TEPZZ ¥9¥58_B_T
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EP 2 393 581 B1
EUROPEAN PATENT SPECIFICATION
(12)
(45) Date of publication and mention
(51) Int Cl.:
B01F 7/00 (2006.01)
of the grant of the patent:
16.01.2013 Bulletin 2013/03
B01F 3/08 (2006.01)
(86) International application number:
PCT/EP2010/051292
(21) Application number: 10701706.3
(87) International publication number:
(22) Date of filing: 03.02.2010
WO 2010/089320 (12.08.2010 Gazette 2010/32)
(54) DISTRIBUTIVE AND DISPERSIVE MIXING APPARATUS OF THE CDDM TYPE, AND ITS USE
MISCHVORRICHTUNG DES TYPS CDDM ZUM VERTEILENDEN UND DISPERSIVEN MISCHEN,
SOWIE DEREN VERWENDUNG
DISPOSITIF DE MELANGE A REPARTITION ET A DISPERSION DE TYPE CDDM, ET SON
UTILISATION
(72) Inventors:
(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR
HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL
PT RO SE SI SK SM TR
(30) Priority: 09.02.2009 GB 0901956
(43) Date of publication of application:
14.12.2011 Bulletin 2011/50
• BROWN, Christopher, John
Glossop
Derbyshire SK13 8RG (GB)
• IRVING, Graeme, Neil
Wirral
Merseyside CH63 3JW (GB)
• KOWALSKI, Adam, Jan
Wirral
Merseyside CH63 3JW (GB)
(73) Proprietors:
EP 2 393 581 B1
• Unilever PLC
London, Greater London EC4Y 0DY (GB)
Designated Contracting States:
CY GB IE MT
• Unilever NV
3013 AL Rotterdam (NL)
Designated Contracting States:
AT BE BG CH CZ DE DK EE ES FI FR GR HR HU
IS IT LI LT LU LV MC MK NL NO PL PT RO SE SI
SK SM TR
(74) Representative: van Benthum, Wilhelmus A. J.
Unilever N.V.
Unilever Patent Group
Olivier van Noortlaan 120
3133 AT Vlaardingen (NL)
(56) References cited:
WO-A1-96/20270
US-A- 3 867 104
US-A- 5 988 866
US-A- 3 174 185
US-A- 4 421 413
US-B1- 6 345 907
Note: Within nine months of the publication of the mention of the grant of the European patent in the European Patent
Bulletin, any person may give notice to the European Patent Office of opposition to that patent, in accordance with the
Implementing Regulations. Notice of opposition shall not be deemed to have been filed until the opposition fee has been
paid. (Art. 99(1) European Patent Convention).
Printed by Jouve, 75001 PARIS (FR)
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EP 2 393 581 B1
Description
Technical Field
[0001] The present invention relates to mixing apparatus for fluids and in particular, to flexible mixing devices
which can provide a range of mixing conditions.
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Background of the Invention
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[0002] It is recognised that mixing can be described as
either distributive or dispersive. In a multi-phase material
comprising discrete domains of each phase, distributive
mixing seeks to change the relative spatial positions of
the domains of each phase, whereas dispersive mixing
seeks to overcome cohesive forces to alter the size and
size distribution of the domains of each phase. Most mixers employ a combination of distributive or dispersive
mixing although, depending on the intended application
the balance will alter. For example a machine for mixing
peanuts and raisins will be wholly distributive so as not
to damage the things being mixed, whereas a blender/
homogeniser will be dispersive.
[0003] Many different types of rotor/stator mixer are
known. Stirring reactors such as those disclosed in US
2003/0139543 A1 comprise a vessel with internally
mounted mixing elements and are generally distributive
in function. Other types of rotor-stator mixer (such as that
disclosed in WO 2007/105323 A1 are designed with the
intention of forming fine emulsions and are dispersive in
character. DE 1557171 B1 discloses a mixer with a plurality of alternately rotating and static, concentric cagelike elements through which the flow is radial.
[0004] EP 0799303 B1 and GB 2118058 A describe a
known mixer type, hereinafter referred to as a "Cavity
Transfer Mixer" (CTM), comprising confronting surfaces,
each having a series of cavities formed therein in which
the surfaces move relatively to each other and in which
a liquid material is passed between the surfaces and
flows along a pathway successively passing through the
cavities in each surface. The cavities are arranged on
the relevant surfaces such that shear is applied to the
liquid as it flows between the surfaces. In a typical embodiment the mixer comprises an outer sleeve and a
close-fitting inner drum. The confronting surfaces of the
sleeve and the drum are both provided with cavities disposed so that the cavities overlap forming sinuous and
changing flow paths which change as the drum and the
sleeve rotate relative to each other. This type of mixer
has stator and rotor elements with opposed cavities
which, as the mixer operates, move past each other
across the direction of bulk flow through the mixer. In
such mixers, primarily distributive mixing is obtained.
