Note: Descriptions are shown in the official language in which they were submitted.
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METHOD OF MANUFACTURING REFINER, AND REFINER
BACKGROUND OF THE INVENTION
[0001] The invention relates to a method of manufacturing a refiner,
the method comprising changing a structure of at least one disc refiner, and
which refiner comprises a frame structure, the frame structure comprising a
pressure frame surrounding a refiner chamber and a base frame supporting
the pressure frame, and the refiner further comprising at least one rotor ro-
tatable via a shaft.
_
[0002] The invention further relates to a refiner comprising a frame
structure, the frame structure comprising a pressure frame surrounding a re-
finer chamber and a base frame supporting the pressure frame, and which re-
finer further comprises an end element of the refiner being in connection with
the frame structure, a stator of the refiner arranged in connection with the
end
element of the refiner, and a rotor rotatable via a shaft.
[0003] The invention still further relates to a double disc refiner
comprising a frame structure, which frame structure comprises a pressure
frame surrounding a refiner chamber and a base frame supporting the pres-
sure frame, and which refiner further comprises at least two oppositely ar-
ranged rotors, each rotor being rotatable via a shaft of its own.
[0004] Refiners are used in a pulp making process to refine ligno-
cellulose-containing material. The refiners comprise a frame which houses a
refiner chamber generally, depending on the refiner type, provided with one or
more fixed refiner element, i.e. a stator or a stator element, arranged
fixedly,
i.e. non-rotatingly, in connection with the frame of the refiner, as well as
one or
more refiner element, i.e. a rotor, rotatable via a shaft.
[0005] As manufacturing processes change, e.g. when production
volumes change, a refiner being used may become redundant. Since particu-
larly the frame structures of refiners last for decades, it may cause
significant
economic losses to purchase an entirely new refiner and remove the redun-
dant one. These losses could be reduced by utilizing some parts of the old re-
finer. However, particularly in situations wherein the line of production
changes
regarding either the raw material to be used or the quality of pulp to be pro-
duced, it is extremely difficult to even to some extent utilize the old
refiner.
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BRIEF DESCRIPTION OF THE INVENTION
[0006] An object of the present invention is to provide a novel solu-
tion for utilizing an old refiner.
[0007] A method according to the invention is chararcterized by
changing the frame structure of the disc refiner at least over a section
belong-
ing to the pressure frame such that the refiner chamber of the refiner is ar-
rangeable to comprise a rotor comprising a conical refining surface section
and
a stator comprising a conical refining surface section or such that two single
disc refiners are combinable into one double disc refiner comprising two
rotors. -
[0008] A refiner according to the invention is characterized in that in
connection with the frame structure of the refiner an extension sleeve or an
extension structure is arranged in order to increase extent of the refiner
cham-
ber in a direction of the shaft of the refiner.
[0009] A double disc refiner according to the invention is character-
ized in that the frame structure of the double disc refiner comprises a first
frame structure section provided by removing from a first used disc refiner an
end element and a stator, and in that the frame structure of the refiner com-
prises a second frame structure section provided by removing from a second
used disc refiner an end element and a stator, and in that the rotors are
placed
towards one another such that a blade gap is provided between the rotors, and
in that the frame structure sections are supported against one another by one
or more support elements arranged in connection with said frame structure
sections.
[0010] The method of manufacturing a refiner comprises changing
the structure of at least one disc refiner. The refiner comprises a frame
struc-
ture which comprises a pressure frame surrounding a refiner chamber and a
base frame supporting the pressure frame. The refiner further comprises at
least one rotor rotatable via a shaft. The method comprises changing the frame
structure of the disc refiner at least over a section belonging to the
pressure
frame such that the refiner chamber of the refiner is arrangeable to comprise
a
rotor comprising a conical refining surface section and a stator comprising a
conical refining surface section or such that two single disc refiners are com-
binable into one double disc refiner comprising two rotors.
