A New or Improved Construction of Paper Pulp Refining Engine.
Year: 1893

page_text: COMPLETE SPECIFICATION.
A New or Improved Construction of Paper Pulp Refining Engine.
We, DAVID PEARSON of Spring View, Radcliffe, Lancashire, Manager, and
DAVID NOBLE BERTRAM of St. Katherine's Works, Edinburgh, Engineer, do
hereby declare the nature of our said invention and in what manner the same is to
be performed to be particularly described and ascertained in and by the following
statement:-
In the treatment of pulp used in the manufacture of paper it is found very
desirable after the pulp has passed through the ordinary beating engine to further
disintegrate or refine the same so that the pulp fibres shall be drawn out to a greater
uniformity in length before the pulp is made into paper.
Our invention has for its object to accomplish this desirable end, and to do so
we employ the improved construction of refining engine hereinafter described.
In accordance with our invention we employ a cylindrical casing which is formed
by preference of cast iron, and bolted to a bed or base plate and one end of said
casing is closed whilst the opposite end is open, but fitted with a loose piston end.
Within this casing a disc or circular plate is enclosed keyed upon a shaft which
passes through one or both ends of the casing and said shaft is supported in
pedestal bearings carried by the bed plate aforesaid and fitted with a driving
pulley.
formed
Upon each side of said disc an annular, by preference, dovetail recess
which serves to carry a number of cutter bars which are more or less of a rect-
angular formation and of comparative thinness with one portion of their extremities
formed dovetail to coincide with the dovetail recesses.
Said cutter bars are arranged radially around the shaft with a tapered strip of
wood between each to allow for this and keep them a sufficient distance apart.
Openings are formed at suitable intervals to allow for the introduction of the bars
into said recesses which are fitted with key strips after the bars are set and screwed
or rivetted in position.
Within the casing two other discs are employed, one bolted or otherwise secured
to the piston end and the other to the closed end of the casing, and in the opposite
faces of these discs annular dovetail grooves are formed similar to those in the disc
aforesaid and in exact register therewith. Cutter bars similar to those aforesaid
are introduced into these grooves, but instead of being set radially they are set
tangentially, the wooden packing strips being shaped accordingly.
Into the casing fitted as above described with a revolving disc and a set of
stationary discs fitted with cutter bars the pulp to be treated is passed, which enters
through an opening in one end of the casing from a pipe communicating with a
supply tank fixed immediately above the engine.
Motion being imparted to the shaft aforesaid the disc mounted thereon is caused
to revolve and the cutter bars acting upon the pulp thoroughly and completely
disintegrate the fibres, the tangential setting of the cutter bars in the stationary
discs producing a shearing action which tends to draw the fibres out to a greater
uniformity of length than heretofore.
The pulp in passing through the casing passes between both sets of cutter bars,
that is, between the bars on one side of the revolving disc, those on the opposite
side and those on the stationary discs, a sufficient space being left between the
revolving disc periphery and the casing interior to allow for the pulp to pass
round. After treatment the pulp escapes in its refined state through an opening
in the closed end of the casing into a suitable pipe and is then led away as
desired.
With refining engines as at present constructed it is necessary in order to pass

page_text: the pulp through the engine to employ a force pump or a "head" of pulp (this
latter necessitating a great length of piping) whereas by our invention neither
expedients are required as the cutter bars owing to their peculiar radial and
tangential setting draw the pulp into the casing and after treatment force it out
through the exit pipe.
As the cutter bars become worn away they may be brought up to each other by
sliding the piston end of the casing inwards, the shaft on which the revolving disc
is mounted being capable of sliding in its bearings. To facilitate such adjustment
we employ a screw working through a fixed cross head on the bed plate aforesaid
and serving to operate a moveable cross-head which is secured by rods to the piston
end of the casing so that by turning the screw the moveable cross head is caused to
push in the piston end of the casing and so cause the discs and cutter bars to
approach each other and compensate for the wear.
In order that our invention shall be more readily understood and carried into
practical effect we have hereunto annexed a sheet of drawings illustrative of the
same and will now proceed to describe the same with the assistance of the various
figures and letters of reference marked thereon :-
Fig. 1 is a sectional elevation and Fig. 2 is a plan view of our improved refining
engine.
In accordance with our invention we employ a strong, by preference, cast iron
casing A which is bolted at each side to and supported by the bed plate B, and said
casing as illustrated is closed at end C, but open at the opposite end.
In the open
end of the casing the piston end D is fitted, which is provided with a spring
packing ring D' to facilitate the sliding in and out of the end and keep the joint
water-tight.
Extending through stuffing boxes or
shaft E supported in pedestal bearings F
Said shaft is fitted with the driving pulley G and is covered at H with a thin
covering or sheathing of brass or other suitable material to protect it from the
action of the pulp and said sheathing is sufficiently long to allow for the sliding of
glands in both ends of the casing is the
rising from the bed plate B.
the shaft.
The interior of the casing at I is likewise lined with a lining of brass or other
suitable material to protect it from the action of the pulp.
Upon the shaft E is keyed the disc J which is less in diameter than the inner
circumference of the casing as illustrated to allow for a passage from side to side
of the disc. In each face of said disc annular grooves or recesses K are formed
which are of the cross section shewn in Figs. 1 and 3, or of the cross section shewn
in Figs. 5 and 7, and said recesses or grooves are fitted with cutter bars L either
formed as shewn in Figs. 1, 4, 9 and 10 to coincide with the dovetail recesses,
or as shewn in Figs. 6 and 8 to coincide with the grooves shewn in Fig. 5 and 7.
These cutter bars are introduced at M, the key strip N being removed and then
a cutter bar L and wooden strip O (see enlarged views Figs. 11 and 12) inserted
alternately and brought round to the fixed key strip P until the groove is full, the
key or locking strip N being then inserted in position and screwed or rivetted to
the disc. The wooden wedges are of such a taper that the cutter bars are caused
when set to lie radially around the shaft E as illustrated in Fig. 13.
Upon the closed end of the casing the disc or plate Q is fixed by means of bolts
or other means and on the piston end of the casing the disc or plate R is likewise fixed.
In the faces of these discs recesses or grooves are formed similar to those in disc J
or those in Figs. 1, 3, 5 and 7, and into these grooves cutter bars S are fixed
similar to those shewn in Fig. 1, or those shewn in Figs. 4, 6, and 8, but said cutter
bais instead of being arranged radially around the shaft are arranged tangentially
or angularly as illustrated in Fig. 14 the packing strips T being formed as shewn
in Fig. 15.
The arrangement of the cutter bars may be reversed, the tangential setting on the
revolving disc and the radial setting on the two stationary discs.
The pulp to be treated passing from the beating engine enters the tauk U which

