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EP 1 368 112 B1 |
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EUROPEAN PATENT SPECIFICATION |
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Mention of the grant of the patent: |
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18.11.2009 Bulletin 2009/47 |
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Date of filing: 21.02.2002 |
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International Patent Classification (IPC):
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International application number: |
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PCT/FI2002/000141 |
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International publication number: |
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WO 2002/072250 (19.09.2002 Gazette 2002/38) |
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ARRANGEMENT FOR MIXING FLOWS IN PAPERMAKING PROCESS
ANORDNUNG ZUM MISCHEN VON STRÖMEN BEI EINEM PAPIERHERSTELLUNGSVERFAHREN
ENSEMBLE POUR MELANGER DES COURANTS DANS UN PROCESSUS DE FABRICATION DU PAPIER
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Designated Contracting States: |
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AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR |
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Priority: |
21.02.2001 FI 20010335 11.05.2001 US 290362 P
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Date of publication of application: |
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10.12.2003 Bulletin 2003/50 |
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Proprietor: Metso Paper, Inc. |
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00130 Helsinki (FI) |
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Inventors: |
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- LAMMINEN, Perttu
FIN-33180 Tampere (FI)
- HIETANIEMI, Matti
FIN-40420 Jyskä (FI)
- SAMS, Juhani
FIN-40520 Jyväskylä (FI)
- LINDROOS, Kati
FIN-33720 Tampere (FI)
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Representative: TBK-Patent |
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Bavariaring 4-6 80336 München 80336 München (DE) |
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References cited: :
DE-A1- 4 211 291
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FI-B- 104 384
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- PATENT ABSTRACTS OF JAPAN & JP 07 204 480 A (KUBOTA CORP) 08 August 1995
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Note: Within nine months from the publication of the mention of the grant of the European
patent, any person may give notice to the European Patent Office of opposition to
the European patent
granted. Notice of opposition shall be filed in a written reasoned statement. It shall
not be deemed to
have been filed until the opposition fee has been paid. (Art. 99(1) European Patent
Convention).
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[0001] The invention relates to a method of mixing flows with each other in a papermaking
process, comprising the features defined in the preamble of claim 1.
[0002] The invention further relates to a mixer for mixing flows in a papermaking process,
comprising the features defined in the preamble of claim 5.
[0003] The invention further relates to feeding equipment of a head box of a paper machine,
comprising the mixer according to the invention.
[0004] There is a plurality of objects in different papermaking processes in which other
pulp flows or various additives, such as coloring, filling and retention agents; are
mixed into the main flow formed of liquid and pulp. It is typical to mix retention
chemicals that bind solid matter particles into the fiber suspension flow headed for
the head box of a paper machine, which retention chemicals allow improvement of the
retention of fines and filler agents in the wire section of the paper machine. The
mixing of different components can be performed with what are called tube mixers.
Thus, the additive is conveyed into the pulp flow through tubes or nozzles arranged
on the side of the pulp tube. However, the arrangement has not brought about a mixing
result that would be sufficiently good. Attempts have also been made to feed a jet
of additive at a very fast rate into the pulp flow, whereby the desired effect would
have been for the additive jet to better penetrate into the pulp flow. Unfortunately,
the problem here is that some additives, such as a retention agent, adheres to the
surface of the fiber or other solid matter in an unpreferred manner when being fed
at a fast rate, which results in what is called flat conformation, for example, and
the additive no longer has the desired retention relative to the filling agent or
fines. Further, the result may be unpreferred degradation of the retention agent because
of too great shear forces. Due to these aspects, the final product is subjected to
detrimental variation of the profile.
[0005] Further, in order to improve the mixing, injection nozzles can be used that extend
some distance into the inside of the pulp tube. The problem is, however, that the
ends of the nozzles inside the pulp tube gather impurities, which makes the feed of
the additive more difficult and deteriorates the quality of the final product.
A mixer comprising the structural features defined in the preamble of claim 5 is disclosed
in document
JP-A-07204480. This document also discloses a method of mixing two flows comprising the method
steps summarized in the preamble of claim 1, wherein, however, this document does
not disclose that the method of mixing two flows is performed in a papermaking process.
A mixer for mixing flows comprising the structural features defined in the preamble
of claim 5 and a method of mixing two flows comprising the method steps summarized
in the preamble of claim 1 is also known from document
US-A-4 123 800 and document
US-A-3 219 483, wherein the mixer and the method of mixing according to document
US-A-4 123 800 are primarily intended for mixing a liquid fertilizer into a carrier stream of a
liquid such as water, and wherein the mixer and the method of mixing according to
document
US-A-3 219 483 are intended for being used for the continuous gelatinization of starch used in the
papermaking industry.
It is an object of the present invention to provide an improved method of mixing flows
in a papermaking process and a corresponding improved mixer.
According to the invention, this object is achieved by the method defined in claim
1 and by the mixer defined in claim 5.
[0006] In the method and mixes of the invention, the first flow of the papermaking process
is conveyed in a tube which is provided with one or more form parts arranged on the
inner periphery of the tube. The form parts comprise form part surfaces which extend
a predetermined distance from the inner periphery of the tube towards the middle of
the tube. In the following, these form part surfaces are called the control surfaces.