[0011] The process of changing an old disc refiner to be removed
from use into a refiner of another type enables a vast majority of the
structure
of the refiner to be removed from use and actuators associated therewith to be
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used when manufacturing a new refiner. On account of such utilization of
parts, it is also rather an inexpensive procedure to change an old refiner
into a
refiner of another type. In addition, the energy consumption per mass ton of a
refiner produced by such a changing procedure is clearly lower than the en-
ergy consumption of the disc refiner being changed.
[0012] According to an embodiment, the method comprises remov-
ing an end element being in connection with the frame structure of at least
one
disc refiner from the connection with the frame structure of the disc refiner,
ar-
ranging in the rotor of the, refiner a rotor element comprising a conical
refining
surface section, arranging in connection with the end element a stator compris-
ing a conical refining surface section, arranging in the frame structure of
the
refiner, in connection with the pressure frame, an extension sleeve or an ex-
tension structure in order to increase extent of the refiner chamber in a
direc-
tion of the shaft of the refiner, and fastening the end element in connection
with the pressure frame of the refiner such that the extension sleeve or the
ex-
tension structure remains located between the end element and the pressure
frame of the refiner.
[0013] The extension sleeve or the extension structure enables the
extent of the refiner chamber of the refiner to be increased in the direction
of
the shaft of the refiner in a simple manner such that a stator comprising a
coni-
cal refining surface section and a rotor comprising a conical refining surface
section may be arranged in the refiner chamber of the refiner.
[0014] According to another embodiment, the method comprises
removing from a first disc refiner an end element and a stator arranged in con-
nection therewith, thereby forming a first frame structure section of the
refiner,
removing from a second disc refiner an end element and a stator arranged in
connection therewith, thereby forming a second frame structure section of the
refiner, placing the rotors of the refiners towards one another such that a
blade
gap is provided between the rotors, and supporting the frame structure sec-
tions against one another by one or more support elements to be arranged in
connection with said frame structure sections, thus forming a double disc re-
finer.
[0015] By removing from two disc refiners to be removed from use
the end element and the stators arranged in connection therewith, two partial
refiner structures are provided which, when combined with one another, enable
a double disc refiner comprising two rotors to be manufactured.
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BRIEF DESCRIPTION OF THE FIGURES
[0016] Some embodiments of the invention are described in closer
detail in the accompanying drawings, in which
Figure 1 is a schematic cross-sectional side view showing a prior art
refiner,
Figure 2 is a schematic cross-sectional side view showning a disc
cone refiner according to the invention,
Figure 3 is a schematic cross-sectional side view showing a double
disc refiner according to the invention,
Figure 4 is a schematic cross-sectional side view showing another
double disc refiner according to the invention, and
Figure 5 is a schematic end view showing a double disc refiner simi-
lar to that of Figure 4.
[0017] For the sake of clarity, the figures show some embodiments
of the invention in a simplified manner. In the figures, like reference
numbers
identify like elements.
DETAILED DESCRIPTION OF THE INVENTION
[0018] Figure 1 is a schematic cross-sectional side view showing a
prior art disc refiner 1. The disc refiner 1 comprises a frame structure 2
which
comprises a pressure frame 3 and a base frame 4 of the refiner to support the
pressure frame 3; Figure 1 only shows part of the base frame 4. The pressure
frame 3 houses a refiner chamber 5 provided with a refiner element, i.e. a
rotor
7, rotatable, i.e. rotating, via a shaft 6 as well as a fixed, i.e. non-
rotating, re-
finer element, i.e. a stator 9, arranged in connection with an end element 8
of
the refiner 1. The end element 8 is fastened to the pressure frame 3, the end
element 8 thus forming part of the pressure frame 3. The rotor 7 is provided
with a refining surface 10 of the rotor 7 while the stator 9 is provided with
a re-
fining surface 11 of the stator 9. The stator 9 and the end element 8 are
further
provided with feed openings 12 through which fibrous material to be refined
may be fed to a blade gap 13 located between the stator 9 and the rotor 7.
