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Патент USA US3073785

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Jan. 15, 1963
L. c. WATERMAN
3,073,775
ELECTRIC TREATER
Original Filed June 5', 1953
2 Sheets-Sheet 1
INVENTOR.
Loan/v C. WHT£RMHN
>
BY HIS HTTORNEKS.
HARRIS, K/ECH, Fos TER' a H?RR/S
Jan. 15, 1963
L. c. WATERMAN
3,073,775
ELECTRIC TREATER
Original Filed June 5', 1953
_
2 Sheets-Sheet 2
IO
/N VENTOR.
Lesa/v C. WHTERMHN
BY HIS ATTORNEYS.
W428
Hn RR/s, K IECH, Fos TER 0¢Hnems
United States Patent 0 f 1C6
3,073,775
Patented Jan. 15, less
2
1
tially non-turbulently along the treating spaces wherein
they are subjected to a unidirectional electric ?eld.
The action in such unidirectional electric ?eld is pre
3,073,775
ELECTRIC TREATER
Logan C. Waterman, Houston, Tex., assignor to Petro
lite Corporation, Wilmington, Del., a corporation of
dominantly one of coalescing the dispersed particles or
droplets into larger masses of su?icient size to gravitate
Delaware
from the system, as contradistinguished from any pro
Original application June 5, 1953, Ser. No. 359,795, now
Patent No. 2,897,251, dated July 28, 1959. Divided
posal to remove the dispersed particles or droplets by
electrophoretically depositing them on one of the elec
trode surfaces.
It is an important object of the present invention to
10
My invention relates to the electric treatment of oil
provide an electric treater which can, if desired, be used
continuous dispersions and, more particularly, to a novel
in the super-treatment of dispersions. A further object
apparatus which will be illustrated as employed in the ' is to provide a novel distribution system by which the
and this application Sept. 26, 1958, Ser. No. 763,650
10 Claims. (Cl. 204—302)
acid treatment of petroleum distillates. It should be un
dispersion is introduced into an entrance zone of the treat
derstood, however, that the invention is not limited there 15 er. A further object is to use such a distribution means
to, being applicable to the electrical treatment of various
in conjunction with a collector means in an exit zone
dispersions or emulsions in which the external or con
of the treater for the purpose of establishing a uniform
tinuous phase is an oil or a fraction, distillation product
flow of the dispersion in a treating zone between the en
or residuum obtained therefrom, whether or not contain
trance and exit zones.
ing a solvent or diluent. The internal or dispersed phase
In one of its aspects the invention provides an improved
of the emulsion may be any liquid suf?ciently immiscible
means for advancing a passage-?lling stream along a pas
with the external-phase material to exist therein as dis
sage, such means including a dispersion-discharge means
persed particles or droplets. The present application is
comprising a plurality of inverted buckets disposed
a division of my application Serial No. 359,795, ?led
around the axis of the passage and pipe means for dis
June 5, 1953, now Patent No. 2,897,251.
25 charging a stream of the dispersion into each of such
The invention relates to an electric treater of particular
buckets, each bucket providing an open end facing away
utility in the relatively new process for the super-treatment
from a zone of treatment containing electrode means for
of dispersions, including emulsions. This super-treat
ment makes possible the removal of the dispersed-phase
electrically treating the dispersion.
,
The invention includes also a plurality of electrode
material to an extent not possible with older commercial 30 members having central portions secured to a support
processes.
means, each electrode member providing ?rst and sec
In the electrical treatment of dispersions, it is often
ond end portions extending oppositely from the support
desirable to subject the dispersion to successive electric
means and respectively substantially parallel to an axis,
?elds which may be of different character. It is an ob
and ?rst and second auxiliary electrode sets each compris
ject of the present invention to provide a versatile treater 35 ing a plurality of substantially parallel electrode members
in which this can be accomplished. In this connection,
spaced from each other distances substantially equal to
the invention includes among its objects the provision of
the spacing of said ?rst and second end portions, together
an electric treater having unique arrangements of elec
with means for mounting the ?rst and second auxiliary
trodes and electric ?elds by which a super-treating action
electrode sets with their electrode members respectively
can be eifected.
Unexpected results are obtained when advancing dis
persions through relatively narrow side-by-side treating
40
xtending into and substantially bisecting the unobstructed
spaces of the ?rst and second end portions to form ?rst
and second sets of treating spaces spaced along said axis
spaces in which are established high-voltage unidirec
in which electric ?elds are established and through which
tional electric ?elds. Thereby, it is often possible to re
the dispersion stream flows in sequence.
45
duce the residual dispersed material to values as low as
Further objects and advantages of the invention will be
a few hundredths of a percent or less. When treating
evident to those skilled in the art from the following
lighter petroleum oils, it is often possible to reduce the
residual material to less than a few thousandths of a per
description of an exemplary embodiment, designed par
ticularly for use in the acid treatment of distillates.
cent and usually to obtain completely clear products.
Referring to the drawings:
With heavy crude oils or lubricating oils, the residual 50
FIG. 1 is a vertical sectional view of one embodiment
material may be in the neighborhood of a few tenths of
of
the invention;
a percent. In all such instances, however, the residual
FIG. 2 is a horizontal sectional view taken along the
material can be much less than would be the case if the
line 2-2 of FIG. 1;
dispersion were subjected to a treatment in an AC.