The form parts influence the flow flowing in the tube and generate turbulence in the
flow. The zone that begins in the flowing direction after the nearest process component
preceding the form part, i.e. after a pump or screen, for instance, and that ends
after the form parts at the point where the mixing effect of the turbulence generated
by the form parts has essentially weakened is in this description and the claims called
the mixing zone of the tube. The inner periphery of the tube and the control surfaces
of the form parts define together the inner surface of the tube in the mixing zone,
i.e. the surface that contacts the flow flowing through the mixing zone. The at least
one form part comprises one or more feed openings on the inner surface of the tube,
which openings are in connection with the feed channels outside the tube. From said
feed openings, at least one second flow is fed into the first flow flowing in the
tube. The form parts function as mechanical mixing members, and the turbulence generated
by them mixes the flows efficiently with each other. Owing to the form parts, the
penetration of the second flow into the first flow is improved. The rate of the flow
flowing through the mixing zone can be kept relatively slow, and yet, good mixing
can be achieved. Owing to the mixing that is better than previously, problems resulting
from poor mixing can be avoided in the manufacturing stages after the mixer. The invention
enables manufacture of products of more uniform quality. In addition, since the mixing
is good, expensive additive chemicals can be used in amounts smaller than previously.
Earlier, it has been necessary to compensate for the poor mixing by feeding an excessive
amount of additive chemicals into the pulp flow.
[0007] Through the feed opening in the form part, the second flow is fed from the outside
of the tube into the first flow flowing in the tube. The form parts allow the flow
to be fed closer to the middle of the flow flowing in the tube, which makes the mixing
of the flows more efficient. Since the feed opening is at the same level as the control
surface of the form part, and further, since the form part is designed to remain easily
clean, the form part and the feed opening arranged in it do not gather impurities.
[0008] In a preferred embodiment of the invention is that the first flow is a mixture of
liquid and solid matter used in papermaking, for example a mixture of fibers and water,
and the second flow is paper making chemical, such as a retention agent.
[0009] In the preferred embodiment of the invention according to claim 12, the mixer is
arranged in the feeder line headed for the head box of a paper machine, after a mechanical
screen. Thus, the first component of a two-component retention agent can at first
be fed via feed openings in the mixing zone into the first flow flowing in the tube,
and the flocs made by the first component are formed as desired by means of the form
parts after the feeding point, after which the second retention agent component is
fed either from the point where the form parts form the flocs as desired or thereafter.
In this way, the shear force required for the formation of the flocs as desired are
achieved by means of the form parts, and not with mechanical screens, as previously.
Hence, the rejecting effect of screens and the degradation of the chemical in the
screen can be avoided, and in this the consumption of expensive retention agents can
be reduced.
[0010] The invention is described in greater detail in the attached drawings, in which
[0011] Figure 1 shows a schematic and perspective view of a tube mixer;
[0012] Figures 2 to 4 show a schematic view of mixers according to the invention, seen from
the side and being cut out;
[0013] Figure 5 shows a schematic view of a mixer according to the invention, seen from
the longitudinal direction and as a cross-section;
[0014] Figures 6a to 6c show a schematic view of applications according to the invention;
and
[0015] Figure 7 further shows a schematic view of an application according to the invention,
seen from the side and being cut out.
[0016] Figures are greatly simplified for the sake of clarity. The reference numerals of
the figures correspond to each other.
[0017] Figure 1 shows the basic structure of a tube mixer without equipment relating to
the feed of an additive or the like. The mixer comprises a tube 1, through which a
first flow V
1 is conveyed; the flow can be a mixture of liquid and solid matter, such as a mixture
of fiber and water, or it can be mere liquid. Form parts 4a to 4c are arranged on
the inner periphery 3 of the tube 1, the cross-section of the tube being wave-like
at this point. The form parts protrude from the inner periphery of the tube and form
control surfaces 5, by means of which the flow V
1 is controlled and turbulence is generated in the flow. The number, form and dimensioning
of the form parts and their positions relative to each other are designed in a case-specific
manner. Preferably, there are at least three form parts arranged on the inner periphery
3 of the tube at even distances from each other and in the direction of the longitudinal
axis of the tube substantially at the same point. One preferred shape of form parts
is indicated in Figure 1. Seen from the direction of flow, the area of the wedge-shaped
form parts 4b and 4c is at first approximately zero, because its front edge is a line-like
surface in the direction of the periphery. When proceeding towards the direction of
flow, the line-like surface grows in the direction of the radius into a cross-section
in the form of a sector of a circle. At the same time as it is growing in the direction
of the radius of the tube 1, the form part begins to diminish in the direction of
the periphery, and the rear edge of the form part becomes line-like again. Hence,
the solids in the flow, such as fibers, do not adhere to it, but the form is substantially
without stagnation points and remains thus easily clean. The form parts can also be
arranged in the way opposite to what is shown in Figure 1 in respect of the form parts
4b and 4c, i.e in such a way that the sharp edge of the radius is directed forwards.
Combining a desired number of form parts having an appropriate shape and dimensioning
at the mixing point of the tube allows an appropriate mixer to be tailored for each
purpose.
[0018] Later, in Figures 2 to 5 and Figure 7, the form parts are illustrated for the sake
of clarity in a simplified manner as wedge-like parts. In addition, figures only illustrate
a part of the form parts of the mixer.
