Technical Field:
[0001] The present invention concerns a head box being part of a paper making machine and
a method of making paper with said head box.
Related Art:
[0002] It is known to produce paper by using a stock solution that is, in one step of paper
making, fed on a forming wire being transported on a roll. An inlet line feeds that
stock solution to a nozzle that distributes the stock solution on the forming wire.
The forming wire is adapted to extract water from the stock solution as a first step
of producing a layer of paper. The hydrodynamic part of the paper making machine including
inlet line and nozzle is usually called head box.
[0003] The conventional technical details of such paper making machines and head boxes are
well known to the expert.
[0004] Although electronic communication technologies increase in importance, the overall
paper consumption is steadily increasing as well. Therefore, it is of interest to
optimize the output of paper making machines. This can be done by increasing the production
velocity and also by increasing the production width. Although there are improvements
in the acceleration of the mechanical parts of paper making machines, the handling
of the stock solution becomes more and more difficult. Namely, this relates to the
homogeneity of the produced paper in the width direction, i.e. in the axial direction
of the roll.
[0005] There are many prior art documents treating the construction of stock solution inlet
lines and nozzles, i.e. the so called headbox. As an example, it can be pointed to
US 6,004,431 being directed to a better control of the cross direction flow of stock
solution by means of flow control valves.
[0006] Also US 5,833,808 is directed to the control of the edge flow of stock solution in
the headbox nozzle through adjustable valves positioned in edge tubes employing fiber
orientation sensors.
[0007] US 5,196,091, however, proposes to control the cross directional homogeneity by means
of a stock diluting source permitting dilution of the stock solution flowing into
a tube bank.
[0008] US 1,687,447 discloses a paper making machine wherein the width of an opening can
be varied in a lateral direction parallel to the roll that feeds the forming wire.
This is accomplished by a wall being movable by a threaded shaft. The wall forms an
end border of the stock supply chamber that is positioned above the roll carrying
the forming wire.
[0009] US 1,772,484 discloses a paper making machine of the Fourdrinier type showing tapered
portions on the end parts of a roll in order to effectively prevent the stock spreading
out over the edge portions of the forming wire under a shaking action. The disclosed
machine "cuts off" the edges of the stock formed on the forming wire to attain sharp
edges.
[0010] Document DE 198 19 659 A1 discloses a fourdrinier section of a paper making machine
that has a gap between the fourdriniers to extract water from the wet pulp web in
the center. The fourdrinier gap is sealed at the sides using seals and has a drive
synchronized with the fourdrinier drive.
[0011] As a final example, US 6,033,527 is concerned with the improvement of the uniformity
of the velocity profile of the stock solution across the nozzle opening. It is proposed
to use pond sides of the nozzle that are angled inwardly. Further, columns of outer
tubes of the tube bank may also be angled inwardly.
Summary of the Invention:
[0012] The present invention has the object to improve the performance of a head box for
a paper making machine and a related paper making method in view of a high production
velocity with a simultaneously good homogeneity of the produced paper.
[0013] According to the invention, a head box for a paper making machine is proposed, that
has a stock solution inlet line for feeding stock solution, a nozzle for being fed
with said stock solution by said inlet line, and for spraying said stock solution
on a forming wire of said paper making machine during a rotating movement of said
forming wire on a roll relative to said nozzle, wherein said nozzle has an output
opening to be positioned directly adjacent said forming wire, side walls being provided
mutually opposed for essentially inhibiting stock solution flowing out in the axial
direction, wherein the side walls are rotatable with said roll. The invention is characterized
in that the sidewalls define a width of said output opening in an axial direction
of said roll for inhibiting stock solution flowing out of said output opening in said
axial direction.
[0014] Further, the invention is related to a method of making paper using such a head box,
that is characterized in that said side walls define a width of said output opening
in a axial direction of the roll for inhibiting stock solution flowing out of said
output opening in said axial direction.
[0015] Preferred embodiments are given in the dependent claims.
[0016] The inventors have discovered that a relevant reason for non-homogeneities of the
paper are based on the fact that the stock solution in the nozzle, especially at the
nozzle output opening, is not as fast at the outer borders of the usually slit-formed
opening as in the middle. This can be understood by the friction of the stock solution
at the outer side walls at the borders. In contrast to the borders, the parts of the
stock solution flowing in the middle of the nozzle come in contact only with a so-called
upper lip and a so-called lower lip or with one of the lips and the surface of the
roll and the forming wire. The parts of the stock solution flowing at the borders
suffer from additional friction at the side walls adjacent the ends of the inner sides
of the lips.
[0017] The basic idea underlying this invention is to provide a construction in which the
side walls at the last part of the nozzle adjacent the opening to the roll and the
forming wire are movable with the roll so that they can be moved along with the stock
solution flow. Thereby, the velocity loss at the side walls can be essentially reduced
and the homogeneity of the velocity profile much improved. With a better homogeneity,
even higher velocities of roll and the stock solution flow are feasible in order to
increase the production rate.
