Improvements in or Relating to Rotary Strainers for Paper Pulp and other Liquids or Materials.
Year: 1897

page_text: Date of Application, 23rd Dec., 1897
Complete Specification Left, 15th Aug., 1898-Accepted, 22nd Oct., 1898
Improvements in or Relating to Rotary Strainers for Paper Pulp and
other Liquids or Materials.
A communication from CHARLES STOREY WHEELWRIGHT, Manufacturer, of No. 1,
Keith Place, Providence, County of Providence State of Rhode Island,
United States of America.
I, ALFRED JULIUS BOULT, of 111, Hatton Garden, County of Middlesex, Char-
tered Patent Agent, do hereby declare the nature of this invention to be as
follows;
-
This invention relates to a certain new and useful improvement in straining
wheels for liquids and matters held in liquid. The invention is of great utility
in the manufacture of paper, being of great advantage and economy when used
for straining off the wash water from the pulp in paper washing machines,
and hardly less so when used for straining paper fillings mechanically held in
water. In practising the invention identically the same wheel is used for either
purpose. The wheel may also be used as a strainer for fillings for cotton cloth etc.,
and even as a filter for water used in various manufacturing purposes. Thus
where a cotton mill is located above a woollen mill on the same stream, the strain-
ing wheel may be employed to collect and hold back from the water to be used
for scouring wool the fibres of cotton that have got into the water at the cotton
mill. In the paper washing machine the strained wash water passes through
the perforations or meshes of the wheel, leaving the pulp material undisturbed,
but when the machine is used simply as a strainer of matters mechanically held
in water, only clear water or matter of considerable firmness can pass through
the perforations or meshes. The objects of the invention are to obtain as large
a straining surface as possible, to lift the wash water or other water with small
expense of power, and, where materials are washed to remove the wash water
without injury to such materials.
The straining wheel embodying the invention like the washing cylinder of
paper washing machines is hollow and is provided with internal lifting
devices which discharge the water passing into the interior of the wheel through
its meshes, whether wash water or river water or water mechanically holding
finely divided materials, into and through the discharge pipe about which it
revolves. The novelty rests largely in the application of the straining gauze
to the sides of the wheel, whereas in the washing cylinders before mentioned it
is applied to the periphery. Other novelty consists in the swelling sides of the
wheel from rim to centre thus giving a U or V shape to the radial cross section
of the wheel from centre to rim and in the shape or lines of the lifter or lifting
buckets within the wheel. Other parts of the invention consist in further
details of construction. When the invention is employed for straining water
mechanically holding finely divided materials, a single wheel in combination
with a discharge pipe will answer every need; but for washing paper pulp or

page_text: paper pulp material several of the wheels upon the same discharge pipe are used
to advantage.
For convenience, the further description of the invention and mode of operation
here following is more full and exact in reference to the use of a single wheel
than where several are used, needless repetition in the description where several
wheels revolve about a single discharge pipe being avoided. But as before stated
the wheel is the same for whatever specific purpose employed.
For clearance the application of the invention to a vat in which a single strain-
ing wheel is employed will be first and more particularly described.
Any tank of proper dimensions will answer the purpose of the vat, the vat of
a strainer for paper fillings being here described and being provided with a pipe
and a chamber through which water containing fillings to be strained enters
the main portion of the vat. Two hollow shafts are employed with bearings at
the side of the vat, the two said shafts being bolted together in order that they may
turn together under power applied to one shaft by means of a sprocket wheel
rigidly secured to said shaft. Two caps bolted to the sides of the vat are used
to hold the hollow shafts in place. A discharge pipe is provided about which
the straining wheel revolves. It is open at one end and at that end enters the
hollow revolving shaft with a closed end so that said hollow revolving shaft
turns freely about it, while at the other end which is closed it is provided with
a projection or rod which passes through a hollow projection within the other
shaft which latter shaft turning with the first shaft to which it is bolted as
aforesaid, thus turns freely about said projection. The discharge pipe is pro-
vided with a slot through which water may enter from the straining wheel, as
hereafter described and it may itself turn within the hollow shaft, but during
the operation of the straining wheel or the operation of the mechanism in which
the straining wheel is embodied is prevented from doing so, and its desired ad-
justment and consequently the desired adjustment of the slot is secured by means
of a ratchet held upon the squared end of the projection or rod, by a screw nut
and a dog pivoted to the vat. An outlet pipe is arranged to receive water flowing
through the discharge pipe and then through the hollow shaft.