[0019] Figure 2 shows a preferred application of the invention. The form parts 4a to 4b
are here provided with a transverse boring 6. The first end of the boring is in connection
with the feed channel of the additive component or another feed channel 7 outside
the tube 1, and at the second end of the boring 6 there is a feed opening 8, which
is in connection with the space limited by the tube 1. Thus, the second flow V
2 can be fed from the feed channel 7 into the first flow V
1, whereby the flows mix with each other owing to the turbulence caused by the form
parts. The second flow V
2 can be liquid or a mixture of liquid and solid matter. The second flow V
2 is for example a mixture of water and fiber pulp, a papermaking chemical, such as
a retention or coloring agent, or it may be for example a filler agent, dilution water
or a paper machine filtrate, e.g. clear or cloudy water. Further, the second flow
may be for example wire water or head box pulp. Furthermore, the second flow may be
a combination of an appropriate gas and solid matter.
[0020] In connection with the feed opening 8, there may be a nozzle 9, which feeds the second
flow V
2 into the first flow V
1 in the desired manner. The nozzle allows control of the flow rate of the flow V
2 and thus also the penetration into the first flow V
1. In the same way, the nozzle allows generation of turbulence in the second flow to
be fed, which improves the mixing of the flows with each other. Further, for instance
the additive can be fed together with the feed water through the nozzle, whereby the
dosing of the additive can be affected by the control of the flow and pressure of
the feed water. As can yet be seen when observing the lower form part in the figure,
there may be several feed openings in one form part. Either different substances or,
as the figure shows, a single substance can be fed from the several feed openings
in a single form part.
[0021] Figures 2 and 3 show the mixing zone S of the tube, where one or more second flows
V
2 is/are mixed into the first flow V
1, the second flow being led from the feed channel 7 outside the tube 1. The mixing
zone S can begin as early as before the front edge of the first form part. The mixing
zone begins as early as after the nearest process component 18 preceding the form
part in the flowing direction, for instance a pump or screen, because in this case,
too, the form part can contribute to the uniform distribution of the additive. The
mixing part S ends after the form parts at the point where the mixing effect of the
turbulence generated by the form parts has substantially weakened.
[0023] The diameter of the tube was 350 mm, the greatest dimension of the form part in the
radial dimension of the tube was 120 mm, and the length of the form part in the direction
of the axis of the tube was 200 mm. Pulp having the flow rate of 3m/s in the tube
was conveyed in the tube to the head box of a paper machine. The mixing turbulence
weakened at a distance of 1,100 mm from the rear edge of the form part.
[0024] In the solution of Figure 3, the form parts 4a and 4b are hollow, whereby one or
more injection tubes 10 is/are conveyed through at least some of the form parts, along
which injection tubes the second flow V
2 is fed from the feed channel 7 into the inside of the tube 1. The outermost ends
of the injection tubes 10 thus form a feed opening 8, which is at substantially the
same level as the outer surface of the form part in such a way that no stagnation
points gathering impurity are brought about in the form part. The outermost end of
the injection tube can be provided with an appropriate nozzle. Further, additives
or other flows can be fed into the first flow V
1 even before the form parts 4a and 4b. Thus, nozzles 11 arranged on the inner periphery
of the tube 1 can be used, or alternatively, second form parts 12a and 12b are arranged
on the inner periphery of the tube 1, through which parts the additive component can
also be fed. Also the second form parts 12a, 12b achieve turbulence in the flow V
1 and improve the mixing. The solution according to Figure 3 enables the use of two-component
additives. Thus, the first additive component L
1 is fed before the form parts 4a, 4b, the second additive component L
2 being fed later through the form parts 4a, 4b and/or after the form parts for instance
via a nozzle 30. This enables the feed of both components of the two-component retention
agent only after the machine screen. Together with the solids of the pulp mixture,
the first retention agent component forms what are called flocs, which are degraded
by means of the shear force provided by the form parts 4a, 4b of the mixer. Then,
the second retention agent component is fed via the feed openings 8 in the form parts
and/or via the nozzle 30, which component re-forms the flocs as desired. This solution
allows a substantial reduction in the consumption of the retention agent compared
with the solutions presently in use, in which the first retention agent component
is dosed before the machine screen, in which case, typically, part of the expensive
retention agent mixes with the reject separated by the screen.
[0025] As can be seen from Figures 2 and 3, the feed openings can be directed in a desired
manner, either perpendicularly relative to the first flow,or upstream or downstream,
depending on the situation.
[0026] Figure 4 shows a mixer having hollow form parts 4a, 4b. Thus, for example, an additive
component is fed from the feed channel 7 into the hollow space 13 of the form parts,
which additive component is dosed into the space limited by the tube 1 through one
or more feed openings 8 formed on the control surface 5 of the form part. The number,
form and position of feed openings can be selected according to the situation. The
feed openings can be formed on the control surface of the form part in accordance
with a predetermined pattern.
[0027] Figure 5 shows a mixer according to the invention, seen from the end of the tube
1. In this case, the form parts 4a to 4d have a curved control surface 5. Through
each form part, a different flow is conveyed into the inside of the tube 1. Further,
a flow can be fed into the first flow through one or more feed openings 40 positioned
between the form parts.