[0018] Certainly, additional measures to improve the homogeneity and the feasible velocity
can be chosen as proposed in the prior art. However, the present invention has revealed
and proposes to avoid one major source of non-homogeneities and thus offers an important
contribution to the art of paper making. In order to have a simple construction with
side walls moving with the roll, these side walls preferably are annular and concentric
with the roll. Is has to be noted that the side walls are to be understood as the
walls being the end of the stock solution flow path in widthwise cross section, i.
e. the start and the end of the slit form. However, they can be a mechanical part
of the roll as well as of the nozzle or independent of both, as detailed in the following.
[0019] Further, it is to be noted that the head box as defined by the invention is to be
understood in the conventional sense, i.e. as the hydrodynamic unit of the paper making
machine with that line and nozzle but without the roll referred to above and in the
following. However, since the movable side walls are an essential part of the invention
and shall be moved with the roll in the rotating movement explained above, a head
box according to the invention that shall replace a conventional head box in a paper
making machine could optionally also comprise a new roll for the paper making machine.
This roll could be specially adapted to the construction of the movable side walls
and could also be a unit with these. Thus, a head box according to the enclosed claims
is already given by a head box without roll but with side walls according to the invention.
However, a set including the roll with the head box is a preferred embodiment of the
invention. Finally, the invention also refers to the paper machine as a whole.
[0020] In order to have a simple construction, it is further preferred that said slit opening
is defined essentially only by said movable side walls and by the so called lips of
the nozzle being the border of the slit opening between the side walls and being opposed
to each other. The lips are fixed with regard to the rotating movement of the roll
and the side walls, of course. However, at least one of the lips can be movable in
other respect, e.g. with regard to an adjustability of the distance between the lip
and the forming wire. For the sake of clarity, it is to be explained that usually
the flow direction of the stock solution within the nozzle is directed in a direction
more or less tangential to the roll. This means that the slit form of the opening
appears in cross-section perpendicular to the flow direction. However, the lower lip
usually ends upstream from the upper lip so that there is an area of stock solution
flow in which the channel of flow is defined also by the forming wire being transported
on the roll and the roll underlying the forming wire and possibly appearing beneath
the borders of the forming wire, instead of the lower lip. In this context, the opening
of the nozzle to which the invention refers appears at the end of the lower lip where
the first contact of the stock solution with the forming wire takes place and where
movable sidewalls shall be present. However, these movable sidewalls should preferably
guide the stock solution flow until the end of the upper lip. Further preferably,
the movable sidewalls are annular and thus go around the complete circumference of
the roll.
[0021] It is further preferred that said lips comprise side parts directly adjacent said
annular side walls and sealed against the side walls in order to keep the stock solution
within the nozzle as regards the direction perpendicular to the main flow direction.
These side parts can be integral parts of one of the lips or separate parts mounted
to the lips in a sealing manner. It is further preferred, that said side parts are
at least in part positioned radially outwards of said annular side walls. This improves
the possibilities for sealing between the side parts and the side walls. For illustration,
it is referred to the description of the embodiments.
[0022] One advantageous choice for a sealing is a pressure water sealing fed by a pressure
water conduit. The pressure water sealing has the first advantage to allow high relative
velocities between the side walls and the side parts without substantial friction
problems in view of temperature, power loss or durability. Second, the pressure water
sealing allows to provide for some water flow from the sealing directed to the stock
solution. This can be advantageous to inhibit a congestion of stock solution or solid
parts of stock in the border areas of the nozzle, i.e. in the region of the side wall.
When there is a small but more or less continuous water flow from the sealing to the
main stock solution flow, the border areas will be kept free.
[0023] An alternative for the above mentioned sealing could comprise conventional sealing
rings (e.g. of elastomers), possibly in combination with conventional bearings as
roller bearings. In order to improve the sealing properties of the sealing rings,
a container filled with a pressurized fluid (water, air and the like) can be used
to press the sealing ring against a sealing surface.
[0024] It is preferred that the sealing rings are pressed against those sealing surfaces
that shall rotate relative to the sealing itself in order to protect the above mentioned
container. The container itself can be a closed container e.g. of plastic with fluid
contents, but can also be a conduct that is fed by an exterior fluid source.
[0025] It has been stated before that the side walls can, but need not be parts of the roll.
In a preferred embodiment, the side walls are axially movable relative to the roll
in a limited manner. This can be preferred in order to compensate for some axial movements
of the forming wire that regularly occur during the transport of the forming wire
on the roll. This applies especially to long-wire machines or so-called Fourdrinier
machines as well as to twin-wire and to inclined-wire machines. These Fourdrinier
machines are a preferred application for the invention independent from the axial
movability mentioned above. In case of a Fourdrinier paper making machine, the roll
mentioned so far in this description is the so called breast roll.
[0026] When having axially movable side walls, the lips can be fixed relative to the side
walls or relative to the roll as regards this axial movement. In the one case, the
lips are moved together with the side walls in the axial direction, in the other case,
there must be some free space at the connection between the lips and the side walls
(or the side parts of the lips and the side walls to be precise) to compensate for
the axial movement.
[0027] It is to be seen that usual forming wires are quite flexible and thus are not well
adapted to exert substantial axial forces during the above mentioned axial movements.