The apparatus thus far described does not differ substantially from apparatus
used in machines for washing paper pulp provided with washing cylinders, ex-
cept perhaps in size and form of the vat.
It remains to describe the wheel forming the distinguishing feature of the
invention and its embodiment in proper machinery.
The straining wheel like a bicycle wheel has a narrow rim made of wood and
an extended hub or more exactly speaking a double hub consisting of two flat
rings also made of wood and again like the bicycle wheel it has two sets of spokes
diverging from the rim, and secured at their inner ends, one set to one ring and
the other set to the other ring. Wire gauze is nailed in sections on both sides
of the wheel from the rim to the hub rings and to some of the spokes the said
spokes to which the gauze is nailed being made of wood and larger and stronger
than the others for this purpose and also for the support of the rim.
A tyre
surrounds the whole. But while some of the spokes are made larger and are
preferably of wood for the purpose stated most of them are preferably strips of
thin metal bent or twisted somewhat like the arms of a common wind mill, so
that in the revolution of the wheel they tend to draw water into the interior
of the wheel or tend to throw water passing through the meshes of the wheel
towards its interior. Each metal spoke at the hub end is driven into the hub
or held in a slot in its hub while at its rim end it is secured to the rim prefer-
ably by a screw. But the twisted form common to the metal spokes is merely a
refinement of the invention. Small round metal rods would answer every pur-
pose. The spokes of the wheel as a whole prevent the wire gauze from caving
inwards.
There is thus formed a hollow basket wheel narrow at the end and increasing
in thickness or in radial cross section from the rim to the hub or centre with
6

page_text: meshes or perforation at the sides and it will readily be seen that a wheel of
this construction, whether or not provided with internal lifting devices, as next
explained, will pass through matters of density or through water containing
matters of considerable density with facility.
-
Buckets or boats are arranged within the wheel rigidly attached thereto for
lifting the wash water or other water which passes through the meshes or per-
forations of the wheel as the latter revolves and discharging the same into the
slotted discharge pipe. These buckets conform in shape largely to the construc-
tion of the above described basket wheel within which they are secured, being
narrow at the nose or the end near the rim of the wheel to which the said end
is suitably secured say by screws the said end being provided with a projecting
lip for that purpose and increasing in width or radial cross-section to the opposite
or rear end, over which as the wheel revolves the contents of the buckets are
discharged into the slot in the discharge pipe. Near the rear end of the bucket
its sides are turned at an angle so as to be parallel to the hub plates or rings
to which they are secured by screws. The general V shape of the bucket is
favourable to the easy lifting of the contents of the bucket, the heavier part of
the load being near the centre of rotation; the inclination of the lower part of the
stern or broad end of the bucket is favourable to the easy discharge of the con-
tents of the bucket into the discharge pipe through the slot and the inclined.
sides of the bucket near the bottom are favourable to the admission of water
through the sides of the wheel to fill the next succeeding bucket. This latter
provision permits the use of a greater number of buckets within the wheel than
could be used if the sides of the bucket were straight and the bottom wide and
flat.
Bolts or rods pass through flanges on the two hollow shafts and are secured
by screw nuts; they pass also through the hub plates or rings of the hollow
basket wheel and secure the same so that the wheel revolves with the shafts
to which power is communicated as before stated. It is immaterial whether or
not these bolts or rods pass through the lifting buckets.
In the application of the wheel for washing paper pulp as before stated, the
wheel itself is the same wheel that is used simply for straining matters
mechanically held in water, but in washing pulp several wheels are preferably
employed in connection with a single discharge pipe. Thus three wheels may be
Employed in connection with a single discharge pipe. The three whe
however, have but a single set of hollow shafts to which they are bolted, and
with which they revolve; flanged sleeves being employed to separate the wheels
along the pipe. These sleeves revolve about the discharge pipe with the hollow
shafts, the lengthened rods which pass through the flanges on the said hollow
shafts and the hub plates of the several wheels, passing also through the flanges
of the said sleeves.