[0028] Figure 6a shows an application according to the invention. A pulp component is fed
with a pump 16 along the primary line 17 to the machine screen 18, after which the
pulp component is conveyed in the tube 1 to the head box 50 of the paper machine.
In this case, the mixing zone S begins after the nearest process component preceding
the head box, i.e. after the screen 18. Form parts have been arranged in the tube
portion between the screen 18 and the head box 50, and additive flows required are
supplied to the mixing zone in the manner according to the invention. The screen 18
can be a screen structure known
per se, such as a slotted basket screen or hole basket screen. In the application according
to Figure 6b, the pulp line is divided into at least two secondary lines 19 after
the screen 18, along which the pulp component is conveyed to the head box of a wire
section functioning with a separate web arrangement of the paper machine, i.e. to
a multilayer head box 20, which doses a web having two or several layers to the wire
section of the paper machine. At least one of the secondary lines 19 comprises a mixer
21 according to the invention, which mixer enables for instance the feed of a two-component
retention agent after the machine screen. The mixing of each secondary line and the
addition of additives can be controlled separately.
[0029] The solution shown in Figure 6c substantially corresponds to the one shown in Figure
6b, except that here the nearest process component preceding the head box (20) is
a pump (16). Thus, the mixing zone (S) extends from the pump (16) to the head box
(20).
[0030] Owing to the improved penetration and mixing, additives can be fed from one or more
smaller feed conduits, whereby in the paper machine, the variation of the web profile
in the machine direction and cross-direction is reduced. In other words, the web profile
is thus more even and there is not so much need for fixing. When the scale of mixing
is reduced in the way described above, the mixing result is better. Thus, the formation,
i.e. the small-scale basis weight variation is improved, in other words the formation
reading is reduced. Owing to the reduction in the profile variation and the basis
weight variation, the feed point of the retention agent, for example, can be positioned
closer to the head box. Thus, chemicals can be saved, because the effect of some retention
agents weakens as the effective time increases. The cross-machine profile of the filling
agent cannot be fixed in the paper machine. Weak or uneven feed of retention agent
results in a poor filling agent profile. The feed of the retention agent can be improved
by means of the invention, whereby the filling agent retention is more even, and therefore
also the filling agent profile is more even.
[0031] The upper embodiment of Figure 7 illustrates a mixer in which a mixture of two different
components L
1 and L
2 is fed through the form part 4. Thus, for example some filling agent or fiber pulp
can be fed via the first feed channel 7, and for example some chemical can be fed
via the second feed channel 31, whereby the components are mixed with each other before
the mixture formed thereof is dosed into the flow V
1. If the first component to be mixed is a mixture of liquid and solid matter, for
example a paper machine filtrate, and the second component is a retention agent, the
time of the pre-mixing of said components is fixed in such a way that the retention
agent does not have time to react in an undesired way with the solid matter particles
in the first component. A solution of this kind enables dilution of a retention agent
and other chemicals also with impure liquids containing solid matter before they are
fed into the first flow.
[0032] In the lower solution of Figure 7, the mixer comprises three successive form parts
in the longitudinal direction of the tube. The additive L
1 is fed through the first form part 12 and a second additive L
2 is fed through the third form part 32. The second, i.e. the middlemost, form part
4 functions as a static mixing member. A solution of this kind is well applicable
to the dosing of two-component chemicals.
[0033] The drawings and the related specification are only intended to illustrate the idea
of the invention. The details of the invention can vary within the scope of the claims.
Thus, the shape of the form part can be selected according to the need. The form part
can thus be wedge-shaped or pyramid-shaped, a part comprising curved surfaces, or
otherwise appropriately designed. What is essential is that the form part comprises
control surfaces which achieve a sufficient turbulence in the pulp flow for the purpose
of mixing. In addition, it is essential that the form parts remain clean in the flow
of pulp components. Further, the form parts can be arranged to be adjustable, whereby
their position relative to the tube (on the periphery of the tube and in the longitudinal
direction of the tube) and/or their shape can be adjusted to achieve the desired mixing.
The control surfaces of the form parts can be controlled to extend a desired distance
from the periphery of the tube towards the inner part of the periphery of the tube,
for example.
1. A method of mixing flows in a papermaking process,
wherein a first flow (V1) is conveyed through a tube (1) to a mixing zone (S) formed in the tube (1),
wherein a second flow (V2) is fed into the first flow (V1) through at least one feed opening (8),
wherein turbulence is generated in the first flow (V1) in the mixing zone (S) by means of flow control surfaces (5) of a form part means
provided on the inner periphery of the tube (1) in the mixing zone (S), the flow control
surfaces (5) extending a predetermined distance from the inner periphery of the tube
(1) towards the middle of the tube (1), and
wherein, for feeding the second flow (V2) into the first flow (V1), the at least one feed opening (8) is positioned in the form part means,
characterized
by composing the form part means of one form part (4) or of more than one form parts
(4a to 4d; 4b, 12b; 12, 32) extending over only a portion of the inner periphery of
the tube (1) such that the inner surface of the mixing zone (S) at the location of
the at least one form part (4; 4a to 4d; 4b, 12b; 12, 32) is defined by the flow control
surfaces (5) of the form part (4) or of the form parts (4a to 4d; 4b, 12,b; 12, 32)
together with the inner periphery of the tube (1).
