WATER ABSORBENT FIRE PROTECTIVE COVER FOR LIQUID HOLDING CONTAINERS

Abstract: A fire protective cover for protecting from warehouse fires non-metallic liquid holding containers including composite intermediate bulk containers and bag-in-box containers. The cover has a heat reflective layer facing the container surroundings, a heat insulating layer adjacent the heat insulating layer on the side toward the container, and a water absorbent layer closest to the container. The cover can be placed over the entire container or, where applicable, between the inner receptable and the rigid outer container.

Description: TITLE WATER ABSORBENT FIRE PROTECTIVE COVER FOR LIQUID HOLDING CONTAINERS CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of copending U.S. patent application Serial No. 08/870,163 filed June 6, 1997. BACKGROUND Field Of The Invention This patent relates to a means for protecting from fire industrial size liquid holding containers. More particularly, this patent relates to a water absorbent fire protective cover used to protect from warehouse fires liquid holding containers such as composite intermediate bulk containers and bag-in-box type containers, as well as other containers . Description Of The Related Art Industrial size containers suitable for holding liquids include composite intermediate bulk containers, bag-in-box type containers, fibre and plastic drums and bulk totes. In general, these containers are made from non-metallic materials of construction and may be used for storing and transporting nonhazardous liquids such as grease, food oils, paint and industrial chemicals. Up until now these container have not been suitable for storing and transporting flammable and combustible liquids, since they have not been approved by appropriate fire protection agencies and insurance underwriters for use in storing such materials in protected warehouses . Composite intermediate bulk containers are a popular means for storing and transporting liquids due to their relative strength and ease of use. Composite intermediate bulk containers, or composite IBCs, comprise a rigid outer packaging enclosing a plastic inner receptacle. The outer packaging is designed to bear the entire load and typically comprises a steel cage. The inner receptacle and outer packaging form an integral package that can be filled, stores, transported and emptied as a unit. Experience has shown that when composite IBCs are exposed to fire, the steel cage heats up, causing a transfer of heat from the steel cage to the plastic inner container exceeding the transfer of heat from the plastic inner container to the liquid contents, resulting in an increase in the temperature of the plastic inner container. If the heat exposure from a fire is great enough, the plastic inner container will melt along those areas where the steel cage contacts the inner container. If failure of the inner container occurs, the flammable contents may spill out and be exposed to the fire, making it extremely difficult to extinguish the blaze. As a result, a significant market for composite IBCs has heretofore been foreclosed, or at least made difficult to serve. Bag-in-box type containers, as the name implies, generally comprise a sealed plastic bag inside a rigid outer box, often used for packaging liquids. The outer box may be made of corrugated paperboard, plastic, wood, or other suitable rigid material. Industrial bag-in-box type containers can range in size from 55 gallons to 300 gallons. Unfortunately, like composite IBCs, conventional bag-in-box containers have heretofore been unsuitable for storing and transporting flammable liquids because of the potential fire hazard. Other industrial size liquid holding containers share this same disadvantage. Fibre drums, plastic drums and bulk totes are all unsuitable for storing and transporting flammable liquids. The present invention solves this problem by providing a water absorbent cover for protecting non-metallic industrial size liquid holding containers from fire, particularly warehouse fires. The water absorbent cover may be placed over the container, or, in the case of composite IBCs and bag-in-box type containers, incorporated into the container design by placing the cover between the inner plastic receptacle and the outer rigid container. The fire protective cover has a heat reflective layer, a heat insulating layer, and a water absorbent layer. Generally, the heat reflective layer faces the outside, the heat insulating layer is located adjacent the heat reflective layer, and the water absorbent layer is located on the inside of the cover, toward the plastic container being protected. As previously noted, the cover may be placed over the entire container or between the plastic inner container and the outer rigid container. By maintaining the temperature of the inner container at less than melting temperature, even in the presence of an intense warehouse fire, the invention allows the survival of the non-metallic inner container for a time sufficient for alternative fire protection means (e.g., sprinklers, fire service personnel with water or foam spray fire suppression equipment) to be deployed. Other fire protective devices for industrial applications are known in the art. None, however, solves the problem of protecting non-metallic flammable liquid holding containers from warehouse fires. For example, Szego U.S. Patent No. 4,249,669 discloses a blanket of porous, heat resistant material that floats on the surface of a flammable liquid held within a tank. On ignition of the vapor/air mixture