For the more uniform discharge of water from the apparatus in which several
straining wheels are used with a single discharge pipe, provision is made that
the corresponding buckets of the several wheels shall empty into the discharge
pipe one after the other, in regular succession instead of all three buckets at the
same time.
This is accomplished by making the several slots through
which the several wheels respectively discharge their contents into
the pipe in the same straight line and setting the second wheel
a little behind the first and the third a little behind the second.
Thus when there are three wheels of eight buckets, each bucket will approach
the slot one-twenty-fourth of a revolution behind the preceding bucket.
It has been stated above that the improved straining wheel resembles the old
washing cylinder of paper washing machines in discharging lifted water into
the discharge pipe about which it revolves. It may be added that the new
washing device, consisting mainly of several basket wheels such as have been
above described in connection with a single discharge pipe, may, like the old

page_text: cylinder with its discharge pipe, be attached to the vat of a paper engine or the
vat in which the paper pulp material is ground. In such arrangement the dis-
charge pipe including the hollow shafts extend from one side of the vat to the
mid-feather of the paper engine. Power is communicated to the wheels from
the shaft of the grinding roll, and the wheels turn in the pulp which is kept
in continual motion around the mid-feather by the bars upon the grinding roll
in the ordinary manner. It will be readily seen that the improved straining
wheels from their shape not only present more straining surface for the wash
water than the old cylinder with perforations upon its periphery, but they pass
much nearer to the bottom of the vat and pass through the pulp with much less dis-
turbance than did the old cylinder.
Dated this 23rd day of December 1897.
BOULT & WADE,
Agents for the Applicant.
Improvements in or Relating to Rotary Strainers for Paper Pulp and
other Liquids or Materials.
A communication from CHARLES STOREY WHEELWRIGHT, Manufacturer, of No. 1,
Keith Place, Providence, County of Providence, State of Rhode Island,
United States of America.
I, ALFRED JULIUS BOULT, of 111, Hatton Garden, in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
-
This invention relates to a certain new and useful improvement in straining
wheels for liquids and matters held in liquid. The invention is of great utility
in the manufacture of paper, being of great advantage and economy when used
for straining off the wash water from the pulp in paper pulp washing machines,
and hardly less so when used for straining paper fillings mechanically held in
water. In pactising the invention identically the same wheel is used for either
purpose. The wheel may also be used as a strainer for fillings for cotton cloth etc.
and even as a filter for water used in various manufacturing purposes. Thus
where a cotton mill is located above a woollen mill on the same stream, the strain-
ing wheel may be employed to collect and hold back from the water to be used
for scouring wool the fibres of cotton that have got into the water at the cotton
mill. In the paper pulp washing machine the strained wash water passes through
the perforations or meshes of the wheel, leaving the pulp material undisturbed,
but when the machine is used simply as a strainer of matters, mechanically held
in water, only clear water or matter of considerable firmness can pass through
the perforations or meshes. The objects of the invention are to obtain as large
a straining surface as possible, to lift the wash water or other water with small
expense of power, and, where materials are washed to remove the wash water
without injury to such materials.
The straining wheel embodying the invention, like the washing cylinder of
paper pulp washing machines is hollow and is provided with internal lifting
devices which discharge the water passing into the interior of the wheel through
its meshes, whether wash water or river water or water mechanically holding
finely divided materials, into and through the discharge pipe about which it

page_text: revolves. The novelty rests largely in the application of the straining gauze
to the sides of the wheel whereas in the washing cylinders before mentioned it
is applied to the periphery. Other novelty consists in the swelling sides of the
wheel from rim to centre thus giving a U or V shape to the radial cross section
of the wheel from centre to rim, and in the shape or lines of the lifter or lifting
buckets within the wheel. Other parts of the invention consists in further
details of construction. When the invention is employed for straining water
mechanically holding finely divided materials, a single wheel in combination
with a discharge pipe will answer every need; but for washing paper pulp or
paper pulp material several of the wheels upon the same discharge pipe are used
to advantage.
For convenience the further description of the invention and mode of operation
here following, is more full and exact in reference to the use of a single wheel
than where several are used, needless repetition in the description where several
wheels revolve about a single discharge pipe being avoided. But as before stated
the wheel is the same for whatever specific purpose employed.
