US3515525A - Fire building device - Google Patents

Description

I June-2,: 1970 v Q 5 R. E. FEARON FIRE BUILDING DEVICE 5 Sheets-Sheet 1 Filed Sept. 5, 1967 FIGURE 1 FIGURE 1A 6M f jg awwlN V EN TOR.

, June 2, 1970 I I Q F A 3,515,525

FIRE- BUILDING DEVICE 7 Filed Sept. 5, 1967 v 5 Sheets-Sheet 2 FIGURE 2 g INVENTOR.

1 June 9 E 'R. E. FEARON 1 3,515,

FIRE BUILDING DEVICE Filed Sept. 5, 1967 5 Sheets-Sheet 5 FIGURE 8 FIGURE 3 INVENTOIEQ.

June 2, 1970 R. E. FEARON 3,515,525

, FIRE BUILDING DEVICE Filed Sept. 5, 1967 I I 5 Sheets-$heet 4.

FIGURE 5 W W INVENTOR.

' R. E. FEARON FIRE BUILDING DEVICE June 2, 1970 5 Sheet's -Sheet 5 Filed Sept. 5, 1967 FIGURE 6 FIGURE 7 United States Patent 3,515,525 FIRE BUILDING DEVICE Robert E. Fearon, Tulsa, Okla., assignor to Electro Chemical Laboratories Corporation, Tulsa, Okla., a corporation of Delaware Continuation-impart of application Ser. No. 340,933, Jan. 29, 1964. This application Sept. 5, 1967, Ser.

Int. Cl. C101 11/00 US. Cl. 4438 3 Claims ABSTRACT OF THE DISCLOSURE This invention relates to structures and compositions of matter, used in combination, to build fires, and particularly to suificiently build a small and slightly kindled fire that it becomes able to ignite diflicultly ignitable fuel such as charcoal or industrial coke. This application is a continuation-in-part of U8. patent application Ser. No. 340,933, filed Jan. 29, 1964 now abandonded. In combination with a relatievely feeble igniter, one capable of releasing not over 200 calories in ten seconds or less in a volume of space not exceeding twenty cubic centimeters, my fire builder constitutes a fire starter of particular effectiveness and usefulness. If the kindling means which I chose to employ is operated by electricity or in some way that does not involve combustible material, the combination of fire builder with the igniter constitutes a fire starter which does not contain any combustible materials at all. The fact that, using my invention, I can construct an effective and powerful fire starter containing no combustible materials at all, is startling and contrary to expectation, and represents one of the most essential attributes of my fire builder, of which the following is a specification. In the following spectification a number of words which I use frequently require definition in order that my meaning may be clearly understood. The definitions follow:

(1) Combustion-An exothermic chemical reaction involving two substances, a first substance which is said to 'burn or undergo combustion and a second substance (chemically classified as an oxidizing agent) which is said to support the combustion, the said chemical reaction being of such a nature that it generates a temperature in excess of 500 C. after it has been initiated, and, being initiated in the presence of an excess of the second substance, the combustion consumes the whole of any connected mass of the said first substance.

(2) Kindling.A process involving the rapid liberation of enough heat energy in a small region of space containing a combustible substance and a supporter of combustion, the said liberation being suflicient that combustion commences.

(3) Combustible substance.A substance which, after being kindled, will undergo combustion as defined herein in the presence of an oxidizing agent.

(4) Combustion supporting substance.A substance capable of performing, supplementing, or supplanting the usual function of the oxygen of the air in its relationship to a combustible substance which has been kindled.

(5) Combustion supporting substances, class one.A sub-class of nongaseous combustion supporting substances capable of supporting the combustion of a combustible substance without being in direct contact with the said combustible substance.

(6) Combustion supporting substances, class two.-- Nongaseous combustion supporting substances which will support the combustion of a combustible substance when mixed with or in contact with same, but will not perform the combustion supporting function when spaced apart from and not in contact with a combustion supporting substance.

' (7) Combustion supporting substances, class three. Gaseous oxidizing agents falling within my general definition of a combustion supporting substance.

Included within the definition of combustion as given above is the burning of such substances as gunpowder (the potassium nitrate supports the combustion) and wood (the oxygen of the surrounding air supports the combustion) the flame of hydrogen burning in an atmosphere of chlorine (the chlorine supports the combustion) the burning of silica in an atmosphere of fluorine (the fluorine supports the combustion).

Substances which illustrate the definition of combustion supporting substance as given above are pure gaseous element oxygen, element chlorine (turpentine spontaneously catches fire in chlorine) nitrogen dioxide, nitrous oxide, fluorine, nitrogen trifluoride, chlorine dioxide, potassium nitrate, barium nitrate, potassium perchlorate, and tetranitromethane. The submitted examples are illustrative and are presented to assist the understanding of the definition which, however, is in no sense limited in its application, but includes many things not contained in the illustrative list.

For convenience in referring to definition 5, combustion supporting substances, class one are called pyrogenerative substances. As one example of the behavior of 'a pyrogenerative substance, if I support a piece of wood above but not in contact with a layer of solid potassium chlorate mixed with manganese dioxide, and if the area of exposure of the two substances, the one above the other, is very large compared with the distance between them, potassium chlorate with the manganese dioxide mixture is a pyrogenerative substance, and will support the combustion of the wood, without any of the potassium chlorate coming in contact with it. A test of the facts relating to this chosen illustration can be made by liberating approximately 200 calories of heat in an interval of ten seconds or less near the center of the area over which the wood and the potassium chlorate both extend. Having done this, a combustion process occurs using an oxygen derived from the decomposition of the potassium chlorate. The oxygen crosses the space and consumes the wood and the combustion progresses until the whole of the area is involved, in fulfillment of the preceding definitions of combustion, combustible substance, and combustion supporting substances.

Many substances that contain oxygen or are capable of yielding oxidizing gases illustrate the pyrogenerative sub-class of combustion supporting materials. Such other substances includes but are not limited to the equi-molecular mixture of ammonium perchlorate and sodium nitrate, potassium percholrate to which has been added and intimately mixed a quantity of manganese dioxide, and numerous other substances.