2. The method according to claim 1, characterized by conveying a fiber suspension as the first flow (V1) through the tube (1) and feeding a papermaking chemical as the second flow (V2) into the fiber suspension.
3. The method according to claim 2, characterized by the first component of a two-component retention agent being fed prior to the at
least one form part (4a, 4b) via a feed opening (11) into the fiber suspension, which
component forms flocs together with the solid matter in the fiber suspension, said
flocs being broken by means of the turbulence generated by the at least one form part
(4a, 4b), wherein the second component of the retention agent, which re-forms the
flocs as desired, is fed into the fiber suspension after the at least one form part
(4a, 4b).
4. The method according to one of claims 1 to 3,
characterized in that the second flow (V2) is formed by mixing with each other a first additive component (L1) and a second additive component (L2) prior to feeding the second flow (V2) into the first flow (V1).
5. A mixer for mixing flows in a papermaking process, comprising
a tube (1) for conveying a first flow (V1),
a mixing zone (S) formed in the tube (1),
a feed channel (7) for conveying a second flow (V2), the feed channel (7) being connected with at least one feed opening (8) for feeding
through the at least one feed opening (8) the second flow (V2) into the first flow (V1), and
a form part means provided on the inner periphery of the tube (1) in the mixing zone
(S),
wherein the form part means comprises flow control surfaces (5) extending a predetermined
distance from the inner periphery of the tube (1) towards the middle of the tube (1)
for generating turbulence in the first flow (V1) in the mixing zone (S), and
wherein the form part means comprises the at least one feed opening (8),
characterized
in that the form part means is composed of one form part (4) or of more than one form parts
(4a to 4d; 4b, 12b; 12, 32) extending over only a portion of the inner periphery of
the tube (1) such that the inner surface of the mixing zone (S) at the location of
the at least one form part (4; 4a to 4d; 4b, 12b; 12, 32) is defined by the flow control
surfaces (5) of the form part (4) or of the form parts (4a to 4d; 4b, 12b; 12, 32)
together with the inner periphery of the tube (1).
6. The mixer according to claim 5, characterized in that the number of the form parts (4a to 4d; 4b, 12b; 12, 32) is at least two, wherein
at least two of the form parts (4b; 12b; 12, 32) are successively arranged, seen in
the longitudinal direction of the tube (1).
7. The mixer according to claim 5 or 6, characterized in that the form part (4a, 4b) comprises a transverse boring (6), the first end of which
being connected with the feed channel (7) outside the tube (1) and the second end
of which being connected with the at least one feed opening (8) comprised in the form
part (4a, 4b).
8. The mixer according to claim 5 or 6, characterized in that the form part (4a, 4b) is hollow, in that the feed channel (7) is connected with the hollow space (13) of the form part (4a,
4b), and in that the at least one feed opening (8) is formed on the form part surfaces (5) of the
form part (4a, 4b).
9. The mixer according to one of claims 5 to 8, characterized in that the position of the form part (4a to 4b) relative to the tube (1) is adjustable.
10. The mixer according to one of claims 5 to 9, characterized in that the shape of the form part (4a to 4d) is adjustable.
11. A feeding equipment for a head box of a paper machine, comprising a primary line (17)
through which a first flow is conveyed to the head box (20; 25), a process component,
such as a pump (16) or screen (18), arranged in the primary line (17), and a mixer
(12) according to one of claims 5 to 10, wherein the mixing zone (S) of the mixer
extends from the nearest process component (16; 18) preceding the head box to the
head box (20; 25).
12. The feeding equipment according to claim 11, characterized by comprising in the mixing zone (S) upstream of the at least one form part (4a, 4b)
a feed opening (11) for conveying the first component of a two-component retention
agent into the first flow (V1) flowing through the tube (1), and a second feed opening (30) for feeding the second
component of the retention agent into the flow mixed by the turbulence generated by
the at least one form part (4a, 4b).
13. The feeding equipment according to claim 11 or 12, characterized in that the primary line (17) is divided after the nearest process component (16; 18) preceding
the head box (20) into at least two secondary tubes (19), along which the first flow
is conveyed from the process component (16; 18) to a multilayer head box (20) or to
a head box of the wire section functioning with a separate web arrangement, and that
at least one of the secondary tubes (19) comprises the mixer (21).
