Created by
Michael D. Kiser.
| PCT |
WORLD
INTELLECTUAL PROPERTY ORGANIZATION
INTERNATIONAL
BUREAU
INTERNATIONAL APPLICATION PUBLISHED UNDER THE
PATENT COOPERATION TREATY
(PCT) |
 |
| (51) International Patent
Classification 6: B32B 31/00,
3/28, B27N 9/00 |
A1 |
(11) International
Publication Number: WO97/15444
(43) International Publication Date: 1 May
1997 (01.05.97) |
| (21) International Application
Number: PCT/US96/17016
(22) International Filing Date: 25
October 1996 (25.10.96)
(30) Priority Data:
08/550,094 27 October
1995
(27,10,95) US
(71) Applicant: FLAME SEAL PRODUCTS,
INC. (US, US); Suite 310, 4025
Willowbend Boulevard, Houston TX 77025
(US). (NEW ADDRESS: 15200 WEST DRIVE HOUSTON
TX 77053)
(72) Inventor: KISER, Mike
D.:
(74) Agents: HALL, Elizabeth, R.
et al.; Winstead Sechrest & Minick P.C., Suite
5400, 1201 Elm Street, Dallas, TX 75270
(US).
|
(81) Designated States:
AL,AM,AT,AU,AZ,BB,BG,BR,BY, CA,CH, CN, CU, CZ, DE, DK,
EE, ES, FL, GB, GE,HU, IL, IS, JP, KE, KG, KP, KR, KZ,
LK, LR, LS, LT, LU, LV, MD, MG, MK, MN, MW, MX,
NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, TJ,
TM, TT, UA, UG, UZ, VN, ARIPO patent
(KE, LS, MW, SD, SZ, UG), European patent (AT, BE, CH,
DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL,
PT, SE), OAPI Patent (BF, BJ, CF, CG, CI, CM, GA, GN,
ML, MR, NE, SN, TD, TG).
Published
With
international search report.
Before the
expiration of the time limit for amending the claims and
to be republished in the event of the receipt of
amendments. |
(54) Title: PASSIVE FIRE PROTECTION
SYSTEMS FOR CONDUITS
(57) Abstract
A
passive fire protection system for the protection of
conduits, cable trays, and support rods, against flame
and heat in a severe total
environment type fire such as a hydrocarbon fire which
includes a multi-layered (laminated), flexible material
(11, 12, 13, 14) containing a plurality of layers
of intumescent materials. This multi-layered
material (11,12, 13, 14) is configured such that it
provides a containment system for the carbonaceous foam
resulting from the expansion of the intumescent
materials. |
United States
Patent [19]
[11]
Patent Number:
5,681,640
- Kiser
[45]
Date of Patent: Oct. 28,
1997
[54]
PASSIVE FIRE PROTECTION
SYSTEMS FOR CONDUIT, CABLE TRAYS, AND
SUPPORT RODS.
[75] Inventor: Michael D. Kiser,
Pearland, Tex.
[73] Assignee: Flame Seal
Products, Inc., Houston, Tex.
[21] Appl. No.: 550,094
[22] Filed: Oct. 27, 1995
[51] Int. Cl(to the
6th)..........B32B 3/28;E02D 5/60 [52]
U.S.Cl...............428/181; 428/34.5; 428/34.6;
428/36.5; 428/245; 428/268; 428/913; 428/920; 428/921;
405/157; 405/211; 405/216; 156/82;156/88
[58] Field of Search
........... 428/174; 181., 428/920. 921. 289. 245. 168.
76. 101. 121. 285. 34.5. 34.6. 36.5. 913; 156/82. 171.
87.88; 405/157. 195.1.211. 216; 166/350. 357. 364.
367
|
(56)
References Cited
U.S. PATENT DOCUMENTS
4,600,634 7/1286
LANGER.......... 428/220
5,158,397 10/1992 KOOS ET AL......
166/364
5,169,265 12/1992 BUTLER..........
405/224.4
5,206,088 4/1993 RAEVSKY.........
428/413
5,378,530 1/1995 METIVAUD ET AL...
428/447
Primary Examiner-Donald
Loney
Attorney,
Agent or Firm-Winstead Sechrest & Minick
P.C.
[57]
ABSTRACT
(57) A passive fire protection
system for the protection of conduits, cable trays,
and support rods against flame and heat in a severe
total environment type fire such as a hydrocarbon fire
which includes a multi-layered (laminated), flexible
material (11, 12, 13, 14) containing a plurality
of layers of intumescent materials. This
multi-layered material (11,12, 13,14) is configured
such that it provides a containment system for the
carbonaceous foam resulting from the expansion of the
intumescent materials.