Combustion supporting substances of class two are illustrated by but not limited to potassium nitrate, barium nitrate, and manganese dioxide.

Referring again to combustion supporting substances class one, I have found that when I determine the pyrogenerativeness of a combustion supporting substance I must use a fixed amount of thermal energy delivered in the region where the pyrogenerative substance and a combusti-ble substance are close to one another. I have found further that the fixed amount of energy must be delivered in a small region of space and in a brief length of time, which is exactly the same type of energy requirement that must be met in a test of combustibility.

The essential ingredients in the use of a fire builder of the kind which I have invented are:

(l) A heat resistant mechanical support which may or may not be combustible, the mechanical support may consist, for example, of asbestos board or ceramic tile, or it may consist of cardboard of the ordinary kind, or cardboard manufactured of the kind heavily loaded with gypsum. The mechanical support must have a degree of oxygen resistance as will be explained later.

(2) A suitable quantity of pyrogenerative substance resting on or attached to the upper surface of the mechanical support.

(3) A source of energy sufficient to ignite the fuel which it is desired to start, in the presence of the pyrogenerative material.

The above combination constitutes a fire starter when item 3 is included; is a fire builder when items 1 and 2 are included, only.

Typical pyrogenerative substances are illustrated by but not limited to manganese dioxide and potassium chlorate mixtures. A typical composition would be in the range of 90 to 98 percent potassium chlorate and 2 to 10 percent finely powdered manganese dioxide. Potassium perchlorate mixed with black copper oxide (cupric oxide) at 5 percent concentration'by weight is a pyrogenerative substance. Potassium perchlorate in pure form is not a pyrogenerative substance. Various mixtures of ammonium perchlorate and potassium nitrate are pyrogenerative, although potassium nitrate alone is not pyrogenerative. Another substance that is not pyrogenerative, although very rich in available oxygen, is barium nitrate. Both barium nitrate and potassium nitrate are combustion supporting substances, class two. I do not use such substances by themselves in my fire builder.

The requirements for the heat resistant mechanical sup port are evident from the determinable properties of the pyrogenerative substances which I use in any given instance. I choose the support in such a manner that it is heat resistant enough, and sufficiently oxygen resistant, that the desired quantity of pyrogenerative substances can be totally decomposed on it without perforating the support material. As an example, a layer of common cardboard 0.06 inch thick is sufficiently heat resistant and oxygen resistant when used in conjunction with five tablets of pyrogenerative substance of a composition 92 percent potassium chlorate, 4 percent bentonite clay, and 4 percent manganese dioxide, and constructed as shown in FIG. 1, of which more detail will be submitted hereinafter. Wt. per tablet=3.2 g.

The cardboard, though not generally categorized as heat resistant and oxygen resistant, is suificiently so to serve my purpose in the given exam le. My fire builder can be improved, made at less cost, and becomes more effective if the cardboard layer is heavily loaded with some inert substance such as calcium sulphate, talc, chalk, or magnesia. Since my fire builder functions chiefly by delivering oxygen against the fuel to be lit, the advantage of greater oxygen resistance of the support is clearly evident in that any oxygen consumed by the support lessens the amount delivered against the fuel to be lit. Thus cardboard, uncontaminated with heat resistant and oxygen resistant adulterants, somewhat decreases the oxygen available to build the fire, whereas cardboard loaded with sucn aoulterants conserves the oxygen needed to build tne fire. A variation in my fire builder comprises a model with a totally oxygen and heat resistant support such as for example asbestos board, or a mixture of asbestos board and Portland cement, glass fiber material hardened with Portland or silica cement, etc.

The combustion supported and built up by a pyrogenerative substance which is in close proximity to a combustible substance is more easily initiated than the combustion of the combustible substance in the presence of air alone. Accordingly, in using my fire builder I divide the design problem into two parts. First is the problem of supplying the requisite initiation energy to kindle the combustible substance in the presence of the chosen pyrogenerative substance, on a suitable support, and second, the provision of a sufiicient quantity of pyrogenerative substance on a suitable support. Thus I may employ three grams of pyrotechnic substance containing a pulverized mixture of a class one or class two combustion supporting substance, together with a combustible powder such as starch, woodfiour, dinitrocellulose, etc., to generate the 200 calories, more or less, which is needed to initiate the pyrogenerative supported combustion of carbon fuel (if indeed it is a charcoal fire I am attempting to initiate).

The pyrotechnic material thus chosen for use in combination with my fire builder is an amount insutficient by itself to initiate a sustained combustion of the carbon fuel in air. However, in the presence of a pyrogenerative substance presented on a suitably heat and oxygen resistant support, combustion of the charcoal is initiated and supported by the presence of the pyrogenerative substance, 2.

process which has a relatively low threshold requirement of heat energy for its initiation. The combustion of the charcoal or carbon in the presence of the pyrogenerative substance proceeds to the complete utilization of all the oxygen available from the pyrogenerative substance, the said combustion liberating a substantial further amount of heat, which, taken together with the heat originally liberated by the pyrotechnic material, is sufiicient to kindle the carbon fuel in air.

Using the foregoing inforamtion, in an alternative way of making a charcoal fire builder I support the pyrogenerative material on a layer of combustible material of limited thickness, under which I place a very incombustible and heat resistant material. The calorie value of the combustible layer of limited thickness is chosen equal to approximately 200 calories when it is totally consumed. A very small initiator of pyrotechnic substance, having a capability of the order of ten gram calories, more or less, is supplied to initiate the reaction by the pyrogenerative substance and the consumable portion of the support. The arrangement, corresponding with this design is shown in my FIG. 2, of which more detail will be presented later.

In a still further variation, I employ a pyrogenerative substance on a totally heat and oxygen resistant support such as asbestos, magnesia, alumina, or the like, and supply the 200 calories by means of a resistance wire to which I supply energy using an electric current. This modification of my fire builder is shown in FIG. 3, of which more detail is submitted hereinafter.

