Note: Descriptions are shown in the official language in which they were submitted.
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PREFORMED PORTABLE SLAB FOR USE AS A FOUNDATION OR
SPLASH PAD FOR INDUSTRIAL EQUIPMENT
Technical Field
The present invention relates to portable pads or slabs, particularly
to portable precast slabs for use as temporary, removable, or permanent
foundations for industrial equipment, bulk storage tanks, cryogenic liquid
pumps, and the like, and related methods of making and using the slab. It
is also suitable as a protective surface, for example as an off loading or
splash pad for liquid oxygen, or liquid hydrogen, or other cryogenic liquids.
Description of the Drawings
FIG. 1 is a perspective view of one embodiment of the invention.
FIG. 2 is a view of a reinforcing means of an embodiment of the
invention.
FIG. 3 is a side view of an attachment means of an embodiment of
the invention.
FIG. 4 is a side view of an attachment means of an embodiment of
the invention.
FIG. 5 is a top view of an embodiment of the invention.
FIG. 6 is a cross-sectional side view of an embodiment of the
invention.
FIG. 7A is a cross-sectional side lengthwise view of an embodiment
of the invention.
FIG. 7B is a cross-sectional side endwise view of an embodiment of
the invention.
FIG. 7C is a side view of an attachment means of an embodiment of
the invention.
FIG. 8 is a side view of an attachment means of an alternate
embodiment of the invention.
CONFIRMATION COPY
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Detailed Description
For purposes of the description of this invention, the terms "upper,"
"lower," "left," "vertical," "horizontal," "top," "bottom," "lower," "side,"
and
other related terms shall be defined in relation to embodiments of the
present invention as described herein and as illustrated in the
accompanying figures. However, it is to be understood that the invention
may assume various alternative structures and processes and still be within
the scope and meaning of this disclosure. Further, it is to be understood
that any specific dimensions and/or physical characteristics related to the
embodiments disclosed herein are capable of modification and alteration
while still remaining within the scope of the present invention and are,
therefore, not intended to be limiting. The present invention relates to
portable pads or slabs comprised of precast concrete or cement for use as
temporary or removable foundations for industrial equipment, bulk storage
tanks, cryogenic liquid pumps, heat exchangers and associated equipment
such as manifolds, distillation columns, small buildings, and the like.
The use of portable or preformed structures that can readily be
transferred to another location and/or can be used immediately after
delivery and set up is very advantageous. In certain locations permanent
foundations cannot be installed and/or there is a need for a foundation that
can immediately be used. In other situations, rather than purchasing and
installing permanent industrial equipment and components, a business
owner may choose to lease portions of equipment for a certain duration,
and such equipment may be best set up on a foundation, which may also
be leased.
Certain suppliers will also lease expensive equipment such as a bulk
storage tanks to third parties that is used in conjunction with the purchase
of commodities such as liquid nitrogen and oxygen that are used and
replenished on a regular basis. Due to the limited duration of the supply
contracfis and/or leases, it may be unfeasible for these business owners to
permanently install bulk storage tanks or other industrial equipment. In
such a case, a foundation for the bulk storage tank or other industrial
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equipment is necessary, and a slab/pad that is portable and removable can
be used in conjunction with the storage tank or other industrial equipment.
Additionally, business strategies as well as investment and
accounting principles may necessitate portable equipment and
components. Supplier response time can be also be shortened; by
inventorying portable pads, equipment can be installed in less time.
Portable structures are also useful in locations such as easements
and leased premises where permanent structures are forbidden and the
structures and equipment can be readily moved or relocated.
The invention contemplates a portable precast slab, with or without
reinforcement, which is used as a foundation or splash pad. The slab/pad
has a top surface, a bottom surface, a plurality of side surfaces, a length, a
width, and a thickness, wherein the thickness varies and a weight bearing
slab/pad is preferably at least about 6 inches to about 24 inches or more,
and may be up to about 48 inches thick. The thickness of the pad is also
important to prevent the slab from breaking apart during lifting, loading,
handling, use, and the like. Further, the slab is preferably at least about 6
feet in length, and may be up to about 20 feet in length. Of course in other
embodiments, slabs of similar square footage ranges may also be
preferable. Similarly, the slab is preferably at least about 6 feet in width,
and may be up to about 12 feet in width and even wider with the ultimate
limitation being portability. In an embodiment, a slab of the dimensions of
10' x 15' x 16" has been especially advantageous for use as a foundation
for cryogenic storage tanks. In another embodiment, slabs of the
dimensions of 10' x 15' by 6" thick, 10' x 15' by 16" thick, and 10' x 15' by
12" thick have been found to be especially desirous for use as a foundation
for cryogenic storage tanks. The sixteen-inch thick slab that is 10' x 15'
weighs approximately 29,250 pounds.