Thus, a passive movability of the side walls that is activated by the forming wire
is usually not preferred in order to avoid damages or crumbling of the wire at the
borders. Instead, a drive by means of an electric motor, pneumatic or hydraulic means
and the like can be provided, that acts in response to signals from a position sensor
detecting an axial position of the forming wire. I.e. the axial movability can be
controlled in an active manner.
[0028] If the side walls are fixed to the roll it is preferred that they have tapered inward
surfaces that are adapted to allow some axial movement but to inhibit excessive axial
movement of the forming wire. Especially, concave tapered surfaces are preferred,
where the term concave is to be understood as seen in a section along the axial direction.
A forming wire can run up said tapered surfaces for some distance but is forced to
increase its length in the circumferential direction of the roll thereby. Thus, a
backdriving force can be created that inhibits too large axial movements. By concave
surfaces, this backdriving force is rapidly increasing with the axial movement distance
of the forming wire.
Description of Preferred Embodiments:
[0029] In the following, several embodiments of the invention are explained. These embodiments
are preferred for individual reasons but are merely meant as illustrative examples.
They shall not be understood to limit the scope of the invention.
[0030] In the drawings:
figure 1 is a schematic drawing of one side portion of a breast roll with a section
through a nozzle in a head box according to the invention as a first embodiment;
figure 2 is comparable to figure 1 but shows a second embodiment;
figure 3 illustrates the first and the second embodiment by means of a side view along
the axis of the breast roll;
figures 4, 5 and 6 are schematic cross sectional drawings of a third embodiment and
show the structure of a nozzle in a head box according to the invention;
figure 7 shows a fourth embodiment, namely a breast roll and a section through a nozzle
of a head box according to the invention; and
figure 8 is comparable to figure 3 but refers to the fourth embodiment of figure 7.
[0031] In figure 1, reference numeral 1 shows a breast roll of a Fourdrinier (long wire)
paper making machine. Only the (in the sense of the figure) right portion of the breast
roll is shown. 2 shows a part of an axis of breast roll 1, the axial direction being
shown as a dash-dotted line in figure 1 as well as in figure 2 and 3.
[0032] A conventional forming wire is numerated with 3 and only schematically shown in section.
4 is a concentric ring on breast roll 1, being an integral part of breast roll 1 and
embodying an annular movable side wall according to the invention. This side wall
4 shows a concavely tapered inward surface 5 on which forming wire 3 can run up as
sketched in figure 1.
[0033] 6 is an upper lip of the nozzle of the paper making machine that is provided with
a side part 7 gripping around side wall 4 in U-shape manner. A conventional sliding
sealing 8 is positioned between the outer arm of side part 7 and the outer side of
movable side wall 4. Sealing 8 prevents stock solution in the channel between upper
lip 6, breast roll 1, side wall 4 with surface 5 and wire 3 from flowing out. It is
adapted to withstand a fast relative movement between side parts 7 and side wall 4.
9 is a stabilization structure for improving the rigidity of upper lip 6 with side
part 7 (and connecting the shown side part with the opposed not shown side part) and
is without fundamental importance for the invention.
[0034] It can be seen that upper lip 6 and side wall 4 with surface 5 together with breast
roll 1 and forming wire 3 define a channel for stock solution flow in which only upper
lip 6 does not participate in the rotating movement of breast roll 1 and wire 3. Further,
a limited axial movement of forming wire 3 is possible according to the concave shape
of surface 5 with relatively large radius of curvature. Namely, the second side of
breast roll 1 and the nozzle (parts 6, 7, 8, 9) is symmetrical. The distance between
shown side wall 4 and the second non-shown side wall is somewhat larger than the width
of forming wire 3 in order to allow some oscillation of wire 3.
[0035] Before a modification of this embodiment is shown along with an explanation of figure
2, reference is made to figure 3. Identical numerals refer to the same parts as in
figure 1. Figure 3 is seen in the axial direction so that breast roll 1 appears as
a circle. Wire 3 runs around breast roll 1 along only somewhat less than half of its
circumference and spreads to other transport rolls as usual in Fourdrinier paper making
machines. That run of wire 3 that is approximately vertical in figure 3 carries the
stock solution away from the channel as described in connection with figure 1 and
extracts water from the stock solution.
[0036] The stock solution originates from nozzle 10 that is fed by means of a manifold 11
and a header 12 of a conventional stock solution inlet line.
[0037] Downstream from manifold 11 begins nozzle 10 with upper lip 6 and a lower lip 14
shown in figure 3. It can be seen that upper lip 6 and lower lip 14 narrow the dimension
of the channel for the stock solution in one direction perpendicular to the flow direction.
However, in the second direction perpendicularly to the flow, the channel is as broad
as breast roll 1 (including manifold 11 and thus fed from several parallel tubes of
tube bank 12).
[0038] When arriving at the circumference of breast roll 1 with lower lip 14 in a nearly
tangential manner, lower lip 14 ends. Thus, the opening of nozzle 10 at breast roll
1 is situated at that end of lower lip 14. Further, upper lip 6 projects in a manner
concentrical to breast roll 1 and in a nearly constant distance from the circumference
of breast roll 1 for approximately a quarter of said circumference. This is in order
to guide the stock solution already on wire 3 until wire 3 becomes distant from the
circumference of breast roll 1. Thus, a channel is formed without lower lip 14, as
can be seen in the section of figure 1.
