Note: Descriptions are shown in the official language in which they were submitted.
122165g
HYD~OCYCLONE FEATURI~G HYDRAULIC JU~P IN OVERFLOW PASSAGE
BACKGROUND OP THE INVENTION:
This invention relates to improvements in hydrocyclones,
which includes centrifugal separators and centrifugal clean-
ers. Its embodiment provides an improved construction forthe overflow tube of a hydrocyclone which has unexpectedly
resulted in the recovery of kinetic energy in the overflow
as well as other significant benefits in the performance of
the hydrocyclone. ~his is particularly evidenced in the
application of the invention to the processing of pulp in
a pulp refining operation. Accordingly, the invention will
be described in this frame of reference, but only for pur-
pose of illustration and not by way of limitation.
A hydrocyclone is a device used for cleaning, separa-
tion and/or classification of the contents of a relativefluid mass. As applied to a pulp slurry, the objective
in its use is to extract and separate therefrom elements
or particles of wood or other fibrous matter in the slurry
best suited, and in a form best suited, for use in a par-
ticular end product. It has been found in many cases thatthe level and amount of energy required for the operation
of prior art hydrocyclones or hydrocyclone systems can be
quite substantial. It has also been found that the extent
of the pressure drop which occurs in the use of prior art
hydrocyclones to process a pulp slurry limits the through-
- put of the slurry as well as its flow rate in moving through
and from the hydrocyclone. The problems noted are and have
been a matter of serious concern for a long period of time.
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The prese~t invention not only overcomes the ~oreqoing
problems to a substantial degree but its application to any
hydrocyclone of a given size provides it with an inherent
mode of operation resulting in an increase in its feed
5 - flow rate as well as a significant improvement in its
cleaning efficiency. ~s a matter of fact, the application
of the invention enables more of the energy applied in use
of a hydrocyclone to contribute, very effectively, to the
spin of the flow of a slurry introduced to and moved within
and longitudinally of the hydrocyclone separating chamber.
The result of this last feature is a cleaner and more ef-
fective separation of the contents of the slurry which is
subjected to a separating procedure.
As far as novelty is concerned, there is no knowledge
of any prior hydrocyclone art which is specific to the
improvements of the present invention. A search of the
records of the 17. S. Paten~ and Trademark Office appears
to confirm this fact. All that the search produced is
exemplified by the following patents:
Patent No. Name Date
3,037,628 G. H. Tomlinson II June 5, 1962
3,129,173 W. G. A. Schulze April 14, 1964
3,261,467 N. A. L. Wikdahl July 19, 1966
3,613,887 N. A. L. Wikdahl Oct. 19, 1971
3,746,173 W. H. Daniel July 17, 1973
4,259,180 Jorma Surakka
et al M.ar. 31, 1981
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S~'.~MARY OF T~IE INVENTION:
Preferred emb~diments of the present invention comprise
a hydrocyclone the body of which defines therein a separating
chamber having an overflo~ end and an underflow end, an inlet
and at least two outlets, one to each of the opposite ends of
the ~eparating chamber. One of these outlets provides an
underflow outlet and the other an overflow outlet. The inner
wall of the hydrocyclone has a tubular configuration and the
underflow and overflow outlets are in a substantially coaxial
alignment. In the introduction of a pulp slurry, the contents
of which are to be separated and/or cleaned or classified, the
inlet applies the slurry tangential to thë inner wall surface
of the hydrocyclone to develop within its separating chamber
a vortex-type flow of the slurry producing counterflowing
vortices thereof. The result of the counterflowing vortices
is to induce, normally, a particularly desired portion of
the contents of the slurry to move to an area within the
separating chamber comprising its central longitudinally
extending core from which such material is inherently in-
duced to flow to and through the overflow outlet of the
hydrocyclone. At the same time another portion of the
contents of the slurry within the separating cham~er in-
cluded in the outer of said counterflowing vortices is
caused to move to and through the underflow outlet of the
hydrocyclone. In accordance with the invention, the over-
~5 flow outlet is defined by an overflow tube structure, here-
- inafter referred to as an overflow tube, the diameter of
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t~e inner surface of which is stepped along its length. ks
will be obvious, the inner surface of the overflow tube de-
fines an overflow passage one end of which communicates with
the overflow end of the hydrocyclone separating chamber and
the other end of which connects to a conduit or conduits for
directing the discharge from the overflow tube to a desired
place of storage or use. Per the invention the inner surface
of the overflow tube and the overflow passaye which it defines
are formed to produce therein a conversion of kinetic energy
in flow therethrough from the hydrocyclone separating chamber
to pressure energy. This produces inobvious and most ad-
vantageous improvements in the performance of the hydrocyclone.
