US3356256A

US3356256A - Safety container for explosive fluids

Info

Publication number: US3356256A
Application number: US503754A
Authority: US
Inventors: Szego Joseph
Original assignee: Individual
Current assignee: Individual
Priority date: 1965-10-23
Filing date: 1965-10-23
Publication date: 1967-12-05
Anticipated expiration: 1984-12-05
Also published as: CH468290A; SE322420B; DE1975171U; GB1131687A

Description

Dec. 5, 1967 .J SZEGO 3,356,256

SAFETY CONTAINER FOR EXPLOSIVE FLUIDS Filed Oct. 25, 1965 2 Sheets-5heet 1 IN VE N TOP.

74 JOSEPH SZEGO.

F/G 5 by Z m.

Agent.

Dec. 5, 1967 J. SZEGO 3,356,256

SAFETY CONTAINER FOR EXPLOSIVE FLUIDS Filed Oct. 23, 1965 2 Sheets-Sheet 2 INVENTOR JOSEPH 52560.

Agen

United States Patent Ofiice 3,356,256 Patented Dec. 5, 1967 3,356,256 SAFETY CONTAINER FOR EXPLOSIVE FLUIDS Joseph Szego, 27 Kenwood Ave., Toronto; Ontario, Canada Filed Oct. 23, 1965, Ser. No. 503,754 16 Claims. (Cl. 220-88) ABSTRACT OF THE DISCLOSURE A container having a filler therein formed of thin netting in the form of thin integrally-connected, heat-conductive ribbons which are deformed to impart stiffness and crush resistance to the netting.

The present invention relates to fluid containers, particularly to containers for inflammable and/or explosive fluids; the term fluids being deemed to cover both liquids and gases.

In the past various safety measures have been adopted to prevent fire and explosions in such containers and these have mainly, if not always, included the provision of a heat conducting filler for the container. The object of such a filler was, of course, to disperse local concentrations of heat throughout the entire filler as well as through the body of the container, and thus prevent the formation of hot-spots capable of igniting the fluid contents of the container.

One type of filler is that disclosed in Canadian Patent No. 652,316 in which I am named as co-inventor, and consists wholly of metal wool, the fluid contents of the container being accommodated in the interstices of the wool. This type of filler has not proved wholly satisfactory because although when the filler was first inserted in the container it might have occupied substantially the Whole thereof, it tended to become displaced and compressed by the action of the liquid in the container to an extent whereby it was squeezed into one corner of the container, for example, leaving whole regions of the container completely unprotected by the filler.

Other types of known filler have also suffered from the same or corresponding disadvantages which need not be enumerated in detail herein.

It is a broad general object of the present invention to provide an improved heat dispersing filler for the interior of a container for inflammable fluids which is of high thermal conductivity, light in weight and economical to produce.

It is a further object of the invention to provide an improved filler as aforesaid which is durable and resistant to corrosion by the fluids to which it is exposed in normal use.

It is a further object of the invention to provide an improved filler as aforesaid which is of high thermal conductivity, light in weight and economical to produce and is yet sufliciently stifi" or rigid strongly to resist crushing or compression within the container by the agitation of liquid therein.

It is a further object of the invention to provide an improved filler comprised of normally pliable, light-Weight material of high thermal conductivity reinforced to provide a relatively stiff or rigid filler structure resistant to the deforming action of liquid within the container.

It is a further object of the invention to provide an improved filler as aforesaid which has a very small displacement in relation to the volume of the container whereby substantially the whole of the container may be charged with fluid, but which yet has sufficient bulk to occupy the whole of said container and procure wide and rapid dispersion of heat applied to the exterior of the container to prevent ignition of the container contents.

It is a further object of the invention to provide an improved filler as aforesaid including a plurality of filler units, each unit being composed of several layers of netting; some of said layers having higher thermal conductivity than others and some of said layers having greater crush resistance than others.

It is a further object of the invention to provide an improved filler as aforesaid which permits free flow of fluid in every direction therethrough and also allows levelling of fluid in the container to avoid obstructing filling and emptying of said container and the free flow of liquid therein.

It is a further object to provide an improved filler as aforesaid having suflicient rigidity to support itself within a container.

It is a still further object of the invention to provide a fluid container including an improved filler as aforesaid.

It is also an object of the invention to provide a method of safeguarding a container for explosive fluids against the effects of heat applied externally thereto.

