Note: Descriptions are shown in the official language in which they were submitted.
1321556
~IQUID 8EPARATOR
This invention relates to a li~uid separator.
The invention generally envisages the use of
a h~drocyclone to ~ra-condition a mi~ture before
admission to a filter device, ~uch as an act~ated
charcoal reverse osmosi8 filtex device.
In one aspect, there i~ provided a liquid
separator comprising a hydrocyclone having a
separat~ng chamber with an ~nlet for inlet o mi2ture
to be separated, an over10w outlet for outlet of a
le~s dense component of tha misture and an underflow
outlet for outlet of a more dense component of said
misture, and a filter device coupled to receive
outlet from saia underflow outlet. The hydrocyclone
i8 in this case effecti~e in u~e to effect a pres3ure
reauction in the material emergin~ from said
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underflow outlet, a8 compared to presJure of said
mi~ture at said inlet, whereby to acilitate any of
said less den~e component present in ~olution in sai~
more dense component breaking out of solution to be
either carriod to said overflow outlet or to emerge
from the underflow outlet with the more dense
component, as droplets thereof in the more dense
component, the filter aevice effecting further
separation of 8ai~ aroplets from the more den~e
component.
The mi~ture to be separated may be passea to
a mi~ing and~or resiaence vessel, such as a coalescer
or precoalescer, for e~ample a cross plate
interceptor s~immer before pa~age to the
hy~rocyclone. In such case, provision may be maae
for in~ection of heatea fluia, such as water, to the
~essel, such as periodically.
The invention also proviaes a method for
separating component~ of a liquia mi~ture one fr~m
the other by use of hyarocyclone to which the mi~ture
i~ admitt8d, the hydrocyclone being operated whereby
~ less dense component of the mi~ture emerges from an
outlet of the hydrocyclono in the form o ~roplets in
a more aense component of the mi~ture, the material
emerging from the outlet being admitted to a filter
devico to effoct further separatlon thereof.
The invention is further aescribea ffl way of
e~amplo only with reference to the accompanyinq
ar~wlng~ ln whlch:
Figure I i8 a flow diagram of a liquid
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separator construct~d in accordance with the
invention; and
Figure 2 i8 a diagram showing a hydrocyclone
used in the ap~aratus of Figure l; and.
Figure 3 is a flow diagram of a further
liquid separator constructed in accordance with the
invention.
~ he liquid separator shown in Figure 1
compri~es a m~ing and~or residence ve~sel.9O to
whieh a misture of oil in water is admitted sueh as
on the line 92 ~hown. The mi~ture is then taken on
line 42 to a hydrocyclone 10 to pro~ide at an outlet
line 44 separated oil and at an outlet line 46
~eparated water whieh may, however, still contain
80me residual oil. The water component i~ passed on
line 46 through a presæure reducing de~ica 50 and
thenee on a line 52 to a filter device 100. Here,
further separation occurs with the water component
be~ng taken on a line 58 from the device 100.
The hydrocyclone 10 may be eonstructed in
known fash~cn, such as in accordance with the
teachings of United States patent 4,237,006,
Australian patent application 84713~79, or in my
International application~ PCT~AU83~00028 or
PCT~AV85~00010. Figure 2 shows, diagrammatically, a
8eparator of thi~ gener~l type. Thi~ is shown as
ha~ing a tapered elongate ~eparating chamber 25 which
18 of eireular eross-seetion ha~ing, at it~ larger
diameter end, a irst cylindrieal portion 12, a
tangential inlet 26 ha~ing an inlet opening 30, and
an asial o~erflow outlet 34 which communicates w~th
an outlet opening 32. A tapered portlon 12a of
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separating chamber 25 i8 provided ad~acent port~on
12, this leading to a second, also slightly tapered,
portion 14 of the separating chamber 25, this in turn
leading to an elongate cylindrical portion 16 of the
separating chamber which open~ to an a~ial underflow
outlet 23 for the separator.
Olly wator misture to be separated is pas~ed
on the inlet 26 through the inlet opening 30 into the
portion 12 of the separatins chamber 25 80 as to
generate a vortes within the ~eparating chamber. The
oil component emerges from the outlet 34 via opening
32 and the water component emerges from the underflow
outlot 23.
As shown, the first portion 12 ha~ a length
ll and a diameter dl, the second portion has a
length 12 and diameter d2 at its larger diameter
end, port~on 16 has a lenqth 13 and a diameter
d3, whilst the overflow outlet has a diameter
do~ A~ de~cribed in Australian patent application
847l3~79, two or more strictly tangent~al inlets 26
may for e~ample be provided or, as shown in
International application PCT~AU85~00010, a single
inlet 26 of involute form may be provided.
In ~ccordance with the above described
construction, the cyclone separator may be
con~tructed in accordanco with any one or more or all
of the following dimensional constraints.
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12~d2 ~ 10, such as 10 ~ 12~d2 ~ 25
~ ~i d2 ~ 30
~.
such as 3 ~ ~ d~ d2 ~ 20
4Ai
do~d2 ~ 0.25~ ~uch as do~2 ~ 0.1
dl > a2
d2 a d3
where Ai i8 th~ total inlet area of all o the
inl~t openingæ combined or the ~nlet opening i~ there
i8 only one. ~, the half angle of th~ taper of ~he
second portion, may ba 20' to 2, such as 1-.
Portion 12a is optional. If provided, it may h~
half angl~, a, of 10-. ~
Other ~uitable constructions for
hydrocyclone 10 flre shown, for ~ample/ in the
specification of Australian patent application
77610~87 and of International ~pplications
PCT~AU87~00402, PCr~AU86/00313, PCT~AU86~00173 and
PCT~AU85~00181.