A further variation under FIG. 3 involves the use of a titanium resistance wire. Using titanium, the heat originally produced by the electricity is greatly augmented by a reaction of the titanium with available oxygen. The titanium wire is not combustible in the ordinary sense, in that it cannot be lit with a fire of any combustible material, nor will the reaction produced in a portion of the resistance wire spread to other portions. Titanium fires of record are confined to processes involving fine powder, or 'finely subdivided turnings, or chips. Combustibility of titanium does not include ordinary thicknesses of wire such as ten mils or more. Similarly, iron wire liberates extra heat by combining with oxygen. Finally there is a variation in the use of my fire builder in which I initiate the fire by a material not ordinarily in the category of pyrotechnic substances, and not combustible under the definition herein, in that it does not produce flame or sparks or the like. An example of such material is a paste or tablet comprising red phosphorus, copper oxide, and manganese dioxide. The manganese dioxide is provided in exactly the correct proportions to produce manganous pyrophosphate containing all the manganese and all the phosphorus in the composition. The extra oxygen that is required and which is not available from the manganese dioxide alone is furnished by the copper oxide, which is totally reduced to metallic copper. The reaction products, manganous pyrophosphate and element copper are neither liquid or gaseous at the temperature of the reaction, which occurs throughout, if the mixture is heated at any point. Such a substance in the form of a cylindrical mass may be heated at one end with a match flame and shortly becomes incandescent. It liberates 200 calories easily without making sparks or flame and without changing its shape very greatly. The 200 calories produced by this mixture is produced in substantially less than ten seconds and in a volume of less than twenty cubic centimeters, meeting the requirements for initiation of a combustible substance in the presence of a pyrogenerative substance on a suitable support.

Another variation generally similar to the above technique for liberating 200 calories to initiate my fire builder comprises a compressed mixture of powders of magnesium element and ferric oxide. This mixture is extremely stable, but reacts with great vigor when the reaction is once initiated, yielding magnesium oxide and element iron. Although the melting point of the iron is exceeded, the mixture reacts in such a manner that it is at all times a gelatinous colloidal suspension, preserving in a greater or less degree the original shape which existed before the reaction began. A compressed mass of this mixture easily liberates 200 calories in a brief time Without flame or sparks.

I now summarize the essential features of my discovery of a new kind of fire builder, including only the pyrogenerative substance, and a suitable heat and oxygen resistant mechanical support. In all events, the support must be heat resistant enough in its entirety that the decomposition of the pyrogenerative substance to yield oxygen can be expected to occur on the support without perforating it. I have discovered that, in employing a pyrogenerative substance on a support, I may initiate the interaction between the pyrogenerative substance and the fuel to be lit, with an initiator or pyrotechnic material in a total amount less than enough to light the fuel unaided. Thus my combination of pyrogenerative substance and its support truly functions as a fire builder.

This discovery of a fire builder contrasts with my provision of a combustible container, in my US. Pat. No. 3,252,770. Following my more recent discovery, I provide no container at all, merely a support, which Works better the more fire resistant it is.

FIGS. 1, 1A, 2, 2A, and 3 are all illustrations of the same model showing a combination of my fire builder with a kindling substance of a pyrotechnic nature. The combination thus presented constitutes a fire starter and will be referred to in connection with these figures as a fire starter. If the pyrotechnic kindling substance 56 is omitted from the structure shown in these figures, the illustrations represent a fire builder Only and not a fire starter. When the structure shown in these figures, by omission, is made as a fire builder, it must be used in combination with a kindling means of some sort capable of releasing 200 calories of heat energy in less than ten seconds. The required kindling means in such as case is arranged to deliver the needed energy in the general vicinity of space where the pyrotechnic substance 56 is illustrated. I now proceed to the detailed description of these figures in the combination in which they in fact are made up as a fire starter.

Referring now to FIG. 1 in which I have illustrated a practical model of my fire builder, the tablets 48 are supported on a piece of cardboard 50 of a nature to function, under the conditions of use, as a heat and oxygen resistant material, the tablets 32 being cemented thereon by the adhesive 52, and surrounded by a thin tissue of wrapping 54. The pyrotechnic layer 56, indicated by the area filled by the diagonal lines in FIG. 1A and by the area filled by the diagonal lines and the thin layer as shown in section in FIG. 1, consists of a material generally similar in its effect and function to the composition of matchheads, and able to deliver, upon being consumed by fire, a total amount of heat between 25 and 200 calories in ten seconds, an amount insufiicient to light a charcoal fire by itself. The thin paper wrapping 54 shown in a cut-away view in FIG. 1A, surrounds the assembly consisting of the cardboard, the pyrotechnic substance 56, adhesive 52, and tablets 48.

For lighting a charcoal fire, the user places the fire builder-igniter combination in its entirely, underneath a mass of charcoal briquets, generally in the manner depicted in the FIGS. 2 and 2A. In these figures for simplicity, I have omitted the showing of the thin paper tissure which surrounds the cardboard. This tissue has very little combustible material, and exerts a negligible effect insofar as its contribution to the fire starting operation is concerned.