FIG. 3 is an enlarged vertical sectional view of one of
?eld in a conventional electric treater.
the insulator housings of FIG. 1;
Modern electric treaters of conventional design pro
FIG. 4 is a diagrammatic view of a similar electric
duce electric ?elds which are substantially more intense
treater having a modi?ed distribution system for the in
adjacent one electrode than adjacent the other. Such
coming dispersion;
treaters also recirculate the constituents of the dispersion 60 FIG. 5 is a fragmentary view taken along the line 5—5
through the electric ?eld for repeated treatment. In ad
of FIG. 4; and
dition, such treaters have been designed to‘ maintain a
FIGS. 6 and 7 are fragmentary views of alternative
high degree of turbulence in the electric ?eld. In the
distribution systems as viewed in the same plane as FIG. 4.
super-treatment of dispersions, including emulsions, it
The electric treater of the invention is shown as in
is desirable to employ ?elds of substantially uniform volt
65 cluding a vessel :10 of unique form having a relatively
age gradient measured along paths joining the electrodes
short cylindrical side wall 11, a domed cover 12 and a
and to avoid both the promiscuous turbulence in the elec
tapered lower section '13 ending in a well 14 from which
tric ?elds of prior art treaters and the recirculation of the
separated acid sludge is withdrawn through a pipe 15, as
constituents through the ?eld. By proper design, a large
will be described.
stream of dispersion can be divided into a plurality of
‘In the exempli?ed acid treating process, proportioning
streams flowing through open-ended treating spaces dis 70 pumps 16 and 17 respectively deliver streams of distillate
posed side-by-side. The how of the large stream can be
and acid under pressure to a mixer 18 of any suitable
straightened so that the smaller streams ?ow substan
3,073,775
3
type. The resulting dispersion may be relatively stable
or unstable but is continuously delivered through a valve
19 to a pipe 20 terminating in a manifold 21 disposed
in an entrance zone 23 of the vessel 10.
Means is provided for distributing this dispersion in
the entrance zone 23 so that it will flow upwardly as a
large passage-?lling stream through a treating zone 24
to an exit zone 25. It is desirable that the upward veloc
4
air valve in a controller 56 to which air is supplied
through a pipe 57. The effluent air, controlled by the
valve, is delivered by a pipe 58 to a diaphragm unit 59
operatively connected to the valve 59. The relationship
is such that a rise in the sludge interface will move the
valve 50 toward open position and vice versa, thereby
maintaining the sludge level substantially uniform in the
lower end of the vessel 10.
ity at all radial positions in this large stream should be
The passage-?lling stream of dispersion is electrically
substantially uniform. The present invention accom 10 treated in the treating zone 24 by being subjected to
plishes this ‘by appropriately designed distribution and
appropriate electric ?elds which coalesce the acid sludge
collection systems, the former including a plurality of
pipes 26 radiating from the manifold 21 and providing
up-turned nipples or nozzles 27 developing substantially
no pressure drop when the dispersion ?ows therethrough.
Each nozzle is covered by an inverted cup-like member
or other dispersed~phase material into masses of su?icient
size to gravitate from the rising stream to collect in the
lower end of the vessel 10. To establish these electric
?elds and also to straighten the flow of the rising passage
or inverted bucket 29 having an open lower end 30 facing
away from the treating zone 24. As a consequence, the
stream of dispersion issuing from each nozzle 27 is de
novel electrode means in the treating zone 24. This
electrode means includes an intermediate electrode set
65, a ?rst or lower auxiliary electrode section or set 66
flected to flow downwardly around the lowermost lip of
?lling stream of dispersion, the invention employs a
the corresponding inverted bucket 29. This method of
distributing the incoming dispersion has been found to be
very satisfactory, particularly if the centers of the inverted
and a second or upper auxiliary electrode section or
set 67.
The intermediate electrode set 65 is an electrode com
mon to the sections or sets 66 and 67. It includes a
buckets 29 are at a radial position about two-thirds the
radius measured from the central axis A—A of the vessel
to the cylindrical wall 11, e.g., at what may be called
central portions perforated to receive a support means
plurality of cylindrical electrode members 63 having
shown as including a plurality of radially extending
the median-volume radius of the cylindrical wall 11.
It is desirable that the passage-?lling stream of the
dispersion should move only once through the treating
Width and each arm is welded to each of the electrode
zone, as distinct from a design in which portions of the
members 63 at the junction.
dispersion would be recirculated. To aid in accomplish
ing this, the invention is shown as including a withdrawal
or collection means in the exit zone 25 comprising a
narrow arms 69.
These arms may be rectangular in
cross-section and are preferably of greater height than
The innermost ends of
these arms 69 are welded or otherwise secured to an
innermost cylindrical electrode member 70 which, together
with the other electrode member 68, is mounted con
centric with the axis A—A of the vessel 10. The outer
plurality of perforated pipes 32, preferably six or eight
in number, radiating from and communicating with a
most portions of the arms 69 rest on and are bolted
manifold 33 formed between inner and outer members
34 and 35 concentric with the axis A—A. The members
to projections 71 Welded to the vessel 10 and through
which the intermediate electrode set 65 is electrically
34 and 35 are secured to a ?tting 36 welded to the cover
connected to the vessel.