above the liquid the flames recede downwardly until they are extinguished when they reach the blanket. The Szego blanket functions inside of a tank to prevent the main body of liquid from igniting, but does not protect the container. Peterson U.S. Patent No. 5,104,700 teaches a fire protective blanket for fireproofing articles such as electrical conductors, cables, pipes, and electric motors. The blanket comprises a plurality of layers of thick but compressible insulative material held together by fasteners that are less resistant to heat than the insulative layers. When the blanket is exposed to heat, the fasteners fail, allowing the blanket to decompress or expand in thickness. The Peterson blanket is not intended for use with flammable liquid holding containers, nor is it suitable as such. Among other deficiencies, the Peterson blanket requires a certain minimum thickness in order to achieve its fire protection function, making it unwieldy for use with industrial sized liquid holding containers, particularly if it were to be placed inside a rigid container. By contrast, as will be shown, the present invention requires relatively little thickness to protect the liquid holding container from heat . Other fire resistant blankets disclosed in the prior art are directed toward keeping flames away from pipes, valves, motors, and other electrical equipment. By contrast, the present invention is directed toward protecting from fire non-metallic flammable liquid holding containers, particularly composite IBCs and bag-in-box type containers . Thus it is an object of the present invention to provide a means for protecting non-metallic flammable liquid holding containers from fire which possesses all of the aforenoted advantages. A further object of the present invention is to provide a fire protection cover capable of absorbing water from a fire sprinkler system to help cool a covered container in the case of fire. A still further object of the present invention is to provide a fire protective cover for use with composite IBCs that acts in tandem with the contained liquid product/heat sink to keep the plastic inner container below melting temperature . Yet another object of the present invention is to provide a fire protective cover for composite IBCs and bag- in-box type containers that can be incorporated into the container design by placing the cover between the inner receptacle and the outer rigid container. Further and additional objects will appear from the description, accompanying drawings, and appended claims. SUMMARY OF THE INVENTION The present invention is a water absorbent fire protective cover for use with non-metallic containers holding flammable liquids. The non-metallic container may be a composite intermediate bulk container, bag-in-box container, fibre or plastic drum, bulk tote, or other non- metallic liquid holding container. Where the non-metallic container is a composite IBC or bag-in-box container, the fire resistant cover may be placed between the plastic inner receptacle and the rigid outer container, or over the rigid outer container. The cover comprises a heat reflective layer, a heat insulating layer adjacent the heat reflective layer on the side toward the container, and a water absorbent layer closest to the inner plastic container. The cover reflects heat and insulates the container, preventing the container from failure due to excessive heat exposure from fire. THE DRAWINGS Figure 1 is a perspective view of one common type of composite intermediate bulk container (composite IBC) without a fire protective cover. Figure 2 is a perspective view of a composite IBC with the fire protective cover of the present invention placed over the steel support cage, with the cover partially cut away to show the plastic inner container and steel cage. Figure 3 is a perspective view of a composite IBC in which the fire protective cover is located between the plastic inner container and the steel support cage, with the steel cage partially cut away to better show the fire protective cover. Figure 4 is a cross-sectional view taken along line 4-4 of Fig. 3 showing the three layers of the fire protective cover and the steel cage . Figure 5 is a perspective view of a bag-in-box type container without a fire protective cover. Figure 6 is a perspective view of a bag-in-box container with the fire protective cover of the present invention placed over the entire container, with the cover partially cut away to show the bag-in-box container underneath. Figure 7 is a perspective view of a bag-in-box container in which the fire protective cover is located between the plastic inner receptacle and the rigid outer container, with the rigid outer container partially cut away to better show the fire protective cover. DETAILED DESCRIPTION OF THE INVENTION Turning to the drawings, there is shown in Figures 1-4 one application of the present invention, a water absorbent fire protective cover used to protect a composite intermediate bulk container (composite IBC) . Figure 1 shows a perspective view of one common type of composite IBC. The composite IBC 11 comprises a plastic inner container 12 surrounded and supported by a steel cage 14 and resting on a molded pulp or other type support pad 15 which in turn rests on a pallet 16. The inner container 12 may be made from non-metallic materials such as high density polyethylene (HDPE) or other plastic, fibre, or composite materials. The support pad 15 protects the inner container 12 from puncture on impact, and also acts as a heat and fire barrier, thus preventing