U.S. patent application number 11/994579 was filed with the patent office on 2008-07-10 for replaceable tank lining.
Invention is credited to Uri Sheffer, Zvika Weber.
Application Number | 20080164261 11/994579 |
Document ID | / |
Family ID | 37604879 |
Filed Date | 2008-07-10 |
United States Patent
Application |
20080164261 |
Kind Code |
A1 |
Weber; Zvika ; et
al. |
July 10, 2008 |
Replaceable Tank Lining
Abstract
Replaceable tank (RT) for installing in metallic storage tanks
for fluids consists of a tank body and one or more orificial
members. The RT conforms with inner walls of the storage tank and
is made of flexible materials, such as rubber or PVC that are
impermeable to the fluids stored. Orificial members having a
tubular neck and conforming with the lumen of the orifices of the
storage tank are typically made of the same material as the RT.
Magnets, attached to, or embedded in, the walls of the RT are
attracted to the walls of the metallic storage tank. A method for
manufacturing, packaging and for in situ installing an RT is
provided.
Inventors: |
Weber; Zvika; (Reut, IL)
; Sheffer; Uri; (Tel Aviv, IL) |
Correspondence
Address: |
YORAM TSIVION
P.O. BOX 1307
PARDES HANNA
37111
omitted
|
Family ID: |
37604879 |
Appl. No.: |
11/994579 |
Filed: |
June 29, 2006 |
PCT Filed: |
June 29, 2006 |
PCT NO: |
PCT/IL2006/000763 |
371 Date: |
January 3, 2008 |
Current U.S.
Class: |
220/560.03 ;
220/723 |
Current CPC
Class: |
B65D 2590/046 20130101;
B65D 2313/04 20130101; B65D 90/046 20130101; B65D 88/76
20130101 |
Class at
Publication: |
220/560.03 ;
220/723 |
International
Class: |
B65D 90/00 20060101
B65D090/00; B65D 25/14 20060101 B65D025/14 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 4, 2005 |
IL |
169519 |
Claims
1. A replaceable tank (RT) for installing in a metallic storage
tank for fluids, comprising: a tank body made of a flexible
material impermeable to said fluids; at least one orificial member
attachable to a hole in said tank body, and at least one magnet
attached to said tank body for attracting to said metallic storage
tank.
2. A RT for installing in a storage tank for fluids as in claims 1,
wherein one end of a tubular neck of said at least one orificial
member has an external ridge.
3. A RT for installing in a metallic storage tank for fluids as in
claim 1, wherein said at least one orificial member is attached to
said tank body.
4. A RT for installing in a metallic storage tank for fluids as in
claim 1, wherein one end of a tubular neck of said at least one
orificial member has a flange.
5. A RT for installing in a metallic storage tank for fluids as in
claim 1, wherein said at least one orificial member is rigid.
6. A method for preventing leakage from metal storage tanks
comprising providing an internal lining to said storage tank by
magnetically attaching a replaceable tank (RT) conforming to the
internal contours of the metal tank.
7. A method for preventing leakage from metal storage tanks as in
claim 6, wherein at least one orificial member is further attached
to said RT.
8. A method for preventing leakage from metal storage tanks as in
claim 6, further comprising folding said RT prior to shipping to
the place of installation, and packaging said folded RT in a
package insertable into said storage tank through an orifice of
said storage tank.
9. A method for preventing leakage from metal storage tanks as in
claim 6, wherein gas pressurizing is used for providing said
lining,
Description
FIELD OF THE INVENTION
[0001] The present invention relates to storage tanks, and more
particularly to a method for prolonging the durability of such
tanks.