The slab can be used as a foundation for a variety of industrial
equipment and/or components. The slab rnay be used indoors or outdoors.
The invention also contemplates a portable precast slab, with or without
reinforcement, which is used as a splash pad for the offloading of liquid
cryogens, especially those that are flammable. Certain types of substrates
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such as asphalt are flammable, and the dripping of certain cryogens such
as oxygen onto asphalt can start a fire. In contrast, a cement or concrete
surface or substrate is not flammable. As such, this invention is also
directed to slabs that are used as splash pads. No special coating or films
are required on the surface of the cement or concrete in order for them to
be used as splash pads.
Of course the slabs of this invention that are used as a foundation
for industrial equipment can also be used as splash pads, with or without
holding industrial equipment. If the slab is to be used as only a splash pad
and not as a weight bearing foundation, it does not require that the slab be
of the same thickness as the slab that is used as a foundation. If for
example the splash pad and foundation pad are to be placed adjacent to
one another, slabs of the same thickness may be easier to install.
Further splash pads may be used alone or in conjunction with slabs
that are used as a foundation. Just like the slabs used as a foundation, the
splash pad has a top surface, a bottom surface, a plurality of side surfaces,
a length, a width, and a thickness, wherein the thickness varies and is at
least about 2 inches to about 48 inches, but is more preferably at least
about 2 inches to 6 inches in thickness. The splash pad is preferably a
minimum of about 6 feet in length, and may be up to about 20 feet in length
or more.
In an embodiment, the splash pad is preferably a minimum of about
6 feet in width, and may be up to about 12 feet in v~ridth or more. In a
further embodiment, a preferable splash pad is of a length of about 4 feet
and a width of about 8 feet. In another embodiment, the preferable splash
pad is of a length of about 8 feet and a width of about 8 feet. Of course, in
other embodiments, splash pads of similar square footage may also be
used. In all other respects, the splash pad can have the same
characteristics and features of the foundation pad.
Further, the slabs/pads may have a means for attachment that
allows the slab to be lifted and/or moved. The means for attachment may
comprise a variety of apparatus, known to one skilled in the art such as at
least one lift pin or eye loop that is accessible from the top or side
surfaces
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of the slab/pad, and that may or may not be recessed. The slab could also
be designed to be moved by a forklift, or alternatively may be rigged
without any specific attachment apparatus.
The slab/pad may also have a plurality of apertures that are cast into
5 the slab and that are visible from the top or side surfaces. The apertures
can be used for a variety of purposes such as to hold posts or to install
fence posts therein.
Further, the slab/pad may interconnect or interface with another slab
or pad that may be portable or permanent. This may include at least one
side surface that is shaped and/or sized to interconnect or interface with at
least one side surface of another slab.
The slab/pad may have structural reinforcement. If so a variety of
means known to one skilled in the art may be used to reinforce the
concrete or cement.
Also, if the industrial equipment comprises a bulk oxygen or
hydrogen storage tank, preferably an at least 10 foot length by 10 foot
width area on the top surface should be available for liquid oxygen delivery
after the bulk storage tank is placed on the surface of the slab (i.e., an
offloading area for the working end of a tanker truck), or a splash pad may
be placed adjacent to the foundation that has the same or similar width
area. In an embodiment, if the slab is used for a bulk storage tank, the slab
should at least support a storage tank that is filled with at least up to
about
300 to about 3000 gallons of liquid or more. Of course the pads may be
used for tanks holding any other liquids and having any other function. The
pads have also been used for Argon and Nitrogen tanks.
Just like the slabs used as a foundation and splash pads, the pads
that are used for cryogenic liquid pumps or other industrial equipment have
a top surface, a bottom surface, a plurality of side surfaces, a length, a
width, and a thickness, wherein the thickness varies and is at least about 4
inches to about 16 inches, but is more preferably at least about 4 inches to
about 10 inches in thickness. The pads used for cryogenic pumps are
preferably a minimum of about 6 feet in length, at least about 15 feet in
length, and may be up to about 25 feet in length or more. A pad that is 8'8"
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x 24' by 8" thick is one such size that has been used to hold a number of
high-pressure cryogenic liquid pumps. Other pads of various thickness and
sizes are also contemplated for use to hold such pumps.