17 Claims, 6 Drawing
Sheets |
1
WO 97/15444
1 /
6
Patent Number:
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& PCT/US96/17016
WO 97/15444
2 /
6
Patent Number:
5,681,640
& PCT/US96/17016
WO 97/15444 3 /
6
Patent Number:
5,681,640
& PCT/US96/17016
FIG. 6
FIG.
7
WO 97/15444 4 /
6
Patent Number:
5,681,640
&
PCT/US96/17016
WO 97/15444
5/
6
Patent Number:
5,681,640
& PCT/US96/17016
WO
97/15444
Patent Number:
5,681,640
&
PCT/US96/17016
WO
97/15444
PCT/US96/17016
PASSIVE FIRE PROTECTION SYSTEMS FOR CONDUITS
FIELD OF THE INVENTION
The present invention
relates generally to the design of a passive fire protection
system and more particularly, to an insulative and fire
resistant/retardant wrap suitable for protecting conduits,
cable trays, support rods, and other components from
destruction during a fire.
BACKGROUND OF THE INVENTION
The following are three types of materials that have
been used to protect conduits, cable trays, and support rods,
and other construction materials from excessive heat during a
fire and to retard the fire itself:
(1)
insulation wraps
(2)
endothermic wraps, and
(3)
intumescent coatings and materials.
Each category of these insulative materials has its
drawbacks.
There are two primary problems with
insulation wraps such as alumina silica blankets or mineral
wool blankets. In order to achieve suitable fire protection in
a severe total environment type fire, viz, a hydrocarbon fire,
the material has to be very thick and as a result causes the
two problems inherent in such systems. First, the fact that
the material is thick causes problems with clearances between
the protected item and adjacent or interfering items.
Secondly, insulation systems cause a problem during normal
operations because of the insulating factor. This problem is
called “ampacity derating,” which means that the heat
generated by electrical cables within the conduit or cable
tray is restricted from escape and causes the safe operating
level of current allowable in said cables to be reduced or
overheating will occur. The more severe the fire protection
requirement, the more difficult this “Catch 22” becomes
because the only way to increase the fire protection effect is
to make the system thicker.
When this option is used to try to
solve fire problems, it is common for the user to have to
reduce the amperage rating of the system within the conduit or
cable tray, thus losing efficiency originally designed into
the systems.
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Endothermic materials are composed
of compounds that activate in a fire situation by breaking
down at the molecular level and releasing trapped water which
then cools the protected item. The most common example of this
is alumina tri-hydrate, which is a dry white powder that
releases large amounts of water at about 1,100 ° F . A well
known endothermic product is the INTERAMä E-50 series flexible wrap systems
available from 3M Fire Protection Products, St. Paul,
Minnesota.
Endothermic wrap materials have
proved to be useful in fire protection in that some of the
“thickness” problems inherent in insulation systems is
somewhat lessened, but endothermics have their own problems.
Due to the fact that the material has water molecules trapped
in dry form, the total system package tends to be quite heavy.
Also, there is still a problem with inherent insulative
properties in products such as the 3M INTERAMä E-50 wrap system because the
system is generally installed in several layers with careful
sealing requirements at all seams to hold in the water that
will be released in a fire. The net effect of this is that, in
every day operations, heat is still trapped within the system
leading to ampacity derating.
Endothermics, such as 3M’s
INTERAMä E-50 wrap
system are also generally difficult to install, with very high
associated labor costs. Also, once installed, these systems
are extremely difficult to remove and replace in order to do
maintenance work on electrical conduits or cable trays.
Intumescent products have gained a
high level of interest recently because of the problems
associated with insulations and endothermics as outlined
above. Intumescent materials are products that “grow” or
“thicken” only when exposed to heat, creating an insulation
layer that separates the protected item from the fire.
One major advantage of intumescent
materials is that the unreacted material is very thin and
non-insulative. This characteristic makes intumescent
materials ideal for insulating conduits and cable trays since
these materials do not require ampacity derating as the
insulation and endothermic systems do. Furthermore,
these materials are simpler to install than insulation or
endothermic systems. In fact, intumescent materials are often
applied as a light weight coating over the area to be
protected. In general, intumescent coatings are a preferred
insulative material because they are thin, non-insulative
(except in a fire), and light weight.
2
However, there are two severe problems with using
intumescent products which make it difficult to provide
consistent insulative protection. These two problems are:
(1) The
carbonaceous “foam” that results when the intumescent
materials expand upon exposure to heat is always very fragile
and is generally damaged by the turbulence of a fire.