Shear is applied by the relative movement of the surfaces
in a generally perpendicular direction to the flow of material. In the typical embodiment described above, this is
accomplished by relative rotation of the drum and the
sleeve. In such a device there is relatively little variation
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in the cross-sectional area for flow as the material passes
axially down the device. Generally, the cross-sectional
area for flow varies by a factor of less than 3 through the
apparatus.
[0005] The commercial application of CTMs has been
largely restricted to the thermoplastics’ conversion industry, where CTM technology originated (see EP 048590).
In part this is because established rotor/stator devices,
such as "Silverson" mixers, offer some of the benefits
and at a significantly lower cost.
[0006] In some mixers, such as that described in EP
0434124 A1 a cage-like rotor and stator elements are
configured such that the bulk flow must pass through
relatively narrow spaces within the reactor. Similar alternation of relatively wide and relatively narrow flow spaces, for the purpose of forming an emulsion, are known
from GB 129757 A. However GB 1297757 A and EP
0434124 A1 are not CTM’s as the relatively wide spaces
form annuli and there it little or no alteration of the flow
path geometry as the rotor and stator move.
[0007] EP 0799303 B1 also describes a novel mixer,
hereinafter referred to as a "Controlled Deformation Dynamic Mixer" (CDDM). In common with the CTM, type of
mixer has stator and rotor elements with opposed cavities
which, as the mixer operates, move past each other
across the direction of bulk flow through the mixer. It is
distinguished from the CTM in that material is also subjected to extensional deformation. The extensional flow
and efficient dispersive mixing is secured by having confronting surfaces with cavities arranged such that the
cross sectional area for bulk flow of the liquid through the
mixer successively increases and decreases by a factor
of at least 5 through the apparatus. In comparison with
the embodiment of the CTM described above, the cavities of the CDDM are generally aligned or slightly offset
in an axial direction such that material flowing axially
along the confronting surfaces is forced through narrow
gaps as well as flowing along and between the cavities.
The CDDM combines the distributive mixing performance of the CTM with dispersive mixing performance.
Thus, the CDDM is better suited to problems such as
reducing the droplet size of an emulsion, where dispersive mixing is essential.
[0008] GB 2308076 A shows several embodiments of
a mixer comprising a co-called. "sliding vane" pump.
These include both drum/sleeve types where the bulk
flow is along the axis of the mixer and mixers in which
the flow is radial. Many other types of reactor can be
configured either as the drum/sleeve type or the "flat"
type. For example DD207104 A3 and GB 2108407 A
show a mixer comprising two movable confronting surfaces with projecting pins which cause mixing in material
flowing in a radial direction between the plates.
[0009] US 3 867 104 A discloses a conveying apparatus for incorporation into a finisher comprising a portion
of a cylindrical member being a helical segment and having number of substantially parallel helical ridges on a
least one surface thereof forming helical channels.
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[0010] Both the CTM and the CDDM can be embodied
in a "flat" form where the drum and the sleeve are replaced with a pair of disks mounted for relative rotation
and the cavities are provided in the confronting surfaces
of the disks. In this modified "flat" form the bulk flow is
generally radial.
[0011] Despite these advances, there is a need to:
(i) improve dispersive and distributive mixing without
recourse to excessive increases in operating pressure and rotational speed;
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(ii) be more flexible through interchangeable parts
specified according to application;
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(iii) increase hygienic security through greater assuredness that the material being processed cannot
stagnate within the device; and
(iv) facilitate deployment and maintenance through
mechanical simplification.
[0012] An important further consideration in certain
CDDM designs concerns the relative axial positions of
rotor and stator components during operation which are
critical to performance. Such relative positions may
change by axial displacement of the rotating parts with
respect to the static parts and this may compromise critical clearances. Under "normal" operating conditions,
such displacement is resisted through thrust bearings,
an approach which becomes more difficult at high pressures and mixer speeds.
[0013] There are practical limits to the spacing between the confronting surfaces in the CDDM and CTM.
As the device is heated, expansion may mean that the
rotor/drum expands in a radial direction. The stator/
sleeve may expand less as it is better able to lose heat.
This can result in a narrowing of the gap between the
confronting surfaces and even contact. At high operating
speeds, contact between the surfaces can be catastrophic.
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one of the confronting surfaces and/or at least one other
cage-like member, and ports (5, 6) are provided for ingress and egress of the process stream such that the
bulk fluid flow within the mixing apparatus is in the plane
of the surface of the or at least one cage-like member
perpendicular to the direction of relative rotational movement.