It will be observed that the arms 69 are mounted
as cantilevers from the projections 71 and that there is
no other vertical support for the innermost electrode
12. It is preferred that the perforations in each pipe 32
be progressively closer together toward the outer end of
the pipe. Preferably the area of all of the perforations
in a particular radial zone will be proportional to the
square of the radius of this zone. The volume of treated
oil collected at any radial position Will then be substan
member 70. The intermediate electrode set 65 should
be rigid in a horizontal plane so as not to sag in its
central portion. At the same time, the arms 69 should
tially proportional to the square of the radius of such 45 have a minimum width so as not to interfere with the
position, thus aiding in producing a rising column of
rising stream of the liquid undergoing treatment. The
liquid below the collector moving upwardly with sub
arrangement shown permits the use of very narrow arms
stantially the same velocity at all radial positions.
69 while still obtaining a rigid structure. In this con
The treated oil entering the perforations of the pipes 32
nection, each cylindrical electrode member 68 stiifcns
?ows to the manifold 33 and is Withdrawn from the 50 each arm 69 at the welded junction thereof, particularly
vessel 10 through a pipe 38 equipped with a valve 39.
because the electrode member is curved. Tne welding
This valve is controlled to maintain an adjustable pres
of the inner ends of the arms 69 to the innermost elec
sure in the vessel 10 as a back pressure against the pumps
trode member 70 also rigidities the structure.
16 and 17. This may be accomplished by transmitting
Each of the cylindrical electrode members 63 and 76
the pressure from the pipe 38 upstream of said valve 55 provides ?rst and second or lower and upper end por~
through a pipe 42 to a controller 43. The pressure in
tions 72 and 73 extending oppositely from the support
this pipe operates the controller 43 and adjusts the
means formed by the arms 69. The end portions 72 are
amount of compressed air entering the controller through
respectively parallel to the axis A—A, as are also the
the pipe 45 and delivered through a pipe 46 to a dia
end portions 73 which are preferably continuations of
the portions 72. The portions 72 are spaced from each
phragm unit 47 connected to the valve 39 to move same
toward closed position upon increase in pressure in the
other to de?ne unobstructed spaces facing away from the
pipe 42 and vice versa.
support means, the same being true of the end portions
73. These spaces are of substantially equal width and
Similarly, the acid sludge separating in the vessel 10,
face respectively downwardly and upwardly. The por
as will be later described, is continuously or intermit
tions 72 include edges 74 facing upstream of the passage
tently withdrawn through a valve 50 in the pipe 15, the
valve being controlled to maintain the sludge interface
51 between predetermined limits. FIG. 1 shows the
?lling stream of dispersion.
sludge interface 51 in substantially normal position, the
ported by a support means 75 to be described and com
dotted lines 51a and 51b indicating the extreme upper
most and lowermost positions beyond which the interface
should not move. A glass ?oat 53 is internally weighted
to sink in the liquid above the interface 51 and ?oat in
the sludge below the interface. This ?oat 53 is carried
spaced apart substantially the same distance as the elec
trode members 68. The electrode members 77 extend
by an arm 54 pivoted about an axis 55 and operates an
The ?rst or lower auxiliary electrode set 66 is sup
prises an interstitial framework 76 carrying tip-standing
substantially parallel cylindrical electrode members '77
respectively into the substantially unobstructed spaces
between the end portions 72, substantially bisecting these
spaces to form a set of lower treating spaces 78 between
3,073,775
5
the overlapping portions of the electrode members 68
and 77. Edges 79 at the bottom of the electrode mem
bers 77 serve as stream-splitting edges as do also the
edges 74 of the end portions 72 of the electrode members
68.
Portions of the electrode members 68 and 77 re—
spectively adjacent these edges serve as ?ow-straightening
6
of substantially smaller diameter than the passage 107 and
is desirable in preventing ?ash-over of the insulator 98.
The pressure in the vessel 10 normally would tend to
- force the treated oil upwardly in the housing 94 to con
tact the lower portion 105 of the insulator and ?ll an an
nular chamber 110 within the housing around such lower
portion and around a portion of the conductor 92. This
means, tending to damp out transverse components of
contact between the treated liquid and the insulator may
motion in the stream rising in the entrance chamber 23.
give rise to surface contamination and electrical failure
The second or upper auxiliary electrode set 67 in
of the latter. The present invention provides for mainte
cludes a support means 82 to be described, an interstitial 10
nance of a body of dielectric ?uid, preferably a body
framework 83 and a plurality of cylindrical electrode
of dielectric gas, in the annular chamber 110 under such
members 84 radially spaced the same as the electrode
pressure as will maintain the treated oil a distance below
members 77 but depending from the framework 83. The
the lower portion 105 of the insulator 98. The dielec
electrode members 84 substantially bisect the upwardly
tric ?uid and the treated liquid will separate at an inter
facing unobstructed spaces between the portions 73 of 15 face, indicated by the numeral 111, if they are immiscible.
the intermediate electrode set 65 and cooperate in de?n
It is desirable that the position of this interface be main_
ing a second or upper set of treating spaces 85 in which
tained substantially constant by control of the amount or
the super~treatment of the dispersion is effected. The
pressure of the dielectric ?uid in the annular chamber 110.
extreme ends of the electrode members 84 comprise
This is almost impossible to accomplish by use of an auto
edges 86 spaced from the arms 69. The same is true as 20 matic valve responsive to level of an interface and serv
to the extreme upper edges 87 of the electrode members
ing merely to add an increment of dielectric ?uid to a
77. By the time the stream is passing through the treat
ing spaces 85, it is moving with substantially laminar
static body thereof to compensate for a de?ciency in
it may be foraminous to permit ?ow through such cylin
drical member. suspending the member 90 and the
quite satisfactory where there is no explosive hazard.
