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Патент USA US3019168

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Jan. 30, 1962
R. M. NEWMAN, JR
3,019,158
WEB FORMING METHOD AND APPARATUS
Filed Dec. 8, 1959
5 Sheets-Sheet 1
INVENTC'R
RALPH M. NEWMAN, JR.
BY
ATTORNEY
Jan. 30, 1962
R. M. NEWMAN, JR
3,019,158
WEB FORMING METHOD AND APPARATUS
Filed Dec. 8, 1959
5 Sheets-Sheet 2
wm“
.mLuw
INVENTOR
RALPH M. NEWMAN, JR
BY
ATTORNEY
Jan. 30, 1962
R. M. NEWMAN, JR
3,019,158
WEB FORMING METHOD AND APPARATUS
Filed Dec. 8, 1959
5 Sheets-Sheet 3
INVENTO,
RALPH M. NEWMAN, JR
BY
ATTORNEY;
Jan. 30, 1962
R. M. NEWMAN, JR
3,019,158
WEB FORMING METHOD AND APPARATUS
Filed Dec. 8, 1959
5 Sheets-Sheet 4
;
INVENTOR
RALPH M. NEWMAN, JR
ATTORNEY
Jan- 30, 1962
R. M. NEWMAN, JR
3,019,153
WEB FORMING METHOD AND APPARATUS
Filed Dec. 8, 1959
5 Sheets-Sheet 5
INVENTOR
RALPH M NEWMAN, JR
BY
gim
ATTORNEY
1
Free
3,819,158
Patented Jan. 30, 1962
2
3,019,158
WEB FORMING METHOD AND APPARATUS
Ralph M. Newman, Jr., Romney, W. Va.
(RD. 1, Cobhler’s Knoll Farm, Kennett Square, Pa.)
Filed Dec. 8, 1959, Ser. No. 858,117
same time overcome the problems incurred due to cen
trifugal force of the rotating cylinder, attempts have been
made to form the web on the interior of a rotating per
forate drum. In this respect, see for example French
Patent 981,228 of 1951. Although this approach is de
sirable from the standpoint of meeting the above men
tioned problems that are incurred in Fourrlrinier and cyl
This invention relates to a method and apparatus for
inder
type machines, it poses the particularly acute prob
continuously forming webs and more particularly, to a
lem of removing the partially formed Web from the in
method and apparatus for forming such a web from a
10 terior of the rotating drum. Because of this problem, this
?ber slurry or suspension.
approach has been generally discarded except where rela
Previous to this invention, the formation of webs from
tively short lengths of web material are required.
?ber slurries, particularly in the manufacture of paper
Accordingly, an object of this invention is to provide
and like products, has been accomplished in most in
a new and unique method and apparatus for forming
stances either by the use of Fourdrinier machines or cyl
continuous webs from ?ber slurries by which the prob
inder-type machines. In the Fourdrinier machine, the 15 lems
previously incurred are elfectively overcome.
furnish or ?brous slurry is introduced onto a traveling
A further object of this invention is that of providing
wire from a head box and slice for passage over rollers
an apparatus particularly suitable to pressure formation
and suction devices to extract the liquid from the de
of a ?brous web from a slurry.
8 Claims. (Cl. 162-212)
posited slurry. Cylinder-type machines, on the other
Another object of this invention is the provision of an
hand, incorporate a rotatable perforate cylindrical drum 20
apparatus of the type aforementioned by which a ?ber
partially immersed in a vat containing the ?ber slurry
slurry may be continuously deposited on the interior of a
to effect passage of the slurry through the drum leaving
rotating drum, the liquid extracted therefrom and the
the ?bers deposited on the drum exterior. In many types
of cylinder machines the slurry is passed through the 25 accretion of ?bers remaining on the interior of the drum
removed as a continuous web for subsequent treatment.
drum under the in?uence of the pressure head in the vat
A further object of this invention is that of providing
while in others, suction means are incorporated within
an apparatus of the type referred to in which the cen
the drum to draw the slurry through the drum periph~
trifugal force developed by a rotating forming drum may
ery. Subsequently, in both of these basic types of ma
be
combined with the action of a vacuum to quickly and
chines, the ?brous web thus formed is passed through 30 effectively
remove substantially all of the liquid from the
various drying, calendering or other ?nishing apparatus
?ber suspension prior to removal of the partially fonned
before the desired product is obtained.
