Note: Descriptions are shown in the official language in which they were submitted.
CA 02639520 2008-09-09
CONTAINMENT DEVICE AND METHOD FOR USE IN CLEANING OF AN OIL
TANK
This invention relates to a device and method for use during cleaning
of an oil tank, and more particularly to a method and device for capturing
materials
exiting such a tank through an access opening therein during cleaning
procedures
relying on access to the tank's interior through this opening.
BACKGROUND OF THE INVENTION
Oilfield production tanks are often cleaned by one or a combination of
(a) running a stinger back and forth within the tank interior through the
manway or
access opening of the tank to flush out the bottom of the tank; (b) mounting a
water
cannon at the manway and delivering high pressure fluid thereto from a water
truck
or other suitable high pressure source to jet or spray down the interior of
the tank;
and (c) entering the tank interior through the manway with a pressure washer
to
rinse down the tank walls with water or chemical cleaners. Materials loosened
from
the tank interior during such processes are typically removed through a
discharge
line, such as the hose of a vacuum truck. To minimize environment
contamination, it
is desirable to prevent debris or material from reaching the ground of the
surrounding environment through the manway or access opening of the tank.
SUMMARY OF THE INVENTION
According to a first aspect of the invention there is provided a
containment device for installation on an access opening of an oil tank to
contain
materials exiting the oil tank through the access opening during cleaning, the
containment device comprising:
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a collection body having a hollow interior, a closed bottom, a top,
opposing front and rear ends and opposing sides interconnecting said front and
rear
ends, the containment body being open at the front end and closed off at the
rear
end and sides by upwardly extending respective wall sections;
the front end of the containment cavity being arranged for removable
mounting to the tank to communicate the access opening of the oil tank with
the
hollow interior of the collection body at the open front end thereof so that
the
collection body projects outward from the oil tank from about a bottom portion
of
access opening therein.
Preferably there is provided gasket material installed on the front end
of the collection body to extend along the bottom of the collection body and
the sides
thereof at the front end for sealing against the tank below and to the sides
of the
access opening therein.
Preferably there are provided mounting elements projecting outward
from the open front end of the collection body along the bottom of the
collection body
and the sides thereof to support the gasket material.
Preferably there is provided an openable lid positioned at the top of the
collection body and movable between open and closed conditions respectively
opening and closing off the top of the collection body.
Preferably the openable lid comprises first and second lid portions, the
closed condition of the lid positioning the first lid portion to extend from
the rear end
of the collection body toward the front end thereof and position the second
lid portion
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to extend upward from the first lid portion to position an upper end of the
second lid
portion over the open front of the collection body.
Preferably, with the lid in the closed condition, the second lid portion
slopes upwardly and toward the open front end of the collection from a
distance
therefrom.
Preferably the lid portions are movably attached to one another to
facilitate lowering of the upper end of the second lid portion away downward
from
over the front of the collection body toward the first lid porition.
Preferably the first lid portion is pivotally supported at the rear end of
the collection body for pivoting of the lid portions together over the rear
end of the
collection body to open the top of the collection body.
Preferably there is provided a cleanout opening communicating the
hollow interior of the collector body with an exterior thereof and arranged to
allow
passage of a vacuum hose into the interior of the collection body.
Preferably there is provided a cover movably supported on the
collection body for movement between open closed position closing off the
cleanout
opening and an open position allowing access thereto.
Preferably the cleanout opening is provided in the lid.
Preferably the cleanout opening is provided in the first lid portion of the
lid.
Preferably there is provided a seal disposed about the cleanout
opening to seal against the vacuum hose when passed therethrough.
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Preferably there are provided clamping mechanisms operable to clamp
the collection body to a flange surrounding the access opening of the tank.
Preferably the collection body is smaller in height than the access
opening of the tank so as to leave a top portion of the access opening
unobstructed
by the collection body.
Preferably there is provided at least one hanger element connected to
the collection body proximate the front end thereof and defining a respective
hook by
which the collection containment device can be hung from a top end of the
access
opening.
Preferably each hanger elements comprises a slidable arm on which
the respective hook is carried, the slidable arm being lockable in an extended
position projecting upward from the collection body further than a retracted
position.
Preferably the collection body comprising handles positioned exteriorly
on the opposing sides thereof.
According to a second aspect of the invention there is provided a
method of cleaning an oil tank having an access opening therein, the method
comprising the steps of:
(a) installing a containment device according to any one of claims 1 to
19 on the tank;
(b) passing a stinger through an open top portion of the collection body
of the containment device into an interior of the tank and operating the
stinger to
flush materials from the tank into the hollow interior of the collection body
through
the access opening of the tank and the open front end of the collection body;
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(c) removing the materials flushed into hollow interior of the collection
body; and
(d) uninstalling the containment device from the tank.
Preferably the method includes, prior to step (d), mounting a high
5 pressure fluid line at the access opening of the tank above the containment
device,
closing the open top portion of the collection body and spraying down the
interior of
the tank through the access opening from a position above the containment
device.
Preferably the step of mounting the high pressure fluid line comprises
mounting a covering to the tank in a position over the containment device and
passing the high pressure fluid into the interior of the tank through an
opening in the
covering to substantially close off the access opening entirely.