A compressed gas, such as air, is derived from a pipe
115 and is reduced in pressure by an adjustable constant
amount or pressure of such dielectric ?uid. This is due
?ow due to the ?ow-straightening action of all of the
in
part to the fact that it is usually not possible to make
25
electrode members 68, 77 and 84.
such a valve close completely, thus permitting gradual
The support means 75 and 82 comprise means for
leakage and destroying accurate control of the position of
respectively energizing the lower and upper electrode sets
the interface. To solve this problem and to circulate the
66 and 67 to maintain a high-potential difference between
dielectric ?uid through the annular chamber 110 to re
these sets and the intermediate electrode set 65. The
move any material that might be transferred from the
support means 75 and 82 also include novel arrange
treated oil through a stagnant body of dielectric ?uid to
ments of insulators, as Will now be described.
the surface of the insulator, I prefer to use a dynamic
The support means 75 includes a member or rod 90
system in which a dielectric ?uid continuously circulates
extending centrally through the innermost cylindrical
through the annular chamber 110. This dielectric ?uid is
member 70 and connected to the framework 76 by any
preferably a gas, e.g., compressed air or any inert gas
35
suitable means. If desired, this means may be a plate
such as helium, nitrogen, carbon dioxide or even an elec
91 which substantially blocks upward ?ow of the dis
tro-negative gas such as sulphur hexa?uoride. In com
persion through the innermost cylindrical member 70 or
mercial practice, compressed air has been found to be
lower auxiliary electrode set 66 is a conductor 92 which
extends upwardly through the lower open end of an
pressure valve means 116 to maintain the pressure in a
insulator housing 94 connected to the top of the ?tting
pipe 117 slightly above the pressure at which the valves
36 and closed at its upper end by a closure plate 95. As
39 and 50 are set. A valve 118 in the pipe 117 is con
best shown in FIGS. 1 and 3, a support in the form
trolled by a level responsive means 120 which includes
of a ?ange 96 is welded or otherwise secured in the 45 a ?oat 121 sensitive to changes in level of the interface
housing at a position intermediate its ends. An insu
111 and operatively connected to the valve 118 to con
lator 98 formed of ceramic or other electrical insulating
trol the ?ow of the gas through a pipe 122 to a mani
material is secured in ?uid-tight relationship with the
fold 123. The level responsive means 120 is of any con
support 96 by a collar 99. The collar 99 may be sepa
ventional form, being illustrated as including a housing
50
rated from a neck of the insulator by a suitable sealing
124 interconnected by pipes 125 and 126 to the interior
material 100 and may be separated from the support 96
of the housing 94 at levels above and below the desired
by a gasket 101, thereby eifectively dividing the interior
position of the interface 111. A corresponding inter
of the housing 94 into upper and lower zones 102
face Will be present in the housing 124 and will control
the position of the ?oat 121. Any other level responsive
and 103.
The insulator 98 is preferably supported at an inter 55 means can be employed to control the valve 118 and thus
mediate position so as to provide an upper portion 104
control the ?ow and pressure in the pipe 122.
exposed to the zone 102 and a lower portion 105 exposed
A pipe 127 conducts gas from the manifold 123 to
to the zone 103. The insulator 98 is preferably a cy
the annular chamber 110. This pipe forms a part of
lindrical member having a passage 107 extending lon
a circulation means for continuously circulating the gas
gitudinally therethrough, this passage being substantially
larger in cross-sectional area than the conductor 92. A
?anged cap 108 engages the top of the upper portion 104
60
through the annular chamber, usually in laving relation
ship with the lower portion 105 of the insulator. An
exit pipe 128 communicates with another portion of the
and provides an opening slidably receiving the conductor
annular chamber 110 and conducts the e?luent gas to a
92. The upper end of this conductor is threaded and re
ceives a nut 109 which can be turned to adjust the ver
manifold 129. The gas normally flows through an ad
65 jutsable constant-pressure valve 130 which maintains the
pressure in the manifold 129 at a set value. The escap
ing gas is discharged at atmospheric pressure into a sam
insulator 98 are sealed in ?uid-tight relationship as by
ple box or funnel 132 which is connected to a sewer line
gaskets or washers. By this arrangement the zones
and which permits inspection of any stream discharged
tical position of the lower auxiliary electrode set 66. The
conductor 92, the cap 108 and the upper portion of the
102 and 103 are effectively sealed from each other. Also, 70 into the funnel. A by-pass valve 133 is connected around
any weight applied to the conductor 92 will result in com
the valve means 130 and is useful in initially ?lling the
pressive forces in the upper portion 104 of the insulator.
vessel.
Furthermore, the hollow insulator construction provides a
The support means 82 of the upper auxiliary electrode
very long leakage path between the cap 108 and the ?ange
75 set 67 includes three equally-spaced conductors 135 ex
96. This results in part from the conductor 92 being
3,073,775
7
tending upwardly into respectively spaced housings simi
lar to the housing 94. In FIG. 1 two of these housings
are shown, indicated respectively at 136 and 137. A
third housing, identical in construction with the housing
137, is omitted for purpose of clarity. The construction
of these three housings will be apparent from the sec—
tional showing of the housing 136 of FIG. 1.