The section shown in FIGS. 2 and 2A illustrates briquets not in contact with the tablets. A section showing the briquets not touching the tablets can substantially always be produced if the vertically extending surface on which the section is taken is deliberatly chosen in a manner to avoid the points at which the briquets may touch the tablets. The vertically extending surface on which the section is taken may, in fact, be curved in various ways, except that its elements, all of them, do extend vertically upward. I choose the section in a deliberate manner to illustrate the region where the charcoal briquets do not contact the tablets to better show the principle of operation of my fire starter. Once the match has been applied to the pyrotechnic layer (having burned through the thin paper tissue, not shown) it burns and liberates an amount of heat sufficient to do three things: (1) decompose a portion of the oxygen yielding pyrogenerative substance in tablet A. (2) ignite a small region 58, of the charcoal briquet 60. (3) ignites the cardboard '50 in the region immediately under the tablet A. The cardboard burns superficially in the region immediately underneath the tablet A. The reason why the burning is only superficial is set out in a succeeding figure. The radiant heat evolved by combustion in the region 58 on the briquet 60, becomes very strong because of the evolution of relatively pure oxygen from the nearby part of the tablet A. The radiant heat emitted by the burning charcoal is indicated by the double lined arrows. The combustion proceeds to the remaining portions of the tablet A, radiating strong heat and causing the tablet A to decompose further, yielding more oxygen, indicated by the single lined arrows at the right of the tablet A. A portion of the radiant heat from the region 58 of the briquet 60 proceeds to the tablet B commencing the decomposition of the tablet B in the region indicated by the short single lined arrow at the left hand side of the tablet B. A further portion of the radiant heat,

indicated by another double line proceeds directly to the region 62 of the briquet 64 raising it to the kindling temperature. The region 62 increases in the intensity of its combustion vary rapidly, being helped by a portion of the oxygen derived from the right hand portion of the tablet A as augmented by the oxygen also being emitted from the left hand portion of the tablet B. In an exactly similar manner the process progresses from tablet to tablet until all the tablets are involved from left to right, as shown in FIG. 2A, in which the tablet E is just commencing to react.

In the FIG. 2A (showing a more advanced stage of ignition) the oxygen from the left hand portion of the tablet E will extend the combustion region of the briquet around to the right hand of the briquet 68 to the region 70 from whence the radiant heat proceeds to kindle the briquet 72, in the region 74, the combustion of which will re-radiate heat to the tablet E causing it also to be fully involved.

The user will note that in the description which has been given there is no reference to the combustion of anything but the fuel to be lit. It is in this particular sense that my newly discovered fire builder is different from all previous fire builders that are known or are disclosed in the literature.

I proceed now to FIG. 3 containing the information which I employ to describe the manner in which the cardboard support 50 is both heat and oxygen resistant in a major degree. A partially decomposed tablet 76 of the same type as the tablets 48 shown in FIGS. 1, 1A, 2 and 2A is shown in a deformed condition such as will occur when it is substantially decomposed by heat, having been melted in whole or in part on the cardboard support. The regions shown by the dashed lines illustrate the limits of the chemical reaction of the tablet on the cardboard downwardly and of the depletion of the oxygen in the tablet, upwardly. These limits occur, and do constitute limitations for the reason that in the mushy condition which the tablet assumes on being decomposed, it is a gelatinous heterogeneous mixture of substances having widely differing melting points. The mushy mixture includes potassium chlorate, potassium chloride (the result of the decomposition of potassium chlorate), bentonite clay, and manganese dioxide and graphite powder. The gelatinous mixture, being very viscous, does not mix vertically, but decomposes in a manner such that at all times it is in fact semi-solid. The portion of the cardboard 50 between the surface 78 and the dotted line 80 is consumed or partly destroyed by the oxygen originating between the surface 78 and the dotted line 82 Within the gelatinous semi-molten tablet of oxygen source (pyrogenerative) substance.

A further region of the cardboard immediately below the dotted line 80 is decomposed by heat but not oxidized, yielding carbon and whatever mineral constituents were mixed in the cardboard when it was made. The carbon and the minerals are entirely heat resistant. Potassium chloride produced from the portion of the tablet in the region between the boundary 78 and the dashed line 82 is complete oxygen resistant. The potassium chloride released from this region, in a molten condition, coats the carbon and the mineral layer produced from the cardboard, preventing the access of oxygen to it. Thus the carbon and mineral layer, already heat resistant, becomes oxygen resistant in use.

FIG. 4 shows a combination of my fire builder and a kindling device of an incombustible nature powered by electricity or by electrical energy. When the resistance wire 22 is omitted, this device is a fire builder only. When it is employed separately as a fire builder, there is added, in use, a source of energy equivalent to the resistance wire, which may be presented at the time of use. The source of energy may be anything at all that is convenient as, for example, the concentrated rays of the sun, electrical energy (as illustrated) or a fuse of the kind known in the trade as Thermalite Igniter cord, cardboard soaked in potassium nitrate solution and afterwards dried, or any other energy source which may be convenient to the user. In the form shown in FIG. 4, the combination constitutes a fire starter that comprises only incombustible materials.

The refractory support 16 has a laterally extending portion 18 on each side in which notches 20 are cut to receive the wire 22, which is laid back and forth between the notches, and over the pyrogenerative material 26. The laterally constraining members 19 confine the pyrogenerative material and are made of heat and oxygen resistant material such as, for example, asbestos board, plaster, ceramic materials, etc. The terminal wires 24 are connected to a source of electrical energy, not shown, sufficient power to deliver to the resistance wire 22, 200

8 calories of energy in ten seconds or less. The resistance wires 22 may, as alternatives, be composed of titanium element of a size such that the wire, in the thickness chosen, is not combustible under the definition of combustibility presented earlier in this specification. When a source of electrical energy is connected to titanium Wire disposed in the manner shown in the FIG. 4, a portion of the heat energy released by the wire results from the delivery of the electrical energy and a substantial further portion is added by the chemical reaction of the titanium wire with the air in its environment. Thus it is possible to deliver the 200 calories of energy more or less which I require, in a period of ten seconds or less, liberated in a volume of space not exceeding twenty cubic centimeters, obtaining the energy from an electrical source of energy less strong, one not able to deliver by itself the 200 calories in less than ten seconds. In this manner a more convenient ignition is achieved requiring relatively small portable electrical energy sources.