[0039] Figure 1 shows that side walls 4 are concentrical rings around the complete circumference
of breast roll 1. Thus, from a point somewhat upstream of the end of lower lip 14
down to the end of the channel (without lower lip 14) mentioned above, rotating side
walls are provided. During this length, the flow of stock solution can develop a uniform
velocity profile in the axial direction.
[0040] Figure 3 further shows that nozzle 10 is held by a pivoting device 13 so that namely
upper lip 6 can be pivoted around the axis given at 13. This helps to adjust the height
defined by upper lip 6 above wire 3 at the end of upper lip 6 and thus helps to define
the thickness of the stock layer at this point.
[0041] It can also be seen from figure 3, side part 7 of upper lip 6 extends around the
complete circumference of annular side wall 4 which is necessary in order to guarantee
the sealing function of sealing 8.
[0042] Figure 2 shows a second embodiment and can be directly compared to figure 1. Here,
the left side of breast roll 1 is shown. Identical numerals refer to similar components.
[0043] Upper lip 6' has a non-integral side part 7' being fixed to upper lip 6' by means
of bolts. Side wall ring 4' shows a somewhat different circumferential surface but
an analogous concave inward surface 5.
[0044] Between the modified circumferential surface of side wall 4' and an inner surface
of side part 7' a pressure water sealing 15 is provided. This pressure water sealing
15 is fed by a pressure water conduit 16 feeding pressure water into a first ring
space 17 distributing pressure water around the complete circumference of ring 4'.
Therefrom, the pressure water is pressed though very small slits being the actual
pressure water sealing 15 and connecting first inner space 17 with second ring spaces
18. These slits are directed radially and have an axial dimension of the order of
0.1 mm. This gives a good sealing effect and minimizes water consumption. From the
outer second ring space 18, the sealing water flows to the exterior and can be recovered,
if necessary. From the inner second ring space 18, the pressure water flows into the
channel of the stock solution flow, as long as in the region of upper lip 6'. This
inhibits congestions as explained earlier.
[0045] First and second ring spaces 17 and 18 have a varying volume depending on the height
that is given by the adjustability of upper lip 6' (compare pivoting means 13 in figure
3).
[0046] The side view of figure 3 applies also to the second embodiment of figure 2. Also
the explanations given in connection with figure 3 apply to the second embodiment.
The main difference between the first and second embodiment consists in the type of
sealing of the stock solution channel.
[0047] Figures 4, 5 and 6 show a third embodiment and show a left and a right side of a
breast roll 1' with sectional structure of a nozzle as in figures 1 and 2 (the middle
of breast roll 1' is omitted).
[0048] Breast roll 1' differs from the embodiments of figures 1, 2 and 3 in that annular
side walls 4" are not an integral part of breast roll 1'. Instead, annular side walls
are implemented by rings 4" that are axially shiftable relative to breast roll 1'.
Therefore, a slide bush 19 is provided between each side wall ring 4" and pressed
roll 1'. Additionally, elastomer sealings 20 inhibit stock solution flowing therethrough.
[0049] Further, side wall rings 4" are slideable against modified side parts 7" fixedly
mounted to a stabilization and holding structure 9' (hollow section) of an upper lip
6".
[0050] Between side part 7" and side wall rings 4", again a pressure water sealing 15' with
a pressure water inlet 16' is provided. Sealing 15' essentially consists in a narrow
slit between a circumferential surface of each side wall ring 4" and an inner circumferential
surface of respective side part 7". Pressure water flows through inlet 16' into a
first ring space 17' and therefrom through sealing slits 15' to the exterior and to
a second ring space 18' that is connected to the interior channel by means of inner
sealing slit 15'.
[0051] A shifting movement of side wall rings 4" relative to breast roll 1' goes along with
a shifting between side wall rings 4" and upper lip 6" with side part 7" because the
latter are in fixed position relative to breast roll 1'. Therefore, ring spaces 17'
and 18' vary in volume and can even disappear as appears from figures 5 and 6.
[0052] In order to allow said shifting movement of side wall rings 4", upper lip 6" has
a width that is somewhat smaller than the distance between both side wall rings 4".
This means that stock solution will flow up to inner sealing slit 15' but not beyond.
Congestions will be prevented by pressure water coming therethrough.
[0053] The main difference between the third embodiment in figures 4, 5 and 6 and the first
and the second embodiments is the axial shiftability of side wall rings 4" in relation
to breast roll 1' and upper lip 6". The third embodiment and the second embodiment
have the pressure water sealing in common.
[0054] The axial movement of side wall rings 4" is activated by a drive (not shown in figures
4, 5 and 6) that will be explained with reference to figure 7. This drive operates
in response to an optical sensor for detection of the position of forming wire 3.
[0055] Figures 7 and 8 describe a last embodiment of the invention. Figure 7 shows a view
analogous to figures 1, 2, 4, 5, 6, whereas figure 8 can be compared to figure 3.