Furthermore, expanded intumescent materials will commonly fall
off of the coated surfaces due to the pull of gravity. This
fragile nature of intumescent materials leads to the formation
of “fissures” in the material which allow heat to penetrate to
the protected surfaces. These fissures appear randomly and
give the system a quality of unpredictability that is
undesirable for fire protection systems. These “fissures” are
particularly prominent where the intumescent materials have
been used on curved surfaces or at the corners of sharp
turns.
(2) In addition to fissure formation,
when expanded intumescent materials are exposed to direct fire
and heat in a hydrocarbon fire Exposure Test, the outer
carbonaceous foam that is in direct contact with the fire
tends to erode, thus exposing lower layers of the materials.
The lower layers also erode, causing a geometric reduction of
the effectiveness of the product over time. This eroding
effect magnifies the unpredictability of the system.
Furthermore, this erosion of the materials accelerates the
growth of the above mentioned “fissures,” once formed.
Thus, there exists a need for a
fire protective system that can take advantage of the
favorable qualities of intumescent materials, while providing
a means of stabilizing the carbonaceous foam resulting from
the reaction of the intumescent materials with heat.
It is therefore an object of the
present invention to provide a system which can stabilize
expanded intumescent materials.
A further object of the present
invention is to provide a fire protective system that is
easily customized to meet the specific fire protective needs
of different environments.
It
is another object of the present invention to provide a fire
protective system that is easily customized to meet the
specific fire protective needs of different environments.
It is yet another object of the
present invention to provide a thin, light weight, low
ampacity derating fire protective system.
Still yet another object of the
present invention is to provide a fire protective system that
can be easily custom fitted to any size or shape
structure.
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SUMMARY OF THE INVENTION
The present invention fulfills the
need discussed above by disclosing a multi-layered containment
system for intumescent materials.
In accordance with one aspect of
the present invention, a fire protective system is provided
that contains multiple layers of fire resistant materials with
intumescent materials located between the layers of fire
resistant materials. The resultant multi-layered material
provides a flexible wrap that provides stability to expanded
intumescent materials.
In
accordance with another aspect of the present invention, a
fire protective system is provided that includes alternate
layers of fire resistant materials and intumescent material
that is designed to expand one layer at a time and that will
expand in all directions to provide a consistent and effective
fire protective system.
One
feature and advantage of the present invention is that it
provides a thin, light weight fire protective system with a
low ampacity derating.
Another
feature and advantage of the present invention is that it
provides a fire protective system that takes advantage of the
favorable qualities of intumescent materials and stabilizes
the carbonaceous material that results from the expansion of
the intumescents in response to heat.
Another feature and advantage of
the present invention is that it provides a fire protective
system that can be optimized to meet the fire protective needs
of different environments.
Another feature and advantage of the present invention is that
it is easily installed, removed, and/or replaced on conduits,
cables, trays, support rods, and any other structural
members.
Yet another feature
and advantage of the present invention is that it allows the
intumescent material to expand evenly in all directions, no
matter what configuration is being protected.
Still yet another feature and
advantage of the present invention is that it provides a fire
protective system that can be custom fitted to any size or
shape structure.
An additional
feature and advantage of the present invention is that it
provides a fire protective system that is non-toxic to plants
and animals, contains no petroleum derivatives, and generates
essentially no smoke during exposure to fire or heat.
4
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The foregoing has outlined rather
broadly the features and technical advantages of the present
invention in order that the detailed description of the
invention that follows may be better understood. Additional
features and advantages of the invention will be described
hereinafter which form the subject of the claims of the
invention. It should be appreciated by those skilled in the
art that the conception and the specific embodiments disclosed
may be readily utilized as a basis for modifying or designing
other structures for carrying out the same purpose of the
present invention. It should also be realized by those skilled
in the art that such equivalent constructions do not depart
from the spirit and scope of the invention as set forth in the
appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of
the present invention, and the advantages thereof, reference
is now made to the following DETAILED DESCRIPTION OF THE
INVENTION taken in conjunction with the accompanying drawings,
in which:
FIGURE 1
shows a side view of a preferred embodiment of the
multi-layered material used in the present invention;
FIGURE 2 is
a side view of one embodiment of the invention, illustrating
the manner in which the layers of material are folded;
FIGURE 3 is
a side view of an alternative embodiment of the invention,
illustrating the manner in which the layers of material are
folded;
FIGURE 4 is
a rear view of one embodiment of the multi-layered material,
showing a method used to secure both sides of the material
during manufacture;
FIGURE 5 is
an end view of an insulative strip showing one embodiment that
allows joints to overlap during installation of the
strip;
FIGURE 6 is a cut-away drawing of two overlapping strips
illustrated in FIGURE 5.