Actually, what has been observed to occur in the use of an
overflow tube havina an overflow passage formed in accordance
with the invention is a "hydraulic jump" phenomena.
Ihen comparing the operation of a conventional hydro-
cyclone having an overflow passage in accordance with the prior
art with the operation of a hydrocyclone of the same size embody-
ing the invention, it is seen that the use of the invention re-
sults in the following benefits and improvements:
a. A decrease in pressure drop in the flow through
the hydrocyclone;
b. An increase in the "spin" of the material introduced
to and passed through the hydrocyclone separating chamber;
c. A significant increase in the cleaning and sepa-
rating efficiency of the hydrocyclone and an increase in
its operating capacity and feed flow rate;
d. ~n increase in the throughput or flow rate of the
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material to be separated or cleaned in the movement thereof
through and from the separating cha~er of the hydrocyclone.
A preferred embodiment of the invention provides that
the outflow passage defined by its overflow tube includes
straight line segments of its length which are spaced by a
relatively short coaxial segment which has the shape of a
truncated cone. In this case the upstream of these straight
line segments will have a diameter corresponding to the small-
est diameter of the relatively short segment which has the
confi~uration of a truncated cone while the straight line
segment of the outflow passage immediately downstream of
this short segment will have a dlameter which is relatively
enlarged as compared to that of the upstream segment and
corresponds with that of the downstream end of said short
segment. In use of this preferred embodiment the efficiency
of the operation of a hydrocyclone of a given size is sub-
stantially improved and there is a corresponding saving and
added utilization of the available energy. A significant
aspect of the invention is the economy possible in its em-
bodiment.
While in describing the invention reference is madeherein to an overflow tube applied to a conventionally opera-
ting hydrocyclone, it is to be understood that an outflow pas-
sage of the nature herein described and claimed may be formed
in any tube or body structure providing an outlet from the
separating cha~er of any type hydrocyclone and ?roduce
similar results and benefits in its use.
It is therefore a primary object of the invention to
provide economically achieved improvements in hydrocyclones
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which are easy to fabricate and which render such devices ~ore
efficient and satisfactory in use, adaptable to a wide variety of
applications and less likely to adversely function.
In one broad aspect, the invention resides in a hydro-
cyclone comprising a housing having a separating chamber, an inlet
to said chamber and at least two outlets therefrom, said inlet
being constructed and arranged to deliver a slurry or other fluid
mass containing solids the contents of which are to be separated,
cleaned or classified, to said chamber in a substantially helical,
swirling, flow pattern to cause the movement thereof within said
chamber in counterflowing vortices inherently causing solids in
the flow which are light and relatively small in size to move to
the inner vortex of the flow and exit from a first outlet while
the remainder of said flow embodying large and heavy solids seeks
another outlet from said chamber, said first outlet being a longi-
tudinally extended passage having an inlet end open to said separ-
ating chamber and a discharge end remote therefrom, characterized
by a truncated cone bounding a relatively short segment of the
length of said passage, at a location spaced downstream from said
passage inlet constructed and arranged to convert kinetic energy
in the helical, swirling vortex of flow passing therethrough to
pressure energy and produce a resultant application of said con-
verted energy to increase the "spin" velocity of said helical
swirling flow of said slurry as it moves in said counterflowing
vortices within said chamber, said truncated cone having its
minimum diameter end upstream from its maximum diameter end
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and having a cone angle as measured from its center line to its
outer peripheral limit in the range from about 40 to about 80.