Again, similar parts are given identical reference numerals.
[0056] Here, as in the third embodiment, axially movable side wall rings 4''' are mounted
on a breast roll 1". Sliding keys 21 for transmitting the rotating movement and allowing
an axial movement, and sealings 20' are shown. An upper lip 6"' is provided between
side wall rings 4''' and slides against them during rotation of breast roll 1" and
side walls 4"'. A sealing is provided there-between but not shown in figure 7.
[0057] Side wall rings 4''' are mounted at structural parts 22 of the nozzle by means of
roller bearings 23. Between structural parts 22 and side wall rings 4''', an elastomer
sealing ring 24 and, axially outwards of ring 24, a pressure air container ring 25
is provided (on each side naturally). Pressure air container ring 25 is adapted to
press sealing ring 24 axially inwardly in order to improve its sealing properties.
Parts 24 and 25 do not participate in the rotating movement, i.e. side wall rings
4''' slide against sealing rings 24.
[0058] Comparing figure 7 with figures 4, 5, and 6 reveals that in the fourth embodiment
the complete set of side wall rings 4''', structural parts 22, upper lip 6"', and
further, according to figure 8, lower lip 14', manifold 11' and header 12, is axially
shiftable as a whole. i.e. the nozzle can be axially moved as a whole. This movability
is compensated by a soft upstream connection of header 12 as seen in figure 7 at 26.
[0059] The movement of the nozzle is activated by a movement drive 27 symbolized in the
lower left part of figure 7 and acting on manifold 11'. Drive 27 can be a pneumatic,
hydraulic or electric motor drive. The details of a shiftable support of the nozzle
are not shown but obvious to the expert.
[0060] Again, the movement of the nozzle with drive 27 is activated in response to a signal
from a (not shown) optical sensor that detects the position of forming wire 3.
[0061] 28 shows another drive for driving the pivoting movement around pivoting means 13
already explained earlier for adjusting the height of upper lip 6"' above forming
wire 3 at the end of upper lip 6"'. During such an adjustment movement, upper lip
6"' can slide against side wall rings 4''' because of the sliding sealing provided
therebetween and mentioned earlier.
[0062] By the way, it has to be noted that manifolds 11 and 11' (being somewhat longer)
and header 12 can have various advantageous structures in order to further improve
the homogeneity of the paper produced. Namely, manifolds 11 and 11' can consist of
single pipes of various section forms, e.g. square or circular.
[0063] The fourth and the third embodiments have in common the axial shiftability of side
walls 4" and 4"'. The differences comprise i.a. pressure water sealings 15' in contrast
to sealing 24, 25 and the shiftability of lips 6"' and 14' and the rest of the nozzle
in contrast to the static nozzle of the third embodiment.
[0064] The first and the second embodiments, however do not have axially shiftable parts
besides the usually unavoidable movements of forming wire 3' (in case of a Fourdrinier
machine). The structure is somewhat more simple, however, there might be some increased
wear of forming wire 3 at the borders depending on its quality.
[0065] All four embodiments produce paper with very good homogeneity. This refers especially
to both the homogeneity of the fiber orientation in the paper (especially at the outer
borders in the width direction) as well as the fiber distribution homogeneity. The
fiber orientation is the ratio of fiber lying in a defined direction, e.g. the machine
direction compared to the cross direction. The fiber distribution is the relative
weight of fibers per unit area across the width of the machine. The homogeneities
of both have been a problem with various machines of the prior art.
1. A head box for a paper making machine, said head box having a stock solution inlet
line (11, 11', 12) for feeding stock solution,
a nozzle (4", 4''', 6 - 6''', 14, 14') for being fed with said stock solution by said
inlet line (11, 11', 12), and for spraying said stock solution on a forming wire (3)
of said paper making machine during a rotating movement of said forming wire (3) on
a roll (1 - 1") relative to said nozzle (4", 4''', 6 - 6''', 14, 14'),
wherein said nozzle (4", 4''', 6 - 6"', 14, 14') has an output opening to be positioned
directly adjacent said forming wire (3),
side walls (4 - 4"') being provided mutually opposed for essentially inhibiting stock
solution flowing out in said axial direction
wherein said side walls (4 - 4''') are rotatable with said roll (1 -1") in said rotating
movement relative to said nozzle (4",4"', 6 - 6"', 14, 14')
characterized in that said side walls defining a width of said output opening in an axial direction of
said roll (1 -1") for inhibiting stock solution flowing out of said output opening
in said axial direction.
2. A head box according to claim 1, wherein said side walls (4 - 4''') are annular and
adapted to be concentric with said roll (1 - 1").
3. A head box according to claim 2, wherein said nozzle (4", 4"', 6 -6"', 14, 14') has
lips (6 - 6"', 14, 14'), at least one of which comprises side parts (7 - 7") being
directly adjacent to said annular side walls (4 - 4"'), a sealing (8, 15, 15', 24,
25) being provided between said lip side parts (7 - 7") and said side walls (4 -4"')
for essentially inhibiting stock solution flowing out and for allowing a rotating
movement of said side walls (4 - 4"') with said roll (1 - 1")relative to said lip
side parts (7 - 7").