FIGURE 7 is
an end view of a preferred embodiment of the present invention
installed around a typical conduit;
FIGURE 8
shows a typical completed installation of a preferred
embodiment of the present invention on an electrical
conduit;
FIGURE 9A
is a side view of one embodiment of the present invention
installed around a cable tray;
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FIGURE 9B is
an end view of an embodiment of the present invention
installed around a cable tray; and
FIGURE 10A
- 10E illustrates the stages of growth of one embodiment of
the present invention during a fire situation.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to the
design and manufacture of an improved passive fire protection
system used to protect conduits, cable trays, and support rods
against the flame and heat of a total environment-type fire,
such as a hydrocarbon fire.
Referring now to the drawings, and initially to FIGURE 1, it
is emphasized that the Figures, or drawings , are not intended
to be to scale. For example, purely for the sake of greater
clarity in the drawings, layer thicknesses and spacing
are not dimensioned as they actually exist in the assembled
embodiments.
FIGURE 1
illustrates one embodiment of a flexible, multi-layered (or
laminated) material 10 that is used to construct a fire
protective or insulative wrap. For example, the embodiment
illustrated in FIGURE 1 is comprised of four layers of heat
resistant materials. An exploded view of those layers is seen
on the left side of FIGURE 1. The component layers of this
multi-layered material 10 may be composed of the same heat
resistant materials or different heat resistant materials.
Interspersed between the layers of fire-resistant materials is
a high-level intumescent material which will expand
significantly during a fire.
Although any flame resistant material can be used in the
present invention, preferred embodiments will include metal
foils, fire-resistant fabrics, or a combination of materials
such as aluminum foil, stainless steel foil, fiberglass, or
alumina silica fabric. A preferred embodiment of the present
invention is illustrated in FIGURE 1. In this embodiment,
layers of fire-resistant material numbered 11,12, and 13 in
FIGURE 1 are made of thin sheets of aluminum foil (such as a
0.002 or 0.003 gauge foil) and folded layer 14 is made of a
fiberglass material. Preferred embodiments of the fire
protective system include at least one layer of folded
material. The material may be folded in any number of
configurations. It may be S-folded, accordion folded or
pleated, as demonstrated in FIGURE 1 by pleats 17. The number
and size of pleats 17 is variable.
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Such variations being dependent upon
the degree of fire protection required. Preferred embodiments
of the present invention have pleats 17 in Folded layer 14
running lengthwise in the multi-layered material 10.
Examples of preferred intumescent
materials that can be used in the present invention to hold
these layered materials together are 3M’s CP-25 intumescent
caulking material that can be obtained from 3M Fire Protection
Products, St. Paul, Minnesota, or a FX-100 coating material
available from Flame Seal Products, Inc. Houston, Texas. Thus,
the embodiment of the present invention illustrated in FIGURE
1 has four layers of heat resistant material held together
with three layers of intumescent materials. The greater the
expansion capacity of the intumescent materials utilized in
the invention the greater the fire protective ability of the
insulative wrap. Preferred intumescent materials will have an
expansion capability of 700% or more. However, materials
having lesser degrees of expansion may suffice in certain
applications depending on the quantity of intumescent used
between layers, the number of layers, the size of the folds,
and the distance between the folds.
A preferred embodiment of the
present invention utilizes two lower layers of .002 gauge
aluminum foil, one middle layer of extreme heat-resistant
fiberglass, and a top layer of .003 gauge aluminum foil. The
top layer uses a heavier .003” foil to increase the strength
and durability of the insulative wrap during installation and
everyday use. The lower layers use a thinner foil since the
lower layers are protected during everyday use and the thinner
foil lowers the total weight of the insulative wrap. The outer
layer of foil is sacrificial in a fire and is essentially
burned or sublimated after about 3-5 minutes. The laminated
multi-layered material 10 described above is further pleated
or folded when made into a fire protective or insulative wrap.
These pleats or folds 15, shown on the right side of FIGURE 1,
run sideways across the multi-layered material 10
approximately perpendicular to pleats 17 in folded layer 14.
Such folds 15 may be simple pleats of S-folds as shown in
FIGURE 1. The number, configuration, and size of fold 15 can
be varied according to the degree of fire protection required,
the expansion capacity of the intumescent materials, and the
size and shape of the protected surface.
The primary containment of the
intumescent materials is accomplished by the system design of
the insulative wrap. Folds 15 in the multi-layered material
will typically expand, or unfold, during the first 10-15
minutes of a fire. Pleats 17 in folded layer 14
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will also contribute significantly to the containment
of the expanded intumescent materials. Fold 15 and pleats 17
allow for linear growth of the insulative wrap as the
intumescent material expands thereby allowing the expanded
insulative wrap to expand around interfering structures and
banded joints. These folds and pleats also allow the system to
expand to seal any penetrations of the system. The ability of
the present invention to expand in a fairly uniform diameter
around protected structures during a fire minimizes the heat
exposure of the protected structure at all points in the
system including sharp corners, banded joints, and points of
intersecting structures.