With respect to the rest of the structure of the refiner 1, Figure 1 shows the
blade gap 13 substantially larger than it really is. The refiner naturally
further
comprises a discharge opening (not shown in the figure) for discharging al-
ready refined material from the refiner chamber. Further, the general
structure
CA 02684191 2009-10-30
and operational principle of refiners are known per se to those skilled in the
art,
so they do not have to be discussed in closer detail herein.
[0019] Figure 2 is a schematic cross-sectional side view showning a
refiner 14. The refiner 14 shown in Figure 2 is a disc cone refiner and it com-
5 prises a frame structure 2 which comprises a pressure frame 3 and a base
frame 4 of the refiner to support the pressure frame 3; Figure 2 only shows
part
of the base frame 4. The pressure frame 3 houses a refiner chamber 5 which
is provided with a rotor 7 rotatable via a shaft 6 as well as a stator 9
arranged
in connection with an end element 8 of the refiner 14. The stator 9 and the
end
element 8 comprise feed openings 12 through which fibrous material to be re-
fined may be fed to a blade gap 13 located between the stator 9 and the rotor
7. Figure 2 further shows an extension sleeve 15 or an extension structure 15
which is placed between the pressure frame 3 and the end element 8 of the
refiner 1 and by means of which the extent of the refiner chamber has been
increased in a direction of the shaft of the refiner 1.
[0020] In the refiner 14 according to Figure 2, the rotor 7 is formed
from a first rotor element 7' and a second rotor element 7". The second rotor
element 7" is arranged in connection with the first rotor element 7' such that
when the first rotor element 7' rotates, also the second rotor element 7" ro-
tates. The second rotor element 7" is provided with a refining surface 10 com-
prising both a conical refining surface section 10' and a disc-like refining
sur-
face section 10". The stator 9 of the refiner 1 is further provided with a
refining
surface 11 which comprises both a conical refining surface section 11' and a
disc-like refining surface section 11".
[0021] The refiner 14 according to Figure 2 may be formed from a
disc refiner 1 which is in use and which is similar to that shown in Figure 1
by
removing the end element 8 from connection with the frame structure 2, i.e.
the
pressure frame 3, and at some stage by removing the stator 9 of the original
disc rerfiner 1 from connection with the end element 8. Next, the second rotor
element 7" of the rotor 7 which comprises a refining surface 10 and which is
shown in Figure 2 is fastened in connection with the rotor of the original
disc
refiner 1, the rotor of the original disc refiner corresponding with the first
rotor
element 7' of the rotor 7 shown in Figure 2. In such a case, it may also be
con-
sidered that the first rotor element 7' forms the frame of the rotor 7. When
nec-
essary, the first rotor element 7' may be machined in order to fasten the sec-
ond rotor element 7" in connection with the first rotor element 7'. In
addition, in
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6
the manner shown in Figure 2, the second rotor element 7" may also be sup-
ported in connection with the shaft 6 or a possible extension thereof.
[0022] At some stage, the stator 9 intended for the refiner being
manufactured is fastened in connection with the end element 8. At some stage,
the extension sleeve 15 or the extension structure 15 is placed between the
end element 8 and the pressure frame 3. The extension sleeve 15 may be
placed between the end element 8 and the pressure frame 3 while end as-
sembling the refiner 14, in which case the end element 8, the extension sleeve
and the pressure frame 3 of the refiner 1 are at the same time fastened to
10 one another by simultaneosly using the same fastening means, such as fas-
tening bolts (for the sake of clarity not shown in the figures), thus closing
the
structure of the refiner 14. The extension sleeve 15 may be situated between
the end element 8 and the pressure frame 3 also earlier, in which case the ex-
tension sleeve 15 is fastened separately to the pressure frame 3 of the
refiner
15 14. The
extension sleeve 15 is used for increasing the extent of the refiner
chamber 5 of the refiner 14 in the direction of the shaft 6 of the refiner 1
since it
would be impossible to accommodate the stator 9 and the rotor 7 comprising
both a disc-like refining surface section 10", 11" and a conical refining
surface
section 10', 11' in the refiner chamber 5 provided in the original disc
refiner.