?brous web from the forming drum.
While the apparatus or" the type aforementioned has
Another object of this invention is the provision in an
met with considerable success in the paper making in
dustry, several objectionable features are present in these 35 apparatus of the type referred to of extremely effective
means for removing the partially formed ?brous web
available types of machines. For example, in Four
from the drum interior.
drinier machines, the principal objection arises due to the
A still further object of this invention is to provide
high rate of speed at which the wire moves relative to
the devices over which it travels, such as suction boxes
a new and improved method of removing a partially
and the like. Because of this relative, high speed move 40 formed ?brous web from the interior of a rotating drum.
Other objects and further scope of applicability of the
ment, excessive wire stresses as well as wear due to fric
present invention will be apparent from the detailed de
tion require frequent replacement and repair of the wire
scription given hereinafter. ‘It should be understood,
and accordingly increases the maintenance expenses in
however, that the detailed description, while indicating
curred by the use of such machines. Additionally, the
preferred embodiments of the invention, is given by Way
wire must be supported at reasonably short intervals by
rolls and as well, requires the use of various tensioning 45 of illustration only, since it will demonstrate to those
skilled in the art that various changes and modi?cations
devices. In order to prevent upsetting the ?ber forma
can be made without departing from the spirit and scope
tion on the wire, these rolls and like devices must be ex~
of this invention.
tremely accurately machined, therefore requiring high
manufacturing costs. Also, in recent years, paper manu
facturers have found it desirable to direct the furnish or
In general, the aforementioned objects are accom
plished by providing a foraminous screen or other per
slurry through the wire under pressure so that the ?bers
forate inwardly facing cylindrical surface on the interior
are deposited on the wire under the in?uence of a pres
of a rotatable drum suitably braced and reinforced. A
sure head. However, such pressure formation has not
head box and slice are arranged interiorly of the drum
worked out in practice due to the extreme stresses im
for the purpose of depositing a ?ber furnish or slurry on
posed on the forming wire and the lack of suitable means 55 the interior of the screen. At a point on the drum cir
to overcome these stresses.
cumference remote from the head box and slice, is lo
cated exteriorly of the drum a nozzle for directing high
the need for wires of the type used in Fourdrinier ma
pressure ?uid inwardly through the screen. A convey
chines or at least alleviate the wire maintenance prob
ing means extends within the drum and terminates in
lems due to friction and the like as aforementioned. 60 a lip positioned adjacent to the screen and opposite from
However, the cylinder-type machine presents a critical
the nozzle so that the web is picked up by the conveyor
problem particularly in high speed operation, as a result
as it is removed from the screen. The conveyor is curved
of centrifugal force developed by rotation of the cylindri
gently in the direction of the drum axis to carry the web
cal perforate drum. Furthermore, since the ?bers de
out of the drum interior and is formed having a plenum
posited on the exterior of the drum are immersed in the
chamber opening through an apertured top wall so that
slurry, there is a strong tendency for the accreted ?bers to
pressurized ?uid may be used to support the web on the
be washed oil? as they leave the slurry. For these rea
conveyor. Further, the drum is exteriorly sealed within
sons, cylinder machines are limited to slow speed opera
a housing and a suction chamber established therein be
tions.
tween point of slurry deposit and web removal for the
To achieve the bene?cial results of the cylinder-type 70 purpose of adding to the water extracting facility af
machine, i.e. the elimination of the wire wear, and at the
forded centrifugal force developed by drum rotation.
The cylinder machines on the other hand, eliminate
3,019,158
displacement of the drum and the rollers. In addition,
a plurality of hold down rollers 44 are mounted on the
cap members 29 to prevent upward displacement of the
ings, in which:
drum.