The foregoing objects are achieved in accordance with the invention by the provision of a fluid container comprising an outer shell enclosing a fluid chamber and a filler occupying substantially the whole of said chamber. The filler is composed, for at least the major part, of a species of netting made up of interconnected metallic ribbons whose widths are misaligned with, and preferably perpendicular to, the general plane of the netting thereby stiffening the netting. The netting as a whole is relatively thin permitting free flow and levelling of fluids within the chamber whereby filling and emptying of the container is not appreciably impeded.

Other features, objects, and advantages of the invention will be apparent from the ensuing illustrative description of one preferred embodiment thereof when read in conjunction with the accompanying drawings wherein:

FIG. 1 is a perspective view of a portable gasoline can in accordance with the invention, certain portions of the can being broken away to reveal otherwise concealed internal detail;

FIG. 2 is a fragmentary plan view of a layer of coarse mesh netting as contemplated by the invention superimposed upon a fine mesh netting layer;

FIG. 3 is an enlarged isometric view of a fragment of metallic netting;

FIG. 4 is a side elevation of the netting of FIG. 3 seen in the direction of the arrow IV of that figure;

FIG. 5 is an end elevation of the netting of FIG. 3 seen in the direction of the arrow V of that figure;

'FIG. 6 is an isometric view generally corresponding to FIG. 3 but showing a different type of netting;

FIG. 7 is a fragmentary isometric view of a filler unit in accordance with the invention;

FIG. 8 is a view generally corresponding to FIG. 7 but showing another form of filler unit, and

FIG. 9 is a much enlarged isometric view of a small portion of the netting shown in FIG. 3.

A container 2 in accordance with the invention is shown in FIG. 1. For the purposes of illustration the container 2 is shown as a portable gasoline can including an outer shell 4 which defines a fluid chamber 6 wherein the fluid contents of the can are held.

The container 2 in accordance with conventional practice also includes inlet and outlet facilities for the chamber 6, said facilities in the present instance consisting of a simple spout 8 which functions as both inlet and outlet for the chamber 6.

In accordance with the invention the chamber 6 contains a filler 10 which occupies substantially the whole of said chamber. It should be noted that the invention is principally directed to the combination of the container and the tiller, although invention is also believed to reside in the filler itself and the ensuing description therefore relates to both these aspects of the invention.

As has already been hereinbefore stated a most obvious desideratum in a container as herein visualized is, of course that it be maximally thermoconductive to dissipate heat concentrations and to avoid or dissipate hot spots which might otherwise conduce to ignition of inflammable fluids contained therein.

This desideratum is achieved by installing in the interior of the container a filler providing numerous interlaced conductors by which a concentration of heat at any one spot is expeditiously disseminated throughout the filler to the farthest extremities of the container and so rendered harmless.

However, it is also of very great importance that the filler diminish the capacity of the container by the smallest possible extent and add as little as possible to the weight thereof.

It also need hardly be stated that a most efficient filler is necessarily one which does not impede the free movement of liquid fuels in the container.

An important component of a filler which is believed to serve the objects of the invention most effectively makes liberal use of netting 12 composed of integrally connected ribbons 14 of thin, relatively malleable metal which is, of course, thermoconductive and non-inflammable. Various types of netting 12 are shown in FIGS. 2-6 and 9. The netting itself is relatively thin-that is to say its dimension perpendicular to its plane P is smail and may be arranged in layers and/ or convolutions and/ or other dispositions within the chamber 6 as will be described in greater detail hereinafter.

For convenience the netting 12 has been shown more or less symbolically in FIG. 1, the structure thereof being better shown in the enlarged scale views of FIGS. 3 and 9. To form the netting 12 the ribbons 14 may be interconnected and merge with each other at spaced points along their edges, an indicated at in FIG. 3.

It is noteworthy, however, that the ribbons 14 are so arranged in the netting 12 that their widths W (or their own planes) are misaligned with the general plane P of the netting. In FIGS. 4 and 9, for instance, it will be seen that the widths W of the ribbons are substantially perpendicular to the plane P, while in FIG. 6 the ribbons 14 are twisted to misalign their widths W with the plane P. In either case it may be said that the planes of the ribbons 14 are disposed at a substantial angle to the plane P. The misalignment has the effect of stiffening the netting 12 to resist bending forces acting generally perpendicularly to the plane P.

As mentioned above the ribbons 14 are formed of thin relatively malleable metal and may be readily bendable about axes parallel to the direction of their widths W. It will be appreciated, however, that the ribbons 14 are much more strongly resistant to bending about axes parallel to the direction of their thickness and that the netting 12 being composed of ribbons 14 with their widths misaligned with the plane P of the netting, is thereby stiffened as aforesaid. Since it is envisaged that the directions of the thickness of the ribbons 14 and of the thickness of the netting 12 as a whole will be more or less perpendicular to each other, to avoid confusion it should be explained that the thickness of the ribbons is the dimension sometimes referred to in the case of sheet metal as the gauge.