To show the unique and unprecedented nature of my fire starting procedure, I refer to my FIG. 5 in which I have disposed on the earths surface 4 (the earth being heat and oxygen resistant) a quantity of pyrogenerative material 2 and a quantity of wood fuel 6 so stacked as to not be in contact with the pyrogenerative material 2. For the purpose of describing what happens, I will assume that by one method or another a quantity of energy in the amount of 200 calories more or less has been delivered in less than ten seconds in the vicinity between the top of the pile of pyrogenerative material above the dashed line 14 and between the said top of the pile and the region 8 on one of the timbers 6. There occurs a delivery of oxygen from the pyrogenerative material and a delivery of heat energy from the region 8. Radiant heat and oxygen interact from one timber to another generally in the manner in which the briquets became successively lit as set out in my FIGS. 2 and 2A. While my FIG. 5 does not illustrate a fire starter as such, it does illustrate a method of starting a fire, the method being described as follows: (1) The use of a quantity of pyrogenerative material usually in excess of 20 grams of material having an available oxygen content not less than 30%. (2) The disposition over the pyrogenerative material of a suitable combustible fuel, and (3) the delivery in the vicinity between the pyrogenerative material and the suitably disposed fuel of an amount of heat energy not less than 200 calories in a period of time not over ten seconds, in a volume of not over twenty centimeters. If because of the way the wood is stacked, the volume requirements (to describe a compactly bounded region of space between the wood and the pyrogenerative substance) are larger, I use an equal amount of energy in ten seconds or less, in each twenty cubic centimeters of such volume.

FIG. 6 generally illustrates a fire builder of another type. This figure is shown and described in combination with a kindling arrangement that if omitted leaves a device of incombustible ingredients only, a fire builder which is particularly effective. The elements that are omitted or substituted to deliver the FIG. 6 device exclusively as a fire builder are the Thermalite igniter cord 32 and the special adhesive layer 29. The igniter cord is omitted and the special adhesive layer is substituted by a suitable incombustible cementing material such as a layer of chloroprene rubber or polyurethane cement. The detailed description of FIG. 6 which follows is particularly directed to the use of a fire builder in combination with these original ingredients. In such combination it functions as a highly effective fire starter.

Referring to my FIG. 6 in the complete form illustrated, I show a slab of pyrogenerative substance 28 cemented on a heat and oxygen resistant mechanical support 30 by cementing agent 29. The fuse 32 is of the kind represented in commerce by the trade name Thermalite Igniter cord. The Thermalite Igniter cord has a steel core 34, a layer of material generally similar to the thermite mixture of powdered aluminum and iron oxide, and an outer covering 32. The outer covering and the steel wire are metallic and electrically conductive. If the outer covering and the steel wire are electrically connected at the far end of the fuse 32, where it is hidden under the pyrogenerative substance 28, the fuse may be ignited by delivering an electric current, applying the terminals of the source of current to the emergent portion of the wire 34, and the outer covering 32. An electric current sufficiently able to substantially heat the wire 34 ignites the fuse very nicely. If electrical ignition is not preferred, a match may be applied to the emergent portion of the fuse 32. The cementing agent 29 is composed of an adhesive containing, as an example, asphalt and potassium chlorate which is a pyrotechnic substance. 'Cementation may also comprise a finely sub-divided powder of barium nitrate mixed in asphalt. Another type of adhesive preparation that I have found saitsfactory is a cement containing black gunpowder (meal) dispersed in nitrocellulose lacquer. Nitrocellulose lacquer of the kind employed in doping model airplanes or generally referred to as bar-top lacquer is satisfactory. The adhesive substance 29 is chosen in such a manner that its calorie yield when fully consumed, added to the calorie yield of the Thermalite Igniter cord is 200 calories more or less. The heat and oxygen resistant mechanical support is composed of asbestos, or some ceramic material. On the other hand, I may employ a smaller amount of the pyrotechnic adhesive 29 and substitute substantially but not totally, oxygen resisting inert substance. The relatively inert cardboard being consumed to a small degree, contributes the calorie value of whatever portion is consumed, thus making a smaller calorie contribution necessary from the adhesive to make up the required total of 200 calories.

FIG. 7, without match 45, is not a fire starter but is exclusively a fire builder, requiring the match in order to be able to function at all. If, as is entirely possible, I sell or supply a structure such as is shown in FIG. 7, but without the match, and If I choose a mechanical support 42 which is totally incombustible (heat and oxygen resistant) then rny FIG. 7 device represents an incombustible fire builder exclusively, and is not in any sense a fire starter.

A further variation in my fire builder can be seen by referring to my FIG. 7 in which I have illustrated a number of tablets 40 which may be but are not necessarily identical with the tablets 48 of my FIG. 1. The tablets 40 are composed of suitable pyrogenerative substances preferably of a type that has a yield of oxygen in excess of 30% by weight of the tablets, and a decomposition temperature in the vicinity of 375 F. The mechanical support 42 is of a substantially heat and oxygen resistant type and may or may not be totally heat and oxygen resistant; in accord with the descriptions which have been given earlier in this specification. The match 45 illustrating a common kitchen match of the large size currently available from the Diamond Match Company and the Ohio Match Company, and weighing about half a gram, is shown with its head 46 barely touching two of the tablets 40 and the wooden stem 44 tangent to all of them. In use, the head 46 of the match 45 is lit by fire from another match. The matchhead substance initiates the combustion of the wooden stem 44 at the point of tangency to the wood which is nearest the head 46. The fire involving the Wooden stern proceeds to consume it and ignites it in contact with the second pair of tangent tablets. They in turn ignite the wood in contact with the third pair of tablets furthest from the matchhead. Using up a portion of the oxygen from the tablets 40, the match stem 44 is entirely consumed, yielding sufficient energy to start a pyrogenerative supported combustion of the fuel, not shown, which is stacked over the fire starter illustrated in my FIG. 7.

FIG. 8 with a mechanical support 84 made of totally incombustible material and with nothing provided for the region A is another clear example of a fire builder.

FIG. 8 is a generalized or diagrammatic embodiment of my fire builder showing how certain of the variations which I envision are made. The region B of the heat and oxygen resistant mechanical support 84 is selected for particular attention because I can, if I choose, illustrate by a magnified view of region B of support 84 a uniform layered structure of the mechanical support. In one variation of my fire starter the top layer is entirely oxygen resistant, resting on an underlying material which, under the conditions of use, is entirely heat resistant. A layer of asbestos on top of cardboard is such a choice. The cardboard, when charred by heat conducted through the asbestos, becomes carbon, which is entirely heat resistant. The asbestos, being oxygen resistant, is able to protect the cardboard from the oxygen sources shown in the form of tablets 86 of pyrogenerative substance.