[0023] In the above-disclosed manner, an ordinary disc refiner may
be modified into a refiner comprising both a disc-like refining surface
section
and a conical refining surface section, i.e. into a so-called disc cone
refiner.
When modernizing a refiner, the old disc refiner may be utilized almost com-
pletely, the original disc-like stator being the only somewhat important redun-
dant part, if not being used for forming a disc-like refining surface section
11"
in the modernized refiner. The extension sleeve 15 enables the extent of the
refiner chamber 5 to be increased in the direction of the shaft 6 in a very
sim-
ple manner. In the embodiment according to Figure 2, the extension sleeve 15
forms an extension element structure within the area of the refiner chamber 5
in order to increase the extent of the refiner chamber 5 in the direction of
the
shaft 6 of the refiner.
[0024] Instead of using in the refiner 14 an old end element 8, it is
possible to form a novel end element 8 e.g. by casting, the novel end element
8 also comprising a section which corresponds with the extension sleeve 15
and which elongates a section corresponding with the frame structure, i.e. the
pressure frame, of the refiner, and fasten this novel end element to the frame
CA 02684191 2009-10-30
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structure 2, i.e. the pressure frame 3, of the refiner 1, thus changing the
frame
structure of the original, used refiner within the area of the refiner chamber
such that the extent of the refiner chamber increases in the direction of the
shaft of the refiner. In such a case, in addition to the end element, the
novel
end element also comprises an extension element structure for increasing the
extent of the refiner chamber in the direction of the shaft of the refiner.
[0025] The rotor 7 of the refiner 14 may also be implemented such
that in addition to the old stator, also the old rotor is removed from the
original
= disc refiner 1 from the shaft 6 of the refiner 1 and, in place thereof, a
rotor 7 is
installed which is formed from at least one rotor element and which comprises
at least a conical refining surface 10' but possibly a disc-like refining
surface
10" as well. This also enables a corresponding stator comprising at least a
conical refining surface 11' but possibly also a disc-like refining surface
11" to
be installed in place of the original disc-like stator. In a similar manner,
both the
original stator and rotor may be replaced by a stator and rotor comprising
coni-
cal refining surfaces only, in which case the old disc refiner may be changed
into a cone refiner.
[0026] Figure 3 is a schematic cross-sectional side view showing a
double disc refiner 16. The refiner 16 according to Figure 3 is thus a double
disc refiner or a DD refiner whose refiner chamber 5 is provided with two
rotors
7 arranged towards one another such that a blade gap 13 is provided between
the rotors 7. With respect to the rest of the structure of the refiner 16,
Figure 3
shows the blade gap 13 substantially larger than it really is. The refiner 16
fur-
ther comprises two shafts 6 such that the rotors 7 may be rotated irrespective
of one another. In the refiner 16, the frame structure has two frame structure
sections separate from one another: a first frame structure section 2' as seen
in Figure 3 on the left side of the left-hand rotor 7, and a second frame
struc-
ture section 2" on the right side of the right-hand rotor 7. The frame
structure
sections 2' and 2" are combined with one another by one or more support ele-
ments 17, whereby the frame structure 2 of the refiner 16 according to Figure
3
comprises a first frame structure section 2', a second frame structure section
2" and one or more support elements 17 which are arranged at least partly, in
their entirety as seen in Figure 3, between the first frame structure section
2'
and the second frame structure section 2", supporting the first frame
structure
section 2' and the second frame structure section 2" against one another and
at the same time forming part of the pressure frame 3 surrounding the refiner
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8
chamber 5 of the refiner 16. The support element 17 may also be an element
similar to the extension sleeve 15 or the extension structure 15 shown in Fig-
ure 2 if the support element 17 is formed from one part only.