[0016] By "cage-like" is meant a member having apertures which allow fluid flow from a first surface of the
member to a second surface of the cage-like member.
In the sleeve/drum form of the CTM/CDDM this can comprise a tube-shaped element having ports communicating between the inside and the outside.
[0017] By providing such a cage-like member (or more
than one such member) between the confronting surfaces it is possible to improve both dispersive and distributive mixing. This occurs due to the significant increase in
the exposure of the process fluid to regions of high shear
and extensional flow, and is obtained without increased
operating speeds or pressure drops.
[0018] By "not freely rotating relative to at least one of
the confronting surfaces or at least one other cage-like
member" is meant that the, or at least one, cage-like
member is not simply a freely moving element being
dragged around by the dynamics of the fluid flow within
the mixer in an uncontrolled manner. The cage-like member motion, relative to at least one of the confronting surfaces is actively driven by a motor.
[0019] The invention is described and presented in
terms of rotary motion. For the purposes of interpretation
of this specification and the intended meaning and scope
of its claims, the phrase "but is not freely rotating" should
be interpreted to Include "oscillates but is not freely oscillating" as the rotary motion need be neither continuous
nor unidirectional.
[0020] A further aspect of the present invention subsists in the use of the mixing apparatus of the present
invention for the treatment of a liquid, emulsion, gel or
other flowable composition.
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Detailed Description of the Invention
Brief Description of the Invention
[0014] We have determined that the CTM/CDDM type
mixer can be significantly improved by providing at least
one cage-like member between the confronting surfaces,
provided that the cage-like member is not freely rotating.
[0015] According to a first aspect of the present invention there is provided a distributive and dispersive mixing
apparatus of the CDDM type comprising two confronting
surfaces and at least one cage-like member disposed
between the confronting surfaces said cage-like member
defining passages for fluid flow adjacent at least one of
the confronting surfaces CHARACTERISED IN THAT at
least one of the at least two confronting surfaces is
smooth, and the or at least one cage-like member is driven by a motor to perform a rotation relative to at least
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[0021] For the purposes of understanding the operation of the CTM or CDDM in general, we refer to EP
0799303. As noted above, the apparatus of the present
invention is similar to the CTM and. CDDM in that it comprises two confronting surfaces and the flow path for liquid along these confronting surfaces through the mixer
varies in width. Regions of distributive mixing (where the
flow path is wide) comprises CTM-like cavities moving
across each other in a direction perpendicular to the bulk
flow of liquid. Between these regions of distributive mixing are regions in which the flow path is narrower and
the flow is more extensional.
[0022] At least one of the at least two confronting surfaces is smooth. The provision of a smooth surface adjacent a cage-like member ensures good dispersive mixing. The provision of a smooth confronting surface in a
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drum/sleeve type of CTM, where the smooth surface is
the inner surface of the sleeve is particularly beneficial
as it avoids the machining difficulties of providing cavities
in the inner surface o the sleeve. One excluded configuration is that in which there is a single cage-like element
and both of the confronting surfaces are smooth, as this
would contain no CTM-like regions. If both confronting
surfaces are smooth then the mixer needs to comprise
at least two cage-like elements to that CTM-like mixing
across the direction of bulk flow can be achieved.
[0023] In particular embodiments of the present invention at least one of the confronting surfaces is provided
with cavities, which cavities may be machined into said
surface or be formed by a smooth surface and an adjoining member defining apertures and secured thereto, The
provision of cavities in the surface adjacent a cage-like
member ensures good distributive mixing especially
when the respective positions of cavities and apertures
are CTM-like. The provision of cavities in the surface adjacent a cage-like member ensures further dispersive
mixing when the overlap between cavities and apertures
is CDDM-like.
[0024] In particular embodiments of the present invention the apparatus comprises either one or more of said
cage-like members. Where two or more cage-like members are present they are typically arranged such that a
surface of a first member is adjacent or adjoins a surface
of a second member.
[0025] The apertures on at least one pair of such adjacent or adjoining surfaces within the mixer are in one
series of embodiments aligned to enhance the extensional component of flow to which the fluid is subjected. In a
drum/sleeve configuration this can be done by ensuring
that the apertures on adjacent surfaces are generally
aligned or slightly offset in the axial direction. Axial flow
from aperture to aperture therefore requires the process
fluid to pass through narrow spaces as in the CDDM and
good dispersive mixing is obtained.
[0026] It is possible for a mixer according to the invention to be provided with one on more regions in which
the juxtaposition is such that the arrangement is CTMlike and one or more regions in which the arrangement
is CDDM-like.