Because the pad/slab structure must be portable and movable, it is
preferably light enough so that it can be lifted by equipment that is
commonly used to lift apparatuses, such as cranes and forklifts. Is should
also be weighted and sized so that it can be carried by a vehicle that can
safely travel on roads (with or without permits) or other carriers such as
boats.
This invention also contemplates a method of making and using a
portable precast reinforced cement or concrete slab.
As shown in Fig. 1, the precast slab/pad 2 has a top surface 4, a
plurality of side surfaces 6, and a lower surface 8. A precast or premolded
slab means a slab, pad, foundation, or foundation component that is
formed by casting cement into a form or mold at a different location, prior to
the time of actual use as a slab, pad, or foundation for industrial equipment.
The slab 2 also has a length 10, a width 12, and a thickness 14.
Preferably, the slab has a thickness of at least about 6 inches to about 24
inches. The slabs that are used for foundations are preferably comprised
of reinforced cement or concrete 24 and preferably have an attachment
means 16, which allows the slab to be lifted. Again, splash pads may also
have such attachment means.
Attachment means are typically employed to lift and/or move the
precast slab, pad, or foundation elements. The term attachment means
refers to a device or apparatus that can be incorporated into the slab that
allows the slab to be moved or movable. For example, the means for
attachment may essentially comprise lift pins, lift rings, lift bolts, and the
like
and a combination thereof that are preferably are cast steel, or other such
apparatus known or used by one skilled in the art for such purposes. The
means for the attachment are preferably accessible from the top surface
and/or side surface. The cable may be directly wrapped around or looped
through the attachment means, and for example in attachment means with
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a loop clips, hooks and the like that is attached to cable can be inserted
into or through the eye of the loop or around the other types of attachment
means. According to the present invention, the attachment means can also
be used to secure other elements to the precast slabs, including elements
from the industrial equipment such as tie down lines, ground lines, and the
like used by one skilled in the art.
When installed, the top surface of the pad is horizontal with regard to
the ground/substrate, and the pad should be level or substantially level.
The term side surfaces refer to the edges or other regions of the slabs
between the top and bottom surfaces, and where a vertical side surface
may begin.
The slab should be heavy enough to provide a force great enough to
resist sliding and movement during wind and seismic events as well as
displacement, overturning and/or sliding of the equipment such as a bulk
storage tank during such events. Additional weight can also be added on
site, and consist of concrete, cement, or other weights, such as steel, lead,
and water. Piers, gripping members, or other methods known to one
skilled in the art can be used in conjunction with the slab to resist sliding
and overturning forces.
The slab should be sized such that it is capable of bearing the
weight of the industrial equipment that sits upon the surface of the slab.
For example, the design criteria of the preferred embodiment of the
slab/pad should resist moving during wind or seismic events. For example,
the slab/pad should preferably withstand wind speeds of about 100 mph,
such as that caused by a hurricane, and preferably should withstand
seismic zone 4 conditions.
The slab/pad may comprise a unitary piece, or multiple pieces that
are placed adjacent to each other that touch or abut each other. A single
piece slab/pad is preferable as it is easier and to set up. If a large slab is
required, such as one larger than 15 feet long by 10 feet wide, or, there are
weight or transportation problems, a slab comprised of multiple pieces
would be more desirable. Yet, there may be disadvantages to using a
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slab/pad comprised of multiple pieces as is may be more difficult to level
multiple pieces, the assembly may be awkward, and the pieces may come
apart. Fig. 1 shows a slab/pad comprised of multiple pieces with
overlapping portions 9 in a stepped fashion that interface or interconnect.
Alternatively, the slab/pad pieces can fit together in a variety of ways
similar to puzzle pieces and may have a uniform depth at the edges with
interlocking or interfitting projections and recesses, or may instead be
square or rectangular pieces or other shaped pieces that abut one another.
