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Патент USA US3095381

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June 25, 1963
' H. c. FITZISIMMONS
3,095,371
CENTRIFUGE mwms GAS VENT
Filed June 16. 1961
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46
N/
o
‘
INVENTOR.
HAROLD c. FITZSIMMONS
BY
[W
ATTORNEY
United States Patent 0
1.
,
,
1
lCe
Patented June 25, 1963»
2
3,095,371
CENTRIFUGE HAVING GAS VENT
Harold C. Fi'tzsimmon's, West‘ Chester, Pa., assignor to‘
The Sharpl‘es Corporation, a corporation‘ of Delaware
FiledJun'e 16, 196‘1,_Ser. No. 117,578v
3 Claims. (Cl. 233-45)
of the design of suchv a centrifuge hereinafter described,
gas introduced with the liquid feed accumulates in. the
bowl of the centrifuge; greatly interfering with its effec
tiveness as a‘ separator or clari?er, and greatly increasing
CI the amount of pressure requiredto; force the liquid to- be
centrifuged through the centrifuge, unless provisions are
This invention relates generally to centrifuges for sepa
made for the release from thebowl of such gas.
In the case of cream separators of‘ the full bowl type,
there has been a‘ ready solution. A passage. has been
rating materials of different densities such as centrifugal
separators and centrifugal c-lari?ers, and more particularly 10 provided connecting. all- parts of the center of the bowl
this invention relates to centrifuges in which the mate
so that any gas entering thebowl may pass from one com.
rials to be separated or clari?ed are introduced or fed
partment to another, and out of the bowl with the sepa
into‘ the rotating‘l rotor or bowl of the centrifuges under
rated cream. However, such a passageway, if. large
pressure.
enough to‘ satisfactorily relieve‘any accumulation of gas,
The liquid materials fed to centrifuges for separation
also permits the passage of unseparated liquid entering
or clari?cation frequently are accompanied by substan
the centrifuge bowl‘. which becomes mixed with the dis—
tial quantities of gas or vapor, ‘hereinafter for conven
ience referred to collectively as gas. The gas may be
charging cream. This can be tolerated in the case of:
cream separation since cream is merely a concentration
coarsely or ?nely dispersed in- the ?owing liquid or there
of butterfat particles: in‘, milk serum,.and a- minor dilution.
may be an alternate flow of what are commonly referred 20 of concentrated cream. with: the whole milk fed to‘ the cen-‘
to as slugs of liquid separated by gas.
trifuge can be compensated for by effecting somewhat
The gas may he air which has been entrained in the
liquid to be‘ centrifuged by agitating in an open con
higher concentration of cream in the main‘ separating
compartment of the bowl.
tainer prior to pumping it to a centrifuge. For example,
The above-mentioned passageway is not a solution to
in the re?ning of vegetable oil to wash soap out of the 25 the problem when the full. bowl type of centrifuge with
oil, the oil may be agitated} with water in ‘an open tank.
sealed feed is used in separations where. it is desired to
The soap‘ dissolves in‘ the water, and the mixture is passed‘
have the lighter component of the mixture discharged
to‘ a centrifuge to separate the oil freed of its soap and
‘from the bow-l unpoluted by the feed to‘ the bowl, as, for:
the soapy water. Agitation which is sui?cient to result
instance, in the separation of oil from‘ water containing’
in a satisfactory transfer of the soap from the oil to the 30 dissolve-d soap, or in the separationof oil from soapstock,
water results in an- oc‘cl'usion of air in» the mixture which
as has been referred to above, or in the separation of'
is carried on to the centrifuge.
neat soap from nigre in the manufacture of soap. In
As another illustration, the gas may be the result of
such cases the passageway in the center of the bowl for
a reaction between constituents of the liquid material to‘
the release of gas would allow the. pollution‘ of the sepa
be centrifuged; For example,- crude vegetable oil contain 35 rated lighter liquid component of the mixture 'with gas
ing fatty acids may be treated with a solution of sodium.
and liquid of the- feed which‘ has not‘ passed through the.
carbonate for neutralization of the‘ acids. The sodium
effective separating devices of the bowl.