[0027] It is possible to envisage a mixing apparatus
according to the present invention in which both of the
confronting surfaces are fixed and at least one cage-like
member is rotated. In the alternative, the confronting surfaces are rotated relative to each other.
[0028] As with the CTM and the CDDM there are several possible configurations for the mixing apparatus. In
one preferred combination the confronting surfaces are
cylindrical and the, or each, cage-like member is generally tubular. In such a configuration the apparatus will
generally comprise a cylindrical drum and co-axial sleeve
with one or more cage-like members disposed between
them co-axially. The confronting surfaces will be defined
by the outer surface of the drum and the inner surface of
the sleeve. However, there are alternative configurations
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in which the confronting surfaces are circular and the, or
each, cage-like member is generally disk-shaped. In this
disk configuration the, or each, cage-like member will
form the "filling" sandwiched between the two confronting
surfaces. Between these two extremes of configuration
are those in which the confronting surfaces are conical
or frusto-conical and the, or each, cage-like member is
generally conical or frusto-conical. Non-cylindrical embodiments allow for further variation in the shear in different parts of the flow through the mixer.
[0029] In one particularly preferred embodiment of the
invention the apparatus comprises surfaces which may
be "stepped" on all or some adjacent surfaces.
[0030] For example, consider a cylindrical apparatus
comprising a "stepped" drum comprising a sequence of
two or more cylindrical regions of differing diameters. The
sleeve is similarly stepped, so as to maintain the separation between the outer surface of the drum and the
inner surface of the sleeve and to define an annular space
between them of varying radius. In one such configuration a region of significant axial bulk flow is either followed
or preceded by a region of significant radial bulk flow.
Advantageously, the axial thrust on the cage will be counteracted by the fluid pressure within the region of radial
bulk flow. Similar benefits are obtained with the conical
configuration discussed above. A particular advantage
of the stepped configuration is that the axial confronting
surfaces can be spaced more widely than the radial confronting surfaces. This minimises the problems of thermal
expansion, as the spacing between the radial confronting
surfaces, where the extensional flow is highest, can be
modified by longitudinal displacement of the, or each,
cage-like member and/or the drum and/or the sleeve relative to each other.
[0031] The steps may be provided on one of the drum
and the sleeve, or on both. In the case of the steps being
provided on only one of the drum and the sleeve then
the cage-like member will be adapted to have a stepped
surface on one side (either inside or outside depending
on whether the steps are provided on the drum or sleeve
respectively) and a surface on the other side which conforms closely to the non-stepped surface. A more preferred arrangement is that corresponding steps are provided on both the sleeve and the drum.
[0032] By varying the normal separation of the confronting surfaces in CTM/CDDM type mixers, it is possible to confine the most intense shear to relatively few
regions.
[0033] The regions where the confronting surfaces (or
where one of the surfaces and a surface of the cage like
member) are most closely spaced are those where the
shear rate within the mixer tends to be the highest. As
noted above high shear contributes to power consumption and heating. This is especially true where the confronting surfaces of the mixer are spaced by a gap of less
than around 50 microns. Advantageously, confining the
regions of high shear to relatively short regions means
that the power consumption and the heating effect can
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EP 2 393 581 B1
be reduced, especially where in the CTM-like regions the
confronting surfaces are spaced apart relatively widely.
A further benefit of this variation in the normal separation
of the confronting surfaces in the direction of bulk flow,
is that by having relatively small regions of high shear,
especially with a low residence time is that the pressure
drop along the mixer can be reduced without a compromise in mixing performance. We have determined that
by machining back the confronting surfaces in the CTMlike regions such that the clearance between the confronting surfaces is at least 2 times that of the closer
regions, preferably 3-10 times that of the closer regions
a very significant power requirement reduction and reduction in operating pressure are obtained.
[0034] Additional features of the known CTM and CDDM may be incorporated in the mixer described herein.
For example, one or both of the confronting surfaces may
be provided with means to heat or cool it. Where cavities
are provided in the confronting surfaces these (and also
the apertures in the cage-like member) may have a different geometry in different parts of the mixer to as to
further vary the shear conditions.
[0035] In order that the present invention can be better
understood it will be described by way of example and
with reference to the accompanying figures, in which:
Figure 1:
shows a mixer with a fixed drum, inner cage
and sleeve, rotating outer cage;
Figure 2:
shows a mixer with a fixed sleeve and inner
cage, rotating drum and outer cage;
Figure 3:
shows a mixer with a fixed drum and sleeve,
rotating inner cage and outer cage (figure
3 is not an embodiment of the invention);
Figure 4:
shows a mixer with a fixed drum, inner cage
and sleeve, rotating outer cage;
Figure 5:
shows a mixer with a fixed inner stepped
drum and outer stepped sleeve, fixed outer
cage, rotating inner stepped cage.