In cases where multiple pieces are used to make a slab, pad, or
foundation, the side surfaces are preferably the area where two pieces are
joined together or placed adjacent to one another to form a pad or a slab. If
so, at least on one side of the slab may have the ability to interconnect
and/or interface other pads or slabs, portable or not, in order to create a
larger surface. Should it become necessary to join the portable foundation
to another, numerous joining means are possible that can be used to
connect one slab/pad to another. Several stakes may be used around the
perimeter of the slab, or a frame may be installed around the perimeter of
the slab to ensure that the slab pieces do not come apart. Alternatively,
metal strap portions may be placed around the joint areas. The slab/pad of
FIG. 1 may also be comprised of a unitary piece, and would lack
overlapping portions 9.
The slab/pad may be of any shape. Preferably, the slab used as a
foundation will be shaped and sized so that there will be a perimeter of slab
left after the industrial equipment is placed on the slab. In some
applications, the slab may be circular, rectangular, square, or of other
shapes that will fit into the area designated for the slab. In certain
applications, a certain slab area is desirable. For example, if the slab is
used as foundation for a bulk storage tank, in an embodiment, at least
about an 8 foot length by an 8 foot width area on the top surface that is
adjacent to the tank should be available for liquid oxygen delivery after the
bulk storage tank is placed upon the pad or slab to comply with industry
requirements for liquid oxygen systems.
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The slab/pad may be made a variety of ways that are known or used
by one skilled in the art. For example, concrete or cement can be poured
into a form that that sits on a table, similar to wooden forms that are built
by
contractors when foundations are constructed on-site, and the table must
be designed to bear the weight of the filled form. The forms may be made
of plastic, wood, metal and other durable materials. The forms are
preferably steel as is the table. Once the concrete or cement is cured,
which typically takes about 1-2 weeks, the sides of the form are removed
leaving the slab/pad sitting on the steel table. When the concrete or
cement dries, it pulls away from the table and the slab can be lifted off the
table. Other methods of molding as well as other types of concrete or
cement may be used that are known or used by one skilled in the art.
Adequate curing is essential to obtaining good quality concrete or
cement and contributes to the durability and the wear resistance of the
slab/pad. During the curing process, the concrete or cement should not dry
out prematurely, but should retain moisture and gradually dry in order to
build up strength and gain durability and wear resistance. The amount of
time required to cure will depend upon the size and thickness of the slab
pieces as well as type of concrete or cement used. To slow the drying, the
slab/pad can be covered with plastic sheeting after the mold is filled.
Alternatively, a commercial curing compound may be sprayed, brushed or
rolled onto the surface of the concrete or cement. Also, for example, a
water-reducing admixture such as one that meets ASTM C494 standards
may also be mixed into the concrete or cement. Further, it is preferable
that calcium chloride admixtures be avoided.
In an embodiment, the bottom of the slab/pad is concrete or cement.
Of course the plates or other apparatuses may also be attached or joined
to the bottom of the slab/pad. For example to increase friction between
the soil and the foundation or to grip the substrate, rebar or other metal or
other materials that are rigid or semirigid could be could be molded into or
otherwise attached the bottom of the concrete or cement pad/slab.
The cement that is used is preferably conventional cement, such as
Portland cement, ASTM C 150, Type 1. The concrete that is used is
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preferably conventional concrete, such as Portland cement, ASTM C 150,
Type 1, which has an ultimate compressive strength of at least about 2000
psi, and preferably to about 4000 psi. Of course, high strength concrete
could also be used for at least a portion of the slab/pad. The maximum
5 water cement ratio is preferably about 0.45, with normal weight aggregate
such as ASTM C33, with preferably no more than about 5% voids in the
concrete. Other aggregates, and criteria that are known or used by one
skilled in the art can also be used with respect to the choice of concrete or
cement, aggregate, and percentage of voids in the concrete or cement.
10 Depending upon the weight requirements, a portion of lightweight concrete
or cement may also be used to form the slab/pad.
Varying densities of concrete or cement can also be used to
increase the stability of the slab. For example, higher density concrete or
cement may be used in certain areas, such as the perimeter and edges,
with lighter weight concrete or cement in locations such as the center. Also
the slab/pad can be weighted such as at the edges to increase the stability
of the slab/pad.
For durability, the concrete or cement is preferably reinforced. For
example, a plurality of wires, rebars, rods, bars, plates, gravel, glass,
glass
fibers, or carbon fibers and a combination thereof can be used as a
reinforcing means and are cast into the concrete or cement. Bars or rods
22, and rebars 26 such as those made from metal, fiberglass, or polymers
or a combination thereof are preferably used to reinforce the concrete or
cement slab. See Fig. 1. Rebars are the most preferable.
