Note: Descriptions are shown in the official language in which they were submitted.
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A DEVICE FOR MODIFYING FLUID FLOW THROUGH A CONDUIT
Field of Invention
The present invention relates to the field of conduit
transfer of fluids and in particular, but not exclusively,
the transfer of slurries.
Background of Invention
Dense medium separator (DMS) plant are used to concentrate
target mineral from a feed comprising a mixture of both
the target mineral and gangue material. The concentration
of the target mineral is achieved by mixing the feed with
a dense liquid medium having a specific gravity between
the specific gravity of the target mineral and the gangue
material. Due to the relative specific gravities one of
the target mineral and the gangue material floats, forming
a "float fraction" and the other sinks, forming what is
known as the "sink". Various well known separators such
as a cone separator or a drum separator may be used to
then separate the float fraction from the sink, both of
which leave the separator as a slurry comprising the dense
liquid medium together with the target mineral or the
gangue material.
The slurries are transferred in conduits to other stations
or locations in the DMS plant for further processing.
Some of these conduits transfer a slurry.between different
vertical levels within the DMS plant and include sections
that maybe inclined to the vertical and/or include one or
more bends. Due to its abrasive nature the flowing slurry
abrades or wears the conduits from the inside. The
abrasion or wear is concentrated at locations along the
conduit where there is a change in direction of the
flowing slurry. The changes in direction of the flowing
slurry in the conduit are typically in the form of bends
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and are an unavoidable design feature in the conduits.
Although at other times there may be more subtle
variations in the layout of the conduit or the iri.terior
shape or configuration that cause a change of direction to
the slurry flow.
Failure of a conduit during operation of the DMS plant is
undesirable. Accordingly operators of DMS similar plants,
implement a maintenance program to replace all such
conduits at-regular intervals to minimize the risk and
expenses associated with conduit failure. A typical
replacement period is every 6 weeks of production time.
The present invention was devised with the view to
extending the time between the required replacement of the
slurry conduit. However resultant embodiments of the
invention are believed to be applicable to other
industries, processes and plants where conduits ducts or
flow channels are worn by action of flowing fluids.
Summary of Invention
In one aspect the present invention provides a device for
increasing turbulence in a fluid flowing through a
conduit, the device comprising:
two or more elements each of which is provided with
an orifice through which fluid flowing through the conduit
passes, wherein the orifice of each element is of a shape
and/or configuration that increases turbulence in fluid
flowing through the conduit downstream of the device when
coupled with the conduit, and wherein at least two of the
elements are spaced by a region through which fluid flows,
the region having a shape and/or configuration different
to that of both the two or more elements.
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It has been found that by placing a device in accordance
with an embodiment of the present invention upstream of a
point in the conduit where it is desired to reduce wear,
particularly localised wear points which may correspond to
a location where the flow under goes a change in
direction, i.e. a bend, abrasion and wear is reduced to
the extent that the routine replacement of conduits can be
extended significantly beyond the current 6 week period.
Without wishing to be bound by theory it is believed that
this occurs due to the device inducing turbulent flow that
is maintained at least adjacent an inner circumferential
surface of the conduit for at least a part of the length
of the bend and has the effect of dispersing fluid energy
over a greater volume of the flowing fluid. While this
may increase overall wear over the length of the conduit
subject to the turbulent flow, wear of localised points
have found to be reduced.
In one embodiment, each element has an inner
circumferential surface which defines the orifice and a
radius of the inner circumferential surface along any line
on the inner circumferential surface and parallel with a
central axis of that element is constant.
Each element may also have an upstream face and a
downstream face each of which lie in respective parallel
planes, the planes being perpendicular to the central
axis.
In one embodiment, the device comprises a housing defining
a fluid flow path and in which the two or more elements
are retained. The housing may have an outer dimension to
allow insertion of the device into a conduit in a manner
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where substantially all of the fluid flowing through the
conduit flowslthrough the fluid flow path. In this
embodiment the device can function as a coupling for
coupling two conduits together.