8
tential is equal to the unidirectional potential of the
source 161, the electrode arrangement produces a unique
relationship of electric ?elds. The dispersion will ?rst
be subjected to an alternating ?eld in the treating spaces
78. It will then be subjected to a double-voltage pulsat
ing DC. ?eld between the edges 56 and 87. Finally, it
will be subjected to the-uniform-gradient unidirectional
electric ?elds in the treating spaces 85. This combination
The housing 136 contains an insulator 138 of the form
previously described. Compressed gas is circulated
of ?elds has been found very efficacious in the treatment
through an annular chamber 139, entering this chamber 10 of certain distillates.
through a pipe 145? connected to the manifold 123 and
In considering the general operation of the treatcr, it
leaving the chamber through a pipe 141 exhausting into
will be apparent that the passage-?lling stream of dis
the manifold 129 Similar pipes circulate streams of the
persion will be quite turbulent in the entrance zone 23.
compressed gas from the manifold 123 to each of the re
However, due to the ?ow-straightening action of the
maining two housings, the gas exhausting to the mani
lowermost portions of the electrode members 68 and 77,
fold 129. By controlling the gas flow in response to the
this turbulence will be substantially completely damped
requirements needed to maintain one interface at a con
out and the flow will be essentially laminar in the treat
stant level, e.g., the interface 111 in the housing 94, the
ing spaces 78 and 85, particularly in the latter where such
flows through the remaining annular chambers will main
flow is desirable to achieve a super-treating action. Dur
tain the interfaces therein at substantially the same level. 20 ing the time the dispersion is between these sets of treat
In each of the four housings it is desirable that the
ing spaces, it is kept from reassuming excessive turbulent
outer zone 102 be ?lled with a dielectric ?uid and that
the pressure thereof be maintained substantially equal to
the pressure in the corresponding annular chamber around
the lower portion of the insulator. I prefer to ?ll each
outer zone 10-2 with a dielectric liquid to surround and
protect from ?ash-over the upper portion 164 of the in
sulator.
To maintain the pressures in these outer zones
flow by the stream-separating central portions of the
electrode members d8.
It is often desirable to be able to sample the material
‘ undergoing treatment and the effluent materials. For this
purpose the invention may provide a small valved line
19b conducting a sample of the incoming dispersion to the
funnel 132. The condition of the dispersion at a position
equal to each other and to the pressure in the correspond
near the arms 69 can be determined by a valved sample
ing annular chambers, e.g., 110 and 139, each outer zone 30 line 191 which provides a portion 192 traversing several
is connected by a pipe 145 with the manifold pipe 123.
of the outermost electrode members 68. This sample line
Each outer zone 102 may be ?lled with a dielectric liquid
may provide a pressure gauge 193 showing the existing
by removing a cap 146 of a ?tting 147 to which the
pressure in the vessel 10. A valved sample line 194 can
corresponding pipe 145 is connected. Alternatively, each
deliver a sample stream of the separated acid sludge to
outer zone 102 may be ?lled or ?ushed by use of valved
the funnel 132 for observation. Similarly, a valved sam
pipes 148 and 149 communicating with upper and lower
ple line 195, shown divided in FIG. 1, may conduct
portions of this zone.
treated oil from the pipe 38 to the funnel 132.
The housings 94 and 135 provide means for conducting
In electrical distillate-treating processes, it is often of
high potentials to the lower and upper electrode sets re
importance that the volume of the treating vessel be a
spectively. This means includes a high-voltage inlet bush 40 minimum. In some processes, for example, it is important
ing i150 carried by the closure 95. Each inlet bushing
that the dispersed phase be removed from contact with
includes a tube of insulating material 151 (see FIG. 3)
the oil in a minimum of time. When shifting from one
connected at its upper end to the closure 95 by a suitable
oil to another, it is also important that the treater volume
?tting 153 to which is also connected a high-voltage cable
be a minimum consistent with a desirably large through
154, the lead or conductor of this cable extending through
put. The treater of the invention has many advantages
the tube of insulating material 151 and being electrically
in this connection. The compactness of the electrode
connected to a terminal 155. This terminal engages and
structure, the relatively small space between the upper
compresses the upper end of a spring 156 which electrical
most electrode unit and the cover 12, and the small volume
ly interconnects the terminal to the cap 103. The insulat
of the vessel below the lowermost electrode unit are im
ing liquid surrounds and protects against ?ash-over the
portant. Minimum volume in the lower end of the vessel
exterior surface of the tube of insulating material 151.
is made possible not only by the disclosed close spacing
The inlet bushings in the housings 94- and 136 are
of the elements but also by the conical or tapered lower
identical. The higlnvoltage cables 154' are connected to
section 13. The latter minimizes the amount of sludge in
separate potential sources 160 and 161 respectively. Each
the vessel and minimizes the area of the interface 51, lead
potential source includes one terminal which is grounded
ing to less degradation of the treated oil. Furthermore,
and which is correspondingly connected to the intermedi
the tapered lower section 13 is disposed at such an angle
ate elect-rode set 65 through a ground connection 162 for
that a mass of acid sludge will slide or settle therealong to
the vessel 10. Each potential source has a high-voltage
drain into the well 14 and thence into the pipe 15.
terminal connected through its respective cable to the re
It is also desirable that the treater may be drained and
spective electrode set.