In an embodiment, the preferable rebar comply with ASTM A 615
specification, and are grade 60 bars. Other standards known or used by
one skilled in the art may also be used. If the bars are bent or deformed,
they are preferably bent or deformed while cold. Further, the rebar or rods
may also be formed into a support frame, and if desired, the means for
attachment can be is removably or securably attached to the support
frame, rebar, or rods. Preferably, there is at least a 2-inch to 3-inch
thickness of concrete or cement that covers the rebars, bars, or rods, or
plates. If glass, gravel, pebbles, broken stone, slag, or carbon fibers are
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chosen, they are preferably interspersed throughout the concrete or
cement. See e.g. Fig. 8. The rebars or rods are placed in the form at the
time of casting and act to strengthen the slab after the slab has cured.
Preferably, conventional rebar 26, such as ASTM A36 steel is used.
The rebars may be arranged and spaced in a variety of ways. Preferably,
the rebars or rods are no more than about 3 feet apart, and are preferably
about 12 inches to about 18 inches on center with respect to each other.
Also, the rebars are preferably at least about #3 to about #10 rebar which is
equivalent to about 3/8 inch in diameter to about 1-'/ inches in diameter or
more. Of course, rebar of a greater diameter can also be used. Further,
the rebars may be parallel to one another and are preferably further criss-
crossed. The rebar may be one layer thick, made into a 3 dimensional
support frame, or instead two layers or more of rebars can be used. For
example, in an embodiment, the top rebars can be #5 or 5/8 rebar in
diameter, are criss-crossed, and are spaced about 16 inches each way,
while the bottom rebars are # 8 rebar or 1 inch in diameter and are criss-
crossed with spacing about 12 inches to about 18 inches on center from
each rebar. Further, when two layers are used and the rebar is criss-
crossed, the rebar may be staggered and spaced such that rebar is present
about every 6 inches to about every 8 inches.
If the slab/pad is such a length that extensions must be used to
splice the rebars to each other, the rebar is preferably overlapped at the
spliced areas 27, such as in accordance with ACI 318, and preferably not
less than 40 bar diameter, not less than about 1 inch to about 6 inches of
rebar in the lapped area. See e.g., Fig. 7A. Other criteria known or used
by one skilled in the arfi may also suffice. The rebars or rods can also be
prestressed prior to molding, if desired. Prestressed refers to an object that
is stretched and stressed prior to being molded in the slab.
Because the slab is portable, it preferably has a means of
attachment that allows the slab to be moved and/or lifted, such as by a
cable. The term cable refers to a line, strand, or chain or other such
devices known or used by one skilled in the art that are which may be
attached or connected to the attachment means. A variety of apparatuses
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can be incorporated into the slab/pad that allows the slab/pad to be moved.
For example, the means for attachment may comprise lift pins or lift rings
that are preferably are cast steel, or other such apparatus known or used
by one skilled in the art and are preferably accessible on and from the top
or side surface. Fig. 3 is a cross-section of a lift pin that is removably
attachable to the slab. The pin 30 is steel and has an enlarged head 32
that allows cable 40 to be wrapped around the head, and has a threaded
end 34 that is insertable into corresponding threads 36 in a metal housing
38. Fig. 3, shows the use of gravel 39 in a cement matrix 40. Mortar could
also be used. Of course the concrete may also be comprised of cement or
mortar with pebbles, broken stone, or slag.
If the lift pin or other attachment means are accessible from the top,
they are preferably perpendicular to the top surface of the slab. If they are
accessible from the side surface, they are preferably perpendicular to the
side surface(s). One such lifting pin is supplied by Jenson Pre-Cast, and is
an 8-ton lift pin. Preferably, the lift pins do not extend beyond the top
surface of the concrete or cement. In an embodiment, attachments known
as "knuckles" are attached to embedded lift pins, and cables are attached
to the "knuckles".
Lift pins are also sold by other companies such as Conac, and come
in varying strengths ranging from at least about 1 ton to about 26 tons. The
required strength of the lift pin will depend upon weight, thickness, and size
of the slab/pad or other such factors known or used by one skilled in the
art. Fig. 4 shows an attachment means that has a looped end 42 that
protrudes from the top surface 4 of the slab 2 that is embedded in the 24
slab. The eye loop allows for cable hooks to be inserted into the eye 44 of
the loop. Preferably, the attachment means do not protrude from the
surface, and are preferably recessed as in Fig. 7C. The eyebolt may be
threaded on one end and looped on the other end. Fig. 7B and 7C shows a
further embodiment of an attachment means that is a pin 50 having an
enlarged end 52 at both the surface of the slab and the end that is
embedded into the slab. Also, the pin may be located in a recessed
surface 5 of the slab so that it does not protrude above the top surface of
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the slab. This can be accomplished by placing a cap on top of the pin to
create the void at the top of the lifting pin. As a further alternative, Fig.
