Improvements relating to Paper Making and similar Machines.
Year: 1895

page_text: Date of Application, 26th Nov., 1895-Accepted, 7th Mar., 1896
COMPLETE SPECIFICATION.
Improvements relating to Paper Making and similar Machines.
1, HENRY FAIRBANKS, of St. Johnsbury, Vermont, United States of America,
Manufacturer, 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 the mold cylinder commonly used in pulp and paper
machinery, for removing from the thin pulp the water of suspension, which flows
through the wire cloth surface, leaving the wet fibre upon that surface, to be
carried up and transferred to the couch roll or felt apron.
My improvements, while somewhat aiding the free deposit of the layer of pulp
upon this peripheral surface, are especially designed to secure by atmospheric
pressure the removal of much of the water from this wet layer while it is being
carried up to the couching line, and to so limit that pressure that it will not act to
prevent the free couching at the line of contact with the roll above. To effect
this, the present invention consists in the combination of the mold-cylinder,
divided into separate longitudinal compartments by means of substantially radial
partitions, with a water outlet, communicating with the interior of said cylinder at
its lowest level, to provide in the usual manner for the outflow of water that passes
from the pulp vat into the immersed portion of the cylinder through its foraminous
periphery, and an exhaust conduit, and means for placing the compartments of the
cylinder in communication therewith during a predetermined portion only of their
revolving movement about the axis of the cylinder; such compartments as at any
time are in communication with the exhaust passage being then cut off from the
water outlet.
These parts are so arranged that the compartments which are at any moment in
communication with the exhaust conduit are those that are travelling upward from
the surface of the thin pulp in the vat toward the couching line; and if desired, the
means for controlling communication between the compartments and the exhaust
may be so adjusted that the exhaust may begin in a compartment before it rises
out of the thin pulp, thereby increasing the deposit of fibre upon the straining
surface.
In the accompanying drawings,
Figure 1 is a sectional elevation with some of the tank broken away, and showing
the moving parts, and a partial section of the exhaust passage in the line XX, the
dotted lines showing the partitions of the cylinder,
Figure 2 is a longitudinal sectional elevation showing a part longitudinal section
through the centre of the mold cylinder,
Figure 3 shows in perspective the construction of part of the exhaust passage
and connections.
The mold cylinder A may be, as shown, in substantially the usual relation to
the pulp vat, and water outlet; the said cylinder turning on a horizontal shaft or
axis & in proper bearings, in such relation to the level of the pulp in the vat that
the lower portion of the cylinder is immersed in this pulp, the water from which
thus strains through the pervious surface of the cylinder in the usual manner,
leaving the pulp fibre deposited thereon; as the said surface rises out from the
thin pulp in the vat, in the rotary movement of the cylinder.
As shown in this instance, the cylinder is closed at one end, (the left hand end,

