Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02745857 2011-07-22
NO-ENTRY BULK OIL STORAGE TANK CLEANING SYSTEM WHEN TANK IS
FULL
BACKGROUND OF THE INVENTION
(A) Field of the Invention
This invention relates to the cleaning of large storage tanks, and more
particularly,
but not by way of limitation, to the no man entry cleaning of a bulk oil
storage tank and
removing sediments from the bottom of the tank when the tank is partially full
or full.
(B) Discussion of Prior Art
Heretofore, large bulk oil storage tanks, ranging in size from 400 to 40,000
plus
barrels of crude oil, have been cleaned periodically to maintain the capacity
of the tank
and remove sediments from the tank such as, sand, clay, water, heavy oil, and
asphaltic
sludge. Also, the buildup of the sediments in the tank can plug up the oil
discharge
valves in the tank incapacitating the efficient removal of tank fluids.
Currently during the bulk tank cleaning process, one or two workman insert a
small
pipe of approximately one inch in diameter with nozzle through a sealing
arrangement
through a tank bottom unloading valve. A vacuum hose is attached to the
unloading
valve at the face of the tank to suck out sediment dislodged by the pressure
pipe which
can extend across the tank in a straight line. No measures are now taken to
bend the
pressure pipe so as to jet water into corners of the tank.
The water pressure guide unit mounted on the tank's surface valve vacuums
sediments, water, and clean oil, relying only on gravity to carry sediments
across the
tank bottom initiated by water flooding from the water injection process. A
large volume
of water is used which must be disposed of later at significant cost and only
a small
portion of the water aided sediment gravitates from across the tank to the
surface valve
where the vacuum hose is attached.
in addition, if the pressure and volume of water is not regulated exactly in
the
intrusive water injection pipe, the sediment is stirred up into the clean oil
causing major
problems in the clean oil carry over tank or tank transfer valves.
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CA 02745857 2011-07-22
The subject no-entry, tank cleaning system eliminates large volumes of
uncontrolled
water to be injected into the tank, no erratic stirring of sediment is
initiated, and the
vacuum source actually enters and crosses the tank to the far side and corners
cleaning most of the tank bottom without stirring up sediment with a 6-8 to
one
reduction in reoccurring costly cleaning events. Sediments are removed without
using
large amounts of pressure water initiated by the intrusive pressure wand, and
without
drawing down large amounts of clean crude oil from the above oil layer which
must be
disposed of at high cost. Disposal companies do not usually give credit for
good crude
delivered to their cleaning plant while charging for the number of cubes in
the delivery
vacuum truck.
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SUMMARRY OF THE INVENTION
In view of the foregoing, it is a primary objective of the subject invention
to provide a
tank cleaning system which reduces cleaning events by 6-8 times or in other
words
extends tank cleaning events up to eight times longer.
Another key object of the invention is the cleaning of tank bottoms with
minimal water
usage which minimizes disposal cost.
Still another objective of the invention is to eliminate the disturbance of
sediment up
into the clean oil layer above the sediment layer.
Another objective is to remove sediment and not clean crude that is lost to
the cleaning
facility while being charged for the delivery.
The subject tank cleaning system includes several configurations of vacuum
conduits
with an inner medium pressure hose with nozzle jet and related sealing
apparatus so as
to allow the actual vacuum pipe source to enter the tank through the clean out
valves
and protrude across the tank and into all areas of the tank for complete
bottom sediment
removal when the tank is full. The pressure hose inside the vacuum conduit has
a
nozzle located in the usnout" of the protruding vacuum pipe and jets low
pressure hot
water down into the sediment dislodging it for vacuum removal.
These and other unique apparatus and methods of the present invention will
become
apparent to those familiar with the cleaning of sediment in large bulk oil
storage tanks
when reviewing the following detailed descriptions, showing novel
construction,
combination, and elements as herein described, and more particularly defined
by the
claims, it being understood that changes in the embodiments of the disclosed
invention
are meant to be included as coming within the scope of the claims, except
insofar as
they may precluded by the prior art.
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BRIEF DESCRIPTION OF THE PICTURES
The accompanying pictures illustrate complete preferred embodiments in the
present
invention according to the best modes presently devised for the practical
application of
subject tank cleaning system, and in which
Picture 1. is a perspective view of subject tank cleaning apparatus threaded
into a tank
plug opening on the side of a large bulk oil tank. The gate valve is inside
the vault valve
closet. When the valve is opened and all vacuum hoses are hooked up, the
cleaning
flex-hose is pushed into the tank body even when it is full of fluid to remove
tank bottom
sediment.