FIG. 1 is a side elevation of the apparatus of this
A motor 46 is provided for driving the drum 22 through
invention;
a spur‘ gear 48, the teeth of which engage the teeth 49
provided on the interior of the bearing ring 26. It thus
FIG. 2 is a cross sectional plan view taken along
line 2—2 of FIG. 1;
FIG. 3 is a cross sectional view taken along line 3-—3
of FIG. 2;
4
having complementing V-shaped surfaces to prevent axial
A more complete understanding of the new improved
web forming apparatus of this invention and its opera
tion may be had by reference to the accompanying draw
becomes apparent that the drum 22 is securely supported
10 between the frame assemblies 19 and i2 and may be ef
fectively driven at high speeds through the gear 43 en
FIG. 4 is an (enlarged fragmentary cross sectional
gaging the teeth 49 on the interior of the bearing ring 26
view showing in detail, the new and improved means of
without in any way interfering with access to the interior
this invention for removing the partially formed web
of the drum.
from the interior of the rotating drum;
The drum 22 is positioned rotatably within a housing
FIG. 5 is an enlarged fragmentary cross sectional 15 56 supported between the front and rear frame assemblies
elevation showing an alternative embodiment of the web
16 and 12. The housing is formed having a pair of side
conveying means of this invention; and
walls 52 centrally apentured to receive the drum and as
FIG. 6 is a partial cross section taken along line 6-6
can be seen in FIG. 2, which sidewalls ?t closely against
of FIG. 5.
20 the radially extending sealing portion of the drum hear
As shown in the drawings, apparatus of this invention
ing rings 24 and 26. Although no particular sealing struc
includes a pair of front and rear frame assemblies gen
ture is shown between ‘the rotatable drum and the hous
erally designated by the numerals 10 and 12 respectively.
ing 59 other than locating the walls 52 of the housing
These frame assemblies are substantially identical and
in close proximity to the sealing ?anges 30, it will be
each include a base member 14, a pair of vertical mem 25 apparent to those skilled in the art that any suitable seal
bers 16 and 18 and a transverse cap member 20*. The
ing device may be used at this point so long as rotation
of the drum is not unduly impeded. The lower portion
front and rear frame assemblies 10 and 12 may be in
of the housing 50 de?nes a sump chamber 54 in which
terconnected by suitable bracing (not shown) or alterna
‘liquid extracted from the ?ber slurry is collected. A
tively may be independently anchored on a suitable sup
port.
30
Centrally positioned between the front and rear frame
assemblies 10 and 12 respectively is a rotatable forming
drum generally designated by the numeral 22 in the
drawings. The drum structure includes a pair of bearing
drainage pipe 56 is provided for draining any liquid so
collected from this chamber. The lower portion of the
housing 50 or chamber 54 is separated from the upper
portion of the housing to de?ne an upper chamber 58
by a sealing assembly generally designated by the numeral
rings 24 and 26, each having an axially extending bearing 35 69 and a nozzle ‘and seal assembly generally designated
by the numeral 62. Funther, a partial vacuum may be
portion 28 and a radially outwardly sealing portion 30.
developed in the chamber 54 by exhausting air through
Extending axially between the bearing rings 24 and 26
is a plurality of supporting blades or struts 32. These
supporting blades are welded or otherwise anchored at
their ends to the respective bearing rings and thus provide
with the bearing rings the supporting structure of the
pipes 63 leading from the chamber to a suction pump or
the like (not shown). The chamber 58, on the other
hand, is vented to atmosphere through ‘a pipe 64.
The seal 60 includes upper and lower sealing blades
65 and 66 pivotally mounted on ‘a pair of shafts 68 and
forming drum. The remaining structure of the drum
70 respectively. Prefenably, the sealing blades are urged
provides (the forming surface for the ?brous web and
against the exterior surface of the forming d-rurn 22 under
preferably includes an annular foraminous screen 34
backed up by winding wires 36, which in turn ‘are weld 45 the in?uence of weights '72 and 74, though it will be
understood that other means for e?ecting the proper
ed or otherwise suitably ?xed at the interior edge of the
seal may be used. The lower sealing blade 66, in addi
blades 32. To give the drum additional strength, an
tion
to engaging the outer periphery of the forming drum
nular rings may be formed by providing between the
engages a resilient seal strip 76 which is ?xed to‘ the
blades 32 a plurality of bracing members 38. The provi
housing 50 such as by bracket 78 and continues down
sion of the members 38 will further facilitate engage 50 wardly and against the outer portion of the housing to
ment of sealing devices with the exterior of the drum
form a trough from which a drain pipe 86 leads to facili
as will be more fully described hereinafter.