4. A head box according to claim 3, wherein said sealing comprises a pressure water sealing
(15, 15').
5. A head box according to claim 4, wherein said pressure water sealing (15, 15') is
adapted to provide some water flow from said sealing (15, 15') to said stock solution
for inhibiting a stock congestion at said side walls (4, 4'").
6. A head box according to one of the preceding claims, wherein said side walls (4, 4"')
are adapted to be axially movable relative to said roll (1, 1") in order to compensate
for some axial movement of said forming wire (3) during said movement.
7. A head box according to claim 6, wherein said nozzle (4"', 6"', 14') is fixed to said
side walls (4"') with regard to said axial movability.
8. A head box according to claim 6 or 7 with a movement drive (27) for said axial movability
and with a sensor for detecting a position of said forming wire (3) in said axial
direction, wherein said movement drive (27) is controllable in response to said forming
wire position sensor.
9. A head box according to one of claims 3 to 8, wherein said sealing comprises sealing
rings (24) and elastic pressure fluid containers (25) for pressing that sealing rings
(24) against sealing surfaces.
10. A head box according to one of claims 1 to 5, wherein said side walls (4, 4') are
adapted to be fixed to said roll (1) and have tapered surfaces (5) on inner sides
thereof for allowing some axial movement and inhibiting an excessive axial movement
of said forming wire (3) on said roll (1).
11. A head box according to claim 10, wherein said tapered surfaces (5) are concave in
a section along said axial direction.
12. A head box according to one of the preceding claims adapted for a Fourdrinier or twin-wire
or inclined-wire paper making machine.
13. A head box according to one of the preceding claims, comprising said roll (1 - 1").
14. A method of making paper using a head box according to one of the preceding claims
and comprising the steps of
providing a stock solution inlet line (11, 11" 12) for feeding stock solution,
providing a nozzle (4", 4''', 6 - 6"', 14, 14') for being fed with said stock solution
by said inlet line (11, 11', 12),
providing a forming wire (3) for receiving said stock solution from said nozzle (4",
4"', 6 - 6"', 14, 14'), for extracting water from said stock solution, and
providing a roll (1 - 1") for a rotating movement for transporting said forming wire
(3),
wherein side walls (4 -4"') being provided mutually opposed, and
wherein said nozzle (4", 4"', 6 -6"', 14, 14') has
an output opening directly adjacent said forming wire (3),
said side walls essentially inhibiting stock solution flowing in said axial direction
wherein said side walls (4- 4"') are rotated with said roll (1 -1") in said rotating
movement during paper making,
characterized in that said side walls define a width of said output opening in an axial direction of said
roll (1 -1") for inhibiting stock solution flowing out of said output opening in said
axial direction.
15. A paper making machine comprising a head box according to one of claims 1 -13.
1. Stoffauflauf für eine Papiermaschine mit einer Papierstoffeinströmleitung (11, 11',
12) zum Zuführen von Papierstoff,
einer Düse (4", 4"', 6-6"', 14, 14') zum mit dem Papierstoff durch die Einströmleitung
(11, 11', 12) Versorgtwerden und zum Aufsprühen des Papierstoffs auf ein Sieb (3)
der Papiermaschine während einer Drehbewegung des Siebes (3) auf einer Walze (1-1")
relativ zu der Düse (4", 4"', 6-6"', 14, 14'),
wobei die Düse (4", 4"', 6-6"', 14, 14') eine direkt dem Sieb (3) benachbart angeordnete
Ausstoßöffnung aufweist,
wobei einander entgegengesetzte Seitenwände (4-4"') zum im Wesentlichen ein Ausströmen
von Papierstoff in der axialen Richtung Verhindern vorgesehen sind,
wobei die Seitenwände (4-4"') bei der Drehbewegung relativ zu der Düse (4", 4"', 6-6"',
14, 14') mit der Walze (1-1") drehbar sind,
dadurch gekennzeichnet, dass die Seitenwände eine Breite der Ausstoßöffnung in einer axialen Richtung der Walze
(1 -1") begrenzen, um einem Ausströmen von Papierstoff aus der Ausstoßöffnung in der
axialen Richtung entgegenzuwirken.
2. Stoffauflauf nach Anspruch 1, bei dem die Seitenwände (4-4"') ringförmig sind und
dazu ausgelegt sind, zu der Walze (1-1") konzentrisch zu liegen.
3. Stoffauflauf nach Anspruch 2, bei dem die Düse (4", 4"', 6-6"', 14, 14') Lippen (6-6"',
14, 14') aufweist, von denen zumindest eine Seitenteile (7-7") aufweist, die zu den
ringförmigen Seitenwänden (4-4"') direkt benachbart sind, wobei zwischen den Lippenseitenteilen
(7-7") und den Seitenwänden (4-4"') eine Dichtung (8, 15; 15', 24, 25) vorgesehen
ist, um ein Ausströmen von Papierstoff im Wesentlichen zu verhindern und eine Drehbewegung
der Seitenwände (4-4"') zusammen mit der Walze (1-1 ") relativ zu den Lippenseitenteilen
(7-7") zu erlauben.