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Examples
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[0036] In each of the illustrative examples the apparatus comprises an inner drum (1) and an outer sleeve (4).
In all the cases illustrated there are two cage-like members (2), (3) present. These are arranged in a concentric
and co-axial manner between the drum (1) and the sleeve
(4). In the first example the inner cage (2) is fixed to the
drum (1) to define cavities in the innermost pair of confronting surfaces. In the fifth example the outer cage (3)
is fixed to the sleeve (4) to define cavities in the outer
confronting surface. In examples 2 and 3, neither of the
cages is fixed to the drum or sleeve. Examples 2 and 3
differ in that the cages are in the one case adjoining and
fixed together and in the other case adjacent and mov-
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able separately. Example 5 shows a "stepped" configuration. Figure 3 is not an embodiment of the claimed invention as there is no CTM-like region present, that is no
region in which cavities are moving relative to each other
across the direction of bulk flow through the mixer.
[0037] None of the figures show the end caps of the
mixer or the means for driving the moving elements as
the figures are intended to be schematic rather than providing full details and dimensions. In the figures, ports
(5) and (6) are provided for ingress and egress of the
process stream. In embodiments of the invention a plurality of ports may be provided for the ingress of different
materials that are to be mixed.
Example 1: fixed drum, inner cage and sleeve, rotating
outer cage.
[0038] Figure 1 shows a three part assembly comprising an inner drum (1) to which an inner cage-like member
(2) is attached to form a single part. In the alternative the
inner drum may be provided with cavities in its outer surface. Outer cage (3) is mounted for rotation around the
inner drum/cage. Sleeve (4) has a plain bore. All parts
are dimensioned and assembled to be concentric. Ports
(5) and (6) are provided for ingress and egress of the
process stream.
[0039] In use, parts (1), (2) and (4) remain static, and
outer cage (3) rotates. A device of the CDDM type is
formed across the annulus enclosed between fixed inner
cage (2) and moving outer cage (3). During rotation of
the outer cage (3) relative to inner cage-like member (2)
and drum (1) material flows between the apertures in
cage (3) and the cavities defined by cage-like member
(2) and drum (1) and as the cages are rotating relative
to each other there is a constant "chopping" of the process stream across the direction of bulk flow through the
mixer. Further mixing occurs as a consequence of flow
through the annulus formed between outer cage (3) and
sleeve (4). This further mixing is a continuous dispersive
mixing operation due to the relative movement of the outer cage (3) and sleeve (4) in the regions of low radial
separation and high shear between the cage (3) and
sleeve (4).
[0040] A particular advantage of this configuration is
that the inner surface of the sleeve (4) only needs to be
machined flat and does not have to be provided with cavities.
Example 2: fixed sleeve and inner cage, rotating drum
and outer cage.
[0041] Figure 2 shows a four part assembly comprising
an inner drum (1) with a plain surface, inner cage (2),
outer cage (3) and outer sleeve (4) with a plain bore. The
four parts are dimensioned and assembled to be concentric with respect to each other. In use, cage (2) and
sleeve (4) remain static, and drum (1) and cage (3) rotate.
A device of the CDDM type is formed across the annulus
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formed between (2) and (3).
[0042] In the embodiment shown it can be seen that
the arrangement of the apertures is different to that in
figure 1, resulting in a different mixing regime.
[0043] Further mixing occurs as a consequence of flow
through the annuli formed between drum (1) and cage
(2), between cage (2) and cage (3) and between cage
(3) and sleeve (4). A particular advantage of this configuration is that the number of regions of high shear within
the mixer can be increased. This enables the pressure
to be reduced while maintaining the same degree of mixing.
Example 3: fixed drum and sleeve, rotating inner cage
and outer cape.
[0044] Figure 3 shows a three part assembly comprising an inner drum (1) with a plain surface, an inner cage
(2) and an outer cage (3) which are joined to form a single
part (2,3) and an outer sleeve (4) with plain bore. The
parts are dimensioned and assembled to be concentric
with respect to each other. The configuration shown in
the Figure 3 and described in this Example 3 is not an
embodiment of the invention as claimed.
[0045] In use, drum (1) and sleeve (4) remain static,
and the cage (2,3) rotates.