As noted above the primary function of the filler 10 is to dissipate heat concentrations and accordingly the netting 12 is required to fill the chamber 6 as completely as possible to achieve maximal heat dispersal. Conversely the primary function of the container 2 is to hold fluid and it is highly desirable that the filler 10 should have a minimal displacement and weight so that the fluid capacity of the chamber 6 is not seriously reduced and the overall weight of the container 2 and its contents is not appreciably increased.

The netting 12 has been found highly satisfactory from this point of view since it is possible to achieve an effective filling of the chamber 6 by using said netting in quantities with a displacement equivalent to between one and three percent of the volume of the chamber 6, a typical filler 10 having a displacement equivalent to approximately two percent of the volume of chamber 6.

For the sake of absolute clarity it should be explained that the expressions filler, fill and filling as used herein in connection with the netting 12 indicate only that the netting as a whole constitutes or forms the major part of a bulky unit which extends over substantially the full length, breadth and height of the chamber 6, although as indicated above the actual displacement of such unit may be as little as one percent of the volume of the chamber 6. It will be obvious that this bulk/displacement ratio is achieved by reason mainly of the large number of open interstices 16 in the netting 12 which communicates with each other, as will be explained in more detail hereinafter, and form, as it were, cells in which the fluid contents of the container 2 are receivable.

The ribbons 14 may be of aluminum and in any event should be resistant to corrosion by the fluids to which they will be exposed in use.

As an example, netting 12 as contemplated by the invention may be formed of aluminum ribbons inch wide and .006 inch thick, the meshes of the netting having a dimension of approximately A inch in the direction of the plane P of the netting. Thus, dimensioned, it will be seen that the various thicknesses of netting 12 offer very little if any impedance to the movement of liquid in the container.

The efficiency of the invention may be further assessed from the following exemplary data.

The coefficient of thermal conductivity of aluminum at 300 C. is .64 c.g.s. units.

To fill a container of 1 cubic metre (or 1,000,000 cubic centimetres) capacity with netting of the above dimensions the actual weight of netting recommended would be approximately 52.4 kilogrammes, while the displacement of this weight of netting would be 19,370 cubic centimetres, which is, of course, 1.937% of the total capacity of the container.

This quantity of netting when spread out in a fiat state would cover a plane area of 354.8 square metres and may be rolled, folded or otherwise layered to make a filler for filling the space of one cubic metre within the container.

354.8 square metres of netting with the above mentioned coefficient of thermal conductivity are capable of conducting 1060 million calories per hour or about 300,000 calories per second.

The container in question may be an aircraft fuel tank, or part thereof, containing gasoline. In typical crash conditions, said container may become fractured and permit leakage of gasoline therefrom; this being a fairly common condition. The gasoline leaking from the tank may then ignite creating a source of intense heat about the fractured tank. The ignition temperature of gasoline is about 280 C. and when burning freely the flames may not be expected to exceed this temperature.

It will thus be seen that by conducting heat away from the fracture at the rate of about 300,000 calories per second, the filler 10 of the invention would be more than adequate to prevent the internal temperature of the tank from attaining the ignition temperature of its contents.

Ribbons formed of anodized aluminum have been found somewhat stronger and, in some applications, more corrosion resistant than those of non-anodized aluminum, and certain alloys, such as aluminum alloyed with beryllium and/or titanium, have also been found suitable for the purposes of the invention.

The foregoing data is given for purposes of illustration only and it should be understood that netting with larger or smaller interstices and formed of ribbons of other material having other widths and thicknesses may be used. The invention contemplates, in fact, that under certain conditions the filler may comprise netting 12 of different mesh sizes and different thicknesses. Thus, for example, a filler formation may be employed wherein layers of relatively fine but weak mesh netting having higher conductivity are interposed between layers of relatively coarse mesh netting; the ribbons in the fine mesh netting being preferably thinner (of smaller gauge) and narrower than those of the coarse mesh netting. The terms fine and coarse indicate that the interstices of the netting are respectively small and large.

This construction is illustrated in FIG. 7 which shows a convoluted filler unit 10a wherein a web of coarse mesh netting and two webs of fine mesh netting are wound together so that the resulting unit comprises a plurality of layers 12a of coarse mesh netting between each pair of which'are disposed two layers 12b of fine mesh netting. For the sake of clear exposition a small air space has been shown between the several layers, although in practice the

respective layers

12a and 12b of the unit are more or less contiguous with the layers adjacent thereto. The interstices 16 of each layer are out of registration with the corresponding interstices of adjacent layers whereby each interstice constitutes, as it were, a fluid cell communicating with other fluid cells. The latter feature is best illustrated in FIG. 2 which shows, in plan, a portion of a layer 12a superimposed upon a portion of a single layer 12!).