page_text: has a partition V, so that any foreign matter or impurities which may enter the
tank with the pulp are intercepted, the pure pulp only flowing over the partition
and passing into the engine. The pulp is led into the engine through pipe W
(fitted with stop cock X to control the flow) and through the inlet opening Y in
the piston end of the casing and after passing between the cutter bars and around
the disc as indicated by the arrows passes out through an opening in the closed end
of the casing. The cutter bars S, S, are placed in precisely the same manner and
position in each of the stationary discs, hence when the discs are placed in the
casing A facing each other the said bars are tangential in opposing directions.
It will therefore be seen that the disc J, which revolves in the direction of the
arrow (see Figs. 13 and 14), will cause the pulp to pass from the centre outwards
on the inlet side of the disc and inwards towards the centre on the outlet side so
producing the flow of the pulp through the casing as aforesaid. The inlet opening
may be arranged in the closed end of the casing and the outlet opening in the piston
end, the cutter bars being arranged accordingly.
To compensate for the wear of the cutter bars the piston end D is caused to slide
forward into the casing A and to facilitate such movement we employ a finely
pitched screw (a), working through a fixed cross head (b) and operating a loose cross
head (c), which is secured to the piston end D by rods (d) as illustrated. By
turning the hand wheel (e) the piston end is caused to slide into the casing and so
adjust the cutter bars as aforesaid. To allow for the movement of the piston end
the pipe W may be flexible or connected by a flexible joint, or the pipe may be
rigidly connected and tank U allowed to slide to and fro on the support (f).
The engine is sometimes provided with a vertical delivery box on the outlet
pipe, by preference, of a height corresponding to that of the supply tank to allow
for the accumulation of refined pulp passing from the engine.
A modified construction of our improved engine consists in carrying the shaft E
through one end of the casing only and supporting the same by two pedestal bearings
on that side of the engine, the inlet orifice in this case entering if desired in the
centre of the opposite side of the casing.
It will be obvious that these improvements are applicable to existing engines,
particularly the means of adjusting the cutter bars when worn, the fine screw and
cross head dispensing with the old form of scroll and worm hitherto used and so
difficult to turn.
Having thus particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that
what we claim is :-
1st. In an engine for refining paper pulp the use and employment of a casing A,
containing a revolving disc J mounted on shaft E and two stationary discs R and Q
mounted on closed and piston ends C and D respectively, the revolving discs
carrying cutter bars L arranged radially and the stationary discs carrying cutter
bars S arranged tangentially or vice-versa, all arranged and acting in operative
combination substantially as set forth and illustrated.
2nd. In a paper pulp refining engine the use and employment of a casing A
enclosing the before mentioned arrangement of discs and cutter bars with closed
end Cand piston end D in combination with a screw (a) cross heads (b)-(c) and rods (d)
for affecting the adjustment of the cutters bar when worn all mounted and operating
substantially as hereinbefore described and illustrated on the accompanying drawing.
3rd. The use and employment of a screw (a), cross heads (b) and (c), piston
end (d) combined with our improved engine or applied to existing engines whereby
the adjustment of the cutter bars when worn is greatly facilitated, giving a
finer adjustment with less friction of the parts than heretofore substantially as set
forth.
4th. The modified arrangement of the driving shaft E, inlet opening Y, and
modified forms of cutter bars and grooves or recesses in the several discs sub-
stantially as hereinbefore described and illustrated on the accompanying drawing.

page_text: 5th. The general arrangement and construction of our improved paper pulp
refining engine including the supply tank U with partition V, also pipe W, inlet and
outlet orifices in casing ends and discs and delivery box substantially as hereinbefore
described and illustrated on the accompanying drawing.
Dated this 16th day of June 1893.
JOHN G. WILSON & Co.,
Agents.