In the drawings, Fig. 1 is a vertical cross section of a straining wheel con-
structed according to this invention, together with a corresponding cross-section
of the discharge pipe about which the wheel revolves, when in operation. In
the same figure are also shown the vat with which the wheel and discharge pipe
are used when the invention is practised for straining paper fillings, and a part
of the adjusting mechanism of the wheel.
Fig. 2 is a sectional side elevation of the principal parts of the apparatus
shown in Fig. 1 on the line of Fig. 1.
Fig. 3 is an adjusting device:
Fig. 4 is a horizontal cross-section of apparatus in which three straining wheels
are employed with a single horizontal discharge pipe.
Figs. 5, 6, 7, 8, 9, 10 and 11 are illustrative details of construction hereinafter
particularly explained.
Fig. 12 is a diagram representing the application of the invention to a pulp-
ing engine.
The same letters of reference are used so far as may be in the several figures
for the same or corresponding parts, whatever may be the application of the in-
vention represented in any particular figure. Numerals are sometimes used
with the letters to distinguish different applications of the invention as will be
readily understood. For clearness the application of the invention to a vat in
which a single straining wheel is employed will be first and more particular
described.
V is a vat. Any tank of proper dimensions will answer the purpose, but at
Figs. 1 and 2 the vat of a strainer for paper fillings is shown it being provided
with a pipe Y and a chamber A, through which water containing fillings to be
strained enters the main portion of the vat. SS are two hollow shafts with
bearings as shown at the sides of the vat the two said shafts being bolted together
as also shown and as will be more fully described in order that they may turn
together under power applied to shaft S by means of the sprocket wheel G rigidly
secured to said shaft S. C, C₁ are two caps bolted to the sides of the vat to
hold the hollow shafts S S¹ in place. H is a discharge pipe about which the
straining wheel revolves. It is open at one end and at that end enters the hollow
revolving shaft S so that said hollow revolving shaft turns freely about it, while
at the other end which is closed it is provided with a projection or rod 7 which
o within the shaft Si which latter shaft turn-
passes through a hollow projection
ing with the shaft S to which it is bolted as aforesaid, thus turns freely about said
projection 7. The discharge pipe H is provided with a slot 6 through which water
may enter from the straining wheel, as hereafter described and it may itself
turn within the hollow shafts S S¹, but during the operation of the straining
wheel or the operation of the mechanism in which the straining wheel is embodied,
is prevented from doing so, and its desired adjustment and
conse-

page_text: of
quently the desired adjustment of the slot 6 is secured by means
a ratchet Theld upon the squared end of the projection or rod 1,
by a screw nut and a dog t pivoted to the vat as shown (see Figs. 1 and 3).
D is an outlet pipe arranged as shown to receive water flowing through discharge
pipe and then through the hollow shaft S.
The apparatus thus far described in detail does not differ substantially from
apparatus used in machines for washing paper pulp provided with washing
cylinders, except perhaps in size and form of the vat."
It remains to describe the wheel forming the distinguishing feature of the
invention, and its embodiment in proper machinery.
W, is the straining wheel, like a bicycle wheel, it has a narrow rim m made
of wood and an extended hub or more exactly speaking a double hub consisting
of two flat rings PP, also made of wood, and, again, like the bicycle wheel, it has
two sets of spokes kk, diverging from the rim m, and secured at their inner
ends, one set to one ring P and the other set to the other ring P. Wire gauze g,
is nailed in sections on both sides of the wheel from the rim m, to the hub
rings Pand P, and to some of the spokes kk, the said spokes to which the gauze
is nailed being made of wood, and larger and stronger than the other, for this
purpose and also for the support of the rim m. A tire m¹ surrounds the whole
as shown. But while some of the spokes kk are made larger and are preferably
of wood for the purpose stated, most of them are preferably strips of thin metal
bent or twisted somewhat like the arms of a common windmill, so that in the
revolution of the wheel they tend to draw water into the interior of the wheel
or tend to throw water passing through the meshes of the wheel towards its
interior. A single spoke of the metal kind is shown at Fig. 11. Each metal
spoke at the hub end is driven into the hub or held in a slot in its hub as shown
in some instances at Fig. 2, while at its rim end it is secured to the rim m
preferably by a screw. But the twisted form common to the metal spokes is
merely a refinement of the invention. Small round metal rods would answer
every purpose. The spokes of the wheel as a whole prevent the wire gauze from
caving inwards.