FIGURES 2 and 3
show side views of preferred folded configurations into which
the above laminated material 10 is formed. Folds 15 are shown
as being a width X and spaced at a distance Y from the center
of one fold 15 to the center of the adjacent fold 15. An
example of folds 15 in the configuration illustrated in FIGURE
2 would be folds 15 that are one inch in width and spaced at
approximately two inches from the center of one fold to the
center of adjacent fold. FIGURE 3 illustrates an alternative
configuration where a similar one inch wide fold 15 would be
spaced such that the distance from the center of one fold to
the center of the adjoining fold would be approximately one
inch. The width of folds 15 and the distance between
folds 15 determine the "unfolded" length of the material and
contributes to the final size of the perimeter of the expanded
insulative wrap exposed to a fire. For example, a one
inch spacing between the center of adjacent one inch wide
folds, as illustrated in FIGURE 3, yields an expansion
capacity of three times the original circumference (or
perimeter) of the protected item. Two inch spacings
between one inch wide folds, as illustrated in FIGURE 2, yield
an expansion capacity of two times the original circumference
(or perimeter).
FIGURE 4 illustrates how the folds
15 in a preferred embodiment of the insulative wrap are
secured to maintain the shape of the insulative wrap for
installation and everyday use. The folded configuration of the
multi-layered material 10 is secured by using an adhesive,
such as an epoxy or a contact glue, between the surfaces of
folds 15. When folds 15 are S-folds, as shown in FIGURE 4,
adhesive is placed on both sides of the middle section 42 of
fold 15. The adhesive will hold the insulative wrap in its
desired configuration during normal use, yet will release the
layers of the S-fold as each layer reaches a certain
temperature and melts or softens the adhesive to allow that
layer of the S-fold to expand and separate from the next
layer.
Preferred embodiments of the
insulative wrap also have an adhesive fire resistant material
46, such as an industrial aluminum or stainless steel tape,
running alone the length of the bottom (or inner) side of the
insulative wrap. The bottom adhesive material
46 can be trimmed to the proper length to fit the dimensions
of the protected item or surface.
This bottom adhesive material 46
serves two purposes. One purpose is to help hold the
insulative wrap in its everyday configuration. The other
purpose is to ensure that the insulative material is held
snugly against the protected item or structure during the
expansion process in a fire. The bottom adhesive material 46
will continue to secure the insulative wrap to the protected
surface during a fire because the insulative wrap will protect
the protected surface from the type of elevated temperatures
that would cause the adhesive material to soften and allow the
insulative wrap to disengage from the protected surface.
By keeping the insulative wrap
firmly in place around the protected surface the expanded
intumescent material will compact as each subsequent layer
begins its expansion. The bottom adhesive material 46 will
thus allow the insulative material to expand in response to
extremely elevated temperatures in an approximately
symmetrical manner. As the insulative wrap is exposed to heat,
its outer layers will expand away from the protected surface
as described in more detail below. This symmetrical expansion
prevents the system from obtaining a “bell shaped”
configuration during a fire which could result in localized
pressure points along the external surface of the insulative
wrap and lead to fissures in the insulative wrap. The bottom
adhesive material thus contributes to the ability of the
insulative wrap to undergo a uniform expansion in all
directions adding to the efficient operation of the fire
protective system.
The insulative wrap may be made in
any number of configurations, shapes and sizes to fit any
shape or size of surface or structural item. However, one
convenient embodiment of the insulative wrap is produced in
strips 50 of any desired length as illustrated in FIGURE 5.
Folds 15 run along the length of the strip 50. One or both
ends of strip 50 may have a narrow area, typically one inch
wide, where the multi-layered material 10 was constructed with
a minimal amount of intumescent material so as to provide a
thinner area, approximately one-half the regular thickness of
the insulative wrap. This thinner area 55, as shown in FIGURE
5, provides a means of overlapping two strips
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50 and securing that overlap with a heat resistant
securing device 68, such as a stainless steel band as shown in
FIGURE 6. When the insulative wrap expands during exposure to
a fire the intumescent materials will expand around the
securing device 68 to protect the securing device 68 and avoid
the production of “hot spots” on the protected surface. The
ability to overlap thinner areas 55 provide an easy means of
protecting surface 62.