[0046] Dispersive mixing occurs as a consequence of
flow through the annulus formed between drum (1) and
cage (2), and between cage (3) and sleeve (4). In the
embodiment shown, flow from the apertures in cage (2)
to cage (3) is restricted to a relatively narrow opening
due to the relative position of the apertures. However, as
only elements (2) and (3) are provided with apertures
and both the drum (1) and sleeve (2) have smooth confronting surfaces there is no region of CTM-like distributive mixing in this configuration. Consequently this example is not an embodiment of the present invention.
Example 4: fixed drum, inner cage and sleeve, rotating
outer cage.
[0047] Figure 4 shows a three part assembly comprising an inner drum (1) with cavities provided in its surface
by means of cage (2) being fixedly attached to it, a cage
(3) and an outer sleeve (4) with cavities (7) in its surface
(in this embodiment the cavities are shown as if machined, which is a less preferred embodiment). The three
parts are dimensioned and assembled to be concentric
with respect to each other.
[0048] In use, drum (1), cage (2) and sleeve (4) remain
static, and the cage (3) rotates.
[0049] Mixing occurs as a consequence of flow through
the pathways defined by the cavities (7) defined by the
sleeve (4), cage (2) and cage (3). The provision of the
cavities in both confronting surfaces allows for a very
broad variation in the shear conditions within the mixer.
[0050] In the schematic embodiment shown, the cage
(3) is shown as displaced to the right. In use, such dis-
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placement of an element of the mixer enables the geometry of the mixer to be changed from CDDM-like to CTMlike. If the cage is displaced far enough then the regions
of high extensional flow may be lost and the mixer will
fall outside of the claims as there will be no CDDM feature
present.
Example 5: fixed inner stepped drum and outer stepped
sleeve, fixed outer cage rotating inner stepped cage.
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[0051] Figure 5 shows a mixer assembly comprising a
stepped cage (2, 2a, 2b) which has an axial section profile
formed from rings of increasing radial section in the direction of bulk flow, and which is sited between an inner
stepped drum (1) with a surface profile which closely conforms to the inner surface of the stepped cage, and an
outer stepped sleeve (4) with a surface profile which
closely conforms to the outer surface of the stepped cage.
Ports (5,6) are provided for the ingress and egress of the
process stream. In the embodiment shown port (6) is the
inlet and port (5) the outlet. In part the cavities in the outer
confronting surfaces are formed by a fixed cage (3). In
the alternative, they can be, for example, machined into
the surface, as at (7).
[0052] Mixing occurs by the flow of materials between
apertures and through the annuli formed between the
confronting surfaces and the surfaces of the stepped
cage.
[0053] In use the spacing on either side of the radial
part of the cage (2a) is set to the desired value by axial
displacement of the cage (2, 2a, 2b) and the drum (1)
relative to the sleeve (4). Mixing also occurs as the process stream flows though this narrow spacing. Typically
the spacing on either side of the region (2a) will be less
than the spacing on either side of the regions (2) and (2b)
of the cage. This is particularly advantageous if the components of the apparatus will expand during use as the
spacing at (2a) can be modified to compensate whereas
the spacing at (2) and (2b) cannot be. Thus, the narrowest
space for extensional flow is arranged to be in the region
(2b). In practice, a mixer would not have a single step as
shown in figure 5, but a plurality of steps.
[0054] Figure 5 also shows a mixer which has different
configurations in different regions. Thus, the wider diameter portion of the mixer is configured like a CDDM, while
the narrower portion is configured like a CTM. As will be
appreciated, for any given rotation speed the relative
rates of movement of the corresponding confronting surfaces and cage surfaces in the region of cage part (2)
will be higher than those in the region of cage part (2b),
due to the increased radius.
Claims
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1.
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A distributive and dispersive mixing apparatus of the
CDDM type comprising two confronting surfaces (1,
4) and at least one cage-like member (2,3) disposed
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EP 2 393 581 B1
between the confronting surfaces (1, 4) said cagelike member (2,3) defining passages for fluid flow
adjacent at least one of the confronting surfaces (1,
4) CHARACTERISED IN THAT at least one of the
at least two confronting surfaces (1, 4) is smooth,
and the or at least one cage-like member (2,3) is
driven by a motor to perform a rotation relative to at
least one of the confronting surfaces (1, 4) and/or at
least one other cage-like member(2,3), and ports (5,
6) are provided for ingress and egress of the process
stream such that the bulk fluid flow within the mixing
apparatus is in the plane of the surface of the or at
least one cage-like member(2,3) perpendicular to
the direction of relative rotational movement.
wherein the normal separation of the confronting surfaces (1, 4) varies in the direction of bulk flow.
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A mixing apparatus according to claim 1, wherein at
least one of the at least two confronting surfaces (1,
4) is provided with cavities.
3.