In a further broad aspect, the invention resides in
apparatus for connection with the housing of a hydrocyclone to
define an~outlet from its separating chamber for receiving a sub-
stantially helical, swirling vortex flow therefrom comprising a
body for connection to the housing, said body having therein a
flow passage the inlet to which in connection thereof to the
hydrocyclone housing opens to its separating chamber, said flow
passage having a discharge end, characterized in that said flow
passage has an upstream portion, a downstream and a truncated cone
portion disposed intermediate therebetween, said upstream portion
having a cross-sectional area smaller in dimension than the cross-
sectional area of said downstream portion, said truncated cone
portion having a minimum diameter end opening to said upstream
portion and a maximum diameter end opening to said downstream
portion, said truncated cone having a cone angle as measured from
its center line to its outer peripheral limit in the range from
about 40 to about 80.
With the above and other incidental objects in view as
will more fully appear in the specification, the invention
intended to be protected by Letters Patent consists of the
features of construction, the parts and combinations thereof, and
the mode of operation as hereinafter described or illustrated in
the accompanying drawings, or their equivalents.
A
12;~1659
Referring to the drawings wherein are shown one or more
embodiments of the present invention,
Figures 1-4 each schematically exhibit the application
of an overflow tube to a hydrocyclone having a form and construc-
tion and composition which is basically similar but somewhat
different in each of the illustrations.
Like parts are indicated by similar characters of refer-
ence throughout the several views.
As noted previously, the invention is herein illustrated
and described with particular reference to its application to a
hydrocyclone of the type advantageously used for the processing of
the contents of a pulp slurry.
The embodiment of Figure 1 illustrates a hydrocyclone of
this type the body or housing of which comprises an integral
tubular shell-like peripheral wall structure 10 one longitudinally
extending section 12 of the length of which is
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cylindrical in configur~tion. The dia~eter of the cross
section of the section 12 is uniform the lensth thereof.
The section 12 has one end thereof integrated with and longi-
tudinally extended by a coaxial section 14 of the tubular
wall structure 10. The section 14 which is thus a direct
extension of the section 12 has the shape of a truncated
cone which conically converges from the end of the section
12 with which it is integrally connected. The truncated
apex end of the section 14 rims a small diameter opPning
16 at this end of the tubular wall structure 10.
Connected with and in bridging relation to the end
18 of the section 12 which is remote from the section 14
is an annular plate 20. The outer limit of plate 20 is
fixed in a sealed tight relation to the end 18 of section
12 and i~s inner limit is fixed about and in a sealed tight
relation to the outer wall surface of a tubular overflow
structure, hereinafter referred to as an overflow tube 22.
A short tube 24 has one end thereof intesrally connected
to the section 12 immediately of the plate 20 to have what
constitutes its discharge end rim an inlet opening 26 in the
wall structure 10. The short tube 24 is so related to the
opening 26 and the opening 26 so related to the inner sur-
face of the wall structure 10 as to provide a tangential
inlet to the separating chamber 28 which is defined by the
plate 20 and the wall structure 10.
As is well recognized by those versed in the pulp pro-
cessing art, the plate 20 defines the overflow end of the
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separating chamber 28 while the opening at the convergent end
of the ~Yall section 14 defines what is considered to be the
underflow end and outlet 16 from the chamber 28. Correspondingly,
the overflow tube 22 defines an overflow passage 30 leadins from
and communicating at its inlet end with the separating chamber 28.