4. Stoffauflauf nach Anspruch 3, bei der die Dichtung eine Druckwasserdichtung (15, 15')
aufweist.
5. Stoffauflauf nach Anspruch 4, bei der die Druckwasserdichtung (15, 15') dazu ausgelegt
ist, ein gewisses Ausströmen von Wasser aus der Dichtung (15, 15') in den Papierstoff
zuzulassen, um einer Papierstoffverstopfung an den Seitenwänden (4, 4"') entgegenzuwirken.
6. Stoffauflauf nach einem der vorstehenden Ansprüche, bei dem die Seitenwände (4, 4"')
dazu ausgelegt sind, axial relativ zu der Walze (1, 1") beweglich zu sein, um eine
gewisse Axialbewegung des Siebes (3) während der Bewegung auszugleichen.
7. Stoffauflauf nach Anspruch 6, bei der die Düse (4"', 6"', 14') im Hinblick auf die
axiale Beweglichkeit an den Seitenwänden (4"') festgelegt ist.
8. Stoffauflauf nach Anspruch 6 oder 7 mit einem Bewegungsantrieb (27) für die axiale
Beweglichkeit und mit einem Sensor zum Erfassen einer Position des Siebes (3) in der
axialen Richtung, wobei der Bewegungsantrieb (27) ansprechend auf den Siebpositionssensor
steuerbar ist.
9. Stoffauflauf nach einem der Ansprüche 3-8, bei dem die Dichtung Dichtringe (24) und
elastische Druckfluidbehälter (25) zum Andrücken der Dichtringe (24) gegen Dichtflachen
aufweist.
10. Stoffauflauf nach einem der Ansprüche 1-5, bei dem die Seitenwände (4, 4') dazu ausgelegt
sind, an der Walze (1) festgelegt zu sein, und schräge Oberflächen (5) an ihren Innenseiten
aufweisen, um eine Axialbewegung des Siebes (3) auf der Walze (1) zuzulassen und einer
übermäßigen Axialbewegung des Siebes (3) auf der Walze (1) entgegenzuwirken.
11. Stoffauflauf nach Anspruch 10, bei dem die schrägen Oberflächen (5) im Schnitt entlang
der axialen Richtung konkav sind.
12. Stoffauflauf nach einem der vorstehenden Ansprüche, der ausgelegt ist für eine Fourdrinier-
oder Doppelsieb- oder Schrägsieb-Papiermaschine.
13. Stoffauflauf nach einem der vorstehenden Ansprüche ausgestattet mit der Walze (1-1").
14. Verfahren zur Papierherstellung unter Verwendung eines Stoffauflaufs nach einem der
vorstehenden Ansprüche und mit den Schritten
Vorsehen einer Papierstoffeinströmleitung (11, 11', 12) zum Zuführen von Papierstoff,
Vorsehen einer Düse (4", 4"', 6-6"', 14, 14') zum durch die Einführleitung (11, 11',
12) mit dem Papierstoff Versorgtwerden,
Vorsehen eines Siebes (3) zum Aufnehmen des Papierstoffs aus der Düse (4", 4"', 6-6"',
14, 14') und zum Abführen von Wasser aus dem Papierstoff, und
Vorsehen einer Walze (1-1") für eine Drehbewegung zum Transportieren des Siebes (3),
wobei die Seitenwände (4-4"') einander entgegengesetzt vorgesehen sind und
wobei die Düse (4", 4"', 6-6"', 14, 14') aufweist
eine dem Sieb (3) direkt benachbarte Ausstoßöffnung,
wobei die Seitenwände ein Ausströmen des Papierstoffs in der axialen Richtung im Wesentlichen
verhindern,
wobei die Seitenwände (4-4"') bei der Drehbewegung bei der Papierherstellung mit der
Walze (1-1") drehbar sind,
dadurch gekennzeichnet, dass die Seitenwände eine Breite der Ausstoßöffnung in einer axialen Richtung der Walze
(1-1") begrenzen, um einem Ausströmen von Papierstoff aus der Ausstoßöffnung in der
axialen Richtung entgegenzuwirken.
15. Papiermaschine mit einem Stoffauflauf nach einem der Ansprüche 1-13.
1. Une caisse d'arrivée pour une machine à papier, ladite caisse étant équipée d'une
conduite d'arrivée pour la pâte (11,11',12) destinée à l'alimentation en pâte, d'une
buse (4", 4"', 6-6"', 14, 14') devant être alimentée avec ladite pâte par ladite conduite
d'arrivée (11,11',12), pour pulvériser ladite pâte sur une toile (3) de ladite machine
à papier, lors d'un mouvement rotatif de ladite toile (3) sur un rouleau (1-1") relatif
à ladite buse (4", 4"', 6-6"', 14, 14'),
où cette buse (4", 4"', 6-6"', 14, 14') possède un orifice de sortie positionné directement
à proximité de la dite toile (3),
des parois latérales (4-4"') disposées de manière à se faire face pour éviter principalement
que la pâte ne s'échappe dans la direction axiale,
lesdites parois latérales (4-4"') pouvant tourner avec ledit rouleau (1-1") au cours
dudit mouvement rotatif relatif à ladite buse (4", 4"', 6-6"', 14, 14')
et étant caractérisées par le fait qu'elles définissent la largeur dudit orifice de sortie dans la direction axiale dudit
rouleau (1-1") pour éviter que la pâte ne s'échappe dudit orifice de sortie dans ladite
direction axiale.