The screen
34 is retained against wires 36 by any suitable means
such as by wiring or the like (not shown) and secured
against the bearing rings 26 and 26 by generally L-shaped
rings ‘40. The rings 40 will further function ‘as deckle
rings since one ?ange thereof extends radially inwardly
of the screne 34 and therefore will serve to mold or
otherwise fashion the edges of the web formed on the
screen so that they are straight and regular.
Although the foraminous forming screen '34 and the
supporting structure incidental thereto is preferred, it is
tate removing any water or other liquid which may accu
mulate in this vicinity. Further, a nozzle 82 is disposed
55 between the upper and lower sealing blades 65 and 66 to
permit a spray of water between the blades.
A head box 84 of standard construction is suspended
within the forming drum 22 from the transverse frame
members 29 such ‘as by angle brackets 86. The head box
84 includes a slurry of furnish inlet manifold 88 from
which the furnish is fed through conduits 90 into a baffle
chamber 92. This chamber is preferably under a head
of ?uid pressure developed by a suitable compressor (not
to be understood that other suitable drum structures could
shown) feeding through a nipple 93. Thus, the furnish
be used. In this respect, any perforate or porous wall, 65 is fed from the chamber 92 forwardly and downwardly
adequately supported to resist forming pressures and
past a pluraiity of distributor rolls 94 to a slice 96 from
which will permit the passage of liquid but not ?bers,
will suffice.
which it is deposited directly against the interior surface
the lower circumference of the drum and engageable
with the bearing portions 28 of the rings 24 and 26 re
spectively. It will be noted that both the rollers 42 and
the bearing portions 28 of the rings 24 and 26 are formed
tioned, this head box and slice arrangement in and of
of the forming drum screen 34 under pressure. A ?exible
slice lip 98 is adjustably retained ‘against the forming
» The forming drum 22 is rotatably supported in its
position between the frame assemblies 10 and ‘12 by a 70 screen 34 by a plurality of adjusting screws 1%‘ arranged
at intervals across the Width of the slice. As aforemen
plurality of rollers 42 positioned at various places about
itself is standard and as such forms no part of the present
invention.
Since the slice 96 opens to deposit the furnish on the
3,019,158
forming screen 34 directly opposite from the upper and
could be positioned obliquely so as to remove the web
‘lower sealing strips 65 and 66 as well as the water spray
progressively and thus possibly facilitate the transfer of
nozzle 82, the principle under which the seal 60 operates
the web from the drum to the chute.
In the form shown in FIGS. 1 through 4, the chute
structure includes a plenum chamber 126 having a lower
Wall 120, an upper wall 1301, and side walls 132. The
sidewalls 132 extend upwardly past the upper wall 130
so that they form with the upper wall an open top chute.
The upper wall 130 is formed having a plurality of aper
to effect a complete ?uid separation between the cham
bers 54 and 58 in the housing 50 can be readily under
stood. In other words, it will be apparent to those skilled
in the art that the blades 65 and 66 in and of themselves
would not be capable of effecting this seal because of
rthe transverse blades 32 and the interrupted surface thus
formed 011 the exterior of the forming drum. However, 10
tures 13d therein, so that a ?uid medium such as steam
since the furnish is introduced on the interior of the
or compressed air may be introduced into the chamber
forming screen 34 at this precise point and since the great
126 and exhausted upwardly through the apertures 134.
est percentage of liquid passes through the forming screen
In this manner, the web 101 which is transferred from the
at this point, the desired seal is accomplished as a result
of the blades 65 and 66 and nozzle 82 maintaining a suf 15 forming drum 1122 to the chute, is pneumatically sus
pended on the chute during its discharge from within the
?cient amount of liquid about this point on the forming
device to effect a liquid seal.