As seen in Fig. 1, the overflow tube 22 is coaxi~lly aligned
with the underflow outlet 16. Furthermore, the inner wall surface
of the overflow tube 22 is so constructed that the overflow pas-
sage 30 has a central longitudinal axis the configux~ion of which
is that of a straight line. As the overflow tu~e 22 is applied
to the hydrocyclone in Fig. 1, its extremity which is innermost
of the chamber 28 occupies a plane commonly occupied by the in-
tegrated ends of the sections 12 and 14 of the wall structure 10.
Correspondingly, the innermost extremity of the overflow tube 22
rims the inlet opening 23 to its overflow passage 30. This in-
let end of the passage 30 exhibits the diameter of a segment 32
of the length of the overflow passage which extends from its in-
let end to a plane transversely of and perpendicular to the cen-
tral longitudinal axis of the chamber 28 which is parallel to
the plane of the inlet end and spaced therefrom slightly more
than one-half the distance between the inlet end and the outer-
most surface of the plate 20. The segment 32 of the passage 30
has a uniform but relatively small diameter and is immediately
followed by a segment 34 of the passage 30 which is very short
in length. The portion of the inner wall surface of the tube
22 bounding the se~ment 34 has and provides the segment 34 with
a configuration corresponding to that of a truncated cone. The
cross sectional ar~a exhibited by one end of this truncated
cone has a diameter corresponding to that of the segment
32 of the overflow passage which is immediately upstream
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thereof and opens thereto. From the segment 32 the segment
34 is configured to conically expand as its larger diameter
extremity connects to the immediately downstream segment 36
of the overflow passage 30. of course the largest diameter
of the segment 34 corresponds to the diameter of the section
3~ of the overflow passace, which is uniform along its length.
Thus, the overflow tube 22 has an inner wall surface which is
stepped as to its diameter along the length thereof, thereby
to provide an upstream segment 32 and a downstream sesment
36 of the overflow passage spaced by the interposed conical
segment 34.
As shown in Fig. 1, the thickness of the wall 40 of the
overflow tube 22 is uniform except at its inlet end 42, where
its outer surface expands to produce thereon a bell-shape
i~mediately a~out the inlet to the overflow passage.
Accordingly, except for the bell-shaped modification at
its inlet end, the outer wall surface of the overflow tube
has a configuration along its length which corresponds in
all respects with the configuration of its inner wall sur-
face which defines the overflow passage. Further notingFig. 1, the overflow tube 22, as shown, has its enlarged
diameter end projected outwardly of the plate 20 a limited
extent and perpendicular thereto.
~ig. 2 shows a hydrocyc}one structure identical to
that shown in and described with reference to Fig. 1 except
for the construction and relative position of the illustrated
overflow tube and the lensth of the section 12 of the wall
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structure 10 being somewhat shorter than that illustrated in
~ig. 1. In Fig. 2 the overflow tu~e 52 of the hydrocyclone
is distinguished by a uniformly cylindrical outer wall sur-
face S0 the diameter of which is uniform from one end thereof
to the other. ~.lso, the overflow tube 52 is so positioned
in its perpendicular relation to the plate 20 that its re-
spective ends are substantially equidistantly spaced from
the adjacent surfaces of the plate 20 and its innermost ex-
tremity is spaced longitudinally and outwardly from the
plane transversely of and perpendicular to the longitudi-
nal axis of the separating chamber 28 which intersects the
connection between the sections 12 and 14 of the wall
structure 10. The inner wall surface 58 defining the
overflow ox outflow passage 60 of the overflow tube 52
has the same general configuration as the inner wall sur-
face of the overflow tube 22 but differs in that here the
length of the smaller diameter upstream segment of the
overflow passage which corresponds to the segment 32 of
Pig. 1 is shorter and the length of its larger diameter
downstream segment which corresponds to the segment 36
of Fig. 1 is longer than the respective lengths of the
corresponding segments of the overflow passage 30 o~ the
overflow tune 22.