1. Verfahren zum Mischen von Strömungen in einem Papierherstellungsprozess,
wobei eine erste Strömung (V1) durch ein Rohr (1) zu einer in dem Rohr (1) ausgebildeten Mischzone (S) geleitet
wird,
wobei eine zweite Strömung (V2) durch wenigstens eine Zuleitungsöffnung (8) in die erste Strömung (V1) zugeleitet wird,
wobei Turbulenzen in der ersten Strömung (V1) in der Mischzone (S) unter Verwendung von Strömungssteuerflächen (5) einer an dem
Innenumfang des Rohrs (1) in der Mischzone (S) vorgesehenen Formteileinrichtung erzeugt
wird, wobei sich die Strömungssteuerflächen (5) mit einem vorbestimmten Abstand von
dem Innenumfang des Rohrs (1) in Richtung zu der Mitte des Rohrs (1) hin erstrecken,
und
wobei die wenigstens eine Zuleitöffnung (8) zum Zuleiten der zweiten Strömung (V2) in die erste Strömung (V1) in der Formteileinrichtung positioniert ist,
gekennzeichnet durch
Ausbilden der Formteileinrichtung aus einem Formteil (4) oder aus mehr als einem Formteil
(4a bis 4d; 4b, 12b; 12, 32), die sich über nur einen Teil des Innenumfangs des Rohrs
(1) erstrecken, so dass die Innenfläche der Mischzone (S) an der Stelle des wenigstens
einen Formteils (4; 4a bis 4d; 4b, 12b, 12, 32) durch die Strömungssteuerflächen (5) des Formteils (4) oder der Formteile (4a-4d; 4b, 12b;
12, 32) zusammen mit dem Endumfang des Rohrs (1) festgelegt ist.
2. Verfahren nach Anspruch 1, gekennzeichnet durch
Leiten einer Fasersuspension als die erste Strömung (V1) durch das Rohr (1) und Zuleiten einer Papierherstellungschemikalie als die zweite Strömung
(V2) in die Fasersuspension.
3. Verfahren nach Anspruch 2, gekennzeichnet dadurch, dass die erste Komponente eines Zweikomponenten-Rückhaltemittels vor dem wenigstens einen
Formteil (4a, 4b) über eine Zuleitöffnung (11) in die Fasersuspension zugeleitet wird,
wobei die Komponente zusammen mit der Feststoffmaterie Flocken in der Fasersuspension
ausbildet, wobei die Flocken unter Verwendung der durch das wenigstens eine Formteil
(4a, 4b) erzeugten Turbulenzen zerkleinert werden, wobei die zweite Komponente des
Rückhaltemittels, die die Flocken wie gewünscht neu bildet, nach dem wenigstens einen
Formteil (4a, 4b) in die Fasersuspension zugeleitet wird.
4. Verfahren nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, dass die zweite Strömung (V2) durch Mischen einer ersten Additivkomponente (L1) mit einer zweiten Additivkomponente (L2) ausgebildet wird, bevor die zweite Strömung (V2) in die erste Strömung (V1) zugeleitet wird.
5. Mischer zum Mischen von Strömungen in einem Papierherstellungsprozess, mit:
einem Rohr (1) zum Leiten einer ersten Strömung (V1),
einer in dem Rohr (1) ausgebildeten Mischzone (S), einem Zuleitkanal (7) zum Leiten
einer zweiten Strömung (V2), wobei der Zuleitkanal (7) mit wenigstens einer Zuleitöffnung (8) zum Zuleiten der
zweiten Strömung (V2) durch die wenigstens eine Zuleitöffnung (8) in die erste Strömung (V1) verbunden ist, und
einer Formteileinrichtung, die an dem Innenumfang des Rohrs (1) in der Mischzone (S)
vorgesehen ist,
wobei die Formteileinrichtung Strömungssteuerflächen (5) aufweist, die sich mit einem
vorbestimmten Abstand von dem Innenumfang des Rohrs (1) in Richtung zu der Mitte des
Rohrs (1) hin erstrecken, um Turbulenzen in der ersten Strömung (V1) in der Mischzone (S) zu erzeugen, und
wobei die Formteileinrichtung die wenigstens eine Zuleitöffnung (8) aufweist,
gekennzeichnet dadurch, dass
die Formteileinrichtung aus einem Formteil (4) oder aus mehr als einem Formteil (4a
bis 4d; 4b, 12b; 12, 32) besteht, die sich über nur einen Teil des Innenumfangs des
Rohrs (1) derart erstrecken, dass die Innenfläche der Mischzone (S) an der Stelle
des wenigstens einen Formteils (4; 4a bis 4d; 4b, 12b; 12, 32) durch die Strömungssteuerflächen
(5) des Formteils (4) oder der Formteile (4a bis 4d; 4b, 12b; 12, 32) zusammen mit
dem Innenumfang des Rohrs (1) festgelegt ist.
6. Mischer nach Anspruch 5, dadurch gekennzeichnet, dass die Anzahl der Formteile (4a bis 4d; 4b, 12b; 12, 32) wenigstens zwei ist, wobei
wenigstens zwei der Formteile (4b; 12b; 12, 32) aus Sicht in der Längsrichtung des
Rohrs (1) nacheinander angeordnet sind.
7. Mischer nach Anspruch 5 oder 6, dadurch gekennzeichnet, dass das Formteil (4a, 4b) eine Querbohrung (6) aufweist, wobei dessen erstes Ende mit
dem Zuleitkanal (7) außerhalb des Rohrs (1) verbunden ist und dessen zweites Ende
mit der wenigstens einen Zuleitöffnung (8) verbunden ist, die in dem Formteil (4a,
4b) enthalten ist.
8. Mischer nach Anspruch 5 oder 6, dadurch gekennzeichnet, dass das Formteil (4a bis 4b) hohl ist, dass der Zuleitkanal (7) mit dem Hohlraum (13)
des Formteils (4a, 4b) verbunden ist, und dass die wenigstens eine Zuleitöffnung (8)
an den Formteilflächen (5) des Formteils (4a, 4b) ausgebildet ist.