Preferably the method includes, prior to step (d), entering the interior of
the tank through the open top portion of the collection body and spraying down
the
interior of the tank from within, once having removed the covering, if used,
from the
tank to reopen a portion of the access opening positioned above the
containment
device.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings, which illustrate exemplary
embodiments of the present invention:
Figure 1 is a side elevational view of a containment device according
to an embodiment of the present invention installed on the manway of an oil
storage
tank with a lid and cleanout cover of the device each closed.
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Figure 2 is an overhead plan view of the containment device of Figure
1.
Figure 3 is an overhead plan view of the containment device with the
lid closed and the cleanout cover opened.
Figure 4 is a side elevational view of the containment device with the
lid in an intermediate position during opening thereof.
Figure 5 is a side elevational view of the containment device with the
lid fully opened.
Figure 6 is an overhead plan view of the containment device in
isolation with the lid fully opened.
Figure 7 is an overhead plan view of a frame of the containment device
with walls of a collection body of the containment device shown in broken
lines.
Figure 8 is an end view of the containment device showing connection
end thereof at which the device connects to the tank.
Figure 9 is a cross sectional view of a hanger of the containment
device.
Figures 10A and 10B show a clamping mechanism of the containment
device installed on a vertical front member thereof as they would be seen from
a
side of the containment device and a rear end thereof respectively.
Figures 11 A and 11 B are partially cross sectioned and side elevational
views respectively of an alternate embodiment hanger of the containment
device.
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DETAILED DESCRIPTION
Figure 1 shows a containment device 10 installed on a conventional
oilfield production tank 200 having a rectangular manway 202 defining an
access
opening through the tank wall into the tank interior. The containment device
features
a frame 11 releasably mounted to the manway frame at a perimeter flange 204
thereof, which in a conventional manner projects outward around the manway
opening on all four sides thereof at a distance outward from the tank wall to
present
surfaces facing outwardly away from the tank interior for fastening of a
removable
manway cover to the flange by engaging threaded fasteners through holes in the
flange spaced about the manway opening with aligned holes in the manway cover.
The frame 11 of the containment device 10 carried a collection body 12 having
a
hollow interior surrounded on three of its four sides by a rear end wall 14
and a pair
of matching parallel sides walls 16. A planar bottom 18 of the collection body
12
closes off the hollow interior of the collection body 12 from below, with a
movable lid
assembly 20 allowing selective opening and closing of a top end of the
collection
body 12. When installed on the manway of an oil storage tank, as shown in
Figures
1 to 5, the hollow interior of the collection body communicates with the
manway
opening through an open front end of the device opposite the rear end wall 14
over a
full width of the manway at the bottom thereof such that oil, sand, water,
cleaning
fluids or other materials that may tend to pass through the manway opening
from the
tank interior during cleaning flow into the hollow interior of the device's
collection
body 12 rather than spilling onto the ground 300 around the tank, thereby
avoiding
environmental contamination.
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The frame 11 of the collection device 10 features a pair of matching,
parallel, and vertically oriented front end frame members 22 are
interconnected at
their bottom ends by a horizontally oriented front end frame member 24, as
best
seen in Figures 7 and 8, such that the vertical and horizontal front end frame
members 22, 24 close around three sides of a rectangular area. To one side of
the
plane in which this rectangular area lies, in a horizontal direction
perpendicular
thereto, a pair of parallel side frame members 26 project an equal distance
from the
horizontal front end frame member 24 at the positions therealong at which the
vertical front end frame members 22 project upward therefrom. At aligned ends
of
the side frame member 26 opposite the front end members 22, 24, a rear end
frame
member 28 horizontally interconnects the side frame members 26. When viewed in
plan, such as in Figure 7, the bottom front end member 24, opposed side
members
26 and rear end member 28 delimit a rectangular area.
In the illustrated embodiment, the front end frame members are each
formed of rectangular tubing, while the side and rear frame members are each
formed of angle iron, each frame member thus having a linearly extending
elongate
structure extending along a respective longitudinal axis. The angle iron side
and
rear end members 26, 28 are each oriented so that its two perpendicular legs
(in
cross section) define a vertical leg 26a, 28a and a horizontal leg 26b, 28b
projecting
horizontally inward relative to the rectangular area bound by these angle iron
members 26, 28 and the horizontal front end member 24 when viewed in plan.
With
reference to Figure 8, the angle iron side and rear end members 26, 28 are
connected to each other and to the front end frame members 22, 24 at such
relative
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elevations that the horizontal ledges defined by the horizontal (egs 26a, 28a
of the
angle iron members 26, 28 are coplanar, with their upper surfaces flush with
the flat
upper surface 24a of the horizontal front end. Still with reference to Figure
8, these
horizontal surfaces thus define a flat support system atop which the bottom
panel 18
of the collection body 12 can sit. The angle iron side and rear end members
26, 28
are connected to each other and to the front end frame members 22, 24 also
such
that the rear end member 28 is parallel to the front end horizontal member 24
and
the together-facing surfaces of the side members' vertical legs 26a are flush
with the
together-facing surfaces 22a of the vertical front end members 22 that define
opposing sides of the rectangular area bound on three sides by the front end
members 22, 24.