BACKGROUND OF THE INVENTION
[0002] Tanks used for storing petroleum and petrochemicals are
normally designed to be leak resistant in order to minimize loss of
their contents in or onto the ground, which in excess amounts might
contaminate the soil and pollute the surroundings. Many states have
enacted laws or regulations to protect the environment by enforcing
restrictions on the use of such tanks. Accordingly, operators or
owners of tanks storing petroleum, chemicals, or hazardous
material, are to provide secondary containment vessels. Secondary
vessels such as an exterior shell or leak-proof housing are
intended to surround the storage tank and serve as a backup safety
vessel to contain any materials which may leak out of the primary
tank. In an effort to comply with these secondary containment laws
and regulations, operative tanks are typically replaced by double
walled tanks. A typical solution often applied with regard to
underground storage tanks includes encasing the existing storage
tanks (usually steel tanks) in concrete. Another common solution
consists of placing an exterior liner or flexible bag around an
existing storage tank. Such techniques require excavation of the
tank sites, or replacement, or reinstallation of the tanks, along
with additional construction.
[0003] U.S. Pat. No. 4,763,805 discloses a system which is suitable
for installation especially in underground storage tanks. The
system has an expandable compartment such as a bladder which is
made of a flexible material like rubber that is impermeable to the
stored fluids. The expandable compartment serves as a primary
container, whereas the operative tank encasing it serves as a
secondary tank. However, the walls of the expandable tank are prone
to damage due to the dynamically changing volume of the space
between the inner tank and the storage tank. Furthermore,
installing such a tank is somewhat complex and may require a
presence of a worker inside the storage tank.
[0004] The present invention facilitates protection of the
environment from faulty tanks, and is applicable especially to
tanks attractive to magnets.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1A is a longitudinal sectional view of a replaceable
tank according to the invention;
[0006] FIG. 1B is a side view of the replaceable tank of FIG.
1A;
[0007] FIG. 1C is an isometric view of an orificial member of a
replaceable tank according to a preferred embodiment of the present
invention;
[0008] FIG. 2A is a frontal view of the replaceable tank of FIG. 1A
after a step of flattening;
[0009] FIG. 2B is a frontal view of a section of a replaceable tank
which is partially folded;
[0010] FIG. 2C is a schematic presentation of a replaceable tank
after a step of folding;
[0011] FIG. 2D is a schematic presentation of a step of packaging a
replaceable tank in a hollow cylinder according to a preferred
embodiment of the present invention;
[0012] FIG. 3 is a schematic presentation of an insertion of a
replaceable tank into an operative tank according to a preferred
embodiment of the present invention;
[0013] FIG. 4 is an isometric view of a jig for drilling an
aperture in a replaceable tank of the invention;
DETAILED DESCRIPTION OF THE PRESENT INVENTION
[0014] Containers or tanks made of a magnetic metal such as steel
are often used for storing fluids considered contaminating and/or
hazardous such as fuel, oil, chemicals, pressurized propane or
natural gas. These containers must not undergo deterioration that
would promote leakage of the contents into the environment. The
present invention provides a method and system for applying an
internal lining to such containers, with the intention of
preventing leakage from the tank. Accordingly, replaceable tanks
(RT) conforming to the internal contours of the metal tank of the
art are provided. The RTs of the invention in effect provide an
internal, replaceable coating to the metal tank. An aged RT is
replaceable by a new one so that the external, metal tank is may
corrode or undergo other structural deterioration without the risk
of environmental damage by spillage of the contents. The RT of the
invention is made of flexible materials such as rubber or PVC,
impermeable to the relevant fluids.
[0015] General Structure of the Replaceable Tank
[0016] Reference is first made to FIGS. 1A and 1B in which a
longitudinal sectional view and a side view of a RT of the
invention are shown respectively. RT 10 has orifices 12 and 13
located at its top side. Magnets 14 are attached to the inner
surface of the RT walls. The distances between magnets 14 are
determined in respect of the weight of the empty RT and the
intensity of the magnetic field which they induce. Side wall 16 is
planar or dome shaped conforming to the internal shape of the metal
tank. Circumferential flange 17 provides for attaching tubular neck
18 to the rim of the corresponding orifices of the metal tank.