9. Mischer nach einem der Ansprüche 5 bis 8, dadurch gekennzeichnet, dass die Position des Formteils (4a bis 4b) bezüglich des Rohrs (1) einstellbar ist.
10. Mischer nach einem der Ansprüche 5 bis 9, dadurch gekennzeichnet, dass die Gestalt des Formteils (4a bis 4d) einstellbar ist.
11. Fördereinrichtung für einen Auflaufkasten einer Papiermaschine, mit einer ersten Leitung
(17), durch die eine erste Strömung zu dem Auflaufkasten (20; 25) hin geleitet wird,
einer Prozesskomponente, wie beispielsweise einer Pumpe (16) oder einem Sieb (18),
das in der ersten Leitung (17) angeordnet ist, und einem Mischer (12) nach einem der
Ansprüche 5 bis 10, wobei sich die Mischzone (S) des Mischers von der nächsten Prozesskomponente
(16; 18) vor dem Auflaufkasten zu dem Auflaufkasten (20; 25) erstreckt.
12. Förderanlage nach Anspruch 11, gekennzeichnet dadurch, dass sie in der Mischzone (S) stromaufwärts des wenigstens einen Formteils (4a, 4b) eine
Zuleitöffnung (11) zum Zuleiten der ersten Komponente eines Zweikomponenten-Rückhaltemittels
in die durch das Rohr (1) strömende erste Strömung (V1) und eine zweite Zuleitöffnung (30) zum Zuleiten der zweiten Komponente des Rückhaltemittels
in die Strömung aufweist, die durch die durch das wenigstens eine Formteil (4a, 4b)
erzeugten Turbulenzen gemischt wird.
13. Förderanlage nach Anspruch 11 oder 12, gekennzeichnet dadurch, dass die erste Leitung (17) nach der nächsten Prozesskomponente (16; 18) vor dem Auflaufkasten
(20) in wenigstens zwei zweite Rohre (19) aufgeteilt wird, entlang denen die erste
Strömung von der Prozesskomponente (16; 18) zu einem mehrschichtigen Auflaufkasten
(20) oder zu einem Auflaufkasten des Siebbereichs geleitet wird, der mit einer separaten
Netzanordnung funktioniert, und dass wenigstens eine der zweiten Rohre (19) den Mischer
(21) enthält.
1. Un procédé pour mélanger des courants dans un processus de fabrication de papier,
dans lequel un premier courant (V1) est acheminé au moyen d'un tube (1) vers une zone de mélange (S) formée dans le
tube (1),
dans lequel un deuxième courant (V2) est introduit dans le premier courant (V1) par l'intermédiaire d'au moins une ouverture d'alimentation (8),
de telle sorte qu'une turbulence est générée dans le premier courant (V1) dans la zone de mélange (S) au moyen de surfaces (5) de commande de courant aménagées
par des moyens constituant des pièces de forme aménagés sur la périphérie interne
(3) du tube (1) dans la zone de mélange (S), les surfaces (5) de commande de courant
s'étendant sur une distance prédéterminée depuis la périphérie interne (3) du tube
(1) en direction du milieu du tube (1), et
dans lequel, pour alimenter le deuxième courant (V2) dans le premier courant (V1), ladite au moins une ouverture d'alimentation (8) est située au niveau des moyens
constituant des pièces de forme,
caractérisé
par le fait de façonner les moyens constituant des pièces de forme d'une pièce de forme
(4) ou de plus d'une pièce de forme (4a à 4d ; 4b, 12b ; 12, 32) pour qu'ils s'étendent
sur seulement une partie de la périphérie interne du tube (1) de telle sorte que la
surface interne de la zone de mélange (S) au niveau de ladite au moins une pièce de
forme (4 ; 4a à 4d ; 4b, 12b ; 12, 32) soit définie par les surfaces (5) de commande
de courant de la pièce de forme (4) ou des pièces de forme (4a à 4d ; 4b, 12b ; 12,
32) et par la périphérie interne du tube (1).
2. Le procédé selon la revendication 1, caractérisé par le fait d'acheminer par le tube (1) une suspension de fibres formant le premier courant
(V1) et d'alimenter dans la suspension de fibres un produit chimique de fabrication du
papier formant le deuxième courant (V2).
3. Le procédé selon la revendication 2, caractérisé par le fait d'alimenter dans la suspension de fibres le premier composant d'un agent
de rétention à deux composants en amont de ladite au moins une pièce de forme (4a,
4b), par l'intermédiaire d'une ouverture d'alimentation (11), lequel composant forme
des flocons avec la matière solide dans la suspension de fibres, lesdits flocons étant
cassés au moyen de la turbulence produite par ladite au moins une pièce de forme (4a,
4b), le deuxième composant de l'agent de rétention, qui reforme les flocons si nécessaire,
étant alimenté dans la suspension de fibres après ladite au moins une pièce de forme
(4a, 4b).
4. Le procédé selon l'une quelconque des revendications 1 à 3, caractérisé en ce que le deuxième courant (V2) est formé par en mélangeant l'un avec l'autre un premier composant d'additif (L1) et un deuxième composant d'additif (L2) avant d'alimenter le deuxième courant (V2) dans le premier courant (V1).