8
shows an anchor bolt 54 with similar stress and weight bearing capabilities
that has an enlarged end 58 that allows cables to be attached thereto. The
anchor bolt may be embedded directly into the concrete or cement, such as
at a depth of 12 inches 56.
If the attachment means such as a lift pin or bolt is not attached to
the rebar, it is preferable to embed the attachment means at least about
one-half to about three-fourths of the width of the slab so that the
attachment means will not pull out of the slab when the slab is lifted and/or
lowered by attaching cables and the like to the attachment means.
All of the foregoing pins and attachment means are preferably
placed within the form before the concrete or cement is poured into the
form or mold and/or before the concrete or cement begins to dry. However,
the attachment means may also be installed after the concrete or cement is
cured. For example, a hole could be drilled through the pad and a rod with
a hook or eyelet with a bottom plate would be installed_ Also the holes may
- be filled with epoxy after the attachment means is inserted.
The attachment means should be placed at a certain depth that
precludes them from pulling out of the concrete or cement, such as a depth
of at least about 4 to about 8 inches to about 12 inches to 14 inches or
more. Of course the depth will be limited by the thickness of the slab. The
slab when used as a foundation is preferably at least about 1 foot thick to
about 4 feet thick, depending upon the specific use. For example, in a slab
that is 16 inches thick, the attachment means such as a pin is preferably
inserted to a depth of about 12 inches. Alternatively, the embedded end of
the attachment means may be attached to the rebar, such as by wrapping
the embedded end of the attachment means around the rebar or otherwise
securably or removably attaching the attachment means to the rebar.
Depending upon the size and thickness of the slab, one or multiple
means for attachment may be used. The number and spacing of the
means for attachment should be apparent to one skilled in the art and will
depend upon the strength of the attachment means as compared to the
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weight and size of the slab so that stresses do not break the means for
attachment or cause the attachment means to pull out of the slab. For
example, in Fig.l, there is only one means for attachment 16 that is located
at or near the center of each slab 2. In contrast, the slab 2 of Fig. 5 has a
plurality of separate means for attachment, and in an embodiment that is
feet width by 15 feet length and 16 inches thick, three to four 8-ton lift
pins are used. In any case, the means for attachment should be spaced
and located so that the slab will be approximately level and easy to control
when it is moved and placed upon the ground or other substrate.
10 The substrate 18 such as asphalt or ground upon which the slab is
placed is preferably level prior to placing the slab on the substrate or
ground. See Fig. 7A. If the surface is not level, the surface will preferably
be leveled by a layer not more than about %2 inch depth to about 1 foot
depth of about °/ inch to about'/2 inch, or more size angular aggregate
below the pad, such as by Air Liquide America. Alternatively, the slab can
be leveled after it is placed upon the substrate or ground. For stability, it
is
preferable that the slab not be installed on wet or soft soil. To ensure
stability, the preferable allowable soil bearing pressure is at least about
1000 psf (pounds per square foot). Also, preferably, there will be positive
drainage from the substrate.
After the slab is installed, there is no waiting for the slab to dry as it
is already dried and cured prior to moving the slab. Therefore the slab can
immediately be used as a foundation for industrial equipment 66 such as a
bulk storage tank 64 that can be placed directly upon the top surface of the
slab. See Figs. 5, 7A. Any equipment can be placed upon the slab as
long as the slab meets the seismic load demands of the equipment, as
determined by a structural engineer or other person skilled in the art.
Further, if the slab is used to support a storage tank that is placed
upon the top surface, the additional weight from the stored liquid must be
taken into account with respect to the size and thickness of the slab. For
example, in an embodiment, for a slab that is 15 foot long by 10 foot wide
slab, and 16 inches thick, the storage tank can be filled with up to about
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1500 to about 3000 gallons of liquid oxygen. The weight of a storage tank
with about 1500 gallons of liquid is about 28,100 pounds, and a storage
tank with about 3000 gallons of liquid is about 47,000 pounds.