In one embodiment the device further comprises a first
stop located at a first end of the housing,and a second
stop located at a second end of the housing, wherein each
stop is provided with an orifice to allow fluid to flow
therethrough, and wherein the one or more elements are
retained between the first and second stops.
In one embodiment at least one of the first and second
stops is demountably attached to the housing. In a
further embodiment both of the first and second stops are
demountably attached to the housing.
Each of the elements may take a general form of a washer
having an outer circumferential surface and an inner
circumferential surface, the inner circumferential surface
defining the respective orifice.
The device may further comprise one or more spacers
disposed between adjacent elements, to define the region
spacing the two elements.
According to a further aspect of the present invention
there is provided a conduit through which a fluid can
flow, the conduit having a plurality of first fluid flow
zones a first hydraulic diameter and a plurality of second
fluid flow zones having a second hydraulic diameter, at
least two of the first fluid flow zones being spaced by a
second fluid flow zone, and wherein the first hydraulic
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diameter is different to the second hydraulic diameter to
induce or increase turbulence in fluid flowing through the
conduit downstream of the first and second zones.
In one embodiment the conduit further comprises a bend
downstream of the two first fluid zones. The two first
fluid flow zones are located relative to the bend so that
turbulent flow exists in the fluid prior to entry to the
bend. The two first zones may be located relative to the
bend and/or have xespective hydraulic diameters arranged
so, that at least a substantially turbulent flow is
maintained for at least one half of an arc length of the
bend and preferably for at least the arc length of the
bend.
According to a further aspect of the present invention
there is provided a method of processing ore comprising:
forming a slurry from the ore;
directing said slurry to flow through a conduit
having one or more bends or points of change in direction
to a slurry processing station; and,
at one or more locations along the conduit, upstream
of at least one of the bends or points inducing or
increasing turbulence in the slurry flow.
In one embodiment the inducing or increasing of turbulence
in the flow of the slurry is achieved by installing a
device in accordance with the first aspect of this
invention in the conduit at each of the one or more
locations.
According to a further aspect of the present invention
there is provided a mineral processing plant comprising:
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a supply of a slurry;
a processing station to which at least a portion of
the slurry from the supply is to be delivered; and,
a conduit providing fluid communication between the
supply and the processing station, wherein either (a) a
device in accordance with the first aspect of the present
invention is coupled with the conduit; or (b) the conduit
is in accordance with the second aspect of the present
invention.
A further embodiment of the invention comprises a slurry
line for conveying a slurry, the slurry line having at
least two spaced apart flow influencing elements for
influencing a flow of slurry through said slurry line,
each flow influencing element having an aperture for flow
of said slurry therethrough and said apertures having a
hydraulic diameter different to the hydraulic diameter of
the slurry line immediately upstream of the flow
influencing elements and said hydraulic diameter of said
apertures being at least 45% of the hydraulic diameter of
the slurry line upstream of the flow influencing elements.
In one embodiment said flow influencing elements are
separated by a distance of at least two and a half times
an expected maximum dimension of a particle in the slurry.
Each aperture is bound by a respective edge. In one
embodiment the edge is spaced by a substantially constant
radial distance from the central axis of the conduit.
However in an alternate embodiment the edge is spaced from
a central axis of the conduit by a distance that varies
between a first radius and a second radius. The variation
between the first and second radius may be at least two
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and one half times an expected maximum dimension of a
particle within said slurry.
In one embodiment the edge has a substantially sinusoidal
circumferential profile. The radius of the sinusoidal
profile is at least one and one quarter times the expected
maximum dimension of a particle in said slurry.
The flow influencing elements can be separated by a
distance up to 450 of the hydraulic diameter of the slurry
line upstream of the flow influencing elements.
In one embodiment said flow influencing elements have an
axial thickness of at least 30 of the hydraulic diameter
of the slurry line upstream of the flow influencing
elements.
Additionally the thickness of said flow influencing
elements may be limited to 45a of the hydraulic diameter
of the slurry line upstream of the flow influencing
elements.