FIGURE 7 illustrates one method of
joining the sides of the insulative wrap where it has been
wrapped around an electrical conduit 72 containing electric
cables 75. If the insulative wrap has been constructed such
that it has a space between folds 15, the insulative wrap is
easy to cut in such a space and to join together using
fasteners 78, such as stainless steel hog rings, Typically
when the insulative wrap is installed on an electrical conduit
72, a fastener 78 is placed every 1/2 to one inch apart along
the linear seams of the insulative wrap such as illustrated in
FIGURE 8. The site where fastener 78 secures two sides of
insulative wrap together may be covered with an adhesive metal
tape. Although not essential, this tape adds to the appearance
of the fire protective system and helps reduce moisture
accumulation on fasteners 78.
FIGURE 8 shows the insulative wrap
installed on a typical electrical conduit. FIGURES 9A and B
show a strip 50 of the insulative wrap installed on a typical
electrical cable tray 92.
Turning now to the operation of the
insulative material, FIGURE 10A shows the insulative wrap
illustrated in FIGURE 1 before it has been exposed to a fire.
FIGURE 10B shows the initial activation of the fire protective
system. In FIGURE 10B folds 15 have been released and have
risen to approximately a 9010 is a series of five drawings
showing the growth stages of the described preferred
embodiment of the insulative material during exposure to a
fire. FIGURE 10A shows the insulative wrap illustrated in
FIGURE 1 before it has been exposed to a fire. FIGURE 10B
folds 15 have been released and have risen to approximately a
90 ° angle as internal pressures from the expanding
intumescent materials begin to exert their effect. The
resultant pressures from the expanding intumescent materials
will seek and equilibrium state, and therefore, due to this
design, will yield a symmetrical expansion around the
protected surface. A major advantage of the present invention
is that even if the insulative wrap is breached or eroded at
one point the pressure of the expanding intumescents will
cause the expanded material to fill the breach in the system,
therefore providing a self-healing system. During this initial
stage of activation the outer layer of aluminum foil will burn
off and expose the layer of intumescent material protecting
the folded fiberglass layer.
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FIGURE 10C shows the early expansion
process under way when the first layer of intumescent material
has expanded. The expanded intumescent material will insulate
the lower layers of intumescent material and delay their
expansion. In FIGURE 10D, two layers of intumescent material
are shown expanding. The outer layer of intumescent material
and the first layer under the folded fiberglass layer are
moving toward a state of equilibrium. FIGURE 10E shows the
final configuration of the expanded insulative wrap. At this
point folds 15 and pleats 17 have expanded to their design
limit, the top two layers of intumescent material remains in
its original state against the protected surface, and the
expanded intumescent material has compacted and reached a
state of equilibrium with a common density throughout the
system.
One advantage of the present
invention is that it is designed to include sufficient
intumescent material that even after it has fully expanded it
has residual expansion ability. This design feature
essentially eliminates the problem of fissure formation since
the expanded intumescent material will always be in the
process of “compacting” during a fire situation as additional
intumescent material expands.
Once the entire system has
completely expanded and all intumescent material has reacted
and reached an equilibrium, the expanded insulative wrap will
act as any other insulative material. This fact is but one of
the considerations that is taken into account when deciding
how thick the final system must be after expansion is
complete.
The fire protective effectiveness of
the present invention has been tested for the preferred
embodiment described above. The insulative wrap was installed
around a one inch conduit and the wrapped conduit was placed
in a furnace. Two teflon jacketed thermocouples (T/C 1 and T/C
2 in Table 1) were placed in a furnace to record the furnace
temperature and two thermocouples (T/C 3 and T/C 4 in Table 1)
were placed along the surface of the conduit underneath the
insulative wrap to measure the temperature of the conduit
surface during the testing procedure. The furnace was lit and
within 7 minutes had reached 2000°F and was maintained at
approximately that temperature for 30 minutes as recorded by
T/C 1 and T/C 2 and set forth in table 1. The surface of the
conduits was efficiently protected from the flames and the
2000°F heat. In fact, the surface of the conduit (as recorded
by T/C 3 and T/C 4) was consistently less that 250°F
throughout the entire 30 minute test as seen in Table 1.
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Patent Number:
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&
PCT/US96/17016
The design of the present invention,
a fire-protective and insulative wrap, utilizes the ability of
intumescents to expand in volume during a fire, when
protection is needed. Thus the insulative wrap can be
installed as a thin, light-weight, and non-insulative
material. Further the present invention solves existing
problems with the use of intumescent coatings (i.e., the
formation of fissures and the tearing away of the expanded
carbonaceous material by the turbulence of a fire). The
present invention contains the the intumescent material within
the system as it expands, much as the foil design contains
expanding popcorn in the product JIFFY POPŌ.
The design can be varied according
to the severity of the fire protection requirement by
adjusting the amount of intumescent material in the layers,
adding more layers and by adjusting the size and dimension of
the S-folds to yield a larger expanded diameter.