The collection body, when so rested atop the horizontal support
provided by the frame, spans generally fully from the vertical leg 28a of the
rear end
frame member 28, against which the collection body rear wall 14 sits, to the
front-
facing side of the horizontal front end frame member 24 opposite the rear end
member 28. The planar open front end of the collection body 12 is situated
generally coplanar with the flush front-facing sides 22b, 24b of the front end
frame
members 22, 24 opposite the sides thereof from which the side members 26
projects. The collection body 12 also spans generally fully between the
vertical legs
26a of the side frame members 26, against each of which a respective one of
the
collection body's planar vertical sidewalls 16 sits. When the collection body
is so
installed to fit into the frame 11, it is permanently fastened thereto. and
sealant is
applied between the collection body side walls 16 and the vertical front end
frame
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members 22 and between the coliection body bottom and the horizontal front end
member to provide a tight seal between the frame 11 an the collection body 12
at
the open front end thereof.
A gasket 30 is fixed to the front-facing sides 22b, 24b of the tubular
5 front end frame members 22, 24 to extend fully therealong in a U-shaped path
about
the bottom and up the sides of the collection body's open front end. The
distance
between the vertical front end members 22 is selected so that each can be
aligned
with a respective one of the two opposing vertical portions of the tank's
manway
flange 204 for face-to-face engagement of the front-facing sides 22b of the
vertical
10 front end members 22 with these vertically elongated manway flange portions
with
the gasket 30 therebetween. During installation of the containment device, the
height of its frame 11 is also adjusted to align the front-facing side 24b of
the
horizontal front end member 24 with the corresponding horizontally extending
bottom portion of the rectangular manway's flange 204.
On the laterally outward side 22c of each vertical front end member 22
facing away from the other vertical front end member is provided a pair of
clamping
mechanisms 40 for securing the containment device to the manway flange 204 of
the tank 200 on which the device is to be used. Each mechanism features a
threaded rod 42 extending through a channel ear or lug 44 projecting
horizontally
outward from this laterally outward side 22c in a direction opposite the other
vertical
front end member 22. The channel ear 44 has a straight sided U-shape defining
a
channel or passage 44a between itself and the outward side 22c of the vertical
front
end member 22 from which it projects. This channel or passage 44a extends
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horizontally and normal to the plane of the flush front-facing surfaces 22b,
24b of the
front end members 22, 24 and the rectangular area partially bound thereby. The
channel or passage 44a defined by the ear or lug 44 has a horizontally
elongated
rectangular cross section of sufficient height to allow the threaded rod 42 to
pass
horizontally through the channel 44a and be rotatable therein and slidable
along the
longer dimension of the passage's cross section.
Disposed around the rod 42 on the side of the vertical front end
member 22 opposite the gasket-equipped front facing side 22b is a cylindrical
tube
43 of circular cross section. The tube 43 features a handle 46 that is located
proximate an end of the tube 43 opposite the ear or lug 44 and is manually
operable
to effect rotation of the tube 43 about the tube's central longitudinal axis,
about
which the tube's cross section closes. As illustrated, the handle 46 may be of
a
known type conventionally used in clamps and vices, comprising a bar slidably
disposed within a diametrical through-hole in the tube 43 and having an
enlarged
cross section at each end to prevent sliding of the bar fully out from the
diametrical
through-hole. A nut 45 is fixed to the tube 43 at the end thereof nearest the
ear or
lug 44 so as to be concentric with the tube 43 and threadingly receive the rod
42
within it. At the end of the threaded rod 42 on the side of the ear or lug 44
opposite
the tube 43, the rod 42 carries a clamping plate 48 that is fixed to the rod
42 and
projects radially outward relative thereto. The nut 45 engaged about the
threaded
rod 42 and the tube 43 to which the nut is fixed have outer diameters larger
than the
height of the channel ear's channel or passage 44a, so as to give them
dimensions
incapable of allowing passage of the nut and tube into and through the passage
44a.
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Similarly, the clamping plate 48 positioned within a vertical plane has
dimensions
exceeding those of the passage's cross section to prevent entry thereto.
To install the containment device on the tank 200, the clamp
mechanisms 40 are first loosened on each side of the device by holding either
the
clamping plate 48 and attached threaded rod 42 or the tube 43 and attached nut
45
rotationally stationary about the axis shared by the engaged rod 42 and nut 45
while
rotating the other of these two assemblies in a loosening direction causing
withdrawal of the rod 42 from the nut 45, for example by holding the clamping
plate
48 stationary while rotating the tube and nut via the handle 46 to move the
clamping
plate 48 away from the respective front end vertical frame member 22. Under
sufficient loosening of the threaded rod 42 and nut 45 to nearly or completely
withdraw the end 42a of the threaded rod 42 opposite the clamping plate 48
from the
tube 43, but without disengaging the rod 42 from the nut 45, pushing the
handle-
equipped tube 46 toward the channel ear 44 to abut the nut 45 thereagainst
slides
the threaded rod through the ear's channel so that the horizontal distance
from the
channel ear 44 to the clamping plate 48 exceeds the combined thickness of the
containment device's gasket 30 and the manway flange 204.
The rotational position of each threaded rod 42 is adjusted such that
the elongated dimension of the respective rectangular clamping plate 48 hangs
vertically downward from the respective end of the threaded rod 42 and the
position
of each threaded rod 42 along the cross section of the ear or lug's channel is
adjusted to position the rod at the distal end of the ear channel opposite the
respective front end vertical frame member 22. These actions maximize the
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horizontal space between the clamping plates 48 on opposite sides of the
containment device to accommodate the manway 202 and manway flange 204
between them during installation of the containment device on the tank 200.