In one embodiment of the slurry line the flow influencing
elements extend over a distance of at least 50% of the
hydraulic diameter of the slurry line upstream of the flow
influencing elements.
In another embodiment of the slurry line the influencing
elements extend axially over a distance of at least 75% of
the hydraulic diameter of the slurry line upstream of the
flow influencing elements.
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One embodiment of the slurry line can be formed so that
the axial length of said flow influencing elements extend
over a distance not exceeding five hydraulic diameters of
the slurry line upstream of the flow influencing elements.
A method of processing an abrasive ore comprising:
treating said ore at a first processing station;
supplying a slurry of processed ore from said first
processing station to a slurry line;
transporting said slurry in said slurry line to a
second processing station; and
causing said slurry to flow through at least two flow
influencing elements each having an aperture through which
said slurry flows and each being located between said
first processing station and said second processing
station and having a hydraulic diameter of at least 55% of
the hydraulic diameter of the slurry line upstream of the
flow influencing elements.
In an embodiment of the method of processing ore the flow
influencing elements are separated by a distance of up to
45% of the hydraulic diameter of the slurry line
immediately upstream of the flow influencing elements.
The method of processing ore may further comprise spacing
the flow influencing elements by a distance of at least
two and one half times an expected maximum dimension of a
particle within said slurry.
According to a further aspect of the present invention
there is provided a device for modifying fluid flow
through a conduit having a hydraulic diameter dc the
device comprising:
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a fluid flow path having at least two flow zones Zl
and Z2 and an intermediate zone Zi between the flow zones
Zl and Z2, where the two flow zones Z1 and Z2 have
respective hydraulic diameters dzl,dz2 both being less
than dc, and the intermediate zone Zi has a hydraulic
diameter dzi greater than each of dzl and dz2, and the
intermediate zone Zi has a axial flow path length of at
least 0.03dc.
In one embodiment the zones Zl and Z2 may each have a
hydraulic diameter governed by: Adc <- dzl, dz2 ~ Bdc [A =
0.45, B = .9]
The intermediate zone Zi may have a hydraulic diameter in
the range: .7d2 < dzi <- 1.3dc. However in an alternative
embodiment the hydraulic diameter may be in the range .9d2
S dzi -< dc.
The zones z1, z2 may each have an axial flow path length
up to .45dc. Moreover the fluid path length of the device
may be between 0.03dc x nz to 0.5 x nz, where nz is the
number of zones in the device.
Each zone may comprise an element having an inner
circumferential surface where respective zones are defined
by the inner circumferential surface of its respective
element.
In a simple embodiment each of the flow zones may be
formed with an inner circumferential surface of constant
radius. However in a more complex embodiment each of the
flow zones may be formed with an inner circumferential
surface may follow an undulating path such as, but not
limited to, a sinusoidal path. More particularly each
flow zone may have an inner circumferential surface
comprising first and second portions having different
radius. Further it is envisaged that adjacent flow zones
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may be arranged so that the portions of different radius
are circumferentially offset.
Brief Description of Drawings
The embodiments of the present invention will now be
described.by way of example only with reference to the
accompanied drawings in which:
Figure 1 is a section view of an embodiment or device in
accordance with the present invention installed in a
conduit;
Figure 2 is a partial section view of the device shown in
Figure 1;
Figure 3 is an end view of the device shown in Figures 1
and 2;
Figure 4 is a partial exploded view of the device shown in
Figures 1-3;
Figure 5 is a perspective view of the device shown in
Figures 1-4;
Figures 6A is an end view of a first element incorporated
in the device shown in Figures 1-5;
Figure 6B is a side view in partial section of the element
shown in Figure 6A;
Figure 6C is a perspective view of the elements shown in
Figures 6A and 6B;
Figure 7A is an end view of a second element incorporated
in the device shown in Figurel-5;
Figure 7B is a side view and partial section of the second
element shown in 7A;
Figure 7C is a perspective view of the second element
shown in figure 7A and 7B;
Figure 8A is a first end view of a stop incorporated in
the device shown in Figures 1-5;
Figure 8B is a side view in partial section of the
stoption in Figure 8A;
Figure 8C is a perspective view of the stoption Figures 8A
and 8B; and
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Figure 9 is a schematic representation of an embodiment of
a mineral processing plant incorporating a flow
influencing device.
