C being
charged with water under pressure the apparatus is ready to be set at
work. This is effected by communicating motion to the driving pulley
G on the shaft M, on which is keyed the bevil wheel N, which gears
into and drives the bevil wheel P on the shaft Q, Fig. 3. On this shaft
Q is keyed the worm R, whereby the worm wheel on the end of the
straining cylinder A is caused to rotate. At the same time the ratchet
O on the shaft M by its rotation causes the pawl f³ to drop from tooth
to tooth, and thus produce the jerking movement of the straining
cylinder, and cause the pulp to pass through the slits and fall into the
vat B, from whence it passes direct by the delivery spout or channel V,
which conducts it to the paper-making machine. The jerking motion is
very short, and does not interfere in any way with the worm R and
worm wheel r.
During these movements of the cylinder the perforated pipe C waters
the top surface of the cylinder and cleanses the slits of all extraneous
substances which together with the washing water are carried away by

page_text: delivered to the paper machine in a pure state and cleansed from knots
and extraneous substances.
Having now described this Invention of "Improvements in Pulp
Strainers," and having explained the manner of carrying the same into
effect, I wish it to be understood that I do not intend to confine myself
to the precise details herein described, inasmuch as the apparatus may
be considerably modified in some of its parts without departing from the
spirit and object of the Invention, but what I claim as secured to me by
Letters Patent aforesaid is,-
First. The rotating cylindrical pulp strainer constructed as herein set
forth so that the straining operation may be continuous.
Second. The employment of a brass cylinder pierced throughout its
entire surface, with thin slits or slots bevilled on one side in the thick-
ness of the metal and towards the exterior of the cylinder as and for the
purposes herein set forth.
Third. Communicating to the cylinder the double rotating and jerking
movements as herein set forth and for the purpose described.
Fourth. Arranging and mounting the cylinder as above described so
that it may be raised from its bed for the purpose of clearing the vat B,
as herein set forth.
Fifth. The use of the perforated tube C for the purpose of throwing
water on to the top surface of the cylinder, and thereby automatically
cleansing the slits while the apparatus is in motion and at work.
Sixth. The general construction and arrangement of the several parts
of the apparatus, as described and shewn, whether the slits, slots, or
perforations in the cylinder be arranged parallel to its axis or circum-
ferentially, both as herein set forth.
In witness whereof, I, the said William Edward Newton, have here-
unto set my hand and seal, the Fifth day of December, in the
year of our Lord One thousand eight hundred and seventy-
four.