carbonate reacts with the fatty acids forming soaps and
The pollution of the separated lighter liquid component
liberating carbon dioxide. The mixture containing dis-v
is exceptionally objectionable in. the case of the separation‘
persed gaseous carbon dioxide and insoluble soap, is fed 40 of neat soap from Inigre'. In that case the shearing of the
to‘ a centrifuge" to separate‘ the soap from the neutralized
air and neat soap mixture, which. occurs as the mixture
oili
'
Frequently a liquid mixture to be separated is heated,
passes from the rapidly rotating bowl. tov the stationary
receiver, results in a very ?ne dispersion of the air inv the
neat soap». This air can only be separated from the neat
for instance to reduce its ‘viscosity to facilitate separa
tion, such as by heated‘ surfaces or by the introduction of 45 soap by very prolonged settling at high temperature.
vapors ‘as it is passed- to a centrifuge, with the result? that
To resolve this problem, a prior patent presents means
the liquid contains free vapor, that is gas when it enters
for disposing of gas accumulating in the feed distribu
the centrifuge.
tion chamber of a centrifuge. It. presents a vent line
On the other hand, a leaky stu?ing box or pipe con
means connecting the upper central portion of‘ the cham
nection on the inlet side of‘ a pump‘ used for feeding a
her and extending axially down the spindle to a point
liquid‘ mixture to a centrifuge may allow air to leak into
below the bowl and turning radially of the spindle to
the‘ mixture fed to the centrifuge. Air may also leak
terminate in an opening to the atmosphere. To avoid
into the bowl feed around the rotary seal at the base of
loss of liquid as-well as gas, special valve means were
the bowl spindle through which feed liquid passes from
contemplated. In one embodiment, for instance, the vent
55
a stationary supply pipe ‘to the rotating spindle.
line means terminated in the feed distribution chamber in
Then too, the gas the mixture fed to the centrifuge
an outwardly ‘facing annular valve seat positioned about
may be the result of incomplete solution or incomplete
the axis of the bowl. A conventional O-ring surrounded
reaction‘ of a gaseous reagent admixed with a feed to the
this seat and served as a valve body, expanding outward
centrifuge as,- for instance, in case of" the addition of
away from the seat by centrifugal force in the absence
gaseous ammonia to neutralize, and form insoluble soaps 60 of liquid to permit gas to vent off through the seat, and
with, the fatty acids contained in vegetable oil.
“?oated” inwardly by the liquid, after the gas Ivent off,
‘Even though the liquid to be centrifuged contains no
to close the valve.
gas, conduits leadingfrom the supply of liquid to be cen
I have developed a centrifuge bowl having an improved‘
trifilged may be full of gas which’ is displaced by- the
gas vent valve which offers great ?exibility of design. It
65
initial how of liquid and is conducted, to the centrifuge.
comprises. a valve body being free for movement bodily
‘Irrespective of the origin of gas which occurs with the
to a valve seat and away from the seat to an outer limit.
liquid fed to a centrifuge, or the nature of such gas, when‘
It is especially sensitive to the buoying pressure of liquid
such mixturesare fed to a centrifuge under pressure with
closing inwardly of the bowl. In the absence of liquid
sealed feeding connections, such as a centrifuge of the
it moves freely outward from the center of the bowl under
70
full bowl type, the gas is forced into the‘ bowl of the
centrifugalforce.
‘
centrifuge‘. As will be seen ‘from a study of the details
Further features of the invention will become apparent
3,095,371
3
to persons skilled in the art as the speci?cation proceeds
and upon reference to the drawings in which:
FIGURE 1 is an elevation, partly in section, illustrating
one form of the invention;
4.
from an upper central portion of the feed distribution
chamber to the outside of the bowl, and comprises a
cylindrical chamber 32 in cap 14 disposed transverse to
the axis of the bowl. As shown, chamber 32 extends
inward from one side of the cap to well past the axis
of the bowl, terminating inwardly in an inner end 34.
