Note: Descriptions are shown in the official language in which they were submitted.
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VESSEL CONSTRUCTION
TEC~INICAL FIELD
The present invention relates to the construction of a
vessel, container, or tank. More particularly, the invention re-
lates to the provision of a detachable section of the wall o-F the
vessel to provide ready access to the interior.
EACKGROUND ART
In the production of oil well fluids, vessels are pro-
vided to receive these fluids and provide time and structure to
separate the coMponents of the produced fluids in reducing the
cost of distributing and transporting the separated fluids to other
processes. Representative of these vessels is the somewhat plebian
free water knockout (FWK). This vessel is little more than alarge
volume in the line providing enough residence time to enable the
first gravity disengagement between water and oil to take place.
Water loosely bound to the oil "-Falls" freely to the bottom of the
vessel, thus giving rise to the descriptive term FWK. The water
and oil, roughly separated, are individually passed to downstream
processing equipment. An interface is formed between the oil and
water in the FWK. The height of this interface is sensed by a
float for controlling a valve in the outlet conduit for water. A
subvessel is mounted in the upper portion of the parent vessel to
receive the oil and control its discharge to downstream processing
equipment. Little economy has been practiced in the construction
of this subvessel, usually referred to as the "oil skimmer". It is
common practice to weld plates together to form a box and mounting
it in some convenient fashion in the upper portion of its parent
vessel and providing an opening near its top through which oil
spills into the interior. A level control may be provided within
the skimmer and a valve in the outlet line from the skimmer is con-
trolled by connection to this level sensor.
The recent tide of economy sweeping through the oil field
has caused reexamination of the oil skimmer. Recogrlizing that it
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is difficult to get into the present skimmer for coating, cleaning
and adjustment of its level control, has stimulated this inventor.
There is need for a basic change in configuration of this vessel
which will provide more ready access to its interior and an over-
all economical construction.
DISCLOSURE OF THE INVENTION
The present invention contemplates a vessel basically
formed by rolling a single sheet of metal into cylindrical form,
bringing the adjoining edges of the sheet together along its upper
length. The adjoining edges at either or both ends are not con-
nected. One end of the cylinder receives a circular plate just
within the interior surFace of the cylinder and oriented normal to
the axis of the cylinder, the adjoining but free edges of the
cylinder being secured to clamp the circular plate .as an end wall
of the vessel.
The invention further contemplates an opening at the ad-
joining edges of the cylinder to receive liquid, the adjoining
edges attached to each other through a nut and bolt which will draw
the adjoining edges toward each other and clamp the circular plate
within the interior surface of the cylinder while a seal body is
arranged between the edges of the circular plate and the interior
surface of the cylinder walls.
Other objects, advantages and features of this invention
will become apparent to one skilled in the art upon consideration
of the written specification, appended claims, and attached drawings.
BRIEF DESIGNATION OF THE DRAWINGS
Fig. 1 is a sectioned elevation of a free water knockout
vessel and a subvessel mounted in the upper portion of its parent
vessel, having a structure embodying the present invention, and
Fig. 2 is an exploded perspective of the subvessel.
BEST MODE FOR CARRYING OUT THE INVENTION
The FWK Parent Vessel
In Fig. 1, the paren-t vessel, the FWK, is disclosed as a
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cylindrical vessel 1 horizontally extended. The cylindrical ves-
sel is, essentially, comprised of a shell 2 with heads 3 and 4
welded to the ends of shell 2. An inlet 5 is a conduit From a
producing well through which a mixture of oil and water is re-
ceived by the FWK. Sufficient residence time is provided by the
size of FWK 1 to enable an interface 6 to form between the lower
body of water 7 gravity-separated from the upper body of oil 8. A
float 9 represents any means with which to sense the interface
level and control a valve 10 in a water outlet conduit 11. As the
interface 6 elevates above a certain height, the valve 10 is opened
and water is drawn from body 7 through outlet conduit 11.
In the fabrication oF FWK 1, the volume will be estab-
lished by the expected quantity of the oil and water mixture re-
ceived. The thickness and composition of the metallic walls will
be determined by the pressure at which the mixture is received.
It is common to refer to these FWK's dimensionally by their diam-
eter and length, followed by the working pressure which establishes
their wall thickness.
Turning to the control of oil discharged from body 8, a
skimmer vessel 15 is mounted in the upper part of the FWK 1 to re-
ceive this oil and control its discharge. As the level of oil
body ~ above the interface 6 rises, oil from the body spills~ or
skims, into subvessel 15. The collection 16 of oil in skimmer 15
is withdrawn through conduit 17 under the control oF a valve 18
connected to a detector 19 sensing the level of oil in skimmer 15.