The hydrocyclone assembly of Pis. 3 is identical to
that of Fig. 1 except for the following differences.
12:~659
Its overflow tube 22' which otherwise has a construction and
configuration identical with that of the overflow tube 22
differs by reason of the elimination of the bell shape at
the mouth of its inlet end. Another difference in the
hydrocyclone assembly shown in Fig. 3 from that of Fig. 1
is that its overflow tube is so mounted with reference to
the plate 20 to provide that the portion of the wall struc-
ture of the overflow tube 22' bounding the segments 34 and
35 of its overflow passage are positioned exteriorly of the
plate 20. As a result the opening in the plate 20 is re-
duced in diameter sufficient to accommodate and seal about
the reduced external diameter portion of the wall of the
overflow tube 22' bounding the upstream segment 32 of the
overflow passage 30. As may be seen with reference to
Fig. 3, the relative position of the overfiow tube 22'
provides that the reduced diameter end of the conically
configured segment 34 of its overflow passage lies in a
plane corresponding to the plane of the outer surface of
the plate 20. Note further that in Fig. 3 the axial
length of the section 12 of the wall structure 10 is
shortened in correspondence with the limited projection
of the inlet end portion of the o~erflow tube with ref-
erence to the inner surface of the plate 20.
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In the hydrocyclone modification of Fiq. 4, the con-
figuration of the wall structure 10 provides that the
sections 12 and 14 thereof are relatively elongated but
otherwise ~imilar to the corresponding sections in Fig. 1.
Here, however, rather-than finding a use of a head plate
such as the plate 20 incorporated in the embodiments of
Figs. 1, 2 and 3, we find the overflow end of the separating
chamber 28 defined by the innermost surface 62 of a gener-
ally cylindrical body forming a head 64 plug fit in and to
the end of the section 12 of wall structure 10 remote from
the section 14. The head 64 is configured to provide the
overflow end of the hydrocyclone with an axial inlet 66
which is a blind bore parallel. to the central longitudinal
axis of its separating chamber 28. m e inlet 66 opens later-
ally to one end of a restricted helical flow passage 68 de-
fined by the head with the inner wall surface¦of the end of
the wall structure 10 in which the head is plug fit. The
flow passage 68 is extended and exits to a continuation of
its helical form defined by the inner surface 62 of the head
which defines the overflow end of the separating chamber 28.
With the arrangement provided, a slurry directed inwardly
of the head by way of the inlet 66 will move in a high
velocity flow through the passage 68 and in exit from the
passage 68 will move over the surface 62 in a continuing
helical flow pattern about a central relatively axially
projected tubular portion 70 of the head. The tubular
projection 70 is thus innermost of.the head 64 and projects
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122~659
inwardly of the separating chamber from the surface 62 to have
its innermost end terminate in a plane parallel to and in an
adjacent spaced relation to and short of a plane transverse
to the separatinq chamber 28 and perpendicular to its longi-
tudinal axis which intersects the wall structure 10 at theconnection between the sections 12 and 14 thereof. The
tubular projection 70 defines part of the inlet segment 74 of
an overflow passage 72 which is directed through the head
from the separating chamber 28. In this case the overflow
passage 72 is composed of successive communicating segments
a portion of which is angularly diverted and offset from
the line of the segment 74 as the overflow passaqe extends
through the head to have its outermost segments position
parallel to the line of the inlet segment 74.