Adjacent the open or outer end the chamber is formed
with an annular groove receiving a snap ring 36. The
FIGURE 2 is an enlarged fragmentary sectional view
taken on the line 2—2 of FIGURE 1;
FIGURE 3 is an enlarged perspective view of a valve
body as used under one form of the invention; and
vent line means 30 further comprises a passage 38 ex
FIGURE 4 is a fragmentary sectional elevation of
tending from the center of the inner end 34 at which
another form of the invention.
juncture is presented a valve seat 40, to an annular chan
Brie?y, in combination with a centrifuge bowl having
nel 42 about the lower face of cap 14.
feed means and discharge means, my invention comprises
Spaced outwardly from the axis of the bowl a distance
vent line means extending from a central portion of the
equal to the radius of channel 42 is an opening 44 in the
inside of the bowl to the outside of the bowl in the vent
line means, a valve seat, and a rigid buoyant valve body 15 upper face of the bowl shell hub. From opening 44
downwardly to the outside of the bowl extends passage
adapted to engage against the seat to close the vent line
46. On either side of opening 44 in the upper face of
means. The body is free for movement toward and away
the bowl shell hub are grooves receiving O-ring seals
from the seat, and is normally held against the seat by
48 adapted to prevent leakage of gas or other fluid at the
centrifugal pressure of liquid in the rotating bowl, but is
thrown away from the seat by centrifugal force in the 20 juncture of passages 38‘ and 46.
'It is obvious from the above~described construction
absence of such pressure.
that if in assembly cap 14 is screwed home against the
Referring now to FIGURE 1, the lower part of a cen
wheel bowl hub and the passages 38 and 46 do not align
trifugal separator bowl, together with associated parts, is
radially, they will still freely communicate through the
shown in section. The bowl shell 10 is surmounted by a
annular channel 42.
bowl top 11 which is held on to the bowl shell 10 by the
coupling ring 12 threadedly connected to the bowl shell
Disposed in the cylindrical chamber 32 is the valve
body 50. In its preferred form it is an elongated cylin
10. The bowl shell 10' is mounted on the bowl spindle
drical body which is rigid and hollow for reasons which
13 and held in place thereon by the nut or cap ‘14 which
will appear. FIGURE 3 shows that the inner end of the
is threadedly connected to the bowl spindle ‘13. The bowl
spindle 13 is mounted in a conventional manner for the 30 body, the seating end 52 is pointed, and the body is formed
with a plurality of circumferentially spaced radially ex
rotation of the bowl and the bowl spindle. The disc stack
tending ?ns 54. The working or outer end 56 is ?at and
support 15 rests on the bottom of the bowl shell 10 and
circular.
is held in contact therewith by engagement with the bowl
In the preferred form of the invention as shown in
top (not shown). The disc stack support 15 is held
in concentric relationship to the bowl shell 10 by means 35 FIGURE 2 the valve body 50 is received within cylin
drical chamber 32 and is only slightly shorter than the
well known in the art.
distance between snap ring 36 and the seat 40. The
A disc stack 16 which is shown for convenience as of
distance between distal edges of diametrically opposite
a conventional type, is located in the main separating
?ns 54 is slightly less than the diameter of chamber 32. In
chamber 17 of the bowl between the disc stack support
15 and the bowl top (not shown). The vertical spacing 40 assembly the proportion of the valve body 50 is such that
of the disc is accomplished by any suitable means such as
by means of spacers fastened to the upper surfaces of the
discs to form thin separating spaces between the discs.
The bowl is mounted to rotate within a frame (not
its center of mass is always disposed on one side of the
axis of the bowl irrespective of the position of the body
50 in chamber 32.
From adjacent seat 40 a drain passage 58 connects the
shown) to which it attached a cover. The cover in turn 45 inner end 34 with the top surface of the cap 14 and slopes
outwardly from the axis upward. In addition an axial
passage 60 connects chamber 32 with the feed distribution
chamber at the top of the cap.
shown in FIGURE 5 of US. Patent 2,717,119, dated
In operation for the separation of feed liquid into sepa
September 6, 1955.