In the constructlon shown in Figure 2, the
overflow outlat 23 communic~te~ with a fourth portlon
18 of the separator, whlch ha8 the effect of
providing a back pres3ure to acilitate the
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separating action. Such a fourth portion 18
aescribed in IntornationJl application PCT~AU83~00028
and may, a8 shown, comprise a ~rst fru~toconical
port~on 18a which leads from outlet 23 followed by a
second cylindrical portion 18b. When used in the
apparatus of Figure 1, this arrangement provide~ a
pressure roducing action and permits omi~sion of the
pres~ure reducing de~ice 50, line 46 in that case
communicating direetly with line 52 to admit material
from the separator 10 direetly to the filter device
100 .
The hydrocyclone 10 acts, as described, to
effect removal of an oil componont from an oily-water
misture when admitted thereto. Generally, the
separator 10 is designea for use where there i8 a
substantially smaller amount of oil than water in the
incoming misture. However, the concentration of oil
may bo of the order of several percent for esample.
After admission through vessel 90, the
hydrocyclono 10 is able to reduce the oil
concentration to a guite low level in the water
component which emerges from the outlot thereof, such
a8 below S00 ppm. Thon, after passage through the
pressuro reducing device 50 or through the portion 18
of the described hydrocyclone, the oily water a8 then
passed to the filter device 100 is furthor separated
to rd uce the oil eomponent to an even lower level.
~hu~, the emergent water from line 58 may be
r-latively very pure indeed, such as having an oil
concentration of only a few parts per milllon.
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The filter deYice 100 may of any suitable
type such as an activated charcoal and~or reverse
osmosis type. Activated clay filters may also be
used.
The prov~sion of the hydrocyclone 10, in
add~tion to providing a separ~ting action, al80
a~4i~t8 ~n that a sub~tantial prs~surs dro~ will
no~mally esist as between th~ inlet line 42 an~ the
outlet 23 from the separator. Thls reduction in
pre~ure, which may for esample be 50%, has the
efect that oil in ~olution in the water will tend to
come out of ~olution snd form ~roplets which, even if
they are not separated totally in the cyclone 10,
emer~e from the outlet line 44, and can be mor~
read$1y saparated from the water component in the
de~ice 100.
The pressuro reducing devlce 50, although
preferable, may be omitted in some instances, as
indicated. It i8 al80 possible to u~e, a~ the
pressure reducing devic~e, ~ suitable valve or, lf
~esired, another hydrocyclone, particularly one
designsd to remove solids from admitted liquid. The
vessel gO may al80 be elimlnated in some instances.
Ths ~escr~bed mi~ing an~or residence vessel
90 may comprise a precoalescar or coalescer, for
example a cross-plate lnterceptor skimmer. It i8
al~o posslble in some instances to facilitate
operation by positioning a low shear pressure
increaslng flevice either in line 92, to ~ct on the
lnlet misture prior to entering the vessel 90, or in
.
; ~
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line 42 to act on mi~ture having left vessel 90 prior
to entry into hydrocyelone 10. By the term ~low
shear pressure increasing device~ is meant any
pre~suro increasing devico, such a~ a pump effectivo
to inerease liquid pre~sure without inducing
substantial shear ~tress in the liquid.
Figure 3 shows a further apparatus
eonstrueted in aeeor~anee with the in~ntion. Thi~
i~ similar to the previou~ly deseribed apparatus, but
i~ de~igned speeifieally for roeovery of water from
an oily water misture. The oily water mi~ture is
first passed to a free water knoekout tank 200, which
effeets partial separation of water and oil
eomponents by settlement. The more dense water,
typieally eontaining 2000 ppm oil, is taken on a line
202 to a mising and~or residence vessel in the form
of a cross plate intereeptor skimmer 204. A heater
treater 207 is also provided, this providing heated
water, such a8 water recovered from oil-water
misturos elsewhere in a processing plant. The
treated water is passed, ~uch a5 periodically, on a
line 206 to mis with the water from tank 200 on lino
202. The ~o mised water is that which i5 passed to
the ~kimmor 204. The skimmer has provision for
take-off of ro~eet oil on a line 208 through ~
~uitable valvo 210. 8eparated water, typically
eontaining 160 ppm i8 taken out on a line 212 and
pumped, via a pump 214, to the inlet of a
hydroeyelone 216, on a line 218. Removed oil from
the water ontering the hydrocyclone is taken via a
valvo 220 on a line 222 to be taken, toqether with
the removed oil passing from valve 210, from the
apparatus, on a line 224. The water emerging from
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the hydrocyclone 16, typically haYing an oil content
of 10 ppm, i8 passea on a line 226 via a ~al~e 228 to
a filter de~iee 100, ~s p~e~iously described.
Removed water i8 then taken on a line 228 to a
suitable so~tener devioe 230 and may be then used,
for esample, in ~ ~team generator 232 to which the
water i8 applied on a l~ne 234.
The apparstus shown in Figure 3 i8
controll~ ueh a8 eleetronieally, from a suitable
control dev~ce 250 which, in addition to controlling
~alves 210, 220 and 228, also controls the rate of
pumping of the pump 214 and i8 effective via a
suitable level control device 256 to control the
liquia le~el in the skimmer 204.
The provision of heater treater 207 has been
found to be particularly useful in providing a supply
of hoated water which facilitates the action of the
sk~mmer 204. ~he heater treater may, in particular,
apply heated water periodically to the skimmer.
~ he deseribed arrangement has been advaneed
merely by way of e~planation ana many modificatio~8
may be made thereto without ~eparting from the spirit
and scope of the invention as defined in the appended
elaims.