With the overall function of the FWK 1 and skimmer 15 un-
derstood, attention is Focused upon the construction of skimmer 15.
Oil Skimmer 15
Both Fias. 1 and 2 may be used to follow the disclosure
of the construction of skimmer 15 under the concepts of the present
invention. The -Function of the oil skimmer 15 and its relation to
its parent vessel is the same as prior art oil skimmers. It is the
construction of this subvessel that embodies the present invention.
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As can be seen from both figures, the skimmer 15 is
basically formed from a single rectangular sheet 20. Sheet 20 has
been rolled into the form oF a cylinder, edges 21 and 22 adjoining
each other at the top of the cylinder as the cylinder is held in
a horizontal orientation. Thus, to begin with, the cumbersome
welding of plates to form a square-sided box of an oil skimmer has
been radically revised. In the actual reduction to practice of
the invention, sheet 20 needs only to be formed from 10-gauge
sheet metal.
To mount oil skimmer 15 within its parent vessel, the
first end of the cylinder 20 is welded to an interior side of the
FWK 1. As disclosed in Fig. 1, the interior surface of head 3 is
specifically utilized for mounting the skimmer vessel. It is only
necessary to shape the First end of the cylindrical skimmer so
that when it is welded to the interior head 3, the resulting
cylinder 20 will extend horizontally from the FWK head. The oil
outlet conduit 17 is then arranged to penetrate head 3 to communi-
cate with the interior of skimmer 15.
The second end of skimmer 15 is closed by a circular
plate 23. This plate 23 can be made of slightly heavier gauge
than that of sheet 20, sufficiently heavy to withstand buckling
under the compression necessary to clamp the plate by the walls of
sheet 20. A gasket or seal body 2~ is provided between the edge
of plate 23 and the interior of -the wall of sheet 20 to ensure a
liquid seal for the resulting container forming skimmer 15. To
clamp the circular plate 23 into orientation normal the axis of the
cylinder formed by sheet 20, lugs 25 and 26 are mounted on the ex-
ternal surface of sheet 20 at adjoining edges 21 and '22. A bolt
27 is extended through aligned holes formed in the lugs and a nut
2~ is threaded onto the bolt to bring the lugs toward each other
and thereby clamp circular plate 23 into the position disclosed.
With a wall of the FWK forming the first end of cylindri-
cal skimmer 15, and clamped plate 23 Forming the second end~ an
opening 30 at the adjoining edges 21 and 22 may be formed on the
top of skimmer 15. This opening 30 provides a spill-over entry
into the skimmer for oil as i-ts level reaches the height of open-
ing 30. The withdrawal of oil from the amount collected within
the skimmer -Follows the present art. However, the construction of
skimmer 15 disclosed in the drawings provides ready access to its
interior for any coating needed to protect it from corrosion by
the fluids. Further, the nut and bolt with which plate 23 is
clamped into position may be readily disconnected and plate 23 re-
leased to provide access to the interior of the skimmer For subse-
quent cleaning, or adjustment oF the level detector controlling
discharge oF the oil from the FWK.
Concluding Observations
The present invention was conceived within the womb oF
the FWK; however, now that its period of gestation is over, there
is no longer need for the invention to lurk solely within the
; Stygian of the upper reaches of the FWK. The idea is ready to be
brought kicking and screaming into the world.
Wherever construction is needed to produce a vessel from
a rectangular sheet oF material formed into a cylinder sealed at
its ends, the present invention has utility. All that is required
is that parallel edges of the sheet brought -to each other as the
sheet is formed into a cylinder have sufficient freedom at each
end so they may be sprung apart to allow a circular plate entry in-
to the end of -the cylinder. The edges can then be brought toward
each other to grip the plate at its periphery and thereby complete
the closure of the vessel. Of course, a seal body between the
edges of the circular plate and the inner surfaces of the cylinder
can be provided. The result is a vessel closure which can be re-
moved by disconnecting whatever fas-tening means has been provided
between the adjacent edges of the cylinder. The sole limitation
is that the edges must be provided with the freedom to enable the
circular plate to be positioned within the cylinder for clamping.
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Therefore, normal entry into the vessel for the oil will be
through an opening at its top, preferably oriented between the
edges which are adjacent to each other and which are not sealed.
From the foregoing, it will be seen that this invention
is one well adapted to attain all of the ends and objects herein-
above set forth, together with other advantages which are obvious
and inherent to the apparatus.
It will be understood that certain features and subcom-
binations are oF utility and may be employed without reference to
other features and subcombinations. This is contemplated by and
is within the scope of the invention.
As many possible embodiments may be made oF the invention
without departing from the scope thereo-F9 it is to be understood
that all matter herein set forth or shown in the accompanying draw-
ings is to be interpreted in an illustrative and not in a limiting
sense.
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