The bowl spindle 13 is tubular and has a concentric 50 rate parts, the feed liquid is fed to the centrifuge and
upwardly through the channel 20 in the bowl spindle 13,
channel 20 throughout its length. The lower end of the
and radially outward through the hole 21 in the nut 14
bowl spindle 13 is adapted to rotate in well-known sealing
into feed distribution chamber 22. In this space the ac
means between it and a stationary conduit by which the
supports an assembly of parts for collecting the separated
products discharging from the bowl, for example, as
materials to be separated are fed to the centrifuge, a
celerating wings (not shown) accelerate said feed liquid
preferred form of which is shown in FIGURE 6 of said 55 to the angular rate of rotation of the bowl. The feed
liquid then passes through the passages 25 and upwardly
U.S. Patent 2,717,119. The nut or cap 14 is provided
through the vertical channels 24 in the disc stack 16, and
with at least one radial hole 21 communicating with the
then into the thin spaces between the discs. In the thin
channel 20 in the spindle and also with feed distribution
strati?ed layers between the discs effective separation of
chamber 22 located between the bottom of the bowl
the liquid components takes place under the in?uence of
shell 10 and the conical skirt of the disc stack support
centrifugal force. The lighter liquid component moves
15. Integral or associated with the conical skirt of the
toward the axis along the upper surface of the individual
disc stack support 15 are a number of accelerating radial
discs into the central channel 26, and ultimately out of
wings (not shown).
the centrifuge in a conventional or other manner. The
Each of the discs of the disc stack '16 is provided with a
plurality of circumferentially spaced holes 24 positioned 65 heavier liquid component moves away from the axis of
the bowl along the lower surface of the individual discs
between its inner and outer edges, and these holes are
into an annular channel (not shown), and ?nally out of
arranged one above the other in the disc stack ‘16 to form
the top of the bowl, also in a convention or other manner.
vertical channels (only one being shown) extending
In view of the large difference in density between gas
through the vertical length of the disc stack 16. The
conical skirt of the disc stack support 15 is provided with a 70 and liquid fed to the centrifuge, and the correspondingly
greater ease of separation of gas from liquid than the
number of passages 25, each passage 25 communicating
at one end with the feed distribution chamber 22 and at
the other end with a separate vertical channel.
A preferred embodiment of the invention is disclosed
in FIGURE 2. As shown, vent line means 30 extends
separation of liquid components from each other, gas fed
to the centrifuge along with the liquid mixture rapidly
separate in feed distribution chamber 22, forming a cylin
drical core of gas surrounded by liquid. In the absence
3,095,371
Qt vent means the gas aeetimhletes until .it reeehes the
Outlet ef the tubular passage 25, and then any further has
The ?ns v54 en beer 5.0; hermit free ?ow ot teed eut
wertlty .alehg body .50 as the ges'eere develops: and drain
58 ass res that feed will het‘eseape cut through. the vent
line means 30 whet1 the valve body .50 epehs after being
elesetlt Axial passage 6.9 provides it): eetnmunieetien of
the spaee- e'hev'e 921314 with, the. .ehamber 3.2- ‘It assures
fed th the centrifuge passes he hits) the. dish Steele rehidly
passing toward. the axis ef the Lew-er dises, and Creating
a turhhlenee in that portion at the bewl whieh impairs
separation
“
‘Even. more undesirable, when gas eeeuthelates, a pul
sating feed he the separating ehember results: As earl be
visualized above thedise stack support 15:. the liquid layer
extends t9 the axis hi the hewl the exerts a high heck
ntessure en the gas trapped beneath the dise steels Shh
Pett 15, end, in some instances, as much as 1.0.0 hehuds
that gets under presshte will not be trapped in the space
above ear 14., and that gas as it aeeutnulletes will immedi
ately Pass. into chamber 32 te in?uence eperatien .ef the
rave been so.