Detailed description of the preferred embodiment
The present embodiment is described with reference to a
dense medium separator (DMS) plant used for concentrating
iron ore (the "target mineral") from a feed material
comprising iron based mineral together with gangue
material. In this particular process the feed material is
added to a dense liquid medium which comprises a mixture
of water and ferro silicon. The liquid medium has a
specific gravity of approximately 3Ø The iron based
mineral has a greater specific gravity and therefore sinks
in the liquid medium. The gangue material on the other
hand has a lower specific gravity than the liquid medium
and therefore floats. Various processing stations are
used to separate the gangue material from the iron based
mineral on the basis of the difference in specific
gravity. The iron based feed material is comprised of
generally coarse hard particles with sharp edges and is
relatively abrasive. Together with the liquid medium the
feed material forms an abrasive slurry that is gravity fed
through conduits between various processing stations of
the DMS plant. The conduits are in the form of
polyurethane hoses that extend substantially vertically
from the separator to the further processing station. The
hoses however do not always hang perfectly vertically and
may also include one or more bends of tight radius along
their length. The wear in the hoses is typically
concentrated at the bends.
The embodiments of the present invention have in
preliminary testing been found to assist in reducing the
wear rate of the hoses at the bends.
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The accompanied drawings illustrate one possible
embodiment of the present invention in the form of a
device 10 that is coupled to or installed in a conduit 12.
Thus all fluid flowing through the conduit 12 also passes
through device 10. The device 10 comprises two or more
elements 14.1, 14.2 (here and after referred to in general
as 'elements 14') each of which is provided with a
respective orifice 16.1, 16.2 (here and after referred to
in general as 'orifices 16') through which the fluid
flowing through the conduit 12 passes.
In the illustrated embodiment, there are four the elements
14.1, and four the elements 14.2. However it is believed
that the total number of elements 14 may be varied from a
minimum of two. The elements 14 are spaced by regions 18
defined by respective spacers 20. Each region 18 is
defined by an orifice 22 formed in a corresponding spacer
20. The orifice 16 of each of elements 14 is of a shape
and/or configuration that induces turbulence in fluid
flowing through the device 10. The orifice 22 of the
region 18 (i.e. spacer 20) has a different shape and/or
configuration to that of both the orifices 16 and may also
contribute to turbulence induced by the device.
Possible shapes and/or configurations of the orifices 16
that have the effect of increasing turbulence in fluid
flowing through the conduit are ones which provide the
orifice 16 with a hydraulic diameter different to and
typically less than the hydraulic diameter of the conduit
12.
The hydraulic diameter d is defined as:
d = 4 x cross sectional area / wetted perimeter.
Thus assuming the conduit 12 to have a circular cross
section, the hydraulic diameter dc of the conduit 12 is
simply the internal diameter of the conduit 12. The
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hydraulic diameters d1, d2 of the elements 14.1, 14.2 may be
defined as follows:
. 45dc ~ (d, , d2) - . 9dc
The orifice 22 of the spacer 20 which forms an
intermediate zone between the two elements 14 may have a
hydraulic diameter di as follows:
.7dc - di - 1.3dc and various ranges within these limits
such as . 9dc <- di - dc
The turbulent flow created by the elements 14 need not
exist across the entire diameter of the conduit 12.
Turbulence in an annular zone adjacent an inner
circumferential surface of the conduit 12 is believed
sufficient to achieve reduction in wear notwithstanding
the existence of lamina flow of slurry interior of the
annular turbulent flow.