As shown in FIG. 3, the nozzle and seal assembly 62
is positioned exteriorly of the drum 22 and removed on
the drum circtunference from the siice 96 so that the
sector ‘as de?ned by that portion of the drum between
the slice 96 and the assembly 62 is su?icient to permit the
desired liquid extraction and ?ber formation or web 101
on the screen 34. structurally, the assembly 62, as best
shown in FIG. 4 includes a pair of nozzles 102 and a pair 25
of sealing strip groups 104 ‘and 106 on either side thereof,
each formed of a plurality of sealing strips 108. To over
come the problem of effectively sealing the drum from
the exterior, it will be noted that each of the sealing
strip groups 104 and 106 extend for a distance slightly 30
greater than the spacing between the blades 32. In this
manner, the nozzles 102 are effectively separated or sealed
off from both chambers 54 and 58 in the housing 50 since
vat all times the sealing strips 108 are covering at least
one of the blades 32. To separate the chamber 54 from 35
the chamber 58, an additional seal strip 110 is mounted
on the exterior of the assembly 62 ‘and engageable with
the interior of the wall of the housing 50.
A plurality of roller assemblies 112 are mounted in the
housing 50 for the purpose of urging the sealing and nozzle 40
assembly inwardly against the forming drum 22. Fur
ther, adjustment of the assembly 62 about the periphery
of the drum 22 may be eifected by a rotatable rod 114
threadedly engageable within a sleeve 116 ?xedly mounted
to the assembly 62 and arranged to be driven through a
forming drum. The chute 122 may be retained in position
by any suitable means, and as shown in the drawings is
suspended from the transverse frame members 20 by
brackets .136 and anchored at the frame base members 14
such as by brackets 138. However, other means for sus
pending the chute 122 properly with respect to the drum
interior may be used.
In operation, the furnish is fed through the slice ‘)6 and
deposited on the interior surface of the forming screen
34 of the rotating drum under the in?uence of the pres
sure head in the head box 84.
Because the screen 34 is
Well supported by the winding wires 36, blades 32 and
members 33, there will be little tendency for the screen
to sag, bend or otherwise be harmed in any manner by the
forming pressures exerted thereagainst. Also, no stresses
are placed on the screen due to friction since there is no
movement thereof with respect to its supporting structure.
The rotational speed of the drum 22 is su?lcient to develop
a substantial centrifugal force tending to urge the slurry
and deposited or collected ?bers outwardly against the
screen 34. In addition, however, due to the sealing func
tion of the seal 60 and the seal and nozzle assembly 62,
a vacuum may be created in the chamber 54 such as by
withdrawing air through the pipes 63. Thus, the liquid
from the slurry is forced through the screen 344 due to the
combined effects of centrifugal force and the vacuum in
the chamber 54. Although the greatest percentage of
water extraction will occur in the vicinity of the slice 96,
the extraction occurs continuously while the web is in
worm gear 11% by worm shaft 120. Because of this ar 45 contact with the screen 34 between the slice 96 and the
rangement, the nozzles 102 may be accurately adjusted
assembly 62 and thus adjacent to the chamber 54.
As the drum 22 continues to rotate, the web 101
about the circumference of the drum 22 to permit re
is carried around on the interior thereof until the seal
moval of the Web 101 at precisely the proper point of
104 is reache . Immediately thereafter, the web is
drum rotation.
For the purpose of conveyins7 the web 101 from the 50 removed from the forming screen 3d under the in?uence
of a high pressure blast of steam or air emanating from
interior of the drum 22 to subsequent drying and ?nish
the nozzles 1432. Since the nozzles are located directly
ing apparatus or the like, a discharge conveyor or chute
opposite the screen from the discharge chute lip 124, the
122 is provided. As shown in FIG. 4, the chute 122 ter
web
is gently folded over the lip 124 and deposited on the
minates at its inner end in a smoothly curved lip 124
chute
upper wall 136 where under the in?uence of steam
55
Which parallels the forming screen 34 and is positioned
or air being ejected through the holes 134‘ therein it is
adjacent to the interior thereof opposite the nozzles 102.