[0017] Typically a metal storage tank such as a fuel tank in a
refueling service station has at least four orifices for performing
the following functions respectively: (i) filling the tank with
fuel; (ii) dispensing fuel; (iii) measuring the level of the fuel;
and (iv) a vent. The vent is the most narrow orifice of the lot,
typically measuring a circumference of 1 inch. The widest orifice
of the storage tank is typically used for the insertion of the RT
into the tank for providing internal lining.
[0018] Construction and Fitting of the RT
[0019] The construction of a RT is carried out in two main stages.
At stage 1, the tank body and appendages are assembled, and at
stage 2 the RT is fitted into the operative tank, typically in
situ, and completed. A RT is produced from sheets of impermeable
matter, for example rubber or PVC usually approximately 2 mm thick.
The sheets are cut into smaller sheets or pieces having a
particular shape as required to assemble the RT. Then, the sheets
and pieces of building material are joined by soldering or gluing
such that the RT formed may fit in with the internal contours of
the metal tank. Magnets are attached or embedded in the inner
surface of the RT typically prior to its assembly.
[0020] Typically a RT is assembled having at least one wide
aperture located in correspondence with the exact location of the
orifice in the metal tank. A prior knowledge of the exact locations
of the other apertures of the metal tank is not necessary for the
assembling of a corresponding RT. Such additional apertures are
made at the site of application. An orificial member having a neck
is inserted in conformity with an aperture, the procedure described
with reference to FIG. 1C. Orificial member 20 has a
circumferential flange 22 located at one end of hollow tubular neck
24 and an external circumferential ridge 26 located at a second end
of the neck. Whether attached to the RT or not, the role of the
ring is to prevent falling off or pulling away of the orificial
member. The external diameter and the length of the tubular neck
fit in the corresponding dimensions of an orifice of the metal
tank. Holes 28 provide for securing flange 22 to a rim of the
corresponding orificial of the metal tank by means of bolts. A
circular aperture matching the external diameter of the tubular
neck is provided by punching, drilling, or cutting the
corresponding piece of building materials used in the assembly of
the RT prior to its assembly. After the assembly is completed the
orificial member is inserted into this aperture such that its
circumferential ridge is pushed over to the other side of the rim
of the aperture. The cylindrical neck is optionally further glued
and or soldered to the body of the RT. Other orificial members are
produced in advance, corresponding to the additional orifices of
the metal tank. Orifices of the storage tank may vary in shapes,
and therefore may differ from the cylindrical shape as described
hereinabove. The shapes of the orificial members conform to the
internal contours of the corresponding orifices of the metal tank
according to the present invention. The external ridge can also be
segmented and the number of segments and/or the dimensions may
vary. Rigid orificial members are partially or completely made of
rigid materials such as metals. In general, an orificial member for
an orifice of a metal tank has a circumferential flange at one end
and an external ridge at its other end of the tubular neck. The
hollow tubular neck conforms to the inner dimensions of the metal
orifice. For the sake of simplicity, the following description of
the invention refers to cases of cylindrical symmetry wherein any
one who is knowledgeable with the art is able to adopt the
description to other geometrical shapes of orifices of such storage
tanks.
[0021] Folding Up and Packaging a RT
[0022] RTs are packaged according to the invention for shipping to
the site of installation. Such packaging provides the background
for a convenient installation process and is also convenient with
regards to shipping. A process of packaging consists of several
steps: Firstly, the RT is flattened forming a planar geometrical
body. Then the flattened RT is folded and ropes are tied to its
folded orificial members. Then, the folded RT is twisted and
packaged for shipping. Reference is now made to FIGS. 2A-2D in
which several views of the RT at different stages of a packaging
process according to a preferred embodiment of the present
invention are correspondingly shown. In FIG. 2A a frontal view of a
flattened, pre-folded RT of FIG. 1A is shown. In FIG. 2B a frontal
view of a section of the same RT, partially folded, is shown. In
FIG. 2C a schematic presentation of same RT, completely folded, is
shown. Fully folded RT 36 has orificial members 38 located at its
topside folded as well. At this stage a rope, not shown, is tied to
each folded orificial member to enable subsequent pulling out of
the corresponding orifice of the metal tank as is described infra.