Another variation which I may choose to illustrate constitutes a layer of combustible material of very limited thickness, supported mechanically by material imme diately under it, which is both heat and oxygen resistant to an extreme degree, such as asbestos or ceramics. In this second arrangement that is envisioned in connection with my FIG. 8, the top layer has a total heat of combustion of the order of magnitude of 200 calories. Other layered arrangements can be visualized to combine mechanical and oxygen and heat resistance properties in a suitable manner.

The region A of my fire builder of FIG. 8 is the spaceof less than twenty cubic centimeters in which, for convenience and effectiveness, the 200 calorie amount of energy is best introduced. A small fraction of an ounce of many different types of fuel or pyrotechnic material can serve for this purpose, or, as I have noted before in my description of FIG. 4, the heat may be developed by the use of electrical energy in whole or in part.

My US. Pat. No. 3,252,770, issued May 24, 1966, relating to a fire starter (Lighter for Charcoal and Like Material) envisions and claims a combustible container and a noncombustible decomposable material susceptible of yielding oxygen. The discovery which I have made and which is presented in this specification is the tremendous advantage received by not employing a combustible container. On the other hand I have found it to be a large advantage to expose the oxygen yielding material in the direction of the fuel to be lit, preferably upward, permitting the unhindered access of oxygen to the fuel to be lit. The further distinction which I have found to be a strong advantage is in the choice of a substantially heat and oxygen resistant support, or the provision of a support which becomes heat and oxygen resistant under the con ditions of use, underneath the oxygen yielding material. In this manner, as set out in the foregoing description and figures, the greatest amount of oxygen is employed to consume and ignite the fuel to be lit. Thus a vastly more effective lighting action occurs involving difficulty ignitable fuels, and particularly the lighting action is more efficient, and more fuel is lit for a given amount of oxygen yielding substance.

Another aspect of my new discovery which is of great importance is in the domain of public safety. The more combustible material is presented in contact with or surrounding the oxygen yielding material, the more violent and disastrous a fire may become. It is a matter of experience (at the time of this specification) that extremely large numbers of fire starters (fire builders in combination with an igniter) can be destroyed by fire without injuring personnel. An accidental fire started by a locomotive cinder consumed over 100,000 fire starters of a kind made pursuant to the teachings of my FIG. 7 with a cardboard base. The fire starters were in a compact arrangement prepared for shipment. There were, in the vicinity, drums containing explosive vapors and various other 11 hazards. In spite of all these unfavorable factors, the growth of fire was smooth and orderly, poviding opportunity for the escape of 25 persons, more or less, without injury to anyone who worked there. In addition, there were no injuries to firemen.

Thus in my discovery as related in this specification, there is an achievement of an unexpectedly favorable combination of powerful fire starting or fire building capability, and extremely valuable public safety features.

For the convenience of the operator desiring to construct fire builders in accord with my specification, a list of materials which are, in fact, class one combustion supporting substances (pyrogenerative substances) is giv en below:

TABLE I (l) NaClO (100%) (2) NaClO (90%) plus MnO (10%) (3) K010 (90%) plus MnO (10%) (4) KClO (45.3%) KClO (51.3%) MnO (3.4%) (5) NaNO (42.2%) NH ClO (54.8%) Cr O (3%) (6) NaSlO (70%) KNO (28%) MnO (2%) (7) KClO, (96.8%) MnO (3.2%)

Further, I have found that materials are pyrogenerative if they fall in either of the following two classes: (A) the substance is decomposable and yields oxygen amounting to at least 20 percent of its weight, or more, and the energy required to produce the pyrolysis falls within the range of plus or minus ten kilocalories per gram atom of oxygen produced, and the temperature at which decomposition becomes complete is not over 475 F., and (B) the substance is decomposable and yields oxygen amounting to at least 20 percent of its weight or more and the energy required to produce the pyrolysis falls within the range of plus or minus ten kilocalories per gram atom of oxygen produced, and the temperature at which the decomposition becomes complete is between 475 F. and 800 F., and the substance is gray or dark colored, exhibiting a difluse reflecting coefiicient (for black body radiation of 2000" absolute) of 50 percent or less.

The preceding statements of categories A and B of materials which are pyrogenerative has been experimentally found to be equivalent to the algebraic statement offered in the application of which this is a continuation-inpart. The algebraic statement is substantially as follows:

As a guide in judging whether or not a given substance is pyrogenerative, the following inequalities may be used:

Second form A -20 Wherein:

F B Equatlon Inequality (II) 5 +20 Where:

A (delta) is an incremental correction.

5 (phi) is energy in kilocalories per gram mole of average yielded gaseous material produced by a heat decomposable substance, corresponding with the pyrolysis of the material to a point sufiicient to release in gaseous form all of the available oxygen contained therein.

(alpha) is the albedo or ditfuse reflection coefiicient of a material not presenting a mirror surface. The coefiicient as used herein is the reflected fraction of the total randomly directed radiant energy incident upon a surface of the material and is evaluated for black body radiation at 2000 Absolute.

-r (tan) is the decomposition temperature at which 50% of the available oxygen is yielded in ten seconds.

a (sigma) is a density factor representing the density of available oxygen in the material. This is determined by finding the weight per cubic centimeter of the material, at the bulk density which prevails, and multiplying it by the factor which represents the proportion of available oxygen in the material.

e (epsilon) is the proportion of oxygen in the gases produced by pyrolysis of the material. The concentration is taken by volume and is considered to have a value of one for pure oxygen and fractional values for mixtures of oxygen with other gases.

The values of the coefficients F, G, B and H can be obtained by calculation, first determining the values of oz, 1-, 0-, e and four compositions at the limit of the composition range set by tests of conformity of material to my definition. Thereafter, the coefficients so deter-mined may then be employed to determine the range of variations which may be made in any of the four types of compositions without destroying their pyrogenerativeness.

