Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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This invention relates to a gravity separator for
separating two dissimilar liquids having different specific grav-
ities. The gravity separator is specifically useful for separating
insoluble oil and water on a continuous basis.
The separators presently known for separating non-soluable
oil and water are of varied types utilizing such as a centrifuge;
settling tanks; various filter systems and baffle systems and the
like, each known system, however, being of relatively large di-
mensions or alternatively being relatively complicated for the
required process.
The gravity separator of this invention is of extremely
simple construction and consists of a vertically oriented cylinder,
an inlet through the side wall of the cylinder in the central
region thereof, an outlet at the top of the cylinder and an outlet
at the bottom of the cylinder. A sight gauge is preferably
utilized, this being installed at the top half of the cylinder.
If automatic operation of the separator is required, a sensor can
be inserted in the top half of the cylinder for controlling both
outlet valves to achieve maximum separation of oil and water.
The invention will now be described with reference to
the accompanying drawings in which:
Figure 1 is a front elevation of the gravity separator;
Figure 2 is a side elevation of the gravity separator
of Figure l;
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Figure 3 is a plan view of the gravity separator of
Figure l;
Figure 4 is a sectional elevation on the line 4-4 of
Figure 2.
Referring to the Figures, a metal cylinder 1 has a
hemispherical base 3 and a partly hemispherical top 5 which is
formed to accept a cover 7. The cover 7 has an annular groove 9
for an O-ring 11, and a pair of lugs 13. A pressure block 19 is
secured diametrically to the upper central portion of the cover. A
pair of pins 15 are secured by welding or the like to the top of
the cylinder and inverted U-shaped retainers 21 are secured to the
top of the cylinder at right angled positions to the pins. The
cover is therefore attached to the top of the cylinder by placing
it in position, rotating it so that lugs 13 pass under the heads of
pins 15, then placing rod 23 which has a central camming region,
through the U-shaped retainers 21 and over the pressure block 19
such that rotation of rod 23 by lever 25 will tightly secure the
cover. An air bleed 24 is located in the cover 7.
The cylinder 1 is held in vertical operating position
upon a stand 27 which is welded in place to the bottom of the
cylinder, and itself is bolted to a base plate 29.
An inlet ferrule 31 is welded into the side of the cylin-
der and has, threaded into its inner end, a pipe 33 which is
divergent and extends so as to exit the inlet mixture relatively
close to the opposite side of the cylinder wall from ferrule 31.
An outlet for liquid having the highest specific gravity is position-
ed at the bottom of the cylinder to ferrule 35 which is welded into
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the bottom 3 of the cylinder. This outlet is fitted with a valve
37. A drain-out plug 39 is fitted in a ferrule 41 which is welded
into the centre of the bottom 3.
An outlet 43 for the low specific gravity liquid is lo-
cated near the top of the cylinder being secured to a ferrule 45
which is welded in the wall of the cylinder. At the inner end of
the ferrule 45, -there is secured an elbow 47 and a short stand
pipe 49 so that the liquid removed is from the top of the cylinder.
The outlet 43 has a valve 51 for controlling the flow and for
convenience an ex-tension pipe 53 and a tee secured to the bottom
thereof for bringing the upper outlet down to a more convenient
place for coupling further piping thereto. A pressure gauge 57
is utilized for determining the pressure in the gravity separator,
and this is shown in a convenient position on the upper outlet 43.
A sensor 59 can be utilized if required for determining the oil/
water interface and controlling, through suitable control pipes 61,
the operation of the valves 37 and 51. Obviously, the valves 37,
51 will in such instance have to be solenoid operated or pneumatic
valves depending upon the type of sensor utilized.
In order to determine the position of the oil/water
interface, a sight gauge 63 is utilized, this being of a conventional
type.
The operation of the gravity separator is as follows:
An oil/water mixture pipe is coupled to ferrule 31, a
water removal pipe to valve 37 and an oil removal pipe to tee 55.
The oil/water mixture is then fed to the inlet and as the mixture
enters cylinderl air is bled out through air bleed 24. When the
cylinder 1 is full the air bleed is closed and valve 37 is opened
so letting liquid flow from the water removal pipe and permitting
oil/water mixture to enter through inlet pipe
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33. The mlxture impinges on the wall of cylinder 1, the velocity
being reduced because of the divergent shape of pipe 33. This
reduced inlet velocity lessens turbulence and contributes to gravity
separation. The water tends to drop towards the bottom of cylinder
1 and the oil floats to the top. The sight gauge 63 is observed
and when the oil/water interface is seen to approach the central
portion of the sight gauge, valve Sl is opened to permit oil to
flow from cylinder 1. It will be seen that, if a consistent mixture
of oil/water is being received through inlet ferrule 31, it should
be possible to set the valves 37 and 51 at a certain opening so that
a continuous steady operation is obtained.
If a sensor 59 is used with the gravity separator, both
valves 37 and 51 will be operated, for instance by solenoids. To
operate the system utilizing the sensor 59, solenoid valve 37 will
be fully opened and as the oil/water interface drops in the cylinder
1, it eventually reaches the sensor probe, so that when the sensor
probe senses oil, valve 37 is closed and valve 51 is opened to
discharge oil. When a certain amount of oil is discharged, the
sensor closes valve 51 and opens valve 37, so repeating the cycle.
Extra sensors can be included to provide limits to the oil/water
interface range of travel, or a timing system can be included,
however it is normally found that such extra controls are not
necessary for the proper operation of the gravity separator.
It has been found that by utilizing a cylinder approxi-
mately 3 1/2 ft. by 10 inch diameter, it is possible to separate
approximately 8 Imperial gallons per minute of water/oil mixture
when operating at a pressure of approximately 60 lbs. per square
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inch gauge.
It is thus seen that a very simple and efficient gravity
separator has been invented which requires no baffles or settling
tanks, and is of small dimensions fo:r the output achieved.