There is thus formed a hollow basket wheel, narrow at the end and increasing
in thickness or in radial cross-section from the rim to the hub or centre with
meshes or perforations at the sides, and it will readily be seen that a wheel of
this construction, whether or not provided with internal lifting devices, as next
explained, will pass through the matters of density, or through water containing
matters of considerable density, with facility.
B, B ete are buckets or boats within the wheel, rigidly attached thereto for
lifting the wash water or other water which passes through the
meshes or perforations of the wheel as the latter revolves and dis-
charging the same into the slotted discharge pipe which has a slot bb
to receive the same. These buckets conform in shape largely to the
construction of the above described basket wheel within which they
are secured, being narrow at the nose or the end near the rim of the wheel to
which the said end is suitably secured say by screws, the said end being provided
with a projecting lip e (see Figs. 2 and 8) for that purpose, and increasing in
width or radial cross-section to the opposite or rear end, over which as the wheel
revolves the contents of the buckets are discharged into the slot b, in the dis-
charge pipe H. Near the rear end of the bucket its sides are turned (see Figs. I
and 9) at an angle so as to be parallel to the hub or plates P, P¹ to which they
are secured by screws (not shown).
A cross section of one of the buckets taken radially of the wheel is shown
at Fig. 8 a plan of the same bucket taken on the same radial line is shown at
Fig. 9 and a cross section at right angles to the cross section at Fig. 8 taken
mid-way between the two ends of the bucket or midway between the hubs and
the rim of the wheel is shown at Fig. 10. It will be seen that the general
V shape of the bucket as shown in plan at Fig. 9 is favourable to the easy lifting

page_text: of the contents of the bucket the heavier part of the load being near the centre
of rotation; the inclination of the lower part of the stern or broad end of the
bucket as shown in Fig. 8 is favourable to the easy discharge of the contents of
the bucket into the discharge pipe H through the slot b and the inclined sides
of the bucket near the bottom (as shown in Fig. 10) are favourable to the admis-
sion of water through the sides of the wheel to fill the next succeeding bucket.
This latter provision permits the use of a greater number of buckets within the
wheel than could be used if the sides of the bucket were straight, and the bottom
wide and flat.
RR etc. are four bolts or rods passing through flanges on the two hollow
shafts S S¹ and secured by screw nuts was shown; they pass also through the
hub plates or rings P P of the hollow basket wheel W and secure the same so
that the wheel revolves with the shafts S S₁ to which power is communicated
as before stated. It is immaterial whether or not these bolts or rods R pass
through the lifting buckets.
The application of the wheel for washing paper pulp is illustrated in Fig. 4
(see also the diagram Fig. 12). As before stated, the wheel itself is the same
wheel that is used simply for straining matters mechanically held in water, but
in washing pulp several wheels are preferably employed in connection with a
single discharge pipe such as is shown in Figs. 1 and 2. Thus in the drawings
at Figs. 4 and 12 three wheels W2 W2 W3 are shown in connection with a single
discharge pipe H2. The three wheels W2 W2 W2, however, have but a single set
of hollow shafts S, S¹, to which they are bolted, and with which they revolve;
flanged sleeves d, d being employed to separate the wheels along the pipe Ha
These sleeves d revolve about the pipe Ha with the hollow shafts S S the lengthened
rods R which pass through the flanges on the said hollow shafts S S¹ and the hub
plates P P of the several wheels passing also through the flanges of the said
sleeves d.
For the more uniform discharge of water from the apparatus in which several
straining wheels are used with a single discharge pipe, provision is made that
the corresponding buckets of the several wheels shall empty into the discharge
pipe, one after the other, in regular succession, instead of all three buckets at
the same time. This is accomplished by making the several slots through
which the several wheels respectively discharge their contents into the pipe H³,
in the same straight line and setting the second wheel a little behind the first
and the third a little behind the second as illustrated in Figs. 5, 6 and 7. Thus
when there are three wheels of eight buckets each bucket will approach the slot
one-twenty-fourth of a revolution behind the preceding bucket.