direct impingement of flame onto the bottom of the inner container 12. Composite IBCs may be used in place of conventional drums to reduce filling, dispensing, handling, storage and disposal costs. Liquid contents may be poured in through a fillport 18 located on the top of the inner plastic container 12 and discharged through a valve 20 located near the bottom. The support pad 15 may comprise a portion 23 extending under the valve 20 to shield the valve 20 from flames during a fire. A marking plate 22 may be located on the front of the IBC 11 for easy product identification. The welded steel reinforced cage 14, molded pulp support pad 15 and steel pallet 16 provide strength, protection, and ease of transport. Composite IBCs may be stacked three high due to the interlocking feature of the steel cages and pallets . It has been found that when composite IBCs are exposed to fire, the steel cage 14 can heat up and melt the inner container 12, particularly where the two are in contact, causing the inner container 12 to melt. However, when a fire protective cover such as that disclosed herein is placed between the steel cage and the plastic inner container, or even over the steel cage itself, the heat transfer from the steel cage to the inner container can be reduced significantly. Using the fire protective cover of the present invention can allow the survival of the non- metallic IBC inner container for a time sufficient for alternative fire protection means (e.g., fire service personnel with water or foam spray fire suppression equipment) to be deployed. Figure 2 illustrates one configuration wherein a fire protective cover 10 is draped over the steel cage of a composite IBC 11 to substantially cover the top and sides of the composite IBC 11. The cover 10 is designed to fit snugly over the composite IBC 11 to facilitate stacking of the composite IBCs. The discharge valve 20 may be protected by the fire protective cover 10 or by a separate cover (not shown) . Figure 3 illustrates the preferred configuration wherein the fire resistant cover 10 fits between the inner container 12 and the steel support cage 14. Preferably, the cover 10 and the optional support pad 15 (not shown in Fig. 3) completely enclose, or encapsulate, the inner container 12 such that no portion of the container 12 is exposed. As best shown in Figure 4, the fire protective cover 10 preferably comprises three layers: a heat reflective layer 26, a heat insulating layer 28 and a water absorbent layer 30, although it is anticipated that the heat reflective layer and the heat insulating layer may be one and the same. The heat reflective layer 26 preferably is the outermost layer, toward the surroundings. The heat insulating layer 28 preferably is adjacent the heat reflective layer 26 on the side away of the heat reflective layer toward the inner container (not shown in Figure 4) . The water absorbent layer 30 is located adjacent the heat insulating layer 28 closets to the inner container. As Figure 4 shows, when the fire protective cover is placed between the inner container 12 and the steel cage 14, the heat reflective layer 26 is the layer closest to the steel cage 14 and the water absorbent layer is the layer farthest from the steel cage. The heat reflective layer 26 may be made from metal foil, foil laminate, or other suitable material. The heat insulating layer 28 may be made from fiberglass, a crosslinked polyethylene foam, DuPont NOMEX ® , or other suitable material . The water absorbent layer 30 may be made of any suitably absorbent material. Such materials include, but are not limited to, paperboard, paper laminates, scrim- reinforced paper, blotter paper, and recycled paper. Other suitable materials include fabrics, cotton, open-cell foams, desiccant materials, and spill control materials. A combination of these materials may also be used. It is advantageous to make the water absorbent layer 42 from the most absorbent material possible. The invention works in the following manner. The heat reflective layer 26 minimizes the radiative heat transfer and the heat insulative layer 28 minimizes conductive heat transfer to the plastic inner container 12. The water absorbent layer 30 absorbs water originating from overhead sprinklers and penetrating the heat reflective layer 26 and the heat insulating layer 28 to help cool the container and/or cage. Part of this cooling is due to the heat absorption capacity of the liquid water and part due to the heat of vaporization required when the water evaporates. The heat reflective layer 26 and the heat insulating layer 28 may be porous to allow water from a sprinkler system to reach the water absorbent layer 30. In addition, various pinholes and gaps in the heat reflective fabric and heat insulating material and openings around the fillport 18 also allow water to reach the water absorbent layer. Even where a nonporous reflective layer is used, during the course of a fire the heat reflective layer 26 and heat insulating layer 28 can burn away, exposing the water absorbent layer 30 to water from an overhead sprinkler system. Thus in the preferred configuration involving composite IBCs, the fire resistant cover 10 is located between the inner container 12 and the steel cage 14. The cover 10 comprises a heat reflective outer layer 26 such as foil or foil laminate facing the container surroundings, a heat insulating layer 28 such as fiberglass or foam material adjacent the heat reflective layer 26 on the side toward the container 12, and a layer of water absorbent material 30 closest to the container 