The segment 76 of the overflow passage 72 immediately
following the inlet segment 74 is angularly diverted from
the line of segment 74 as it extends outwardly from the
separating chamber and forms a continuation of the segment
74. The segments following the segment 76, in succession,
which form a continuation thereof and each other, are re-
spectively numbered in succession 78, 80 and 82. The seg-.
ments 78, 80 and 82, which have a coaxial alignment, are
diverted, commonly, from the line of the segment 76 to
extend in a line offset from and parallel to the line of
the inlet segment 74. The diameter of the segments 74, 76
and 78 of the overflow passage are essentially the same and
these segments are generally elongate, but in the case
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illustrated successively somewhat shorter in length. rrhe
segment 80, however, is very short in length and its cross
section exhibits the shape of a conically expanding truncated
cone. The smallest diameter of this cone is at its end im-
mediately of the segment 78 and corresponds in dimension tothe dimension of its diameter. The largest diameter end of
the cone of the segment 80 opens to the segment 82 the di-
ameter of which corresponds thereto.
The operation of any one of the foregoing embodiments
of the invention is essentially the same, as are the unexpected
benefits and advantages attendant its use. Basically, a slurry
the contents of which are to be separated, cleaned and/or
classified is in each case directed through the hydrocyclone
inlet to the separating chamber 28 to move therein and the
length thereof in a helical flow pattern producing counter-
10wing vortices which inherently result in a portion of
the slurry contents which have the form of fibers and fiber
bundles which are light in weight and desirable in form being
caused to move to the inner vortex portion of the slurry flow.
As this most desirable portion of the slurry contents reaches
the inner vortex portion or core of the cleaner, as a re-
sult thereof it will move, inherently, to and through the
overflow passage 30, 60, or 82, as the case may be, de-
pending upon the modification. The outer portions of the
slurry flow will, in the case illustrated, exit from the
separating chamber by way of the underflow outlet 16. It
has been found in test and by practice that by virtue of
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the inner wall surface of the overflow tube which bounds and
defines the configuration of the overflow passage and in
particular the inclusion therein of its conical segment 34,
80 there is produced in the flow through the overflow passage
the equivalent of a "hydraulic jump". The consequence of this
is that there is an actual conversion of kinetic energy to
pressure energy in the overflow. This is extremely signif-
icant since as far as has been ablP to be determined in any
prior art, no one has heretofore achieved "hydraulic jump"
in a flow through a pipe. Apparently no one practicing in
applied fluid mechanics has heretofore observed this phenom-
ena or contemplated the same in flow through a pipe, either
as a scientific curiosity or as a natural phenomena which
may be harnessed for beneficial purposes. The construction
of an overflow passage as described in reference to each em-
bodiment of the invention has been found to serve to make
additional energy available and cause the swirl velocity
within a hydrocyclone of a given size to be higher than in
a hydrocyclone of the same size having a conventional over-
flow tube configuration. More than this, the result ofmaking such additional energy available is the production
of greater separating and cleaning forces within the sepa-
rating chamber of the hydrocyclone.
It has been determined that the expansion of the over-
flow passage as here provided triggers a flow condition in
the overflow tube that causes a conversion of the kinetic
energy to pressure energy with a reasonably high efficiency
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estimated at about 75%. As an adjunct to the improved sepa-
rating efficiency caused by the incorporation of the inven-
tion, there is not only improved cleaning efficiency result-
ing but an increase in the throughput as well as the flow
rate of a slurry as it is moved through and from a hydro-
cyclone per the invention.
Accordingly, common to the various embodiments of the
invention illustrated is an expansion from an upstream to
a downstream segment of an overflow passage achieved through
the medium of a short expanding segment of the overflow pas-
sage which has impressive results.
In preferred and effective embodiments of the invention
the conically expanded segment 34, 80,of the overflow passage,
which is very short in length, has a "free expansion" cone
angle expanding down~tream in the direction of flow which
can range from about 40 to about 80 as measured from the
center line of the truncated conical segment to the conical
~urface defining its expansion and shape.
In most preferred embodiments of the invention, the
length of the segment of the overflow passage immediately
upstream of the conically expanding segment should be equal
to at least three times the dimension of the diameter of the
inlet to the overflow passage. Furthermore, it is preferred
and most desirable that the extension of the conical segment
of the flow passage in the segment of this passage which is
immediately downstream thereof should have a length equal to
at least twice the dimension of the maximum diameter of the
conical segment of the flow passage.