The
frame 11 and the collection body 12 mounted thereon is elevated off the ground
300
in front of the manway 202 and moved about as needed to generally align the
vertical and horizontal front end frame members 22, 24 of the containment
device
with the vertical sides and horizontal bottom of the manway flange
respectively.
These generally aligned objects are brought together to bring the gasket 30
into
contact against the respective portions of the manway flange 204 and position
the
clamping plates 48 of the clamping mechanisms 40 on the side of the manway
flange 204 opposite the frame 11 and collection body 12 of the containment
device
10, the manway and flange being disposed between the clamping plates on the
opposite sides of the containment device. Each clamping plate 48 is then
rotated so
as to project toward the respective clamping plate on the opposite side of the
containment device. This, together with sliding movement of the rod 42 and the
nut
45 and tube 43 engaged therewith toward the respective front end vertical
frame
member 22 within the channel or passage defined by the ear or lug 44, if
needed,
positions the distal end of the clamping plate 48 behind the manway flange
204.
The clamping plate 48 is initially held in place while the tube 43 and
attached nut 45
are rotated in a tightening direction pulling the threaded rod 42 further into
the tube
43 toward the handle 46, this acting to pull the clamping plate 48 back toward
the
respective vertical front end members 22 of the containment device frame 11,
thus
clamping these frame members against the manway flange 204 with the gasket 30
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therebetween. This is performed for each clamping mechanism 40 such that the
clamping mechanisms releasably fix the containment device 10 in place on the
tank
200 with the hollow interior of the containment device in communication
through its
open front end with a bottom portion of the manway opening, with the gasket 30
providing a good seal between the tank and the containment device to prevent
leakage therebetween.
The horizontally elongated channels or passages provided by the
channel ears or lugs 44 allowing horizontal sliding of the threaded rods and
attached
nuts and tubes to give an installer control over the distance between the
clamping
plates 48 on opposite sides of the containment device, thereby facilitating
adjustment of the clamping mechanisms to accommodate variations in width
dimensions of manways and associated flanges from one tank to another. In an
alternate embodiment, ears or lugs with round threaded bores therethrough
could
instead be used to directly engage a threaded rod carrying a clamping plate,
in
which case the nut and tube would not be required and the handle could instead
be
provided on the threaded rod itself. Such an embodiment would not allow
sliding of
the threaded rod, but rather only allow loosening and tightening of the
clamping
mechanisms by threaded rotational engagement of the rod with the threaded bore
of
the ear or lug. In such an embodiment, connection of the clamping plate 48 to
an
unthreaded end portion of the rod by a bearing would allow relative rotation
between
the rod and the clamping plate so that the clamping plate can be manually held
in a
position projecting inward from the relative front end vertical member 22
behind the
manway flange 204 while the threaded rod is rotated in a tightening direction
in the
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threaded bore of the ear or lug to pull the clamping plate against the manway
flange
and clamp the containment device in place thereaginst.
In the illustrated embodiment, two clamping mechanisms 40 are
provided on each vertical front end frame member 22, one proximate the bottom
end
5 thereof and another upward therefrom approximately three quarters the way up
the
respective frame member 22. The clamping mechanisms at the bottom are at the
same elevation as the horizontal front end frame member 24 and corresponding
bottom portion of the manway door flange 204 and thus each encourage a good
seal
at both the bottom of the containment device's open front end and the
respective
10 side thereof. It will be appreciated that the number and positioning of the
clamping
mechanisms may be altered. For example, one or more clamping mechanisms of
the type described could be used at a position along the horizontal front end
frame
member 24, with the ear channel projecting vertically downward therefrom to
allow
vertical sliding displacement of the respective rod 42 and the tube 43 and nut
45
15 engaged thereto, to improve sealing of the gasket 30 against the bottom
portion of
the manway flange 204, but with reference to Figure 1, 4 or 5, the bottom of
the
collection body 12 may interfere with convenient operation of the mechanisms
handle. In such an arrangement, the threaded rod and or the tube could thus be
extended to reach back past the rear end 14 of the collection body 12,
preferably
with at least one additional channel or other support depending downward from
the
frame closer to the rear end of the collection body to support the added
length and
weight. However, using the side-mounted clamping mechanism arrangement of the
illustrated embodiment reduces not only the overall weight of the device
relative to
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the aforementioned use of longer rods, but reduces the tendency for the upper
end
of the device to pull away from the manway flange under a cantilevered effect
caused by weight acting downward at a distance from the mounting of the device
to
the tank. In other embodiments, commercially available clamping mechanisms
sold
separately or with the containment device could be used to clamp it in place
on the
tank.
The movable lid assembly 20 features two interconnected lid portions
50, 52 corresponding to two differently sloped sections of the top end of the
collection body 12. A first planar top portion extends from the top of the
rectangular
rear end wall 14 toward the open front end at an upward sloping angle defined
by
oblique linear sloping of a first portion 16a of the side walls' top edge.
From an end
of this first portion 16a opposite the rear wall 14, the top edge of each side
wall 16
then slopes more steeply upward and forward at a greater angle at a second
portion
16b oblique to the first portion 16a along the top of the planar side wall 16.