60 re?lled with a minimum of effort. Draining of the
To obtain a super-treating action in the treating spaces
treater is ordinarily no problem but it is very desirable
85, it is essential that the potential source 161 be unidirec
that the housings 94, 136, 137, etc., should ?ll almost
tional. The electric ?elds in the treating spaces '78 may
automatically and entrap bodies of gas in the respective
also be unidirectional, in which event the potential source
annular chambers even before the gas or other dielec
169 may be substantially identical with the source 161 or
tric ?uid is circulated through the valves 116 and 130.
a unidirectional source of somewhat lower potential.
However, the electric ?elds in the treating spaces 78 serve
the primary function of preparing the dispersion for treat
ment in the treating spaces 85, as by coalescing an initial
portion of the dispersed particles so that these can sepa
rate gravitationally before the residual dispersion enters
the super-treating ?elds in the treating 5 aces 85. In
many instances alternating-current ?elds will su?'ice in the
treating spaces 78. In that event, the potential source
160 may be a high-voltage transformer. If its peak po
This is particularly important when it is remembered
that neither the interface 111 nor any of the correspond
ing interfaces should ever be allowed to rise into contact
with or submerge the lower portions 105 of the insulators.
The following description will indicate superior features
of the present invention in such respects.
As the vessel It} is being initially ?lled, the incoming
liquid will displace the gas in the upper end of the vessel
through suitable vents. So long as any of the perforations
of the collector pipes 32 remain not submerged, the gas
3,073,775
9
will escape therethrough, passing through the manifold
33 and out the pipe 38 through the now-open valve 39.
When these perforations are submerged, the gas may
escape for a period through a pipe 205 having its lower
open end depending into the tank to a level B——B. This
19
These principles will be clear from the embodiment of
FIG. 1 and also from the embodiment of FIGS.
4-7. In the embodiments of FIGS. 4 and 5, for
example, the treated oil is withdrawn through the per
forated pipes 32 and manifold 33 as before, but the in
coming dispersion is introduced substantially at the
median-volume radius of the vessel 10, e.g., at a radius
about two-thirds the radial distance from the axis A——A
to the cylindrical wall of the vessel. This introduction of
pipe opens into a larger pipe 206 in which is disposed a
housing 207 similar to the housing 124. The pipe 206
opens on the pipe 38 and discharges gas therein until
the liquid level in the tank rises above the level B—~B
to submerge the lower end of the pipe 205. Thereafter, 10 the dispersion is through side openings of pipe T’s 220
secured respectively to the outer ends of the pipes 26.
any gas entrapped in the upper end of the vessel can
The
plane of the side openings of each T 220 is sub
escape only through a weep hole 209‘ in the ?tting 36,
stantially horizontal and while short nipples or nozzles
entering the housing 94 and displacing liquid which may
may be threaded into these side openings, I prefer to
already have started to rise therein or in the ?tting 36.
discharge the dispersion directly from the openings pro
15
The valve 130 being closed, the interfaces 111 will form
vided by the side arms of the pipe TS and with substan
and rise in the respective housings 94, 136, 137, etc.,
tially no pressure drop due to ?ow through these open
as the pressure builds up in the vessel 10 to a value above
ings. Ordinarily, six or eight pipes 26 will be used so
atmospheric pressure. This rising pressure will compress
that the incoming dispersion will be well distributed at
the masses of gas entrapped in the housings. The internal
different circumferential positions within the vessel.
volumes of the housings are so designed, with reference
Alternatively, the outer ends of the pipes 26 may pro
to the operating pressure in the vessel 10', that the inter
vide
elbows 222 each providing a single side opening,
faces will assume approximately their ultimate positions
these side openings facing upwardly (FIG. 6) or down
in their respective housings merely by bringing the in
wardly (FIG. 7) or in some other direction.
terior of the vessel up to operating pressure. The sys
It is very desirable that the dispersion-discharge open—
25
tem for circulating the dielectric ?uid through the an
ings be relatively few in number, usually less than about
nular spaces of these housings can then be put into opera
sixteen, and that each of these openings be relatively
tion, the ?oat 121 and the valve 118 controlling the con
large, usually not less than about 1” in diameter and
tinuous ?ow to adjust and maintain the interfaces in the
typically 1~2”, so as not to develop any substantial pres
desired positions.
It is also desirable to de-energize the electrode units 30 sure drop. It is undesirable to jet the dispersion from the
pipes 26 at high velocity both because this increases the
should the level in the housings 94, 136, 137 and 207
turbulence in the entrance zone 23 and also because this
drop dangerously close to the upper end of the vessel 10.
requires a substantial pressure ‘drop in the distribution
To accomplish this, a ?oat 210 is disposed in the housing
system at the point of e?luence from the distributor.