Looking at the present embodiment in greater detail, the
device 10 comprises an outer housing 24 in which the
elements 14 and spacers 20 are disposed, and first and
second stops 26, 28 coupled at opposite axial ends of the
housing 24. The device further comprises a flanged
element 30 located midway along the axial length of the
housing 24.
The housing 24 defines fluid flow path for slurry flowing
through the device 10 and conduit 12 and comprises two
cylindrical sleeves 32 each of which has one end fixed to
the flanged spacer 30. The fixing may be achieved by any
conventional means including by screw threads, for a
demountable fixing (or coupling) or by welding for a
permanent fixing. The flanged spacer 30 has a flange 34
that extends radially outwards from a circumferential
surface of the sleeves 32. The elements 14 and spacers 20
are inserted into the housing 24 through ends of the
respective sleeves 32 distant the flange spacer 30. The
elements 14 and spacers 20 are then retained in the
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housing 24 by the stops 26 and 28 that are fixed to the
ends of the housing. Demountably fixing the stops 26, 28
to the housing has a potential benefit of allowing
reconditioning of the device 10 for example by replacement
of selected elements 14 and/or spacers 20.
The outer diameter of the stops 26 and 28, and the housing
24 are substantially the same as each other, and
marginally less than the inner diameter of the conduit 12,
with the flanged element 30 having a diameter greater than
the inner diameter of the conduit 12. Accordingly the
sleeves 32 and stops 26, 28 fit within the conduit 12 with
a degree of clearance, and ends of separate lengths of the
conduit 12 can abutt opposite sides of the flange 34.
Clamps (not shown) may be provided to secure the lengths
of the conduit 12 to the device 10. However in an
alternative embodiment a plurality of ribs may be formed
on the outer circumferential surface of the sleeves 32 to
engage and grip, the inner surface of the lengths of the
conduit 12. Alternatively, the housing may be provided
with flanges that connect with corresponding flanges on
conduit 12.
With particular reference to Figures 6a-6c each element
14.1 of the preferred embodiment is in a form of a planar
disc or washer having an outer circumferential surface 36
of constant radius but an inner circumferential surface 38
that is profiled, having a radius measured from a central
axis A of the device 10 (and conduit 12) that varies
between a minimum radius ri and a maximum radius r2. The
inner circumferential surface of the elements 14 define
the orifice 16. While the radius varies between rl, and
r2 in a circumferential direction, the radius is constant
along any line on the inner circumferential surface that
is parallel to the central axis A. For example in Figure
6c the radius ra is constant along the line la. Thus the
shape and orientation of upstream and downstream inner
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circumferential edges 17a, 17b of any particular element
are identical. It will also be apparent that upstream and
downstream faces 19a, 19b of each element lie in
respective parallel planes, the planes being perpendicular
to the central axis A.
Figures 7a-7c depict an embodiment of the flanged element
30. This element is of the same general configuration of
the element 14.1 but with the addition of the outer flange
34 that extends in a radial direction. The flange 34 is
located centrally of an axial length of the element 30.
The element 30 also has a greater axial length than the
element 14.1 so as to produce outer shoulders or seats 40
that fit within, and facilitate fixing to, the sleeves 32.
The element 30 has an inner circumferential surface 42 of
the same configuration as the inner surface 38 of the
element 14.1.
With reference to Figure 4, both the elements 14.2 and the
spacers 20 are in the form of disc or washer having inner
and outer circumferential surfaces of constant radius.
The radius of the outer circumferential surface of the
elements 14.2 and spacer 20 are the same as each other.
However radius r3 of the inner circumferential surface 44
of the element 14.2 is less than radius r4 of the inner
circumferential surface 46 and the spacer 20. Further,
the radius r4 is greater than the radius r2 (Fig 6a), and
the radius r3 is equal to r1 (Fig 6a) though it may also
be of a different size to either or both rl and r2.
From the view point of fluid flow through the device 10,
the elements 14.1, 14.2 and spacers 20 are equivalent to
the fluid flow zone of a shape and/or configuration
identical to that of respective orifices 16.1,16.2 and 22
Figures 8a-8c depict an embodiment of the stops 26,28.