If it is desirable to install fencing around the perimeter of the slab
andlor the industrial equipment, multiple apertures 70 which can hold fence
posts can be incorporated, into the slab, such as by molding or drilled into
the molded slab. See Fig. 5. The apertures 70 may comprise blind holes
that extend part way through the depth of the slab, or may comprise holes
that extend through the thickness of the slab. See Figs. 6, 7A. The holes
may be of a diameter that is sufficient to receive fence posts. For example
4-inch diameter holes are used to receive 3-inch diameter fence posts that
are installed in the field. To create the holes, 4-inch PVC capped pipe is
placed in the mold/form before the concrete or cement is poured. The PVC
pipes create the multiple 4-inch diameter voids. At a minimum, it is
preferable to provide holes at least in every corner of a rectangular or
square slab. It may also be advantageous to provide additional holes for
the fence posts 7. For example, in a 15 foot long by 10 foot wide slab that
holds a bulk storage tank or vessel 64, it has been determined that at least
nine holes should be molded into the slab.
The slab must preferably also adequately drain. In most
circumstances, a flat slab will adequately drain. As an alternative, the slab
may further have a plurality of furrows 75 in the top surface of the slab to
ensure drainage of water from the slab. See Fig. 5. Furrows may be
incorporated by pressing a form into at least a portion of the top surface of
the concrete or cement, which has not hardened, or the furrows may be
made by other ways known to one skilled in the art. However, the furrows
should be strategically located so that they do not cause the top surface of
the slab to be unlevel. Further, the concrete or cement may be finished by
a broom before it hardens so that the top surface is not slick.
In an embodiment, a vessel leg plate 62 of the vessel leg 66, such
as for a bulk storage tank, is also anchored to the slab, such as by an
anchor bolt and epoxy. In an embodiment, a hole of a diameter of
approximately 3/ " to about 1 %2 " that may extend as deep as the thickness
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of the slab is drilled into the slab and/or vessel leg plate at the desired
position, then an epoxy pack is inserted and is ruptured by the bolt, mixing
the epoxy portions together. A nut may then be installed upon the bolt to
further secure the leg plate, which is accessible through a portion of the
vessel leg that is typically open. For example, Hilti supplies such epoxies
and anchor bolts, and other such adhesives and fasteners are also
commercially available. Of course other such methods of securing the
vessel leg and leg plate known to one skilled in the art may also be used.
In an embodiment, a layer of grout 60 may also be used between the
vessel plate and the top surface 4 of the slab. The legs or portions of other
types of industrial equipment may also be secured to the slab.
Again, a method of using a portable precast slab as a foundation for
industrial equipment is contemplated comprises: providing a portable
precast slab that has a top surface, a plurality of side surfaces, a lower
surface, a length, a width, and a thickness. During use, the lower surface
of the slab is placed on ground, and the level of the slab is checked and/or
the slab is leveled. Next, at least one piece of industrial equipment can be
placed on the top surface of the slab.
The method also contemplates the step of casting reinforcing means
into the concrete or cement, wherein the reinforcing means is selected from
the group consisting essentially of wires, rebars, rods, bars, plates, gravel,
glass, or carbon fibers or a combination thereof.
The method also comprises the step of providing means for moving
or lifting the slab that is accessible from the top surface or side surface of
the slab. The means for lifting or moving may be selected from the group
consisting essentially of at least one lift pin, at least one lift ring, at
least
one lift bolt, an anchor bolt, and a combination thereof. The means for
attachment may be securably attached or removably attachable. Also, the
method further comprises the step of attaching a cable to the lifting means
and lifting the slab.
In this method, for example, the industrial equipment may comprise
a bulk storage tank. If so, it may be desirable to provide a slab that has at
least a 10-foot length by a 10-foot width area on the top surface adjacent to
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the tank that is available for liquid oxygen delivery after the bulk storage
tank is placed on the top surface of the slab.
The slab may comprise multiple pieces and the pieces may be
placed adjacent to each other to form the slab.
Further in this method, fencing may be installed around the
perimeter of the slab and/or the industrial equipment.
Also this method may further comprise the step of using at least a
portion of the slab as a splash pad.
A method is also contemplated for making a precast reinforced slab
that is used as a foundation for at least one bulk storage tank or system
that comprises providing a mold or form, at least partially filling the mold
with concrete and placing at least one rebar or rod within the concrete or
cement to reinforce the concrete or cement, wherein at least one rebar or
rod has at least one lift pin or means for attachment that is integral with or
removably attached to the at least one rebar. Next, the rebars or rods are
covered with concrete or cement.