It has been stated above that the improved straining wheel resembles the old
washing cylinder of paper pulp washing machines in discharging lifted water
into the discharge pipe about which it revolves. It may be added that the new
washing device, consisting mainly of several basket wheels such as have been
above described in connection with a single discharge pipe, may, like the old
cylinder with its discharge pipe be attached to the vat of a pulping engine
or the vat in which the paper pulp material is ground. This arrangement is
illustrated by a diagram at Fig. 12, where W2, W2, W2, represent three wheels
constructed and arranged as shown at Figs. 4, 5, 6 and 7, V², being a vat of a
pulping engine or so much thereof as it is necessary to show, F is the mid-
feather of the pulping engine and G2, the grinding roll or the roll carrying the
grinding bars which, however it is not necessary to show. Nor is it necessary
to show the bed plate with which they operate to grind the pulp. The discharge
pipe H including the hollow shafts S S¹, not distinguished in the diagram,
extend from one side of the vat to the mid-feather as shown. Power is com-
municated to the wheels from the shaft of the grinding roll as indicated in the
drawing; and the wheels turn in the pulp which is kept in continual motion
around the mid-feather by the bars upon the grinding roll in the ordinary
manner. It will be readily seen that the improved straining wheels from their

page_text: shape not only present more straining surface for the wash water than the old
cylinder with perforations upon its periphery, but they pass much nearer to the
bottom of the vat and pass through the pulp with much less disturbance than did
the old cylinder.
Having now particularly described and ascertained the nature of this in-
vention, as communicated to me by foreign correspondent, and in what manner
the same is to be performed, I declare that what I claim is :-
:-
1. A. hollow straining wheel for liquids and matters held in liquid, narrow at
the rim and increasing in radial cross-section or width from rim to hub or from
rim to near its centre of rotation with perforated sides and lifting buckets be-
tween said sides, substantially as described.
2. A hollow straining wheel for liquids and matters held in liquid, narrow at
the rim and of increasing width in radial cross section from rim to hub with
perforated sides and lifting buckets between said sides, the said lifting buckets
conforming in longitudinal cross section to the radial cross section of the wheel,
substantially as described.
3. A hollow straining wheel for liquids and matters held in liquid, narrow at
the rim and of increasing width in radial cross section from rim to hub, with
perforated sides and lifting buckets between said sides the said lifting buckets
conforming in longitudinal cross section to the radial cross section of the wheel
and having inclined or sloping sides and rear, substantially as described.
4. A hollow straining wheel for liquids and matters held in liquid, narrow at
the rim and of increasing width in radial cross section from rim to hub, with
two sets of spokes diverging, one set from the other, from rim to hub and pro-
vided with wire gauze upon each side and lifting buckets within between said
sides substantially as described.
5. A hollow straining wheel for liquids and matters held in liquid, narrow
at the rim and of increasing width in radial cross section from rim to hub, with
two sets of spokes diverging, one set from the other, from rim to hub, and pro-
vided with wire gauze upon each side, and lifting buckets within, a portion of the
said spokes in each said set being bent or twisted, substantially as described.
6. The combination with a hollow discharge pipe, of a hollow straining wheel
for liquids and matters held in liquid adapted to revolve about said discharge
pipe, the said wheel being narrow at the rim and of increasing width in radial
cross section from rim to hub and provided with hollow sides and lifting buckets
between said sides, and the said discharging pipe being provided with a slot
adapted to receive the contents of said buckets as said wheel revolves about said
discharge pipe, substantially as described.
7. The combination with a single hollow discharge pipe, of a number of hollow
straining wheels for liquids and matters held in liquid adapted to revolve together
about said discharge pipe, the said wheels being each narrow at the rim and of
increasing width in radial cross-section from rim to hub and provided with per-
forated sides, and lifting buckets between them, the said discharge pipe being
provided with slots adapted to receive the contents of said buckets as said wheels
revolve around it, substantially as described.
Dated this 15th day of August 1898
BOULT & WADE,
Agents for the Applicant.