?oated downwardly and outwardly from the interior of
Since the web 101, of necessity, must be removed axially
the drum. Thereafter, the partially formed web from
of the drum 22, the chute 122 is ‘formed having a curved
which substantially all of the Water has been removed
con?guration of such characteristics that the web 101 may
be transferred to conventional apparatus for sub
engage the lip 124 while moving radially from the drum 60 may
sequent ?nishing and treatment.
interior and be conveyed in a path having an axial com
ponent of direction equal to or greater than the width of
the drum
Thus, as shown in FIGS. 1 and 2, the chute
A modi?ed form of the chute 102 is shown in FIGS.
5 and 6 of the drawings, In this instance, the chute in
cludes a bottom wall 140, a pair of side walls 142 and a
top
wall 144 to de?ne a plenum chamber 146 and differs
65
and as well, is suitably banked so that the stresses placed
from the embodiment as shown in FIGS. 1 through 4 in
on the Web ‘101 as it is conveyed on the chute are kept
1212 curves downwardly and outwardly from the lip £124,
that the upper wall is formed having a plurality of trans
at a minimum. It will be understood, however, that the
verse
pockets 141$. Positioned concentrically within the
speci?c curve or path taken by the chute 122 is shown
pockets are rolls 150 having shaft extensions 15.2 jour
for illustrative purposes only and that other con?gurations
could be used in this invention. It is to be noted further 70 naled in bearings 154. The bearings are suitably ?xed to
L-shaped runners 156 extending along each side of the
that while the lip 1241 as well as the nozzles 102 are dis
chute and attached to bracket members 158 ‘which in turn
posed horizontally, it is contemplated that these members
are welded or otherwise a?ixed to the bottom Wall 140.
could be arranged otherwise without departing from the
It will be noted that the pockets 148 open upwardly
true spirit and scope of this invention. For example, they 76
along the line intersection of chords established by the
3,019,158
4
plane of the top wall 144 and that the upper portion
of the circumferential surface of the rolls 15% extend
past the top wall 144.
In this manner, the rolls are
positioned to support the web 11H prior to engage
ment thereof with the stationary top Wall 144.
‘As in the previous embodiment, the plenum chamber
f5
chute including bottom, side and top walls de?ning a
plenum chamber adapted to receive ?uid under pressure,
said top wall being formed having apertures for discharg
ing said ?uid upwardly to support said web; and means
for directing a jet of ?uid inwardly through said drum
to transfer the web of the interior of said drum to said
chute.
146 is adapted to receive ?uid under pressure such as
2. An apparatus for forming a continuous ?brous web
compressed air or steam through suitable conduits such
comprising: a rotatable drum having a foraminous cylin
as a nipple 160 and further, the top wall 144 as well as
drical wall; means for depositing a ?ber slurry on the
the pockets 148 therein are formed having apertures 10 interior of said wall, whereby rotation of said drum ef
162 to pneumatically support or ?oat the web 101 on the
fects liquid extraction from said slurry leaving a ?brous
chute. It will be noted, however, that in addition to the
web on the interior of said wall; a chute having a por
apertures 162, nozzles 164 are positioned on the upstream
tion positioned inside and adjacent to said drum wall,
side of the pockets 148 and arranged to direct steam or
said chute including bottom, top and side walls de?ning
15
air from the plenum chamber against the rolls 15%. In
a plenum chamber adapted to receive ?uid under pres
this manner, the rolls 150 are gently rotated and thereby
sure, said top wall being perforate and formed having a
substantially eliminate the possibility of the moving web
101 coming in contact with a stationary surface since
the upper roll surface extend slightly past the upper wall
144 as aforementioned. Although, in FIG. 5, the mov
ing web 101 is shown following the contour of the con
plurality of open top transverse pockets; and rotatable
rolls supported within said pockets, the circumferential
surface of said rolls extending upwardly past said top
wall; and means for directing a jet of ?uid inwardly
through said drum to transfer the web of the interior of
veyor surface, it is contemplated that by properly regu
said drum to said chute.
lating the ?otation pressure or the ?uid pressure in the
3. The apparatus recited in claim 2 including nozzles
plenum chamber 146, the web will be suspended in gentle
extending through the upstream side of said pockets
25
catenaries, virtually unsagging and in a substantially un
whereby steam from said plenum chamber is impinged
stressed condition. Moreover, while rolls 150 are shown
against the surface of said rolls to impart rotation
to be cylindrical, it will be obvious to those familiar in
this art that conical rolls can be used to achieve effective
thereto.