An enhancement of the insulative
effect of this invention is realized when progressive,
separate “layers” of intumescent materials are designed to
grow outward toward the fire or heat one at a time, thereby
protecting and delaying the successive lower layers from
expanding outward, This delayed effect on the inner
intumescent layers creates an endothermic effect, in addition
to the insulative and heat absorptive properties of expanding
intumescent materials. The protected lower layers, during the
expansion of the upper layers of intumescent materials,
release water in the slowed process of heat exposure and
growth, thereby cooling the protected item with greater
efficiency. During the exposure and growth of successive
layers outward toward the fire, lower layers are protected by
three mechanisms operating at the same time.
1. The
reaction temperature of most intumescent products is 350°F to
500°F. As long as there is any unreacted product within the
system, the layer directly below the reacting product will not
reach its reaction temperature.
2. As
carbonaceous foam forms an grows, an increasingly thicker
insulation layer is formed and acts purely as an
insulator.
3. As the
temperature increases, the exposure of inner layers of
intumescent material to moderate temperatures will release
water producing an endothermic effect, thereby temporarily
preventing the temperature of the inner layers of the
insulative wrap from surpassing 212°F due to the boiling point
of water. The present invention will also
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temporarily trap any steam that is formed which will
also lessen the rate of temperature increase above 212°F.
In summary, the growing material
insulates lower layers and slows them from reacting or
growing. As the heat builds up and reacts the first layer of
intumescent materials the second layer is protected from the
heat. Once the heat gets through the first layer of
intumescent material, or the insulative wrap has completed its
first phase of growth, the next layer of intumescent material
reacts and grows outward further compacting the carbonaceous
foam resulting from the expansion of the first layer of
intumescents. The expansion of the second layer of
intumescents protects the third layer of intumescents from
reacting or expanding to the heat, and so on until the entire
system is expanded to its final size and all intumescent
materials within are compacted within the containment system
provided by the heat resistant materials that are layered
throughout the system. This entire process, plus the above
described endothermic effects and successive reaction
processes, takes time to complete as the entire process is
cyclic in nature. Once the system has completely reacted and
expanded to its full extent the resultant insulative wrap will
act strictly as an insulative material of considerable
thickness.
Although the present invention has
been disclosed in connection with conduits, cable trays, and
support rods in a petrochemical environment, the present
invention may be used wherever fire protection is needed such
as in a home or an office building. The configuration of the
insulative material is easily customized to surround any
circular, square, rectangular, or irregularly shaped
item.
As described earlier, the design
uses layers of metallic foils and fire resistant fabrics to
contain the intumescent materials and protect them from direct
contact with the fire environment, However, modifications can
be made to resist more severe situations such as explosions or
jet fires by using a stainless steel foil outer layer and a
stainless steel mesh lower layer for stronger system
integrity.
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Patent Number:
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The invention provides industry with
an ideal product for fire protection of conduits, cable trays,
and support rods as it has the following properties
(1) Thin;
(2) Light
weight;
(3) Low ampacity
derating (non-insulative except in a fire);
(4) Easy to
install (one layer; simple techniques);
(5) Can be removed
and re-installed;
(6) Safe and
environmentally friendly; and
(7) Easily custom
fitted to any size and shape structure.
TABLE 1
THERMOCOUPLE
TEMPERATURE READINGS
TIME
MINUTES |
T/C 1
FURNACE |
T/C 2
FURNACE |
T/C 3
CONDUIT |
T/C 4
CONDUIT |
| 1 |
1037 |
1289 |
82.8 |
82.4 |
| 2 |
1193 |
1299 |
82.8 |
80 |
| 3 |
1335 |
1484 |
83 |
82.6 |
| 4 |
1615.6 |
1700 |
83.4 |
83.2 |
| 5 |
1742 |
1839 |
84.8 |
84.4 |
| 6 |
1887 |
1938 |
87.6 |
87 |
| 7 |
2032 |
2036 |
90.4 |
89.6 |
| 8 |
1982 |
2010 |
94.8 |
93.8 |
| 9 |
1970 |
1980 |
100.4 |
99.8 |
| 10 |
2008 |
1992 |
108.6 |
109.8 |
| 11 |
1973 |
1974 |
122.6 |
124.2 |
| 12 |
1966 |
1990 |
148.4 |
147.2 |
| 13 |
1922 |
1926.6 |
164 |
176.4 |
| 14 |
1904 |
1900 |
166 |
180.4 |
| 15 |
1995 |
2052 |
173.2 |
183.6 |
| 16 |
1934 |
1938 |
178.4 |
183.8 |
| 17 |
2005.6 |
2014.4 |
183.6 |
183.4 |
| 18 |
1950 |
1948.4 |
187.4 |
184.4 |
| 19 |
1965 |
1964.8 |
190.4 |
190.4 |
| 20 |
1988 |
1993 |
195 |
197.8 |
| 21 |
1987 |
1987.8 |
198 |
201.8 |
| 22 |
2020.4 |
2022.2 |
201.8 |
203 |
| 23 |
1922.2 |
1921.8 |
206.4 |
204.6 |
| 24 |
2024.4 |
2019.4 |
209.8 |
206.2 |
| 25 |
1976.8 |
1986 |
211 |
209.6 |
| 26 |
2004.2 |
2002.8 |
213 |
210.3 |
| 27 |
1987.4 |
1987 |
216.4 |
210.6 |
| 28 |
1968.4 |
1968.6 |
219.2 |
211.2 |
| 29 |
1878 |
1878 |
223.6 |
213.4 |
| 30 |
1968 |
1962.6 |
230.4 |
221.8 |
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Patent Number:
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&
PCT/US96/17016
Having described preferred
embodiments of the present invention, it is believed that
other modifications, variations and changes will be suggested
to those skilled in the art in view of the description set
forth above. It is therefore to be understood that all such
variations, modifications and changes are believed to fall
within the scope of the invention as defined in the appended
claims.