207 and is operatively connected to ?oat switches 211
Such pressure drops have been found to induce clogging
35
and 212, respectively connected in the energizing circuits
of the system, as by depositing foreign material in the.
of the potential sources 160 and 161. The housing 207
discharge ori?ces so that they become progressively
is positioned below the normal position of the inter
clogged. In prior practice, it has often been customary
faces 111. If an air-oil interface should form in the hous
to employ a perforated-pipe distributor for the incoming
ing 207 and if this interface should drop sufficiently to
lower the ?oat 210, the potential sources 160 and 161 40 dispersion, this distributor having a large number of
small ori?ces. The pressure drop in such a system was
Will be immediately de-energized to avoid any danger
in the neighborhood of 0.5—3 pounds per sq. in. In prac
of explosion.
tice it has been found that materials from or carried by
Another important feature of the invention is the man
the incoming stream will tend to deposit in the distribu
ner in which the liquid is distributed to and withdrawn
from the vessel to create a rising column which ?ows 45 tion system, often acting progressively to block the dis
charge ori?ces and thus interfere with the previously
through the grid of'electrodes with substantially equal
desired introduction at a very large number of different
velocity at all radial positions. It has previously been
proposed that the incoming dispersion should be jetted
radial positions. Also in prior practice, it has sometimes
pipe system. The present invention proposes to introduce
In contradistinction, the present invention discharges
the dispersion through a relatively small number of rela
tively large outlets or openings so that the pressure drop
been proposed to withdraw the treated oil from a single
into the entrance zone 23, either ‘from a central distrib
utor or from a plurality of small holes in a perforated 50 outlet, there being very little pressure drop at this point.
the dispersion at a limited number of positions in a nar
row annular zone substantially at the median-volume
radius of the entrance zone 23, usually at a radial posi
at this point is usually no more than a few ounces, being
usually less than two ounces per sq. in. In the collector,
tion substantially two-thirds the distance from the axis
A-A to the cylindrical wall of the treater. At the same
time, the present invention contemplates use of a network
of perforated pipes in the exit zone 25, typically the
formed by the perforated pipes 32, the pressure drop
maybe in the neighborhood of 0.2-2.0 pounds per sq. in.
(3.2—32 ounces per sq. in.), making the pressure drop in
the collector at least about 1.646 times the pressure drop
in the distributor largely as a result of the intentionally
perforated pipes 32 previously described. Thus, while the
incoming dispersion enters the entrance zone 23 in_ a 60
small size of the openings through which the treated oil
rather narrow annular zone, the withdrawal of the treated
passes. A pressure drop at this point is not detrimental
oil from a pluarlity of radial positions and the passage of
and the concept of transferring the zone of pressure drop
the intermediate vessel-?lling stream through the an
from the inlet zone 23 to the discharge zone 25 is im
nular treating spaces 78 and 85 causes the rising stream
to flow with substantially equal velocity at all radial
positions. This action is assisted by the minute pressure
drop from end to end of the electrode structure. Thus,
even though the incoming dispersion is introduced pri
marily at the median-volume radius, the upward velocity
65
portant. Additionally, the distribution of ori?ces in the
perforated pipes 32 makes entirely practicable the dis
charge of the incoming dispersion in a relatively narrow
annular zone near the median-volume radius of the en
trance zone of the treater.
changes and modi?cations can be made with
of ?ow through the various treating spaces at different 70 outVarious
departing from the spirit of the invention as de?ned
radial positions will be substantially equal. By median
in the appended claims.
volume radius, I have reference to a radius such that the
I claim:
area inside the corresponding circle will substantially
1. A treating structure for the electrical treatment of
equal the area of the annulus around such circle within
oil~continuous
dispersions, said treating structure includ
75
the cylindrical portion of the vessel.
11
3,073,775
12
ing: a support means; a plurality of electrode members
spaces; mounting means for said electrode members of
having central portions secured to said supportmeans,
said central portions being formed of imperforate ma
said intermediate set comprising arms of electrically con~
ductive material extending from said vessel in the space
between said upper and lower edges through aligned
openings of the electrode members of said intermediate
set in mounting relation; and means for establishing a
potential difference between said electrode members of
said intermediate set and said electrode members of both
tcrial, said electrode members and said support means
comprising an intermediate electrode set, each electrode
member providing ?rst and second end portions extend
ing oppositely from said support means, the end portions
of each electrode member being extensions of said cen
tral portion thereof, the ?rst and second end portions
of the electrode members being respectively substantially 10
parallel to an axis and spaced from each other to de?ne
unobstructed spaces facing away from said support
means; a ?rst and second auxiliary electrode set each
most cylindrical electrode, said arms providing inner ends
terminating at and welded to said innermost cylindrical
electrode.
7. An electric treater as de?ned in claim 5 in which all
of said electrode members are metal cylinders concentric
with a vertical axis, and in which the electrode members
comprising a plurality of substantially parallel electrode
members spaced from each other distances substantially
equal to the spacing from each other of said ?rst and
second end portions of the electrode members of said
intermediate electrode set; means for mounting said ?rst
and second auxiliary electrode sets with their electrode
members respectively extending into and substantially bi
secting said unobstructed spaces of said first and second
end portions to form ?rst and second sets of treating
spaces spaced along said axis; means for ?owing a stream
of the dispersion through said sets of treating spaces in
sequence; and means for applying a potential difference
between said intermediate electrode set and each of said
auxiliary electrode sets to establish electric ?elds in said
said upper and lower sets.