5. Un mélangeur permettant de mélanger des courants dans un processus de fabrication
de papier, comprenant
un tube (1) pour transporter un premier courant (V1),
une zone de mélange (S) formée dans le tube (1),
un conduit d'alimentation (7) pour alimenter un deuxième courant (V2), le conduit d'alimentation (7) étant relié à au moins une ouverture d'alimentation
(8) pour introduire le deuxième courant (V2) dans le premier courant (V1) au travers de ladite au moins une ouverture d'alimentation (8),
des moyens constituant des pièces de forme aménagés sur la périphérie interne du tube
(1) dans la zone de mélange (S),
les moyens qui constituent des pièces de forme comprenant des surfaces (5) de commande
de courant s'étendant sur une distance prédéterminée depuis la périphérie interne
du tube (1) en direction du milieu du tube (1) pour générer une turbulence dans le
premier courant (V1) dans la zone de mélange (S), et
dans lequel les moyens constituant des pièces de forme comprennent ladite au moins
une ouverture d'alimentation (8),
caractérisé
en ce que les moyens constituant des pièces de forme sont constitués d'une pièce de forme (4)
ou de plus d'une pièce de forme (4a à 4d ; 4b, 12b ; 12, 32) s'étendant sur seulement
une partie de la périphérie interne du tube (1) de telle sorte que la surface interne
de la zone de mélange (S) au niveau de ladite au moins une pièce de forme (4 ; 4a
à 4d ; 4b, 12b ; 12, 32) est définie par les surfaces (5) de commande de courant de
la pièce de forme (4) ou des pièces de forme (4a à 4d ; 4b, 12b ; 12, 32) et par la
périphérie interne du tube (1).
6. Le mélangeur selon la revendication 5, caractérisé en ce que le nombre de pièces de forme (4a à 4d ; 4b, 12b ; 12, 32) est au moins égal à deux,
de sorte qu'au moins deux des pièces de forme (4b, 12b ; 12, 32) sont agencées en
succession l'une de l'autre selon la direction longitudinale du tube (1).
7. Le mélangeur selon la revendication 5 ou la revendication 6, caractérisé en ce que la pièce de forme (4a, 4b) comporte un alésage transversal (6), dont une première
extrémité est reliée au conduit d'alimentation (7) sur l'extérieur du tube (1) et
dont la deuxième extrémité est reliée à ladite au moins une ouverture d'alimentation
(8) située au niveau de la pièce de forme (4a, 4b).
8. Le mélangeur selon la revendication 5 ou la revendication 6, caractérisé en ce que la pièce de forme (4a, 4b) est creuse, en ce que le conduit d'alimentation (7) est relié à l'espace creux (13) de la pièce de forme
(4a, 4b), et en ce que ladite au moins une ouverture d'alimentation (8) est aménagée sur la surface (5)
de commande de courant que comprend la pièce de forme (4a, 4b).
9. Le mélangeur selon l'une quelconque des revendications 5 à 8, caractérisé en ce que la position de la pièce de forme (4a à 4b) par rapport au tube (1) est réglable.
10. Le mélangeur selon l'une quelconque des revendications 5 à 9, caractérisé en ce que la forme de la pièce de forme (4a à 4d) est réglable.
11. Un équipement d'alimentation d'une caisse d'arrivée d'une machine à papier, comportant
une conduite principale (17) au travers de laquelle un premier courant (V1) est acheminé dans la caisse d'arrivée (20 ; 25), un composant de traitement, tel
qu'une pompe (16) ou un tamis (18), agencé sur la conduite principale (17), et un
mélangeur (12) selon l'une des revendications 5 à 10, la zone de mélange (S) du mélangeur
s'étendant depuis le composant de traitement le plus proche (16 ; 18) qui précède
la caisse d'arrivée jusqu'à la caisse d'arrivée (20 ; 25).
12. L'équipement d'alimentation selon la revendication 11 ; caractérisé en ce qu'il comprend, dans la zone de mélange (S) en amont de ladite au moins une pièce de
forme (4a, 4b), une ouverture d'alimentation (11) pour acheminer le premier composant
d'un agent de rétention à deux composants dans le premier courant (V1) s'écoulant au travers du tube (1), et une deuxième ouverture d'alimentation (30)
pour introduire le deuxième composant de l'agent de rétention dans le courant mélangé
par la turbulence produite par ladite au moins une pièce de forme (4a, 4b).
13. L'équipement d'alimentation selon la revendication 11 ou la revendication 12, caractérisé en ce que la conduite principale (17) est divisée, après le composant de traitement (16 ; 18)
le plus proche précédant la caisse d'arrivée (20), en au moins deux tubes secondaires
(19), le long desquels le premier courant est acheminé depuis le composant de traitement
(16 ; 18) vers une caisse d'arrivée multicouches (20) ou vers une caisse d'arrivée
de la section toile fonctionnant avec un agencement à bande séparé, et en ce qu'au moins un des tubes secondaires (19) comporte le mélangeur (21).
REFERENCES CITED IN THE DESCRIPTION
This list of references cited by the applicant is for the reader's convenience only.
It does not form part of the European patent document. Even though great care has
been taken in compiling the references, errors or omissions cannot be excluded and
the EPO disclaims all liability in this regard.
Patent documents cited in the description