In many instances, Inequality I may be employed for guidance without determining the values of its coefiicients. For example, the term is inversely responsive to the albedo, 0:. Thus, if the proposed composition is light colored and is tested and found not pyrogenerative, it will be seen that, by adding a substance to darken the color of the composition, the albedo, or, can be decreased and the composition will be more likely to be pyrogenative. Similarly, the term G(5801-) indicates that substances having low decomposition tem peratures are favored. Accordingly, if the decomposition temperature of a proposed composition is high, it would be indicated to add a catalyst which would tend to lower the decomposition temperature.

It should be understood that, in employing the foregoing expression, it is not necessary to assume that all of the oxygen contained in a proposed composition will be released. If over 20% of the oxygen contained in the composition is released in accordance with Inequalities I and II, the composition may be considered to be pyrogenerative.

A procedure of manufacture and design which I have found particularly valuable in the discovery set out in this specification relates to compacting the pyrogenerative material into a solid, self-supporting, self-containing, mechanically durable, cohesive mass. By so doing, and only by so doing, am I able to make a coherent fire builder or fire starter not requiring a container for the pyrogenerative material. The composition sodium chlorate 70% and potassium nitrate of 30%, which may be used in the presence of manganese dioxide (which mixes with it in use) may be made into ingots by melting at a temperature of its decomposition. At 440 F. the material is entirely molten, and can be poured and cast readily. Thus, by a die casting procedure, it is possible to make a structure such as I have illustrated in my FIG. 6. On the other hand if the operator finds it more convenient to use tableting machinery, any of the compositions shown in my Table I may be employed with a suitable quantity of bentonite clay added, generally 5 percent or less, as a tableting additive. Pressures of approximately 30,000 to 50,000 p.s.i. readily compact the materials into cohesive masses, mechanically durable, and of any desired shape compatible with tableting procedure. Tableting procedure, in respect to these materials, is successful in producing all shapes except only those that have extremely sharp corners. Sharp corners are difiicult to make in a tableting procedure, but since they are not needed to carry out the teachings of this specification, there is no problem.

In the production of fire starters or fire builders, the

' manufacturing procedure may, if the operator desires, be

related to the use of a tableting machine by a mechanical interlock. Tableting machines of conventional type (as for example the kind made by the'Stokes Machinery Company of Philadelphia for many years) produce one tablet each time the main crankshaft rotates one revolution. The manufacturing of a fire starter or fire builder containing a certain number of tablets may be coordinated with the crankshaft rotations by the use of electrical switches suitably geared to the crankshaft, through which the controls are exercised. Thus it is easily pos sible to coordinate the manufacture of fire starters or fire builders to employ any desired number of tablets for each unit manufactured.

I have found tableting procedures to be particularly de sirable and useful for the reason that a wide variety of class one combustion supporting substances may be incorporated into the fire starter, at the whim of the operator. The ingot casting procedure, on the other hand, is limited to materials or mixtures of materials which are at the same time pyrogenerative, and have a melting range of temperature falling lower than the temperature ofdecomposition of the substances or mixtures. Very few substances fulfilling these requirements for ingot making can be found. By contrast, a much larger freedom of choice exists when tableting is used as the method of manufacture. Furthermore, tablets have proved mechanically more durable, and can be chosen from materials that are more resistant to weather and relative humidity. Therefore tableting is a preferred form of compaction of the material, a form especially adapted to fit in with my plan of avoiding the provision of a substantially important external container for the pyrogenerative substance.

Following the teachings contained in this specification, and the reasonable variations of them, the operator can discover many useful ways of making fire builders, or (adding an ignition means) constructing the combination of a fire builder with an igniter, to produce a fire starter.

The advantage of my fire builder arrangement can be understood when it is considered that an electric igniting unit for igniting a charcoal fire entirely by electrical energy requires approximately 30,000 calories of total energy to bring about sustained combustion of the charcoal. On the other hand, using the teachings contained in this specification the electrical energy requirement can be lowered easily by a factor of 100 and, employing careful design, can be lowered by a factor of 1000 below that which is required for direct electrical ignition of a charcoal fire. The electrical energy demanded for fire starting, using my discoveries is, in fact, so much lowered that it is entirely feasible and practical to employ an automobile battery with its nondangerous low voltage as a source to deliver the energy. For camping and for fire starting and fire building far removed from established electrical power sources, this achievement becomes of great importance to the user.

For camping I have discovered a variation of my fire builder-fire starter arrangement that has particular merit. In FIGS. 1 and 1A the operator will note the designation of the pyrotechnic substance 56. For the purpose of the camping model I manufacture the pyrotechnic substance 56 with a very thin crust of adherent but exposed small crystals of potassium chlorate on its outside surface, as it is presented in the structures of FIG. 1 and FIG. 1A. To ignite such a fire starter the camper simply tears back the paper envelope 54 to expose the front end of the starter as shown in FIG. 1A in the cut-away view, and touches or rubs the surface of the pyrotechnic substance 56 with the end of a small wand coated with an extremely thin layer of red phosphorus glued on it. The red phosphorus on the wand is made sufiiciently thin that the wand cannot be ignited by its red phosphorus coating. The reaction occurring when the red phosphorus is rubbed on the potassium chlorate ignites the pyrotechnic substance 56. The importance of this arrangement is in the fact that such a fire starter can be ignited in a high wind,

not requiring the doubtful and ditficult procedure of applying a match and burning through the paper envelope 54 under such unfavorable conditions.

An additional camping variation which can readily be visualized by the operator consists in providing integrally with the fire starter of FIG. 1 or FIG. 1A a string, a portion of which is coated with red'phosphorus, and adapted to be pulled through an eyelet or otherwise so that the red phosphorus impregnated portion of the string rubs on the potassium chlorate coated pyrotechnic substance 56.