In a
closed position, the first lid portion 50 is a rectangular panel that lies
flat atop, and
fully covers, the top edge of the rear wall 14 and the first portion 16a of
each side
wall's top edge. In a respective closed position, the second lid portion 52
projects
upward toward the open front end of the collection body 12 from an end of the
first
portion 50 opposite the rear wall 14, lying against and fully covering the
second
portions 16b of the top edges of the side walls 16. The two lid portions 50,
52 are
pivotally interconnected, by a piano hinge 54 in the illustrate embodiment,
for
pivoting relative to one another about an axis extending across the top edges
of the
opposing side walls 16 at the intersections of the first and second portions
'16a, 16b
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of the top edges thereof with the first lid portion 50 closed. With both lid
portions 50,
52 closed, the entire top of the collection body is closed off from the rear
wall 14 to
the open front end. With the lid portions closed, the first lid portion 50
prevents
materials collecting therebelow within the collection body's hollow interior
from
passing upward out of the containment device into the surrounding environment,
while the second lid portion 52 forms a shield-like flap having a more
vertical
orientation to prevent splashing or spraying out from the interior of the tank
on which
the containment device is mounted through the manway thereof.
To secure the second lid portion 52 in the closed position, a rubber
longitudinal strap 56 is fastened to each of the vertical front end frame
members 22
at a height therealong part way up the second portion 16b of the respective
side
wall's top edge. A first end of this strap 56 is fixed to the vertical frame
mernber 22
by a threaded fastener 58 passed through a central slot 56a in the strap
extending in
the elongate direction thereof to clamp this end of the straps against the
frame. A
catch 60 is defined on a side of the second lid portion 52 facing away from
the open
front end of the collection body 12 with the lid closed, at a position
proximate but
inward from the side of the second lid portion 52 adjacent the respective
vertical
frame member 22 on which each strap 56 is carried at an elevation similar to
that of
the fastener 58. When the second lid portion 52 is closed, the free end of the
strap
56 is pulled around this side edge of the second lid portion 52 past the
respective
catch 60 and the strap is lowered over the catch 60 so as to close therabout
with the
catch 60 disposed in the slot 56a and catching on the free end of the strap
56. The
tension of the resilient strap 56 pulls the second lid portion 52 toward the
respective
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vertical frame member 22 against the second portion 16b of the respective side
wall's upper edge, thereby holding the second lid portion 52 closed. The strap
56 is
pulled against its resilient tension to disengage from the catch 60 and then
pulled
outward away from the catch-equipped face of the second lid portion 52 to
remove
the strap 56 from about the catch to release the second lid portion 52 and
allow
opening thereof. It will be appreciated that the fastener 58 may be positioned
elsewhere on another stationary part of the containment device proximate the
open
front of the collection body to cooperate with the strap to retain the second
lid portion
in the closed position, for example mounted on the side wall 16 beneath the
second
portion 16b of the side wall's top edge.
As shown in Figure 4, during opening of the lid assembly 20, the
second lid portion 52 is pivoted on the hinge 54 to fold its catch-equipped
face
downward toward a face-to-face compacted arrangement against the still-closed
first
lid portion 50, thereby opening the top of the collection body 12 only along
and
between the second portions 16b of the side walls' top edges. A pair of hinges
62
connects the first lid portion 50 to the rear wall 14 at spaced positions
along the top
edge thereof for pivoting of the first lid portion 50 out of the closed
position about an
axis extending along this rear wall top edge. With the second lid portion 52
opened
to sit against the first lid portion 50, the lid portions can thus be pivoted
together
about this axis extending along the top edge of the rear wall 14 to pivot over
the rear
wall 14 into a fully open position where the entire top end of the collection
body 12 is
completely unobstructed by them. With the containment device installed on a
conventional tank 200 in which the bottom of the manway flange is only a few
inches
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19
off the ground 300, as shown in the Figures, the two lid portions engage the
ground
300 at their hinged-together edges in the completely open position of the lid
assembly.
As shown in Figure 3, the first lid portion 50 features a cleanout
opening 64 therein, defined by a circular hole through this plate or panel
like lid
portion 50. An annular rubber, or other suitable material, seal 66 surrounds
and
projects into this circular hole on an exterior side of the first lid portion
50 opposite
the interior space of the collection body 12, leaving the round cleanout
opening 64 in
the center of the seal 66 and circular hole. A plate 68, having a rectangular
periphery and a central circular hole equally sized and aligned with circular
hole in
the first lid portion 50, is fixed to the exterior face of the planar first
lid portion 50 over
the seal 66 to clamp the seal 66 flat in place against this .face or side. In
the
illustrated embodiment, threaded fasteners 70 spaced about the cleanout
opening
64 pass through the rectangular plate 68, first lid portion plate 50 and seal
66
therebetween for fixing these elements together. A cleanout cover 72 produced
from the circular portion of the plate cut out to communicate with the
circular hole in
the first lid portion 50 is pivotally connected to the plate 68 by a hinge 74
mounted
on a side thereof opposite the first lid portion 50. The cover 72 is thus
pivotable
about a horizontal axis disposed just above the plate 68 into and out of a
closed
position sitting atop the seal 66 within the circular hole in the plate 68 so
as rest
generally flush therewith, so close and open the cleanout opening 64. A handle
76
fastened to the cleanout cover 72 has a stem projecting from the side thereof
opposite the cleanout opening 64 to support a knob at a distance from the
cover to
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facilitate easy lifting thereof out of the closed position recessed flush into
the plate
68.