Twisting of the folded RT is carried out by rotating the upper and
lower ends of RT 36 in opposing directions around axis 42 as is
indicated by arrows 42A and 42B correspondingly. In FIG. 2D a
packaged, folded and twisted RT is schematically shown. RT 46 is
inserted into hollow cylinder 48 such that folded orificial members
50 and ropes 52 tied to them are the last to be inserted. The
length of each of ropes 52 is not smaller than the height of hollow
cylinder 48. The free ends of these ropes are further secured to
the inner wall of the hollow cylinder near its upper end. Lids, not
shown, optionally cover the two orifices of hollow cylinder 48
after the folded and twisted RT, folded orificial members 50 and
ropes 52 are completely inserted into cylinder 48. The external
radius of cylinder 48 is smaller than the inner radius of the
corresponding main orifice of the metal tank. The width of the wall
of cylinder 48 which is made of standard packaging material such as
cardboard or plastic sustains the stresses applied by the twisted
RT and protects the RT from being damaged during shipment and/or
storage. Optionally the inner surface of hollow cylinder 48 is
coated with a lubricant such as a talcum powder which does not harm
the RT. Orificial members, intended for other orifices of the metal
tank and are made of flexible materials, are similarly packaged in
corresponding cylinders.
[0023] The shape of the package need not be cylindrical. Any shape
that fits in with the shape of the corresponding orifice of the
metal tank, such that the packaged RT, or the orificial members,
can be inserted into the corresponding orifices, is acceptable.
Nevertheless the packaging is constructed such that it is removable
from the RT, or the orificial members, after the package is
inserted into the interior of the metal tank.
[0024] Installing the RT
[0025] First the metal tank is emptied, any existing sediments are
removed and the inner surface of the tank is rinsed and cleaned. A
thorough cleaning such as by chemical solvents, detergents and/or
steam, is particularly required in a periphery of any edges or
sharp bulges that may damage the RT. Such surfaces optionally
require further smoothing. Such smoothing can be carried out by
inner surface coating of the metal tank with plaster or sprayed
with a foamy plastic resin. The RT can then be inserted into the
metal tank through its main orifice.
[0026] Reference is now made to FIG. 3 in which a schematic
presentation of a RT being inserted into a storage tank is shown.
Storage tank 70 has a main orifice 72 through which the packaged RT
is inserted. Hollow cylinder 74 in which the RT is packaged is
pulled upwards from main orifice 72 while RT 76 is forced
downwards. The ropes, not shown, which are tied to the orificial
members of the RT are released at this stage from the upper end of
the cylinder and are manually held while cylinder 74 is completely
removed from the RT. Twisted RT 76 is released and is partially
unfolded by the elastic forces applied by its deformed walls and by
gravity. The releasing and unfolding are manually assisted by
shaking and rotating the ropes.
[0027] The process of fitting the orifices of the RT to the
corresponding orifices of the metal tank is described in the
following. If the RT has more than one orifice, the rope tied to
each orificial member other than the orificial member corresponding
to the main orifice of the metal tank, is pulled out of its
corresponding orifice of the metal tank. Pulling the ropes tied to
such different orificial members is effected by means of a catching
device. Such a catching device is inserted into the metal tank
through the corresponding orifice. Each of the orificial members is
untied and unfolded and further pulled upwards through the
corresponding orifice of the metal tank. The circumferential flange
of an orificial member is rotated around its axis so that the
topside wall of the RT is straitened. By means of such rotations
the topside of the RT and all its assembled orificial members fit
in the corresponding portion of the lumen of the metal tank. The
flanges of all orificial members are secured to the rim of their
corresponding orifices of the metal tank by bolts. Then, all other
orificial members other than the one corresponding to the main
orifice are sealed off. The RT is inflated by pressurizing gas such
as air through the main orifice. Keeping the RT pressurized for a
predetermined time at a predetermined pressure completely untwines
and unfolds the RT and further attaches it to the inner walls of
the metal tank by means of the magnetic pieces. The RT remains
attached to the inner walls of the metal tank conforming to its
lumen even after being depressurized.