2. Une caisse d'arrivée conforme à la revendication 1, avec lesdites parois latérales
(4-4"') sont annulaires et adaptes pour être disposes concentriquement sur ledit rouleau
(1-1").
3. Une caisse d'arrivée conforme à la revendication 2, où ladite buse (4", 4"', 6-6"',
14, 14') possède des lèvres (6-6"', 14, 14'), l'une d'entre elles au moins équipée
de parties latérales (7-7") directement adjacentes aux dites paroi latérales annulaires
(4-4"'), un dispositif d'étanchéité (8,15, 15', 24, 25) étant monté entre lesdites
parties latérales de lèvres (7-7") et les dites parois latérales (4-4"') essentiellement
pour éviter que la pâte ne s'échappe et pour permettre un mouvement rotatif des dites
parois latérales (4-4"') avec ledit rouleau (1-1") relatif aux dites pièces latérales
de lèvres (7-7").
4. Une caisse d'arrivée conforme à la revendication 3, où ledit dispositif d'étanchéité
est équipé d'un joint à eau sous pression.
5. Une caisse d'arrivée conforme à la revendication 4, où ledit joint à eau sous pression
(15,15') et adapte pour permettre une certaine alimentation en eau depuis le dit joint
(15,15') à la dite pâte, pour éviter une congestion de la pâte sur lesdites parois
latérales (4, 4"').
6. Une caisse d'arrivée conforme à l'une des précédentes revendications, où lesdites
parois latérales (4, 4') sont adaptées pour être mobiles axialement relativement audit
rouleau (1, 1") pour permettre la compensation d'un mouvement axial de ladite toile
(3) pendant ledit mouvement.
7. Une caisse d'arrivée conforme à la revendication 6, où ladite buse (4"', 6"', 14')
est fixée aux dites parois latérales (4"') en ce qui concerne ladite mobilité axiale.
8. Une caisse d'arrivée conforme aux revendications 6 ou 7, avec un moteur (27) pour
ladite mobilité axiale, et avec un capteur pour la détection de la position de ladite
toile (3) dans ladite direction axiale, où ledit moteur est contrôlable en réponse
audit capteur de position de la toile.
9. Une caisse d'arrivée conforme à l'une des revendications 3 à 8, où ledit dispositif
d'étanchéité est équipé de bagues jointives (24) et de conteneurs de fluide sous pression
élastiques (25) pour presser ces bagues jointives (24) contre les surfaces d'étanchéité.
10. Une caisse d'arrivée conforme à l'une des revendications 1 à 5, où lesdites parois
latérales (4, 4') sont adaptées pour être fixées sur ledit rouleau (1) et ont des
surfaces coniques (5) sur les faces intérieures pour permettre un certain mouvement
axial et éviter un mouvement axial excessif de ladite toile (3) sur ledit rouleau
(1).
11. Une caisse d'arrivée conforme à la revendication 10, où lesdites surfaces coniques
(5) sont concaves dans une coupe dirigée le long de ladite direction axiale.
12. Une caisse d'arrivée conforme à l'une des précédentes revendications adaptée à une
machine à papier Fourdrinier ou à double toile ou à toile inclinée.
13. Une caisse d'arrivée conforme à l'une des revendications précédentes, équipée dudit
rouleau (1-1").
14. Une procédé de fabrication de papier utilisant une caisse d'arrivée conforme à l'une
des précédentes revendications comportant les phases suivantes:
prévoir une conduite d'arrivée de la pâte (11,11', 12) pour l'alimentation en pâte,
prévoir une buse (4", 4"', 6-6"', 14, 14') alimentée par ladite pâte par ladite conduite
d'arrivée (11, 11', 12)
prévoir une toile (3) recevant ladite pâte de ladite buse (4", 4"', 6-6"', 14, 14')
pour extraire l'eau de ladite pâte, et
prévoir un rouleau (1-1") pour un mouvement rotatif transportant ladite toile (3),
où les parois latérales (4-4"') sont disposées face à face et
où ladite buse (4", 4"', 6-6"', 14, 14') a
un orifice de sortie directement adjacent à ladite toile (3)
lesdites parois évitant essentiellement que la pâte ne s'échappe dans ladite direction
axiale
lesdites parois latérales (4-4"') tournant avec ledit rouleau (1-1") au cours dudit
mouvement de rotation pendant la fabrication du papier,
caractérisée par le fait que lesdites parois latérales définissent la largeur dudit orifice de sortie dans la
direction axiale dudit rouleau (1-1") pour éviter que la pâte ne s'échappe dudit orifice
de sortie dans ladite direction axiale.
15. Une machine à papier comprenant une caisse d'arrivée conforme à l'une des revendications
1-13.