[0027] The refiner 16 shown in Figure 3 may be formed from two
used disc refiners 1 shown in Figure 1 by removing the end elements of said
disc refiners from connection with the frame structure of the refiner.
Together
with the end element, the stator provided in connection with the end element
is
removed from the refiners. Next, when necessary, some frame structure is re-
moved by machining from at least one or both of the used refiners from the
area of the refiner chamber from the pressure frame surrounding the rotor 7
such that said refiners may be installed with respect to one another such that
the refining surfaces of the rotors 7 thereof come towards one another such
that a blade gap 13 is provided between said refining surfaces. Next, the
frame
structures of said refiners that are still separate from one another, the
frame
stuctures in Figure 3 thus corresponding with the first frame structure
section 2'
and the second frame structure section 2", are combined with one another by
means of one or more support elements 17 such that one refiner structure is
formed wherein the frame structures of the originally separate disc refiners
and
one or more support elements 17 form a substantially closed refiner chamber.
The support elements 17 increase the extent of the refiner chamber in the di-
rection of the shaft of the refiner such that the refiner unit formed from two
ro-
tors is more easily accommodated inside the refiner.
[0028] In the solution shown in Figure 3, two used disc refiners may
thus be changed into one double disc refiner provided with two rotors which
rotate irrespectively of one another. Such a change is easy to make only by
removing the end elements and stators of the used disc refiners and, when
necessary, by removing either from one disc refiner or from both disc refiners
at least part of the frame structure surrounding the rotor as well as by
combin-
ing with one another the remaining sections of the original refiners by
suitable
support elements. In addition to this, only feed openings 12 have to be ar-
ranged through one of the rotors and through the frame structure section in
connection with said rotor in order to feed material to be refined into the
blade
gap 13 located between the rotors 7. The feed openings 12 are shown sche-
matically in Figure 3 in the right-hand rotor 7 and in the second frame
structure
section 2". The gap between a background surface of the rotor and the frame
structure may be sealed by a mechanical seal such that the material fed to be
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9
refined may enter the refiner chamber only via the blade gap 13. Naturally, a
discharge opening or channel (not shown in the figure) for refined material is
also provided in connection with the refiner chamber of the refiner.
[0029] Figure 4 is a schematic cross-sectional side view showing
another double disc refiner 18, and Figure 5 is a schematic end view showing
a double disc refiner similar to that of Figure 4. The refiner shown in
Figures 4
and 5 has a frame structure 2 which comprises, as the refiner according to
Figure 3, a first frame structure section 2' and a second frame structure
section
2", a pressure frame 3 housing a refiner chamber 5, and a base frame 4 of the
refiner to support the pressure frame. Inside the refiner chamber 5 are two ro-
tors 7, each being rotatable irrespective of one another via a corresponding
shaft 6. Between the rotors 7 a blade gap 13 is provided whereto the fibrous
material to be refined is fed via feed openings 12 arranged in the right-hand
rotor 7 as seen in Figure 4 as well as via a feed channel 19. The feed channel
19 may be provided with a screw conveyor for making the feed of the material
to be refined more efficient. Figure 4 further schematically shows a discharge
opening 21 for discharging refined material from the refiner.
[0030] The structure of the refiner according to Figures 4 and 5 is
similar to that of Figure 3, differing, however, from the refiner according to
Fig-
ure 3 in that the first frame structure section 2' and the second frame
structure
section 2" of the refiner 18 are supported against one another by a support
element 20 connecting or fastening the base frame 4 of the first frame struc-
ture section 2' and the base frame 4 of the second frame structure section 2"
to one another; Figure 4 shows the support element 20 schematically in dotted
line. The pressure frame 3 resides between the first frame structure section
2'
and the second frame structure section 2" but does not support the frame
structure sections 2', 2" against one another. In addition, the refiner
chamber 5
is formed by a separate pressure frame 3 added during the change of the re-
finer and formed from an upper part 3' and a lower part 3".