WHAT IS CLAIMED IS:
1. A fire protection
system comprising:
a folded
sheet of fire resistant material. said folded sheet having a
plurality of folds running substantially parallel to each
other;
a flexible layer of
heat resistant material; and
a
layer of an intumescent material localized between said folded
sheet and said flexible layer. said intumescent material
expanding when subjected to elevated temperatures;
wherein said folded sheet will
unfold in response to the expansion of said intumescent
material to provide stability to said expanded intumescent
materials.
2. The fire protection
system of claim 1, wherein said layer of fire resistant
material is comprised of a metallic foil.
3. The fire protection system of claim 2,
wherein said metallic foil is aluminum foil.
4. The fire protection system of claim 1,
wherein said layer of fire resistant material is comprised of
fiberglass.
5. The fire protection
system of claim 1, wherein said intumescent material has an
expansion capacity of about 700% or more.
6. The fire protection system of claim 1,
wherein said intumescent material is FX-100 intumescent.
7. The fire protection system of claim 1.
wherein said folded sheet, said flexible layer of heat
resistant material and said intumescent material are assembled
into a multiple layered wrap and folded to form a plurality of
folds running substantially perpendicular to said plurality of
folds in said folded sheet.
8. The
fire protection system of claim 1, further comprising an
adhesive metallic tape, wherein a one side of said metallic
tape adheres to a surface being protected by said fire
protection system and a second side of said metallic tape
adheres to said flexible layer of heat resistant material,
said metallic tape useful in the installation of said fire
protection system.
9. A fire
protective system comprising:
a plurality
of sheets of metallic foil;
a
fiberglass material having a plurality of primary folds
therein; and
a plurality
of intumescent layers, said intumescent layers disposed
between said sheets of metallic foil and between said metallic
foil and said fiberglass material;
wherein
said metallic foil. said fiberglass material. and said
intumescent layers are assembled into a multi-layered wrap
having a plurality of secondary folds. said secondary folds
extending in an approximately perpendicular direction to said
primary folds.
10. The fire
protective system of claim 9. wherein said secondary folds
unfold in response to the expansion of said intumescent layers
when said intumescent layers react to heat.
11. The fire protective system of claim 9.
wherein said metallic foil is alumina.
12. The fire protective system of claim 9.
wherein said primary folds will unfold as said intumescent
layers expand in response to increased temperatures.
13. The fire protective system of claim 9.
wherein said intumescent layers are comprised of an
intumescent with an expansion capacity of about 700% or
more.
14. The fire protective of
claim 9. wherein said intumescent layers are comprised of
FX-100 intumescent.
15. The fire
protective wrap of claim 9. said insulative wrap having three
layers of intumescent material.
16.
The fire protective wrap of claim 9. wherein said intumescent
layers are configured such that said layers will react to heat
in a sequential manner.
17. A method
of manufacturing a fire protective system. said method
comprising the steps of:
providing a plurality of sheets of heat resistant
material:
providing a folded
sheet of fire resistant material having a plurality of primary
folds therein:
providing an
intumescent material:
assembling a multi-layered wrap by placing said
intumescent material between said sheets of heat resistant
material and between said folded sheet and said heat resistant
material; and
folding said
multi-layered wrap to form a plurality of secondary folds that
are substantially perpendicular to said primary folds:
wherein said primary and said
secondary folds will unfold as said intumescent material
expands in response to elevated
temperatures.