12. Alternatively, the water absorbent layer 30 may be interposed between the heat reflective layer 26 and the heat insulating layer 28. The fire protective cover 10 requires very little thickness to insulate the inner container 12 from hea . This is partly because the fire protective cover 10 is not the sole means by which the inner container 12 is protected from heat due to fire. The contents of the inner container 12 also help protect the container 12 from heat by acting as a heat sink to help keep the container 12 below the temperature at which it will melt. Because the cover 10 works in tandem with the container 12 contents to maintain the temperature of the container 12 at a level below the container melting point, the cover 10 does not require a thick layer of insulation. As a result, the cover can be made conveniently thin. Thinner covers are easier to install and remove, are easier to store when not in use, and are more economical to use for large numbers of containers. It is anticipated that the cover 10 can be placed over incoming composite IBCs when they are delivered to a warehouse and removed before the composite IBCs are shipped out. When not in use, the fire protective covers 10 can be easily stored by folding and stacking. The water absorbent fire protective cover 10 of the present invention can also be used to protect bag-in-box type liquid holding containers, such as that depicted in Figures 5-7. As shown in the figures, a typical bag-in-box container 50 comprises a plastic bag or bladder inside a rigid outer box or container 54. A box cap or lid 56 fits over the outer box 54. The container 50 rests on a pallet 58. Vertical steel straps 60 secure the container 50 to the pallet. The outer box 54 and box cap 56 may be made of corrugated cardboard, plastic, wood or other suitably rigid material. Bag-in-box containers typically are used to store and transport grease, edible oils, agricultural chemicals and the like. The water absorbent cover 10 may be placed over the outer box 54 or between the bladder and the box 54. Figure 6 shows a perspective view of a bag-in-box container 50 with the fire protective cover 10 placed over the outer box 54. Figure 7 shows a perspective view of a bag-in-box container 50 in which the fire protective cover 10 is located between the plastic bladder (not shown) and the rigid outer container 54, with the rigid outer container 54 partially cut away to better show the fire protective cover 10. As with the composite IBC, it is advantageous that the cover 10 be thin enough to easily fit between the inner receptacle and rigid outer container. Although the foregoing discussion was limited to composite IBCs and bag-in-box type containers for purposes of illustration, it is anticipated that the fire protective cover of the present invention also may be used with fibre and plastic drums, bulk totes or other liquid holding containers. Depending upon the container, the cover can be placed over the entire container, as in Figures 2 and 6, or between an inner bag or liner and an outer rigid container. Of course, for containers not having an inner bag or liner, as is usually the case with plastic drums, the cover 10 is placed over the container. In any event, it is preferable that the cover 10 completely encapsulate the non-metallic container to best prevent excessive heat from reaching the container. Where multiple liquid holding containers rest on a single pallet, a single fire protective cover 10 may be designed to fit over all of the containers. Other modifications and alternative embodiments of the invention are contemplated which do not depart from the spirit and scope of the invention as defined by the foregoing teachings and appended claims. It is intended that the claims cover all such modifications that fall within their scope.

Claims: WE CLAIM AS OUR INVENTION: 1. A cover for protecting from warehouse fires a non- metallic liquid holding container, the cover comprising: a heat reflective layer; and a heat insulating layer adjacent the heat reflective layer on the side toward the container. 2. The fire protective cover of claim 1 further comprising a water absorbent layer adjacent the heat insulating layer on the side closest to the container to be protected. 3. The fire protective cover of claim 2 wherein the heat reflective and heat insulating layers are water permeable. 4. The fire protective cover of claim 2 wherein the cover is thin enough to fit between an inner bottle and an outer steel cage of a composite intermediate bulk container. 5. The fire protective cover of claim 2 wherein the heat insulating layer is made from material selected from the group consisting of fiberglass, crosslinked polyethylene foam and DuPont NOMEX ® , and the heat reflective layer is made from metal foil or metal foil laminate. 6. The fire protective cover of claim 2 wherein the water absorbent layer is made from a material selected from the group consisting of paperboard, paper laminates, scrim- reinforced paper, blotter paper, recycled paper, fabrics, cotton, open-cell foams, desiccant materials, and spill control materials. 7. In combination, a composite intermediate bulk container and the fire protective cover of claim 2, the container comprising an inner container formed from non-metallic material and a rigid outer cage, wherein the cover is interposed between the inner container and the rigid outer cage . 8. In combination, a composite intermediate bulk container and the fire protective cover of claim 2, the container comprising an inner container formed from non-metallic material and a rigid outer cage, wherein the cover is placed over the rigid outer cage . 