A rttedi?ed apparatus euthedyihg the invention is shown
in FIGURE 4 wherein the primed‘form of the same refer
per square inch additional pressure may be requi d to
feed‘ liquid htte a hewl ef eenventienal size and speed
when. gas is se trape'etiv in the h-ewl- This high heels pres‘
sure Will build upland hate the level at the liquid in the
ence numeral is used to designate parts corresponding to
15
parts 0t the preterretl FIGURE 2 etnhetlitttent’
In the FIGURE 4 embodiment the seat 40' is. substan
tially en- the exit 92 the hewh and the axial Passage 60'
settis?es the Purposes eeeemplishesi by Passages .60 and
distribution chamber 22 outward to the point at which
gas escapes through feed passage 25. This escape is of
5s in the FIGURE? embodiment,‘
'
course accompanied by an immediate drop in back pres—
To seat the body 5.0’ the eehtrifugel Ptesshre of the
sure as the liquid level moves inward only vto be followed 20 liquid must ottset the outward urging of the valve body
by ahether pressute build up, ete- Sheh ?uctuation in
haek pressure results in pulsating teed Whieh results in
variable separation the he
In a eenvehtieual. hewl, passageway is PI°Yid¢d from
an axial eesltleu 9t the. teed distribution chamber 2:2
thteugh the dise stack. seepert .15 to‘ the central ehenhel
26., All of. the gas. Whieh. is it; tueh :1 state of aggregation
that. eett be separated the feed distribution ehetnher 22
?ows through this passageway together with a part of the
liquid mixture fed, to the centrifuge. Both the gas and this
portion. of the liquid feed mixture are picked up, by the
discharging stream of separate lighter component ?owing
through the central‘ channel 26, and are discharged to
gether therewith at the top of the centrifuge bowl. With
this conventional method of releasing the gas which is
separated beneath the conical skirt of the disc stack sup
port 15, the lighter liquid component which has been
eifectively separated in the disc stack is polluted with
both the gas and a portion of the feed liquid. The rotat
ing stream discharging from the rotating centrifuge bowl
into the non-rotating receiver is subjected to intense shear
with the result that the polluting gas and feed liquid is
intimately intermixed with the pure lighter liquid compo
50’- acted upon by centrifugal ‘force at its center of mass,
The centrifugal pressure required to “?oat” body 50' in
Ward Will be greater than were portions ef hetiy 5.0’ dis
posed on Opposite sides. of the axis as in the FIGURE 2.
25
embodiment.
The reliability of operation of the apparatuses ‘embody
ing my invention is attributable to a number of factors.
Primarily because body 50 is rigid and eeted 9a with
certainty" by de?nite opposing forces is it e?ectiye, Ad
ditionally' its reliability ‘is attributable to its freedom for
bodily motion within‘ limits transverse of the axis. Its
motidn is unhampered by attachments to other parts of
the apparatus. Finally the walls of chamber 32 acting
on the distal edges of ?ns 54 assures perfectly directional
movement toward and away from seat 40 for a sure
precise seating.
While for the purpose of convenience the invention has
been described in connection with a particular type of
centrifugal separator bowl, it may advantageously be used
40 with other types of centrifugal bowls whether adapted for
separation of liquids, their clari?cation or otherwise, as
for example, centrifugal clari?er bowls for the separation
of non-liquid or solid particles from- a liquid. It may
also be used as a deaerator wherein the prime purpose is
soap from nigre where a slight pollution of the neat soap 45 to separate gas from the feed liquid, and the clari?ca
with a portion of nigre may be tolerated, the subsequent
tion of the liquid is incidental. There would be no need
separation of the very ?nely divided air ‘from the viscous
to provide such apparatus with a disc stack.
neat soap is accomplished only with considerable di?iculty.
In the embodiment shown the vertical channel 24 ex
An apparatus embodying the present invention will vent
tending through the disc stack may be closer to or farther
the gas from the feed distribution chamber so that gas
away from the outer edges of the discs, or, and partic
does not enter the separation chamber. Means are pro
ularly in the case of clari?er bowls, they may be omitted
vided to close the vent when the gas is vented and the
nent.
Even in those cases as in the separation of neat
entirely, these and other modi?cations being well known
feed distribution chamber is ?lled with liquid. When
to those skilled in the art. Also, and particularly in the
the feed ‘distribution chamber is ?lled with feed liquid
substantially to the axis of the bowl, the liquid under 55 case of clari?er bowls, the conical skirt of the disc stack
support may be so modi?ed, such as in well known man
centrifugal pressure will work against the working end 56
ner, that the liquid ?owing through the centrifugal bowl
to “?oat” the valve body to its inward or closed position.
is fed directly from the feed distribution chamber to the
In this position the pointed or seating end 52 will rest
against seat 40 to close the vent line means 30. It is
apparent that to be effective, the buoying pressure on the
Working end 56 must overcome the mass of the valve body
50 as acted on by centrifugal force. This is assured by
annular channel surrounding the discs.