A mixing apparatus according to any preceding
claim, wherein the confronting surfaces (1, 4) can be
rotated relative to each other.
4.
A mixing apparatus according to any preceding
claim, which comprises at least two of said cage-like
members (2,3).
5.
6.
7.
8.
9.
A mixing apparatus according to claim 4, wherein
said at least two cage- like members (2,3) can be
rotated relative to each other.
A mixing apparatus according to any preceding
claim, wherein at least a portion of the confronting
surfaces (1, 4) are cylindrical and the, or each, respective portion of the cage-like member (2,3) is generally tubular.
A mixing apparatus according to any of claims 1 -5,
wherein at least a portion of the confronting surfaces
(1, 4) are circular and the, or each, respective portion
of the cage-like member (2,3) is generally diskshaped.
A mixing apparatus according to any of claims 1 -5,
wherein at least a portion of the confronting surfaces
(1, 4) are frusto-conical and the, or each, respective
portion of the cage-like member (2,3) is generally
frusto-conical.
A mixing apparatus according to any of claims 1 -8.
wherein at least one of the confronting surfaces (1,
4) is stepped.
10. A mixing apparatus according to any of claims 1 -9,
wherein at least one of the surfaces of a cage-like
member (2,3) is stepped.
12. A mixing apparatus according to any of claim 1-11,
wherein the normal separation of at least one confronting surfaces. (1, 4) and an adjacent cage like
member (2,3) varies in the direction of bulk flow.
13. Use of mixing apparatus according to any preceding
claim for the treatment of a liquid, emulsion or gel.
Patentansprüche
15
2.
12
1.
Mischvorrichtung des Typs CDDM zum verteilenden
und dispersiven Mischen, die zwei sich gegenüberliegende Oberflächen (1, 4) und wenigstens ein käfigartiges Element (2, 3), das zwischen den gegenüberliegenden Oberflächen (1, 4) angeordnet ist,
umfasst, wobei das käfigartige Element (2, 3) Durchlässe für eine fluide Strömung benachbart zu wenigstens einer der sich gegenüberliegenden Oberflächen (1, 4) definiert, DADURCH GEKENNZEICHNET, DASS wenigstens eine der wenigstens zwei
sich gegenüberliegenden Oberflächen (1, 4) glatt ist
und das eine oder wenigstens eine käfigartige Element (2, 3) durch einen Motor angetrieben wird, um
eine Drehung in Bezug auf wenigstens eine der sich
gegenüberliegenden Oberflächen (1,4) und/oder
das wenigstens eine weitere käfigartige Element (2,
3) auszuführen, und Öffnungen (5, 6) zum Eintreten
und Austreten der Prozessströmung vorgesehen
sind, so dass sich die fluide Gesamtströmung innerhalb der Mischvorrichtung in der Ebene der Oberfläche des einen oder wenigstens einen käfigartigen
Elements (2, 3) senkrecht zu der Richtung der relativen Drehbewegung befindet.
2.
Mischvorrichtung nach Anspruch 1, wobei wenigstens eine der wenigstens zwei sich gegenüberliegenden Oberflächen (1, 4) mit Hohlräumen versehen ist.
3.
Mischvorrichtung nach einem der vorhergehenden
Ansprüche, wobei die sich gegenüberliegenden
Oberflächen (1, 4) in Bezug zueinander gedreht werden können.
4.
Mischvorrichtung nach einem der vorhergehenden
Ansprüche, die wenigstens zwei der käfigartigen
Elemente (2, 3) umfasst.
5.
Mischvorrichtung nach Anspruch 4, wobei die wenigstens zwei käfigartigen Elemente (2, 3) in Bezug
zueinander gedreht werden können.
6.
Mischvorrichtung nach einem der vorhergehenden
Ansprüche, wobei wenigstens ein Abschnitt der sich
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11. A mixing apparatus according to any of claims 1 -10,
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sortie du flux de traitement, de telle sorte que l’écoulement de la masse de fluide à l’intérieur du dispositif
de mélange s’effectue dans le plan de la surface de
l’au moins un élément en forme de cage (2,3) perpendiculairement à la direction de mouvement de
rotation relatif.
gegenüberliegenden Oberflächen (1, 4) zylinderförmig ist und der oder jeder entsprechende Abschnitt
des käfigartigen Elements (2, 3) im Allgemeinen röhrenförmig ist.
5
7.
8.
9.
Mischvorrichtung nach einem der Ansprüche 1-5,
wobei wenigstens ein Abschnitt der sich gegenüberliegenden Oberflächen (1, 4) rund ist und der oder
jeder entsprechende Abschnitt des käfigartigen Elements (2, 3) im Allgemeinen schreibenförmig ist.