6. An electric treater as de?ned in claim 5 in which all
of said electrode members are metal cylinders, and in
which said intermediate electrode set includes an inner
20
of said intermediate set include radially aligned openings
of rectangular shape each greater in height than width,
said arms being correspondingly rectangular in cross
section, said arms extending through said aligned open
ings and being welded to said electrode members of said
intermediate set to rigidity said intermediate electrode set
against sagging at its center.
8. In combination with spaced parallel electrodes de
?ning upright side-by-side interelectrode treating spaces
sets of treating spaces.
within a vessel of a high-voltage electric dispersion treater,
2. A treating structure as de?ned in claim 1 in which
the
interelectrode treating spaces having high-voltage
all of said electrode members and said end portions of 30 electric ?elds therein coalescing the dispersed-phase ma
said intermediate electrode set are thin cylindrical mem
terial of an oil-continuous dispersion containing a small
bers concentric with said axis, the electrode members of
said ?rst and second auxiliary sets providing edges facing
but spaced from each other, the edges of said ?rst and
percentage of such material dispersed in the oil phase of
the dispersion, the coalesced material largely separating
from the dispersion while in said electric ?elds and col
second auxiliary sets being on opposite sides of said sup
' lecting as a body in the bottom of said vessel leaving a
port means and facing same.
treated oil having a substantially smaller content of such
dispersed-phase material rising in the upper ends of said
interelectrode treating spaces, an arrangement for mini
mizing the pressure drop applied to the dispersion and
3. A treating structure as de?ned in claim 1 in which
the electrode members of said auxiliary electrode sets
provide edges on opposite sides of said support means
facing but spaced from each other, said support means
comprising narrow widely-separated arms traversing and
inducing a substantial pressure drop on the treated oil
to equalize the upward ?ows in said interelectrode treat
welded to said central portions of said electrode members
ing spaces, said arrangement including: a dispersion
of said intermediate electrode set so as to offer substan
discharge pipe means in a lower portion of said vessel
tially no impedance to the ?ow of said stream of disper
sion, said edges being spaced from said arms.
4. A treating structure as de?ned in claim 3 including
having a relatively small number of relatively large
45
diameter dispersion-discharge openings communicating
with the lower ends of said treating spaces; means for
means for electrically insulating each of said auxiliary
inducing a pressure drop on said treated oil at least about
electrode sets from said vessel and from each other, two
1.6_l6 times the pressure drop across said discharge
potential sources each having a ?rst terminal and a second
openings, said last-named means comprising a treated-oil
high-voltage terminal, means for connecting said ?rst 50 collection means in an upper portion of said vessel, said
terminals together and to said intermediate electrode set,
collection means including a larger number of treated
and means for electrically connecting said high-voltage
terminals respectively to said auxiliary electrode sets.
5. In an electric treater for oil-continuous dispersions,
the combination of: a closed vessel having in?uent and
ei?uent means; an upper electrode set comprising a plu
rality of depending electrode members substantially paral
lel to an axis and spaced from each other, said depending
electrodes having lower edges; a lower electrode set pro
viding a plurality of tip-standing electrode members spaced
from each other and substantially parallel to said axis,
said upstanding electrode members being respectively
below the electrode members of said upper electrode set,
said tip-standing electrode members having upper edges
spaced from said lower edges of said depending elec
trodes; means for electrically insulating each electrode
set from said vessel; an intermediate electrode set com
prising a plurality of electrode members of impervious
material substantially parallel to said axis, each electrode
member of said intermediate set providing an upper por
tion nested between the depending electrode members of
oil-receiving exit openings in communication with the
upper ends of said treating spaces and receiving said
treated oil, said exit openings being of smaller cross
sectional size than said discharge openings, said pressure
drop-inducing means including a pump means supplying
the dispersion to be treated to said dispersion-discharge
pipe means at a rate to create a small pressure drop across
said dispersion-discharge openings and said pressure drop
of at least about 1.6-16 times higher across said exit
openings; means for conducting the thus-collected treated
oil from said collection means to a position outside said
vessel; and means for Withdrawing the coalesced and
separated material from said body thereof.
9. A combination as de?ned in claim 8 in which the
cross-sectional size of said discharge openings are such
as to create a pressure drop of less than about 2 oz./sq. in.
thereacross, and in which said exit openings are of a size
to create a pressure drop about 2-2.0 lbs/sq. in. there
across.
lO. A combination as defined in claim 8 in which each
said upper set to de?ne an upper series of treating spaces,
of said discharge openings is of a diameter not less than
each electrode member of said intermediate set providing
about 1 inch.
a lower portion nested between said electrode members
of said lower set to de?ne a lower series of treating 75
(References on following page)
3,073,775
14
13
References Cited in the ?le of this patent
Worthington __________ __, Mar. 10,
Bailey _______________ __ Dec. 22,
Stenzel _______________ .._ Oct. 7,
Turner _______________ __ July 14,
2,033,167
UNITED
Harris ________________
STATES PATENTS
__ June 2, V
2,894,895
1,838,822
Gassaway _____________ __ Dec. 29, 1931
,5
1,838,847
Lawrason ____________ __ Dec. 29, 1931
*
’
’.
1,838,925
Fisher _____________ _,___ Dec. 29, 1931
472,511
2,033,129
Eddy ______________ ____ Mar. 10, 1936
515,455
'
1936
1953
1958
1959
FOREIGN PATENTS
'
Italy _________ _; ______ .._ June 23, 1952
Germany ___y__.___l_ ____ __ July 5, 1935
_
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