Furthermore,
while I have described the invention as applied to cen
trifugal bowls provided with discs for the accelerating
and decelerating of the liquid as it ?ows radially outward
ly and inwardly, respectively, within the bowl, and for
the stratifying of the liquid into thin layers, other types
the preferred arrangement disclosed in FIGURE 2 where
in a portion of the valve body is disposed on the opposite
side of the axis of the bowl from the working end 56. 65 of accelerating-decelerating devices may be used, for ex
ample, the main separating chamber 17 may be provided
This portion offsets a portion of equal mass on the oppo
with the well known wing type of accelerating~decelerat~
site side of the axis to reduce the outward urging of cen
trifugal force on the valve body 50.
ing device as illustrated in U.S. Patent 1,401,196, or the
spiral blade type of accelerating-decelerating device as
Obviously when a core of gas develops centrally in the
distribution chamber 22 so that the centrifugal pressure 70 illustrated in US. Patent 2,138,468. There is also shown
of the liquid working on the end 56 is not su?icient to
in these patents means for distributing the vfeed. Combi
“?oat” body 50 to seating position, the body will move
nations of various types of accelerating-decelerating de
outward to an outer limit established by the abutment of
vices also may be employed, such as those known in the
the working end 56 against snap ring 36 to permit vent
art.
ing the gas out of the bowl through passage 46.
75
Having more particularly described my invention, it is
3,095,371
7
to be understood that this is by way of illustration and
not by way of limitation, and that modi?cations may be
made without departing from the spirit of the invention.
Thus while my invention has been more particularly de
scribed in connection with a bowl adapted to be rotated
8
rigid elongated cylindrical valve element disposed for
reciprocation in said valve chamber and having a plu
rality of outwardly directed ?ns engaging the walls of
said valve chamber and serving to guide said valve ele
ment in movement toward and away from said seat, the
end of said valve element toward said seat being pointed,
said valve element normally held against the seat by the
tion is similarly adaptable to a bowl rotating about any
centrifugal pressure of liquid in the bowl but thrown
other axis, such as a horizontal axis.
away from said seat to the stop means by centrifugal
Other modi?cations will occur to persons skilled in
the art upon becoming familiar herewith. Accordingly, 10 force in the absence of sufficient pressure.
2. The centrifuge of claim 1 wherein the passage in
it is intended that the patent shall cover, by suitable ex
the
hub and the passage in the hub cap are connected
pression in the claims, the various features of patentable
through an annular channel communicating with both
novelty residing in the invention.
passages.
I claim:
3. The centrifuge of claim 1 wherein the seat is spaced
1. A centrifuge bowl divided internally by a partition
from the axis of the bowl and on the opposite side of the
segregating a lower distributing compartment from an
axis from the center of gravity of the valve element.
upper primary separating zone, means for feeding feed
about a vertical axis, it will be understood that my inven
mixture into the distributing compartment, said partition
having ports spaced below the top of the compartment
through which feed passes into the primary separating 20
zone, the bowl having a central hub with an axial open~
ing adapted to receive a drive spindle, said hub having
a vent opening in its upper end and a vent passage from
the undersurface of the bowl to the vent opening, a hub
cap removably secured against and over the hub and hav 25
ing a valve chamber with a valve seat opening at one end
and a passage extending between the vent opening and
the valve seat opening, the valve chamber being disposed
in a direction transverse to the axis of the bowl and hav
ing a seat surrounding the valve seat opening, the op 30
posite end of said valve chamber from the seat mounting
stop means and being open to the inside of the distribut
ing compartment above the uppermost of the ports, a
References Cited in the ?le of this patent
UNITED STATES PATENTS
1,277,676
2,141,025
Wright ______________ __ Sept. 3, 1918
Strezynski ___________ __ Dec. 20, 1938
2,417,747
2,712,896
2,712,897
2,717,119
2,873,910
2,985,361
Flowers ____________ __ Mar. 18, 1947
Boldrin ______________ __ July 12, 1955
373,560
610,305
Great Britain ________ __ May 26, 1932
Germany ____________ __ Mar. 9, 1935
Kusserow et al. _______ __ July 12, 1955
Jones ________________ __ Sept. 6, .1955
Steinacker ___________ __ Feb. 17, 1959
Smith _______________ __ May 23, 1961
FOREIGN PATENTS
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