Each stop 26,28 is in the form of an annular r'ing 48.
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Each ring 48 has an outer circumferential surface having a
major section 50 of an outer diameter equal to the outer
diameter of the sleeves 32, and a contiguous second
section 52 of a reduced outer diameter. The section 52
fits within an end of a sleeve 32, sleeve 32 abutting the
section 50. The"rings 48 can be fixed to the sleeves 32
by any conventional means including welding or the use of
mating screw threads. Inner circumferential surface of 54
of each ring 48 is formed with a radius that decreases in
a direction from the section 50 to the section 52. The
minimum radius r5 of the ring 44 is greater than the
radius r4 of the spacers 20.
Figure 9 depicts an embodiment of a mineral processing
plant 60 incorporating a device 10. The plant 60
comprises mineral processing stations 62 and 64, and a
hose or conduit 66 through which slurry is conveyed or
transported from station 62 to 64. The hose or conduit 66
may be made of a material that is flexible and softer than
the materials being conveyed. Examples of this include,
but are not limited to, hoses made of polymeric substances
such as polyurethane; and, rubber including reinforced
rubber. As previously described the materials being
conveyed are typically abrasive in nature and in order to
extend the service life of the device 10 it is prudent to
arrange for the portions or components of the device 10
through which material flows, e.g. the elements 14 and
spacers 20 to be made of a material of a comparable or
greater hardness than the hardness of particles within the
slurry. In the plant 60 the station 62 is physically
above the station 64 and the device 10 is placed upstream
of bend 68 in the conduit 66. The above relationship
between the device 10, hoses and slurry material is
exemplified in the test described below.
Preliminary tests have been conducted in relation to a
device in accordance with the above described embodiment
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of a DMS plant for concentrating iron ore. This device
was installed in a 200mm polyurethane conduit or hose used
for the transport of slurry between processing stations of
the DMS plant. The slurry comprised iron ore in a liquid
medium comprising a mixture of water and ferro silicon in
the approximate ratio 1:10. The iron ore comprises
particles that were passed through a 6mm screen. The
effect of the installation of the device 10 in the conduit
was to extend the time between routine replacements of the
conduit from 6 weeks to 12 weeks of production time. In
the devices tested, each of the elements 14, spacers 20,
and stops 26,28 were made from mild steel. The outer
radius of the housing 24 was 197mm with radiuses rl-r5 as
follows:
r1 = 60mm
r2 = 80mm
r3 = 60mm
r4 = 75mm
r5 = 182.5mm
The oizter radius of the elements 14, and spacers 20 is
91mm. The outer radius of the flange 34 of the flanged
element 30 is 115mm. Each of the elements 14 and spacers
20 have a thickness or axial width of approximately 16mm,
with the width or axial length of the flange element 30
being in the order of 30mm.
Given these dimensions, the hydraulic diameters for
various components of the device 10 are as follows:
Hydraulic diameter of the elements 14.1(dl) =
approximately 95 - 100mm. The Hydraulic diameter of the
elements 14.2 (d2) = 120mm
The hydraulic diameter of the spacers 20 (di) = 150mm
The hydraulic diameter dc of the conduit 12 equals 200mm.
Inspection of embodiments of the device 10 in use indicate
substantial wear of the first element 14.1 and element
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14.2 at the upstream end of the device 10 with reduced
wear on the adjacent downstream elements 14.1 and 14.2.
Initial testing indicates noticeable effects of the device
10 when the axial length of the elements 14.1 , 14.2 is at
least 0.03d, (i.e. 3a of the hydraulic diameter of the
conduit 12). The axial length of the elements 14 and
spacers 20 may be up to approximately .45d,, (i.e. 45% of
the hydraulic diameter). The overall length of the device
10 may be between 0.03dcn to 0.5d,n where n is the number
of individual elements 14 and spacers 20 within the device
10, and dc is the hydraulic diameter of the conduit 12.'