To ease installation of the containment device 10 on the tank 200, it is
provided with hangers 78 by which the device can be hung on the manway of the
5 tank prior to clamping of the device to the manway flange to sealed
installation. This
way, the installer(s) need not support the device themselves while trying to
align the
gasket equipped frame of the device with the manway flange and subsequently
tighten the clamping mechanisms 40. In the illustrated embodiment, each hanger
features a slidable elongate arm 80 telescopically received within a
respective one of
10 the two vertical frame members 22 so as to project vertically from the open
top end
thereof. Each arm is formed of a piece of rectangular solid stock having a
cross
section slightly smaller than that of the vertical member 22 in which it is
received so
as to be slidable therealong between a retracted position projecting slightly
upward
from the open top end of the vertical member 22 and an extended position
projecting
15 further upward from this open top end. A hook 82 is fixed to the arm 80 at
the top
end thereof before and is bent or curved to extend downward along the arm to
form
a hook having a mouth of suitable size to fit over the horizontal top section
of the
tank's manway flange 204. In the illustrated embodiment, the hook is defined
by a
right angle member having a first leg fixed flush atop the arm 80 so as to
project
20 horizontally therefrom past the open front end of the collection body 12
and a
second leg projecting perpendicularly downward from a distal end of the first
leg
opposite the arm 80 to hook over the top of the manway flange.
CA 02639520 2008-09-09
21
Figure 9 shows a cross sectional view of one of the hangers 78 to
illustrate the use of ball and detents to form stops for automatically locking
the arm
80 in each of the extended and retracted positions when slid thereinto. A
blind
cylindrical hole 84 extends horizontally into the rectangular arm 80 from one
of the
side faces thereof at a central position horizontally across this side and
houses a
compression spring 86 having one end thereof situated against the closed end
of the
blind hole 84. At an end of the spring 86 opposite the closed end of the blind
hole
84 is situated a spherical metal ball 88 that is biased outward away from the
central
longitudinal axis of the arm 80 against the interior surface of the respective
side wall
of the tubular vertical frame member 22 faced by the side of the arm in which
the
blind hole 84 is formed. The blind hole 84 is positioned at a short distance
upward
from the arm's bottom end. Corresponding through holes 92 each of a diameter
slightly less than that of the metal ball 88 are positioned near the bottom
and top
ends of the tubular vertical frame member 22 in the respective wall thereof at
central
positions horizontally thereacross. Figure 9 shows the arm 80 in the retracted
position, in which the ball 88 projects partially through the bottom hole in
the
respective side wall while remaining partially within the blind hole 84 in the
arm 80
due to the close spacing between the similarly sized arm 80 and tubular frame
member 22, thereby blocking sliding of the arm 80 out of this position. In
this
position, the top end of the arm projects only slightly out of the top end of
the frame
member 22. To extend the arm 80, the user pushes the ball 88 from outside the
frame member 22 to release it from the bottom hole so that the arm 80 can be
siid
upward along the frame member 22 until the ball 88 reaches the top hole 92 and
CA 02639520 2008-09-09
22
automatically pops thereinto to once again lock the arm 80 in place, this time
in the
extended position of Figures 1 to 8. This way, the arms can be left retracted
when
the containment device is not in use to make it relatively compact for storage
and
transportation, until the device is to be installed on the tank 200. Then the
arms are
extended to a height suitable for hanging of the device on the tank manway
flange to
support the boftom of the collection body at a height at or shortly below the
bottom of
the manway, so that the device can be manually moved by small amounts to align
the gasket-equipped frame members with the manway bottom and side flanges for
clamping thereo..
Figures 11A and 11 B show an alternate embodiment hanger that also
makes use of a spring to achieve automatic locking of the telescoping hanging
arm
in the fully extended position. In this embodiment, the arm 80' is a piece of
holloe
rectangular tubing having a cross section slightly smaller than the
rectangular tubing
of the vertical member 22 in which it is received. At the same height along
the front
end vertical frame member 22 that the upper one of the two through-holes 92 of
the
first embodiment hanger of Figure 9 is found, the front end vertical frame
member
22' of the second embodiment hanger features a through-hole 92' in laterally
outward side 22c thereof. To this same side is fixed a U-shaped member 100
having two parallel legs 100a that project perpendicularly outward from this
side of
the front end vertical frame member 22' and are interconnected at their distal
ends
by a central portion 100b that is perpendicular to the parallel legs. The U-
shaped
member 100 is positioned to span over the through-hole 92' in side 22c of the
front
end vertical frame member 22' with a through-hole 102 in the central portion
of the
CA 02639520 2008-09-09
23
U-shaped member 100 axially aligned with through-hole 92'. A pin 103 passes
through aligned through-holes 92', 102 and has a stop-collar 104 or other
structure
of larger diameter than the shaft portions of the pin 103 passing through
aligned
through-holes 92', 102, this enlarged portion 104 projecting radially outward
relative
to the shaft portions and being positioned between the front end vertical
frame
member 22' and the central portion 100b of the U-shaped member 100. Between
the stop collar 104 and the central portion 100b of the U-shaped member 100 is
a
compression coil spring 106 disposed about the pin shaft and having an inner
diameter less than the diameter of the stop collar 104 and an outer diameter
greater
than through-hole 102. The spring forces the stop collar 104 against side 22c
of the
front end vertical frame member 22'.