page_text: Figure 2,) preventing the inflow of pulp therethrough into its interior, and at the
other (right hand) end is in free communication, in the usual manner, with the
water outlet: that is, the ring a forming one end of the cylinder, and the ring or
flanger, projecting from the water outlet chamber have their corresponding edges
adjacent, so that a packing strip r¹ applied in the usual way maintains substantially
tight connection between the two, so that the thin pulp cannot enter, but the interior
of the cylinder, to its lowest point, opens into the water delivery chamber, and
outlet f, for the free discharge of the water from that interior. The connection
between the end of the cylinder and the water outlet chamber is continued above
the level of the thin pulp, and quite around the circumference, and is made
practically air tight for a reason that will appear later in the description.
The sectional cylinder in my improved machine may be constructed in any known
way, but as shown, it is made with longitudinal radial partitions m reaching from
the closed head to the end spider or skeleton head c, which divide it into compart-
ments, as indicated by the dotted lines of Figure 1, while the peripheral surface
is supported by light bridges between these partitions. In order to apply
atmospheric pressure to the layer of pulp that is deposited upon the immersed
strainer surface of the cylinder, as the said deposited pulp fibre is carried up by
the motion of the cylinder from the surface of the thin pulp to the couching line, or
point where it is removed therefrom (that is in substantially the space from k
around to in Figure 1), it is necessary to provide means for placing the com-
partments that are at any time travelling through this space, in the rotary
movement of the cylinder, in communication with an exhaust passage; and in
order to render the exhaust effective, these compartments must at the same time be
otherwise closed, or cut off from communication with the water outlet chamber, and
from the external atmosphere, except through the straining surface and layer of
fibrous pulp thereon, in order that the air pressure due to the exhaust may be
effective only on said layer of fibrous pulp, supported on said straining surface, or
pervious periphery of said compartments. The means for effecting this result, as
herein shown, consist of a flat circular plate or detached head p, adapted to fit
closely upon the skeleton end c of the cylinder, that otherwise opens into the water
outlet chamber, said head being of smaller diameter than the open interior of the
cylinder, and excentrically supported with relation thereto so that the portion of
greatest excentricity overlaps a portion of the peripheral end of the cylinder, while
the side of least excentricity does not reach the outer rim of the skeleton end c, but
leaves an open space outside the detached head p, for free communication from the
compartments on that side of the water outlet chamber.
The said head p has a flanged central opening which fits closely upon the outer
surface of the end of the exhaust conduit e, which conduit is excentric to the
axis or shaft of the cylinder, and supports within it one bearing of this shaft
as shown.
The said exhaust conduit e, at its end, also makes close contact with the end of
the cylinder, and has an inlet opening or port in the side of greatest excentricity,
which overlaps the portion of the compartments nearest the axis, as these
compartments pass it, thus giving free openings, as shown at i, i, from the interior
of these compartments into said exhaust conduit, and from all the compartments in
turn as they pass the excentric side in their rotation. The detached head P, is
preferably free to rotate about the end of the exhaust conduit e, turning with the
cylinder, against which it is held by the pressure of the air toward the exhausted
compartments, there being only comparatively small frictional movement between
the end of the cylinder and its detached head, as they rotate about their different
centres.
It is however essential only that means be provided for closing the compartments
while in communication with the exhaust conduit, except at the passages through
which such communication is afforded, and to open them, at least while immersed
in the pulp, into the water outlet chamber, so that the water level inside these
compartments may be lower than the level of the thin pulp in the vat, and the

page_text: inward flow of the water of suspension may cause a free deposit of pulp fibre upon
the straining surface.
A loose packing between the two sections of the exhaust conduit is shown at o,
which would be required in case the cylinder instead of the couch roll is mounted
in yielding bearings, for which mounting this cylinder is well adapted. The
shaft d of the cylinder turns with it, and the two sections of the exhaust conduit
are so connected that the one next the cylinder, while having some freedom of
motion up and down, cannot rotate with the shaft.
This exhaust conduit e communicates through its extension n with an air pump,
syphon or strong fan not shown, and we prefer to connect the water outlet falso
with a light exhaust through the branch pipe s. In my improved machine it will
be understood that the pulp vat, and immersed portion of the mold cylinder serve
their usual functions and the fibrous pulp is deposited upon the pervious peripheral
surface of each compartment, while the water of suspension flows freely toward the
open end.
At this end, the detached head being held high by its excentric
mounting, the outlet is open to the lowest level for the free discharge of the waste
water. This would give a satisfactory result, and the cylinder would take up its
layer of fibrous pulp precisely as though it had no partitions if it moved slowly
enough. But if it is turning rapidly, the water in the compartments may not have
time to flow to the end, and is liable to be carried above the level of the thin pulp
outside, and to tend to flow out through the porous surface, and to wash off the pulp
deposited thereon.
1'
In order to obviate this difficulty, we arrange for a slight vacuum in the
compartments as they rise. This can be effected by adjusting the exhaust
passage e so that the strong suction current will begin to act through each compart-
ment just before it rises above the level of the thin pulp outside the cylinder. . But
it is much more satisfactory to apply a light exhaust by a branch pipe at s to the
outlet f, and to so pack the ring a of the cylinder against the corresponding ring
of the water outlet chamber that this exhaust will act through all the compartments
that are not closed by the detached head p. And experience proves that the
pressure due to this light exhaust causes a very uniform layer of pulp to be
deposited and held, so that in this particular my improved sectional cylinder proves
valuable, loading much better and having the thickness of the pulp deposit easily
it may be
regulated by varying the exhaust; and for the sake of these advantages
used without the strong exhaust which removes the water from the pulp fibre after
it is deposited. When a section carrying a layer of pulp fibre upon its curved
surface rises above the thin pulp in the vat at k Figure 1, the excentricity of the
outside of the exhaust passage e has already carried the circular plate p so far to
that side that its edge overlaps the rim of the skeleton head against which it rests,
and closes that opening into this compartment, the pulp layer prevents the air
entering through the pervious surface, and, when the passage i is opened, the
exhaust through which it acts upon a closed compartment, and the weight of the
atmosphere presses the water from the wet fibre, which water, and any air that leaks
in passes off by the exhaust pipe e, n. This pressure continues until that com-
partment has moved to the point near the line of couching, when the opening i into
the exhaust passage is closed, and the pulp layer, freed from outside unbalanced
pressure, by the air beginning to enter past the edge of the circular plate p, is in
condition to be surely transferred when it reaches the couch roll.
It is plain that the action of the exhausted sectional cylinder will be the same,
whether the couching transfers the pulp layer to the couch roll itself, or to an apron
passing around it or under it, and that such a cylinder is adapted equally to use
in paper making machines having one or more cylinders, and to wet machines
for making pulp sheets for shipment. It is also evident that the mechanism
described can be applied to both ends of the cylinder, as would be advantageous if
the cylinder was very long. It is further apparent that nothing in this sectional
construction of the cylinder interferes with the use of the usual dandy roll.
I am aware that sectional rolls have been proposed, mainly for use as rotary