It will be appreciated that fluid can circulate within the filler unit 19a not only through the interstices 16, but also, to some extent, between the

layers

12a and 12b, and that it is free to circulate in all directions and rapidly levels itself within the container 2, this feature being due to the fact that the netting 12 does not include any single element of substantial area which could form a dam and obstruct the free flow offiuid within the container. The container 2 is shown in a tilted condition in FIG. 1 and the level of gasoline therein 'is indicated by the broken line 18.

The filler 10 may be composed of or include one or more units Ilia. In either case the fine mesh netting, which, although stiffened by the disposition of its component ribbons as previously described, may yet be relatively flexible in comparison with the coarse mesh netting, serves to disperse and dissipate heat more rapidly than the coarse mesh netting, whereas the coarse mesh netting is stiffer than and reinforces the fine mesh netting against crushing and compression within the chamber 6 such as may be caused by movement of fluid within a partly filled container. That is to say if a container 2 contains a quantity of fluid short of its total capacity, said fluid will tend to swill about within the container when the latter is agitated and such movement may stress the filler 10 and exert compressive forces thereon. It will be clear that if the filler 10 is crushed or compressed to any substantial extent, leaving voids unoccupied by the filler material, the degree of the protection afforded by the filler 10 will be correspondingly reduced since heat applied to the exterior of the container 2 in a region adjacent such a void will not be disseminated through the filler 10 in the manner visualized by the invention and could cause an explosion.

It is contemplated that the netting 12 as a whole (i.e. in FIG. 7 the combination of

layers

12a and 12b) will be sufliciently stiff or rigid to support itself within the chamber 6, although additional reinforcements may be. added if desired.

The netting 12 may, of course, be arranged in other Ways, one possible alternative arrangement being illustrated in FIG. 8 which shows a filler unit 10b. As shown the unit 16b includes a layer 120 of stiff coarse mesh netting which is corrugated to enhance its stiffness still 6 further. Layers 12d of relatively flexible fine mesh netting are disposed on each side thereof, the whole being fastened together as by wire (not shown) to form a laminar structure.

A plurality of units 1012 may be used to form a complete filler 10, or one or more units 10b may be assembled with one or more units 10a or other filler units to make up a complete filler.

For example the filler 10 of FIG. 1 is shown as including a filler unit 10b disposed horizontally in the lower part of chamber 6, a plurality of filler units 10a disposed horizontally in the middle part of the chamber 6 and a filler unit 100, which may consist entirely of convoluted fine mesh netting, horizontally disposed at the top of the chamber 6. It will be apparent that the filler unit is positioned where it will be least exposed to compressive forces but where it protects a space which becomes filled with an explosive mixture of gasoline and air as gasoline is poured from the container 2, and where rapid dissipation of heat concentrations is particularly important.

Also shown in FIG. 1 is a plug 26 filling the container spout 8. The plug 20 is composed of netting 12 and may be a narrow strip of such netting rolled into cylindrical form as shown. The inner end of the plug 20 may contact one or more of the filler units in the chamber 6 and it will be understood that the plug permits free flow of fluid through the spout 8 during filling or emptying of the container 2.

Although the invention has been described with particular reference to a portable gasoline can, its application is not, of course, restricted thereto. Other exemplary applications are the fuel tanks of land vehicles and aircraft and containers for inflammable gases.

By way of resume it may be said that the invention provides an explosion inhibiting filler for the interior of a container for inflammable fluids comprising a netting ofintegrally connected, thermoconductive ribbons. Each ribbon is composed of thin, relatively malleable, corrosion-resisting metal such as the alloys previously mentioned. The disposition of the ribbons within the netting is arranged to enhance the stiffness of the netting as a whole, this being achieved by misaligning the widths of the ribbons relative to the general plane of the netting. .Conversely the netting structure is such as to permit free flow and circulation of fluid within the container without giving rise to undesirable damming effects.

Many changes and modifications in the exemplary embodiment of the invention described herein will be obvious to a person skilled in the art to which this invention relates and it will be understood that the invention comprehends all such changes and modifications as fall within the scope of the claims now following.