Picture 2. Is a perspective view of the subject tank cleaning apparatus
showing a solid
pipe that can extend across the diameter of a full tank through a ball valve
or gate valve
to remove tank bottom sediment. A curved pipe is incorporated in the system as
well to
access the right and left tank quadrants.
Picture 3. is a perspective view of the inside the vacuum pipe low pressure
hose
installation and water spray nozzle located in the "snout" of the vacuum
cleaning pipe.
Picture 4. Is a perspective view of the water jet input system with pressure
gauge and
pressure control valve to limit over stirring of tank sludge. Note also the
flexible vacuum
hose connected to the tank vacuum pipe leading to the vacuum truck.
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CA 02745857 2011-07-22
Picture 5. Is a perspective view of three features of this apparatus. Note
pressure gage
and valve to regulate a counter pressure against the tank's static crude oil
pressure.
Note the vertical valve designed to regulate the amount of vacuum input air so
as to not
suck oil from tank into the leakage reservoir shown below with the "clear"
joint of pipe
but solely to keep the leakage compartment dry. Note the vacuum hose connected
to
the leakage chamber such that any tank oil leakage past seals around the
vacuum pipe
will be vacuumed into the vacuum truck. Not visible are 3 seals and guide
bushings
arranged in front and back of the pressure equalizer chamber and one seal at
the rear of
the leakage chamber to keep leakage from contacting the ground.
Picture 6. Is a perspective view of my proprietary designed sliding mechanical
seal to
accommodate a bowed vacuum pipe such that as the bowed pipe is pushed into the
tank the seal moves side ways so the vacuum pipe does not bind on the rear and
front
guide bushings and seals. Also, note the long extension on the end of the pipe
guide
apparatus. It is designed to keep the flex-tubing straight through the vault
valve entry
pipe 24 inches within the valve vault of the tank.
While the invention has been particularly shown, described and illustrated in
detail with
reference to the preferred embodiments and modifications thereof, it should be
understood by those skilled in the art that equivalent changes in form and
detail may be
made therein without departing from the true spirit an scope of the invention
as claimed
except as precluded by the prior art.
CA 02745857 2011-07-22
DETAILED DECRIPTION OF THE PREFERRED EMBODIMENTS
In picture 1, a perspective view of subject tank cleaning system is shown
having a general
reference numeral 10. The cleaning system 10, in this embodiment, is shown
connected to the
tank plug opening by way of the vacuum tube guide apparatus 5A. The tube guide
5A is screwed
into the tank with threaded portion9. The guide pressure equalizer
compartment) I is then
connected to the large bulk crude at the base of the tank as an element of the
tube guide5A.
The pressure equalizer compartment 11 has bushings and seals forward and aft
and maintains
an equalizing pressure by allowing water under pressure to enter the equalizer
chamber via the
valve 15 and the internal pressure is adjusted to the oil static pressure by
observing the pressure
gage6 and estimating the pressure in the tank by observing the tank fluid
level indicator. So, if
the tank has 20 feet of static pressure the equalizer pressure is adjusted to
approximately 20'x
.4psi = 12psi.. At this point, the oil does not enter the equalizer
compartment and water slowly
enters the tank oil side of the seals. In the event some oil and sediment
enters the equalizer and
then passes to the vacuum"T"l2 it is readily vacuumed up and carried to the
vacuum truck via.
the down spout with clear view pipe 14 connected to the vacuum"T"12
compartment. A seal and
mechanical guide is placed aft of the "T" 12 compartment to avoid sediment
leaking onto the
ground. Hose 19 is under vacuum by the vacuum truck so the tank valve is
opened and the
vacuum tube/ hose is pushed into the tank through the bushings and seals.
Vacuum hose 17 has a
pressure line inside and a nozzle to pressure dislodge the tank bottom
sediment and the vacuum
generated by the vacuum truck sucks up the sediment.