The elements 14.1 that comprise the profiled inner
circumferential surface maybe the axially aligned or
axially offset relative to each other. In the event that
the elements 14.1 are axially aligned their respective
radii r1 and r2 are aligned. However in the event of a
maximum offset, the radius rl of one element 14.1 is
axially aligned with the radius r2 of an adjacent element
14.1. Of course the offset between adjacent elements 14.1
and 14.2 can range anywhere there between.
In the above embodiment, the device 10 is described as
being comprised of individual elements and spacers.
However it is also envisaged that the device 10 maybe
formed as a single integrated unit for example by way of
molding. In such an embodiment it would be more
appropriate to refer to fluid flow zones (as described
above) rather than elements 14 and spacers 20.
Various parameters of the device 10 may also be defined in
terms of the maximum expected dimension of particles
within a slurry flowing through the device. It should be
understood that while the particles may be passed through
say a mesh screen prior to mixing with a liquid to form
the slurry the maximum dimension of a particle can readily
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exceed the mesh size of the screen. For example a
particle having dimension of 4mm x 4mm x 8mm can pass
through a 5mm square mesh screen.
In terms of particle size it is believed that in one
embodiment the elements 14 may be separated by a distance
of at least two and a half times an expected maximum
dimension of a particle in the slurry. In addition the
shape and configuration of the inner circumferential
surface of the elements may be arranged to provide an
increase in turbulent flow while minimising the
probability of blockage due to accumulation of particles
in a slurry. This may be achieved by providing an inner-
circumferential surface that is profiled or that has
protrusions or surface irregularities. A minimum gap or
space between such profiled elements, protrusions or
irregularities is preferably greater than the expected
maximum dimension of the particles forming the slurry.
Thus with reference in particular to Figure 6a the
difference between the radii ri and r2 (representing a
"depth" of a trough in the inner surface) may be at least
1.25 times and preferably at least 2.5 times a maximum
particle size.
Additionally the distance between adjacent peaks on the
inner surface may be at least 1.25 times and preferably at
least 2.5 times a maximum particle size.
Now that the embodiment of the present invention has been
described it would be apparent to those skilled in the
relevant arts that numerous modifications and variations
may be made without departing from the basic inventive
concepts. For example while the embodiment depicts the
device 10 comprising four elements 14.1, four elements
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14.2, eight spacers 20, and a flanged element 30,
different numbers of such elements and spacers maybe used
however it is believed that a minimum of two spaced apart
elements 14 is required. Additionally, the flanged
element 30 maybe replaced by forming the housing 24 as a
single sleeve with a flange extended radially outward from
an outer circumferential surface of the sleeve. While the
elements 14.1 are depicted as having an inner
circumferential surface following a substantially
sinusoidal path, different configurations may be
incorporated. Indeed, it is not a requirement that the
elements 14.1 have a profiled inner circumferential
surface. In an alternate embodiment the elements 14 (or
corresponding fluid flow zones) may be provided with an
inner circumferential surface that is oval shaped, non-
symmetric or even of constant radius. In yet a further
embodiment the elements 14.1 or fluid flow zones may be
formed with orifice of constant radius or generally
identical shape but with their central axis radially
offset from a central axis of the device 10. In such an
embodiment the,center of the orifice of such elements may
also be offset relative to each other about the central
axis of the device 12. In yet another embodiment each of
the elements 14 and the spacers 20 may be provided with
radially extending flanges similar to the flange 34 on the
flanged element 30, and a plurality of such flanged
elements 14 and 20 could then be coupled by mechanical
fasteners such as bolts, to flanges provided at adjacent
ends of lengths of conduit 10. Such an embodiment may
also incorporate seals and/or gaskets between the flanges
on the conduit and flanges on the elements 14 and spacers
20. This embodiment does not require the use of the
housing 24 nor the stops 26,28 as all of the elements 14
and spacers 20 are coupled to each other and respective
flanges on the conduit by the mechanical fasteners.