Another camping variation is achieved in the use of the structure of FIG. 7. Instead of the common kitchen match which is ordinarily available, the kitchen match shown may be constructed with its head having the composition of a safety match. The operator may then take the entire firelighter and rub the safety matchhead on a sensitive strip, thus igniting the matchhead or, conversely, he may rub the strip on the head of the safety match with the fuel stacked over the fire starter.

If for the FIG. 7 device a thin paper envelope generally similar to the one pictured in FIG. 1 and 1A is furnished, the sensitive coating containing the red phosphorus may be presented on the outside of the said thin paper container. The camper simply tears off the container and rubs the portion of the sensitive strip provided on the outside against the head of the safety match.

For survival kit camping uses, the heat and oxygen resistant supports which I have provided may be varied to include such substances as stainless steel or other durable metallic structure. For the stainless steel supported model, it is entirely feasible to provide stainless steel cover that fits over the entire structure, sealing it completely against weather and moisture. The stainless steel cover, in fact, may be fitted over and secured by water resistant tape or by plastic resin glue of a kind that can be broken loose by the user. In such a manner the camper is provided with a fire builder or fire starter which is assured to be functional at the time of use regardless of exposure, and is independent even of such eventualities as immersion in water. In view of the foregoing descriptions, the operator will readily understand how models that are of particular value to campers can be constructed.

As a further variation, the stainless steel support may constitute a shallow basin, covered by a fiat, waterproof fitted stainless steel cover. This enclosed and thoroughly protected model has special value when it is combined with the pull-string, red phosphorus wand, or safety match ignition feature. Thus the user has the benefit of a fire starting or fire building device which is entirely weather and immersion resistant, and which can be used successfully under the most adverse weather conditions. I have succeeded in lighting a brush pile in the rain, after three days of steady rain with such a device. The user will easily understand the importance of such characteristics in employing my device under survival kit service conditions.

Concerning the amount of pyrogenerative material needed in constructing a fire builder, I have discovered that the amount which must :be used depends on the type of fuel in which I am attempting to build a fire. Particularly for charcoal and other common fuels, I have found that a quantity not less than 2% grams of potassium chlorate (or the equivalent pyrogenerative substance) is sufficient. The 2% gram quantity works if made into a tablet or ingot and if the charcoal is presented over it in the form of very small chips. I have tested quantities of pyrogenerative material on substantially heat and oxygen resistant supports up to amounts as large as six pounds of potassium chlorate. In the use of a very large amount such as six pounds, the process of supporting combustion and building a fire takes longer, because more time is required for the heat radiation from the fire to penetrate the pyrogenerative material and decompose it. Nevertheless, in using very large amounts of pyrogenerative material fire building proceeds smoothly. A six pound quantity supported over an area slightly more than one-half a square foot, builds a fire, reacting and supporting the fuel of which the fire is being built, during the time of about 240 seconds. On the other hand, a 2 /2 gram tablet, situated under a quantity of charcoal chips, goes to a complete reaction and ceases to build the fire any further after about fifteen seconds.

In keeping with my discoveries, I do not define a working upper limit since it is my experience that very large amounts of pyrogenerative material may be used safely. On the other hand, for those fuels in which fire building assistance is needed, 2% grams of potassium chlorate, or roughly one gram of yielded element oxygen is the least amount that will build the fire so that it doesnt go out.

For the average type of charcoal briquets currently being made in the United States, I have found that three or more tablets of approximately 3.2 grams each are sufficient and convenient to build a fire involving such briquets. A moderate size of tableting press can conveniently tablet potassium chlorate, with suitable tableting additives, in tablets that are between 2 and 4 grams each. Accordingly it is convenient to produce a fire builder comprising three or more tablets of potassium chlorate (or equivalent pyrogenerative substance) with suitable additives, each tablet weighing between 2% and 4 grams.

In mixing potassium chlorate and potassium, perchlorate with other things, I have found that the amount of manganese dioxide can be increased to percentages as large as 47% without doing any harm, except that it decreases the total percentage of available oxygen. Although manganese dioxide is not a decomposition catalyst for potassium perchlorate, I have found that it may be used as a blackening agent. It does not harm the utility of the composition containing potassium perchlorate up to 47% by weight.

What is claimed is:

1. A self-contained fire builder comprising the combination of one or more tablets of a material consisting essentially of not less than 45.3 percent by weight potassium chlorate, from 2 to 51.3 weight percent manganese dioxide and as a binder therefore, 3 to 48 weight percent bentonite clay, each of the said tablets weighing about 2.5 to 4 grams, said tablets being afiixed to the upper surface of a substantially heat and oxygen resistant support selected from me group consisting of cardboard not less than 0.06linch thick, asbestos board, plaster, or ceramic materia 2. A self-contained fire builder comprising the combination of one or more tablets of a material consisting essentially of not less than 45.3 percent by weight potassium perchlorate, from 2 to 51.3 weight percent manganese dioxide and as a binder therefore, 3 to 48 weight percent bentonite clay, each of the said tablets weighing about 2.5 to 4 grams, said tablets being afiixed to the upper surface of a substantially heat and oxygen resistant support selected from the group consisting of cardboard not less than 0.06 inch thick, asbestos board, plaster, or ceramic material.

3. A self-contained fire builder comprising the combination of one or more tablets of pyrogenerative substance consisting essentially of 30 weight percent sodium chlorate and 70 Weight percent potassium nitrate, said tablets being affixed to the upper surface of a substantially heat and oxygen resistant support.

References Cited UNITED STATES PATENTS 58,567 10/ 1866 Allen 149-70 1,882,365 10/ 1932 Lubelsky 44-3 2,000,414 5/1935 Neukirch 1-49-70 2,217,994 10/ 1940 Rick et a1. 44-16 2,876,084 3/ 1959 Leggin 44--3 X 2,953,443 9/1960 Lloyd 44-3 3,252,770 5/1966 Fearon 4440 3,293,187 12/1966 Markowitz 443 X DANIEL E. WYMAN, Primary Examiner C. F. DEES, Assistant Examiner U.S. Cl. X.R. 44-16,

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