Then, the concrete or cement is allowed to dry and/or cure, thereby
forming a slab/pad, wherein the slab/pad has a top surface, a bottom
surface, a plurality of side surfaces, a length, a width, and a thickness. The
slab is removed from the form when the slab is at least partially dried. In
this method, there may also be a plurality of apertures that are cast into the
slab that are visible from the top surface. The apertures have a variety of
uses and for example can be used to install fence posts therein.
In this method, the mold or form provides at least one side surface
shaped so that the slab is capable of interconnecting or interfacing with at
least one side surface of another slab.
Further, in this method, a plurality of rebars or rods are used as a
reinforcing means, and the rebar is placed parallel to one another and/or in
a criss-cross fashion.
Further, where a plurality of rebars or rods are used/as a reinforcing
means, the rebars or rods are arranged to form a three-dimensional
support structure that is cast into the concrete or cement. Also in this
method, the rebar or rod may be prestressed prior to molding.
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In this method, the slab is dried and/or cured prior to use.
In this method, at least a portion of lightweight concrete or cement or
other materials designed to reduce the weight of the preformed pad may be
used to form the slab.
Further, as part of this method, a plurality of furrows may be made in
the top surface of the slab to ensure drainage of water from the top surface
of the slab.
Additionally, if the pad is used as a foundation for a bulk storage
tank, the slab preferably has at least a 10-foot width by 10-foot length area
on the top surface that will be available for liquid oxygen delivery after the
bulk storage tank is placed on the top surface of the slab.
The method of invention also contemplates the creation of a
cryogenic liquid storage and supply system, which can be easily installed
and removed as desired. Various embodiments of the invention include a
cryogenic liquid storage tank; and optionally, one or more of the following
pieces of equipment, which are typically used in the industrial gas industry:
a vaporizer; a pressure control means; a gas filtering means; a telemetry
unit means; a pump means; a tank filling means; piping, a piping support; a
gas storage cylinder; and a splash pad.
In one preferred embodiment, the cryogenic system has a fence
enclosure. The fence enclosure is added for safety reasons to protect
against unauthorized entry by personnel not trained to properly operate the
cryogenic system. Additionally, the fencing provides a demarcation of the
boundary lines between what belongs to the cryogenic system owner and
what does not.
The method further includes installing the concrete foundation at
substantially the same time as any other members of the system. As
described earlier, the foundation is placed into position by offloading it
with
a crane. Once the system is no longer required at the specific location, the
system is disassembled in accordance with standard engineering practices.
The equipment is first removed, and then the slab is removed in a similar
manner as it was installed.
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Once the system is dismantled, each of its pieces is available, either
separately or together, for use at another location. In one preferred
embodiment, the entire system, including the foundation, is re-assembled
for use at another location.
The invention also contemplates an apparatus for storing and
supplying cryogenic liquids comprising at least one portable pre-cast slab
foundation, as described earlier in the specification, and a cryogenic liquid
storage tank. Preferred embodiments include one or more of the following
pieces of equipment, which are typically used in the industrial gas industry:
a vaporizer; a pressure control means; a gas filtering means; a telemetry
unit means; a pump means; a tank filling means; piping, a piping support; a
gas storage cylinder; and a splash pad.
The stored cryogenic liquid contained in the tank may be nitrogen,
oxygen, argon, carbon dioxide, hydrogen, and helium.
The details associated with the construction of such a portable pad
suitable for this use have been previously described.
It is noted that the methods and embodiment of apparatus described
herein in detail for exemplary purposes is of course subject to many
different variations in structure, design, application and methodology.
Because many varying and different embodiments may be made within the
scope of the inventive concepts) herein taught, and because many
modifications may be made in the embodiment herein detailed in
accordance with the descriptive requirements of the law, it is to be
understood that the details herein are to be interpreted as illustrative and
not in a limiting sense.
Further, it will be understood that many additional changes in the
details, materials, steps and arrangement of parts, which have been herein
described and illustrated in order to explain the nature of the invention, may
be made by those skilled in the art within the principle and scope of the
invention as expressed in the appended claims. Thus, the present
invention is not intended to be limited to the specific embodiments in the
examples given above and/or the attached drawings.