Mischvorrichtung nach einem der Ansprüche 1-5,
wobei wenigstens ein Abschnitt der sich gegenüberliegenden Oberflächen (1, 4) kegelstumpfförmig ist
und der oder jeder entsprechende Abschnitt des käfigartigen Elements (2, 3) im Allgemeinen kegelstumpfförmig ist.
Mischvorrichtung nach einem der Ansprüche 1-8,
wobei wenigstens eine der sich gegenüberliegenden
Oberflächen (1, 4) gestuft ist.
Dispositif de mélange selon la revendication 1, dans
lequel au moins l’une desdites au moins deux surfaces en regard (1, 4) est pourvue de cavités.
3.
Dispositif de mélange selon l’une quelconque des
revendications précédentes, dans lequel les surfaces en regard (1, 4) peuvent tourner l’une par rapport
à l’autre.
4.
Dispositif de mélange selon l’une quelconque des
revendications précédentes, comprenant au moins
deux desdits éléments en forme de cage (2,3).
5.
Dispositif de mélange selon la revendication 4, dans
lequel lesdits au moins deux éléments en forme de
cage (2,3) peuvent tourner l’un par rapport à l’autre.
6.
Dispositif de mélange selon l’une quelconque des
revendications précédentes, dans lequel au moins
une partie des surfaces en regard (1, 4) est cylindrique et la partie, ou chaque partie respective de l’élément en forme de cage (2,3) est globalement tubulaire.
7.
Dispositif de mélange selon l’une quelconque des
revendications 1 à 5, dans lequel au moins une partie
des surfaces en regard (1, 4) est circulaire et la partie, ou chaque partie correspondante de l’élément
en forme de cage (2,3) est globalement en forme de
disque.
8.
Dispositif de mélange selon l’une quelconque des
revendications 1 à 5, dans lequel au moins une partie
des surfaces en regard (1, 4) est de forme tronconique et la partie, ou chaque partie respective de l’élément en forme de cage (2,3) est globalement tronconique.
9.
Dispositif de mélange selon l’une quelconque des
revendications 1 à 8, dans lequel au moins l’une des
surfaces en regard (1, 4) est étagée.
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11. Mischvorrichtung nach einem der Ansprüche 1-10,
wobei die Normalentrennung der sich gegenüberliegenden Oberflächen (1, 4) in Richtung der Gesamtströmung variiert.
30
13. Verwendung der Mischvorrichtung nach einem der
vorhergehenden Ansprüche zum Verarbeiten einer
Flüssigkeit, einer Emulsion oder eines Gels.
2.
10
10. Mischvorrichtung nach einem der Ansprüche 1-9,
wobei wenigstens eine der Oberflächen des käfigartigen Elements (2, 3) gestuft ist.
12. Mischvorrichtung nach einem der Ansprüche 1-11,
wobei die Normalentrennung wenigstens einer der
sich gegenüberliegenden Oberflächen (1, 4) und eines benachbarten käfigartigen Elements (2, 3) in
Richtung der Gesamtströmung variiert.
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Revendications
1.
Dispositif de mélange distributif et dispersif de type
CDDM comprenant deux surfaces en regard (1, 4)
et au moins un élément en forme de cage (2,3) disposé entre les surfaces en regard (1, 4), ledit élément
en forme de cage (2, 3) définissant des passages
d’écoulement de fluide adjacents à au moins l’une
des surfaces en regard (1, 4), CARACTÉRISÉ EN
CE QUE au moins l’une desdites au moins deux surfaces en regard (1, 4) est lisse, et l’au moins un élément en forme de cage (2,3) est entraîné par un moteur pour effectuer une rotation par rapport à au
moins l’une des surfaces en regard (1, 4) et/ou au à
moins un autre élément en forme de cage (2,3), et
des orifices (5 , 6) sont prévus pour l’entrée et la
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10. Dispositif de mélange selon l’une quelconque des
revendications 1 à 9, dans lequel au moins l’une des
surfaces d’un élément en forme de cage (2,3) est
étagée.
55
11. Dispositif de mélange selon l’une quelconque des
revendications 1 à 10, dans lequel la séparation normale des surfaces en regard (1, 4) varie dans le sens
du flux de masse.
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12. Dispositif de mélange selon l’une quelconque des
revendications 1 à 11, dans lequel la séparation normale d’au moins une des surfaces en regard (1, 4)
et d’un élément en forme cage adjacent (2,3) varie
dans le sens du flux de masse.
5
13. Utilisation d’un dispositif de mélange selon l’une
quelconque des revendications précédentes pour le
traitement d’un liquide, d’une émulsion ou d’un gel.
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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
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