4. An apparatus ‘for forming a continuous ?brous web
conveying along the curved chute. ‘In other words, by in
comprising: a rotatable drum having a foraminous cy
creasing the diameter of the rolls toward the outside of 30 lindrical wall; means for depositing a ?ber slurry on the
the curve, the increased distance traveled by the outside
interior of said wall; a housing positioned about said
of the web is compensated for in a manner well-known
in the conveying roll art.
Thus, it will be seen that by this invention an extreme
ly effective apparatus is provided for continuously form
ing a ?brous web from an aqueous suspension of ?bers.
‘It will be noted that the forming screen 34 is adequately
drum; means for producing a reduced pressure between
said drum and said housing, whereby liquid passes from
the slurry on the interior of said drum wall to said
housing under the combined effects of centrifugal force
due to rotation of said drum and the reduced pressure
to leave a ?brous web on the interior of said drum wall;
supported on the drum 22 in such a manner that the
and means for continuously removing said web from the
entire operation may be effected without in any way
of said drum wall.
bending, ?exing or otherwise stressing the forming screen 110 interior
5. The combination recited in claim 4 in which said
to cause wear and other damage thereto. Accordingly,
means for producing a reduced pressure includes seal
high formation pressures may be used. ‘Further, and
means between said drum and said housing to de?ne a
perhaps most signi?cantly, the combined advantages of
chamber in said housing extending between said slurry
suction and centrifugal force are taken advantage of to
depositing ‘means and said web removing means.
obtain a high degree of water extraction in a brief pe
6. The combination recited in claim 4 in which said
45
riod of time. Moreover, because the effects of the vac
means for continuously removing said web from the in
uum and centrifugal force are combined, the need for a
terior of said drum Wall comprises a chute having a lip
high vacuum and elaborate seal is not needed.
portion positioned inside and adjacent to said drum wall;
It will be noted further that because of the ?uid dis
and means for directing a jet of ?uid inwardly through
charge nozzles in the top wall of the chute plenum cham
50 said drum wall to transfer the web from the interior of
ber the partially formed and still delicate web is re
said drum onto said lip portion.
moved from the wire substantially by ?uid mediums.
7. The method of forming a continuous web from a
First, the blast of steam emanating from the nozzles 102
?ber slurry comprising: pressure forming a ?ber accre
removes the web from the wire 34 in a manner such that
tion to establish a web on the inside of a rotating per
no damage is imparted thereto, and then the gradual 55 forate drum; extracting excess liquid from said web
curving and slopping of the chute 122 and as well, the
under the combined in?uence of centrifugal force and
?uid suspension of the web thereon results in no dele
suction; directing a jet of ?uid under pressure against
terious effects to the web.
Thus, the unique structural arrangements and methods
referred to above, as well as any other features inherent
the exterior of the drum to remove the web inwardly
therefrom; and conveying the web out of the drum On a
upwardly directed ?uid current.
in the new and improved web forming apparatus of this 60 generally
8. The method of removing a ?brous web from the
invention as can be seen completely ?ll the aforemen
interior of a perforate drum comprising: separating the
tioned objectives and generally improve upon the ap
web from the drum under the in?uence of a ?uid jet; and
paratus of this type presently available. It is to be fur
conveying the web from the drum interior on a current
ther understood that since many possible changes can be
65
of compressible ?uid.
made in the web forming apparatus of this invention
without in any way departing from the spirit and scope
References Cited in the ?le of this patent
thereof as de?ned in the appending claims.
UNITED STATES PATENTS
I claim:
1. An apparatus for forming a continuous ?brous web
70
1,531,482
Hang _______________ __ Mar. 31, 1925
comprising: a rotatable drum having a foraminous cylin
drical wall; means for depositing a ?ber slurry on the in
terior of said wall, whereby rotation of said drum effects
liquid extraction from said slurry leaving a ?brous web
on the interior of said wall; a chute having a portion
positioned inside and adjacent to said drum wall, said 75
1,885,334
Darrah' _______________ __ Nov. 1, 1932
981,228
France _______________ __ May 23, 1951
FOREIGN PATENTS
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