[0031] The refiner 18 shown in Figures 4 and 5 may be formed from
two used disc refiners 1 shown in Figure 1 by removing the end elements of
said disc refiners from connection with the frame structure of the refiner.
Along
with the end element, a stator provided in connection with the end element is
removed from the refiners. Next, at least part of the pressure frame 3 is also
removed from both refiners from connection with the rest of the frame struc-
ture. The rotors and frame structures remaining from the refiners are arranged
CA 02684191 2016-03-10
in connection with one another such that the refining surfaces of the rotors 7
come
towards one another such that a blade gap 13 is provided between said refining
surfaces.
5 A new pressure frame 3 is arranged around the rotors 7, the pressure
frame 3 consisting
of an upper part 3' and a lower part 3" and being received between a frame
part
corresponding with the first frame structure section 2' and remaining from one
old disc
refiner and a frame part corresponding with the second frame structure section
2" and
remaining from the other old disc refiner. In this case, the frame structure
of the old disc
10 refiners is thus changed over the section belonging to the pressure
frame of the refiner
such that at least part of the old pressure frame is removed from both
refiners and said
two pressure frames or sections removed therefrom are replaced at least partly
by one
new pressure frame. However, the new pressure frame 3 does not support the
first frame
structure section 2' and the second frame structure section 2" against one
another but one
or more support elements 20 are arranged in connection with the first frame
structure
section 2' and the second frame structure section 2" to fasten the first frame
structure
section 2' and the second frame structure section 2" to one another and to
support them
against one another. The support element 20 may be e.g. a disc-like structure,
as shown
in Figures 4 and 5, which may be made e.g. of metal.
[0032] In the disclosed manners, an old disc refiner may be changed e.g. into
a
disc cone refiner or two old disc refiners may be changed into a double disc
refiner. This
enables the structural parts and the related actuators of old refiners to be
utilized in an
extensive manner when updating the refining processes, which lowers the costs
caused
by the changes. For example, by changing two old disc refiners into one double
disc
refiner a considerable amount of energy can be saved since double disc
refiners consume
typically about 10 to 30% less energy than disc refiners. In addition, the
quality of pulp
produced by a double disc refiner is, however, usable for high-quality
printing papers.
[0033] In some cases, the features disclosed in this application may
be used as such, irrespective of other features. On the other hand, when
necessary, the
features disclosed in this application may be combined in order to provide
different
combinations.
[0034] The drawings and the related description are only intended to
illustrate the
idea of the invention. The scope of the claims should not be limited by the
specific
embodiments disclosed herein, but should be given the broadest interpretation
consistent
with the description as a whole.
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11
[0035] In the implementation of a disc cone refiner, it may be nec-
essary to machine the frame structure, i.e. in practice the pressure frame, of
the original refiner inside the pressure frame within the area of the refiner
chamber in order to enable the conical refining surface section of the stator
to
be installed in an easy manner concentrically with respect to the conical
refin-
ing surface section of the rotor. In the case of a double disc refiner, the
con-
centricity of the rotors does not set equally high requirements. The machining
may be carried out such that the refiner chamber is at the same time carved
out not only in -a direction of the shaft but also in a direction of a radius,
whereby the length and diameter of a refiner blade solution to be arranged in
the refiner chamber may be larger. The machining of the frame structure of the
refiner within the area of the refiner chamber may also be carried out because
it enables refiner blades to be replaced or replacement of the refiner blades
to
be made easier to implement, which constitutes grounds for machining the
frame structure of the refiner when applying the solution of the invention to
the
case of the double disc refiner in particular.