In picture 2 we have an almost identical vacuum pipe guide5B to perform the
tank bottom
cleaning process 10 except it has smaller seals and bushings as the pipe
vacuum tube is smaller
than theflex hose style of vacuum tube and hence the guides and seals are
designed for each style
of vacuum tube. Cleaning processl0 is accomplished by initiating a suction
from the vacuum
truck and the vacuum pipe 17 is pushed into the tank through the guide
apparatus5B until it
engages the sediment. A water pressure line is attached to the outside truck
end of the vacuum
pipel7described under a different picture and plumbed inside the vacuum pipe
with a nozzle on
the tank end designed to dislodge sediment with medium pressure and
150 degree water. 6
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A vacuum relief valve 13 mounted on the leakage"T"12 compartment is designed
to relieve
too much vacuum suction if sediment is sucked over into the leakage
compartment12 from the
equalizer compartment. An operator then performs the tank cleaning proceedure
10 by pushing
the vacuum hose/pipe into the tank until it engages the sediment which is
vacuumed into the
vacuum truck.
In picture3 the view is of the "snout"tank end of the vacuum pipe 17 that
engages the tank
sediment with minimal water/sediment disturbance. There is a water pressure
line20 inside the
vacuum hose/pipel7 with a water jet nozzle21 attached. The jet spray is in a
fan shape pointing
downward to cut the sediment sufficiently with hot water to dislodge and cause
the material to
vacuum up speedily without stirring the sediment up into the clean oil layer
above the vacuum
pipe 17. The hooked snout22 is on top as the tube enters the tank and is
designed to direct the
water jet flow fan shape and down to avoid stirring the sediment into the
clean oil layer above.
In picture4 the view recognizes the water jetting input system consisting of
pressure gauge-23,
90degree elbow26 connected to the internal pressure line, pressure adjusting
valve24 and input
fitting25. The pressure line is internal to the vacuum hose and water at 60-
100psi is jetted out
through the vacuum cleaning pipe snout as shown in picture 3. Hot water
atl50degress is jetted
against the snout downward from a small oval shaped orifice dislodging
conglomerate sediment
without excessive water use and without stirring the sediment into the clean
oil layer. Sediment
contamination of valves can be very costly if the sediment is carried to a
pipe line or over into a
clean oil tank.
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In picture5 the pressure equalizerl I compartment of the vacuum pipe guide5A
or 5B is
designed to counter balance the intrusion of semi-fluid sediment from the
static oil pressure
exerted by the full or partially full crude oil tank. Every foot of static
pressure for heavy oil is
approximately 0.4psi. per vertical foot so by observing the tank float gauge
height the pressure
needed to counterbalance the intrusion of sediment into the equalizerl 1
chamber is calculated
and a slight over pressure is regulated by adjusting the input valvel5on the
pressure line from
the truck pressure system to one plus psi allowing some minimal amounts of
water to enter the
tank.
The leakage catcher chamber "T"l2 is designed with seals for and aft and with
a continuos
vacuum exerted sucking any leakage of sediment that gets past the
counterbalance chamber. Any
sediment is readily vacuumed to the vacuum truck. So as to not over suck the
equalizer
compartment and needlessly cause sediment to inter the leakage compartment a
vacuum control
valve 13 is threaded into the leakage chamber for easy adjustment to allow
free air to enter the
leakage chamber reducing the vacuum suction when needed. The 90 degree down
fittingl4 is
designed to be removed when the guideunit5A is screwed into the tank's valve
as the height of
the valve will not allow the guide5A to be threaded into the tank valve. When
the guide unit is
upside down the down tube 14 is installed and afterward rolled over to the
side.
In picture-6 there is a proprietary sliding mechanical seal 18 designed to
shift sideways in the
guide units 5A and 5B allowing a curved vacuum pipe to pass through the vacuum
pipe guide
units 5A or 5B without binding in the seals. The need for a curved vacuum pipe
with internal
pressure hose and nozzle is needed to access the right and left quadrant of
the tank bottom for
quick cleaning, Picture6 also shows an extension27 to fitting9 to be used when
the flex vacuum
hose is used at the vault valve which is recessed 24inches and it is necessary
to keep the flex
hose straight so as not to bind and jam at the internal (24`+) gate valve in
the tank vault
compartment.
While the invention has been particularly shown, described and pictured in
detail with
reference to the preferred embodiments and modifications thereof, it should be
understood by
those skilled in the art of tank cleaning that an equivalent changes in form
and detail may be
made therein without departing from the true spirit and scope of the invention
as claimed except
as precluded by the prior art. 8