The blind hole 86 in the solid arm 80 of the first embodiment hanger is
replaced with a through-hole 86' through a side of the hollow tubular arm 80'
facing
side 22c of the front end vertical frame member 22' in the second embodiment
hanger. When the arm 80' is pulled upward into the extended position, through-
hole
86' aligns with through-holes 92', 102 and the force of the spring 106 pushing
on the
stop collar 104 and forcing an inner end 103a of the pin 103 further into the
interior
of the hollow front end vertical frame member 22' causes the inner end 103a of
the
pin 103 to slide into the interior of the hollow tubular arm 80' through the
through-
hole 86' therein. To retract the arm 80' back further into the front end
vertical frame
member 22' or to widthdraw it therefrom through the top end thereof, the pin
103 is
pulled outward by a user against the spring force to retract the pin's inner
end 103a
out of the tubular arm 80' via through-hole 86' to once again allow sliding of
the arm
CA 02639520 2008-09-09
24
80' within the front end vertical frame member 22'. The spring 106 between the
stop
collar 104 and the central portion 100b of the U-shaped member 100 limits
movement of the stop collar 104 toward the central portion 100b to an amount
insufficient to withdraw the inner end 103 a of the pin from through-hole 92'.
As
shown in Figure 11A, an outer end 103b of the pin opposite the inner end 103a
may
be provided with a head 108 or other feature having an enlarged outer diameter
relative to an adjacent portion of the pin to form a shoulder 110 which the
user can
use to better grip the pin for pulling thereof to release the telescoping arm
from the
locked extended position.
In this second hanger embodiment, the bottom of the front end vertical
frame member 22' is closed off by a blocking plate 112 so that the arm 80'
merely
sits atop the blocking plate 112 in the retracted position, rather than being
locked by
a second locking mechanism on the same front end vertical frame member 22'. In
other embodiments where the bottom of the front end vertical frame member 22'
is
left open, engagement of the hook 82 with the top end of the frame member 22
may
instead defined the stop that determines the fully retracted position. In the
embodiment using the pin-based locking mechanisms, the spring biased locking
component is carried on the frame of the containment device, not the
telescoping
arm of the hanger. The telescoping arm 80' can thus be completely withdrawn
from
the front end vertical frame member 22' without fear of damage to or loss of
any
locking mechanism components. Such removal of the telescoping arms from the
containment device after securing thereof to the tank using the clamping
mechanisms is useful, for example to provide access to the manway flange at
the
CA 02639520 2008-09-09
portion of the manway left open above the collection body and frame of the
containment device to allow securing of an additional covering over this
portion
during spray down, as describe herein further below. Alternatively, access to
the
manway flange above the collection body and frame ma be provided in another
5 embodiment by having the hook 82 mounted for swiveling about a vertical axis
extending along the front end vertical frame member, so that after the
containment
unit is clamped to the manway flange, the arm can be unlocked and moved upward
to disengage the hook from about the upper portion of the manway flange, where
the
hook can then be rotated or pivoted about this vertical axis to point away
from the
10 manway flange so that the arm can be subsequently lowered back into its
retracted
position, leaving the manway flange unobstructed above it.
Further alternative locking mechanisms for locking of the arm 80 into
the extended position may instead rely on completely removable pins rather
than pin
or ball and detent mechanisms carried entirely on the containment device
itself.
15 However, the device-carried mechanisms of the illustrated embodiments have
the
advantages of avoiding the potential to lose, misplace or forget to bring pins
and
providing spring actuated automatic locking upon pulling of the arm into the
extended position for hanging the device on the tank. Embodiments not
featuring
telescoping hanger arms could feature bolt holes in the front end vertical
frame
20 members of the containment device frame that are alignable with existing
bolt holes
in the manway flange to facilitate coupling thereto using bolts. Use of
horizontally
elongated bolt holes could accommodate variations in manway and manway flange
widths from one tank to another.
CA 02639520 2008-09-09
26
The illustrate embodiment of the containment device features linearly
extending strip-like planar brace members 94 extending diagonally upward from
the
side frame members 26, proximate the connection thereof to the rear end frame
member 28, to the vertical frame members 22 to strengthen the frame 11 of the
containment device for better support of the collection body 12. Each brace
member
94 is fixed to the outer face of the vertical leg 26a of a respective one of
the side
frame members 26, opposite the face of this vertical leg 26a against which the
respective side wall 16 of the collection body 12 sits against, proximate the
lower
end of the brace mernber so that one side of the planar brace member's faces
toward the respective collection body side wall 16. An opposite end of the
brace
member is fixed to the respective vertical tubular frame member 22 at the face
or
side thereof opposite the gasket 30 at a position across this face proximate
the inner
face 22a facing the other vertical frame member 22 so that the brace members
94 sit
in close proximity to the collection body 12 situated between them. Each brace
member 94 connects to the respective vertical frame member 22 at a height
therealong corresponding to the steeper second portion 16b of top edge of the
respective side wall 16. The illustrated embodiment also features a pair of
generally
D-shaped handles 96, each mounted to a respective one of the collection body
side
walls 16 on an exterior side thereof in a position beneath the respective
brace
member 94. The handles 96 project laterally outward away from the collection
body's hollow interior, with the handle opening defined between the handle
body and
the respective side wall 16 opens about an axis parallel to the side wall and
perpendicular to a longitudinal axis of the brace member.