What I claim is:

1. A container for fluids comprising,

an outer shell enclosing a fluid chamber;

means communicating between the exterior and interior of the chamber providing it with inlet and outlet facilities;

a filler occupying substantially the whole of said chamber, and netting arranged in layers and constituted by integrallyconnected, thermo-conductive, non-inflammable ribbons forming a major part, at least, of said filler;

said ribbons being composed of thin metal which is malleable and relatively wide in relation to its thickness and said ribbons having their width misaligned with the general plane of said netting imparting stiffness to the latter;

the respective layers of netting being relatively thin permitting free flow of fluids therebetween conducing to relatively unimpeded leveling of the fluid within said chamber.

2. A container as claimed in Claim 1 wherein:

said ribbons have their widths disposed substantially perpendicular to the general plane of said netting.

3. A container as claimed in claim 1 wherein:

the layers of netting are convoluted within said chamber.

4. A container as claimed in claim 1 wherein:

said netting is formed of anodized aluminum.

5. A container as claimed in claim 1 wherein:

said netting is formed of an alloy of aluminum, beryllium and titanium.

6. A container as claimed in claim 1 wherein:

said layers are contiguous;

each said layer including meshes disposed out of registration with corresponding meshes of adjacent layers permitting free circulation of fluid in all directions within said chamber 7. A container as claimed in claim 1 wherein:

said layers are contiguous;

some of said layers comprising relatively fine mesh netting wherein the gauge of said ribbons is relatively low providing a relatively high rate of heat dispersal therefrom and others of said layers comprising relatively coarse mesh netting wherein the gauge of said ribbons is relatively high providing rigidity for said coarse mesh layers and reinforcing said fine mesh layers to enhance the rigidity and crush resistance of said filler as a whole.

8. A container as claimed in claim 7 wherein:

the gauge of said ribbons comprising said coarse mesh netting is such as to render said netting self-supporting within said chamber and to resist crushing of said netting by the movement of liquids within said chamber.

9. An explosion-inhibiting filler for the interior of a container for inflammable fluids comprising:

netting arranged in layers and constituted by integrally-connected, thermo-conductive, non-inflammable ribbons;

said ribbons being composed of thin metal which is malleable and relatively wide in relation to its thickness and said ribbons having their widths misaligned with the general plane of said netting imparting stiffness to the latter;

the respective layers of netting being relatively thin permitting free flow of fluids therebetween.

10. A filler as claimed in claim 9 wherein:

11. A filler as claimed in claim 9 wherein:

said layers are contiguous;

12. A filler as claimed in claim 11 wherein:

said coarse mesh layers are corrugated reinforcing said fine mesh layers and further enhancing the rigidity and crush resistance of the filler as a Whole.

13. A filler as claimed in claim 9 wherein:

said netting is formed of anodized aluminum.

14. A filler as claimed in claim 9 wherein:

said netting is formed of an alloy of aluminum, beryllium and titanium.

15. A filler as claimed in claim 9 wherein:

said netting includes relatively flexible fine mesh netting and relatively stifl coarse mesh netting;

said fine and coarse mesh netting being convoluted together procuring reinforcement of the fine mesh netting by the coarse mesh netting.

16. A filler as claimed in claim 9 wherein:

said layers are contiguous;

each said layer including meshes disposed out of registration with corresponding meshes of adjacent layers permitting free circulation of fluid in all directions between said layers.

References Cited UNITED STATES PATENTS 958,944 5/1910 Steward 22088 1,693,958 12/1928 Patten 22088 2,850,083 9/1958 Frost 22088 3,069,042 12/1962 Johnston 22010 FOREIGN PATENTS 652,316 11/1962 Canada.

705,745 3/ 1965 Canada.

601,374 11/ 1925 France.

329,822 11/ 1920 Germany.

531,610 l/1941 Great Britain.

RAPHAEL H. SCHWARTZ, Primary Examiner.

Claims

1. A CONTAINER FOR FLUIDS COMPRISING, AN OUTER SHELL ENCLOSING A FLUID CHAMBER; MEANS COMMUNICATING BETWEEN THE EXTERIOR AND INTERIOR OF THE CHAMBER PROVIDING IT WITH INLET AND OUTLET FACILITIES; A FILLER OCCUPYING SUBSTANTIALLY THE WHOLE OF SAID CHAMBER, AND NETTING ARRANGED IN LAYERS AND CONSTITUTED BY INTEGRALLYCONNECTED, THERMO-CONDUCTIVE, NON-INFLAMMABLE RIBBONS FORMING A MAJOR PART, AT LEAST, OF SAID FILLER; SAID RIBBONS BEING COMPOSED OF THIN METAL WHICH IS MALLEABLE AND RELATIVELY WIDE IN RELATION TO ITS THICK-