[0028] At this stage, installation of all the orificial members not
yet installed is completed. Orifice 84 is an exemplary orifice that
corresponds to either a wide orifice in which a corresponding
orificial member has not been installed during the stage of
assembling a RT, or another orifice such as an orifice for
measuring the level of the fluid which is different from a vent.
Venting orifices such as orifice 85 typically have pipe 86
extending upwards of which one of its ends is connected to the
topside of the metal tank and other end 88 is curved downwards.
[0029] An installation process of orificial members is carried out
preferably as herein described. First an aperture is made by
drilling or punching or cutting the top side wall of the RT which
is attached to the inner walls of the metal tank. The cover of the
metal orifice is removed prior to that. In a case in which the
metal orifice is a vent, a section of the pipe having its curved
end is removed prior to cutting. Cutting such as by drilling is
effected through the corresponding orifice of the metal tank by
employing a corresponding jig. The packaged orificial member is
inserted into the aperture drilled in the topside of the RT.
Insertion of an orificial member is similarly carried out as the
insertion of the RT as described herein above. The cylinder in
which the corresponding orificial member is packaged is inserted
into the metal orifice so that its open bottom end protrudes into
the lumen of the RT. The packaged orificial member is pushed down,
and concomitantly the cylinder is pulled up to completely remove it
from the corresponding orifice of the metal tank. Then the twist of
the orificial member is released further unfolding by elastic
forces applied by its deformed walls. In the case of a rigid
orificial member, the lower end to be inserted in the metal tank is
squeezed, before forcing into the orifice of the metal tank. A
slight upward pulling attaches the circumferential ridge of both
types of orificial members to the rim of the aperture cut in the
topside wall of the RT. Then fitting the orificial member to the
metal orifice of the tank is similarly carried out as described
hereinabove. After bolting the circumferential flanges of the
orificial members to the rim of the metal orifices the covers of
corresponding orifices are replaced and or the sections of a pipe
having a curved end of a vent are reattached to the rim of the
pipes fitted with the corresponding orificial members.
[0030] Reference is now made to FIG. 4 in which an isometric view
of an exemplary jig according to the invention is shown. Jig 100
has tubular guide 102 having cylindrical lumen and circular
aperture 103. The inner diameter of tubular guide 102 is slightly
larger than the diameter of the drill to be employed. The diameter
of circular flange 104 at the top of tubular guide 102 exceeds the
diameter of the metal orifice to which it is to be attached. Neck
106 has a diameter that closely reaches the inner diameter of the
metal orifice. The bottom of the wall of tubular guide 108 is
beveled so that its external lower diameter slightly exceeds the
inner diameter of its lumen. Such a jig is inserted into a metal
orifice so that its tipped end is placed on top of the surface of
the RT and its neck 106 fits in the rim of the metal orifice of the
metal tank. By means of such a jig the aperture formed in the RT by
drilling through the jig is aligned with the orifice of the metal
tank. Optionally after drilling a first hole in the upper wall of
the RT through the lumen of such a jig, the hole is widened by
means of additional drilling through this hole employing a drill
whose diameter is slightly smaller than the diameter of the metal
orifice and is larger than the diameter of the first drill.
[0031] An aged RT need not be removed from an operative metal tank
prior to replacing. A new RT may be installed in a tank
supplemented with a RT of the invention, much in the same way as
described above. The metal tank furnished with the additional new
RT would thereby be converted to a multi-walled tank by such
internal lining with the new RT. Obviously the new RT slightly
differs from the old one previously installed.
* * * * *