CA 02639520 2008-09-09
27
In use, the containment device is installed on the manway opening of
the tank to seal against the flange thereof about a bottom portion of the
manway
opening so to catch materials flowing outward from the tank therethrough
during one
or more cleaning processes. An exemplary use of the containment device is
outline
in the following paragraphs.
First the containment is installed on the tank in a sealing arrangement
with the manway flange as described herein above. In first cleaning step, the
lid
assembly of the collection body is completely opened and an operator passes a
stinger through the resulting open top of the collection body of the
containment
device into the interior of the tank and operates in the stinger in a known
manner to
flush materials from the tank into the hollow interior of the collection body
through
the communicating manway opening of the tank and open front end of the
collection
body. Materials flushed into the hollow interior of the collection body by the
stinger
are removed from the containment device, for example using the suction hose of
a
vacuum truck.
The lid assembly of the containment device is then returned to the fully
closed position to close of the top of the collection body and seal the
interior thereof.
A water cannon connected to a high-pressure water source is mounted in a known
manner on the manway flange of the tank for positioning above the collection
body
at a top portion of the manway opening left open thereabove and used to spray
down the interior of the tank through this open top portion of the manway
opening.
Installation of the water cannon may include mounting a covering to the tank
in a
position over the containment device and passing the high pressure fluid into
the
CA 02639520 2008-09-09
28
interior of the tank through an opening in the covering, so that the manway
opening
is substantially closed off in entirety around the water cannon. Canadian
Patent
Application No. 2,571,597 of the present applicant teaches a sheet or skirt
like
manway or door covering device described for covering a full access opening in
an
oil storage tank. Simply by cutting away a bottom portion of this covering or
producing the covering without the bottom portion would allow use of such a
device
with that of the present application, the bottom portion being taught in the
aforementioned to include a draped opening therein for passage of a vacuum
truck
suction hose therethrough, as the containment device described and illustrated
herein would replace such a bottom portion of the sheet-like covering to
complete
full closure of the manway opening. During or after one or repeated cycles of
spraying down the tank interior with the water cannon or jet, the suction hose
of the
vacuum truck can be used to empty out the interior of the collection body of
the
containment device without opening thereof. That is, when not spraying, the
hose is
passed through the closed lid assembly of the collection body through the
cleanout
opening, the seal of which is dimensioned to seal around the hose to ensure
that the
interior of the collection body remains closed off from the surrounding
environment.
Once the jetting and vacuum cleanout operations are complete, the
water cannon and cover are removed and the lid assembly of the containment
device is once again opened. The operator then enters the interior of the tank
with a
pressure washer through the open top of the collection body and the open front
end
thereof communicating with the manway opening and uses the pressure washer
wand to spray down the interior of the tank from with cleaning chemicals. The
CA 02639520 2008-09-09
29
containment device remains installed during this step to continue collecting
materials
leaving the tank through the manway to prevent environment contamination. As
the
collection body of the illustrated containment device extends only a partial
height of
the manway opening when installed at the bottom thereof, a significant portion
of the
manway remains open to ensure the safety of the pressure washer operator
therein
by ensuring adequate air exchange and allowing quick uninterrupted escape from
the tank interior in an emergency. Even if a person were to close the lid
assembly
with the operator in the tank, a good push on the second lid portion 52 from
within
the tank through the manway opening would be sufficient to release the
resilient
rubber straps 56 from the catches 60 to allow the lid to be quickly opened
from
within the tank with little effort. Other easy-release fasteners such as hook
and loop
fasteners could similarly be used to facilitate opening of the lid with little
effort or
manipulation.
It will be appreciated that the containment device may be used in any
oil tank cleaning process conventionally carried out with a manway or other
access
opening of the tank in an open state, or may be used in place of other
containment
devices previously used to prevent or reduce the possibility of environmental
contamination through such an opening. Used as described above, the
containment
device provides the advantage that it can be installed once and left in place
through
multiple cleaning processes requiring different degrees or positions of access
to the
manway opening.
Prototypes of the containment device have been produced using steel
frame members and puck board collection body walls, lid portions and cleanout
CA 02639520 2008-09-09
covering. Production of a future frame from aluminum components will reduce
the
overall weight of the device while still providing sufficient strength for its
intended
functions, while production of the walls and bottom of the collection body as
a single
integral unit, for example using plastic molding techniques, will minimize the
5 possibility of leakage and ease production by eliminating the need to not
only fasten
together different wall components, but take care to provide sufficiently
tight seals
therebetween to prevent oil, sand, water, cleaning chemicals or other debris
or
materials from escaping the collection body. It will be appreciated that other
materials and constructions may also be applied, for example constructing the
10 collection body from metal or plastic sheet or panels.
Since various modifications can be made in my invention as herein
above described, and many apparently widely different embodiments of same made
within the spirit and scope of the claims without department from such spirit
and
scope, it is intended that all matter contained in the accompanying
specification shall
15 be interpreted as illustrative only and not in a limiting sense.