page_text: suction boxes for paper machines, and I make no broad claim to such rolls, but my
device is different from these in construction, connections, relation of parts,
and use.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
―:
1. The combination of a pulp vat, a mold cylinder adapted to rotate therein,
having a pervious periphery and longitudinal internal compartments formed against
such periphery, a water outlet arranged below the axis of the cylinder, an exhaust
conduit arranged above the water outlet and an appliance having a solid portion
arranged above the axis and adjacent to those compartments upon which the pulp
has been deposited and establishing communication between such compartments and
the exhaust conduit, and also having an open portion adjacent to the water outlet,
to open communication between such outlet and the compartments next to it,
substantially as described.
2. The combination of the pulp vat b, and the rotary mold cylinder therein,
having a foraminous periphery, and separate internal longitudinal compartments
formed against this periphery, and closed at one end, with a water outlet fat the
other end of the cylinder and a conduit s communicating with a light exhaust and a
detached head p, fitting the cylinder, and means for supporting the said head
excentrically to the cylinder, whereby it is adapted to cover and close compartments
above the axis, and to uncover a certain number of those below, and establish
communication between them and the said conduit and water outlet, substantially
as described.
3. In combination with a pervious cylinder having internal longitudinal com-
partments formed against its curved surface, and closed at one end, a detached
head p, mounted excentrically to cover and close a pre-determined number of
such compartments at the other end, and an exhaust conduit e, also excentric
with the cylinder and communicating with said compartments when closed, as
herein set forth.
4. The combination of the pulp vat b, and the rotary mold cylinder therein,
having separate longitudinal compartments formed within its foraminous periphery,
closed at one end against ingress from the pulp vat, with a water outlet and an
exhaust conduit at the other end of the cylinder, and a detached head p, in an
opening of which the exhaust conduit ends, of which head the portion above the
axis of the cylinder has more surface than the portion helow, whereby it is adapted
to cover and close said compartments during a certain portion of their upward
movement as they revolve about the axis of the cylinder, and place them in com-
munication with the exhaust, while during the remainder of their movement, and
when submerged in the vat, they are in open communication with the water outlet,
substantially as set forth.
5. In combination with the pulp vat b, and the foraminous periphery and closed
head of the mold cylinder therein, the partitions m m, forming internal, longitudinal
compartments, and reaching to the skeleton end c, the detached head p fitting this
skeleton end, but excentric with it, an exhaust conduit e, and a water outlet f, the
said exhaust conduit being excentric with the cylinder, and arranged to communicate
at the ports i, i, with a certain number of such compartments as in the rotation of
the cylinder are emerging from the vat, while the said head, by reason of its
excentricity, uncovers such compartments as are submerged in the vat and leaves
them in open communication with the water outlet, substantially as and for the
purpose set forth.
6. The combination of a pulp vat, a mold cylinder adapted to rotate therein,
having a pervious periphery, and longitudinal internal compartments formed against
such periphery, a water outlet arranged below the axis of the cylinder, an exhaust
conduit arranged above the water outlet and an appliance having a solid portion
arranged above the axis, and adjacent to those compartments upon which the pulp

page_text: has been deposited, and establishing communication between such compartments
and the exhaust conduit, and also having an open portion adjacent to the water
outlet, to open communication between such outlet and the compartments next to it,
and, in connection with the water outlet, a light exhaust, as described.
Dated this 26th day of November 1895.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.