9. The combination cover and container of claim 7 wherein the heat reflective layer is located on the side of the cover facing the rigid cage, the water absorbent layer is located on the side of the cover closest to the inner container, and the heat insulating layer is interposed between the heat reflective and water absorbent layers. 10. The fire protective cover of claim 7 wherein the heat insulating layer is made from material selected from the group consisting of fiberglass, crosslinked polyethylene foam and DuPont NOMEX ® and the heat reflective layer is made from metal foil or metal foil laminate. 11. The fire protective cover of claim 7 wherein the water absorbent layer is made from a material selected from the group consisting of paperboard, paper laminates, scrim- reinforced paper, blotter paper, recycled paper, fabrics, cotton, open-cell foams, desiccant materials, and spill control materials. 12. The combination cover and container of claim 8 wherein the heat reflective layer is located on the side of the cover facing the container surroundings, the water absorbent layer is located on the side of the cover facing the rigid cage, and the heat insulating layer is interposed between the heat reflective and water absorbent layers . 13. The fire protective cover of claim 8 wherein the heat insulating layer is made from material selected from the group consisting of fiberglass, crosslinked polyethylene foam and DuPont NOMEX ® and the heat reflective layer is made from metal foil or metal foil laminate. 14. The fire protective cover of claim 8 wherein the water absorbent layer is made from a material selected from the group consisting of paperboard, paper laminates, scrim- reinforced paper, blotter paper, recycled paper, fabrics, cotton, open-cell foams, desiccant materials, and spill control materials. 15. In combination, a bag-in-box container and the fire protective cover of claim 2, the container comprising a bag inside a box, wherein the cover is interposed between the bag and the box . 16. In combination, a bag-in-box container and the fire protective cover of claim 2, the container comprising a bag inside a box, wherein the cover is placed over the box. 17. The combination cover and container of claim 15 wherein the heat reflective layer is located on the side of the cover facing the box, the water absorbent layer is located on the side of the cover closest to the bag, and the heat insulating layer is interposed between the heat reflective and water absorbent layers . 18. The fire protective cover of claim 15 wherein the heat insulating layer is made from material selected from the group consisting of fiberglass, crosslinked polyethylene foam and DuPont NOMEX ® and the heat reflective layer is made from metal foil or metal foil laminate. 19. The fire protective cover of claim 15 wherein the water absorbent layer is made from a material selected from the group consisting of paperboard, paper laminates, scrim- reinforced paper, blotter paper, recycled paper, fabrics, cotton, open-cell foams, desiccant materials, and spill control materials . 20. The combination cover and container of claim 16 wherein the heat reflective layer is located on the side of the cover facing the container surroundings, the water absorbent layer is located on the side of the cover facing the container, and the heat insulating layer is interposed between the heat reflective and water absorbent layers. 21. The fire protective cover of claim 16 wherein the heat insulating layer is made from material selected from the group consisting of fiberglass, crosslinked polyethylene foam and DuPont NOMEX ® and the heat reflective layer is made from metal foil or metal foil laminate. 22. The fire protective cover of claim 16 wherein the water absorbent layer is made from a material selected from the group consisting of paperboard, paper laminates, scrim- reinforced paper, blotter paper, recycled paper, fabrics, cotton, open-cell foams, desiccant materials, and spill control materials. 23. In combination, an industrial liquid holding container and the fire protective cover of claim 2, the container comprising an inner liner and a rigid outer container, wherein the cover is interposed between the liner and rigid outer container. 24. In combination, an industrial liquid holding container and the fire protective cover of claim 2, the container comprising an inner liner and a rigid outer container, wherein the cover is placed over the rigid outer container. 25. The combination cover and container of claim 23 wherein the heat reflective layer is located on the side of the cover facing the rigid outer container, the water absorbent layer is located on the side of the cover closest to the liner, and the heat insulating layer is interposed between the heat reflective and water absorbent layers. 26. The combination cover and container of claim 24 wherein the heat reflective layer is located on the side of the cover facing the container surroundings, the water absorbent layer is located on the side of the cover facing the container, and the heat insulating layer is interposed between the heat reflective and water absorbent layers.

Inventors: APOSTOLUK PETER, GORDON GERALD A, MIKULA JOHN, APOSTOLUK, PETER, GORDON, GERALD, A., MIKULA, JOHN
Applicants: APOSTOLUK PETER, GORDON GERALD A, GREIF BROS CORP, MIKULA JOHN, APOSTOLUK, PETER, GORDON, GERALD, A., GREIF BROS. CORPORATION, MIKULA, JOHN
Application year: 1998
Main classification: A62C3
IPC codes: A62C3