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r optimal results, the segments of the overflow passage
immediately upstream and downstream of the conically expanding
short segment thereof should have a coaxial relation.
As far as the Pxpansion ratio is concerned,for a most signif-
icant conversion of kinetic energy to pressure energy in theoverflow passage 30, 82, its diameter downstream of th~ con-
ically expanded portion of the flow passage should be from
about 1-1/2 to 2 times its diameter immediately upstream
thereof. Smaller ratios could provide some benefit but
would not achieve the practical gains so advantageous in
the use of a hydrocyclone as herein described.
Laboratory tests have established that when a 6" diameter
hydrocyclone has an overflow tube construction such as herein
described, there is an approximately 15% increase in its feed
flow rate as compared to that found in the operation of a
hydrocyclone of the same size having the same inlet and out-
let sizes and a conventional overflow tube. This increase in
flow rate is somewhat larger for smaller diameter hydrocyclones
and somewhat less for larger diameter hydrocyclones. In any
case, the invention does provide a sisnificant increase in
flow rate. At the same time it has been found that the
cleaning efficiency is likewise sianificantly improved
thereby, by about 7%.
Considering the advantages and benefits of achieving
hydraulic jump in the flow throu~h an overflow tube of a
hydrocyclone in accordance with the present invention, it
follows that one can operate a hydrocyclone using a smaller
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diameter for the inlet ~o the overflow tube than would nor-
mally be provided and achieve therein better cleaning and
separating efficiency with the same overall pressure drop
as would be conventionally experienced using a prior art
overflow tube. By the same token, one can bave the benefit
of the invention and operate a hydrocyclone with a pressure
drop reduced, for example, from 35 to 25 p.s.i.g. and still
get a cleaninq and separating efficiency equivalent to that
found in the operation of a conventionally constructed hydro-
cyclone unit wherein the-pressure drop is 35 p.s.i.g. In
this latter case, the invention application provides an ad-
ditional benefit, namely an approximately 20~ increase in
the throughput of the hydrocyclone.
It is noted that the somewhat de~ious overflow passage
which is illustrated in the invention em~odiment shown in
Fig. 4 of the accompanying drawings has been found to function
equally as well as the other embodiments illustrated.
While tbe foregoing sugg~sts certain limitations as to
the lengths and diameters of the critical segments of the
ovèrflow pas~age, there may be limited deviation therefrom
without departing from the principles and basics of the
teachiny herein set forth. One caution is definitely to
be observed. If the expansion provided in the overflow
passage by virtue of the short segment 34, 80, which induces
hydraulic jump in flow therethrough, is immediately followed
by a sharp turn in the overflow passage, this will be
detrimental to the efficiency of the hydrocyclone structure
which it services.
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In summary, simple though the invention might be the
advances af~orded thereby are so sisnificant that hydro-
cyclones em~odying the same are not only highly advantageous
for use in pulp processing systems but they inherently pro-
vide means and methods of a highly improved nature which maybe applied to the cleaning of coal, the dressing of minerals,
commercial extraction systems, starch processing systems and,
for that matter, the removal of light particles from any
liquid vehicle.
~0 r'rom the above description it will be apparent that
there is thus provided a device of the character described
possessing the particular features of advantage before enu-
merated as desirable, but which obviously is susceptible of
modification in its form, proportions, detail construction
and arrangement of parts without departing from the principle
involved or sacrificing any of its advantages.
~ 'hile in order to comply with the statute the invention
has been described in language more or less specific as to
structural features, it is to be understood that the inv~-
tion is not limited to the specific features shown, but thatthe means and construction herein disclosed comprise but one
of several modes of putting the invention into effect and
the invention is therefore claimed in any of its forms or
modifications within the legitimate and valid scope of the
appended claims.
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