US3252770A - Lighter for charcoal and like material - Google Patents

Description

i y 1966 R. E. FEARON 3,252,770

LIGHTER FOR CHARCOAL AND LIKE MATERIAL Filed July 3, 1962 2 Sheets-Sheet 1 ROLLED NEWSPAPER TUBE 3 IMPREGNATED WITH POTASSIUM NITRATE CORK mums SEALANT LAYER (PYROXYLIN LACQUER) FILLING (TETRANITROMETHANE THIN WALLED GLASS TUBE WITH KIESELGUHR) HERMETICALLY SEALED y 1966 R. E. FEARON 3,252,770

LIGHTER FOR CHARCOAL AND LIKE MATERIAL Filed July 5, 1962 2 Sheets-Sheet 2 i -n I I TOP CARD OF HIGHLY INFLAMMABLE MATERIAL I WOODEN CONTAINER DUGOUT CANOE DEL l l OF FIRELIGH'I'ER, T0

icAvnY FILLED WITH OXY- i i SCALE :GEN SOURCE MATERIAL I REPRESENTATIVE, usa- L- J FUL DIMENSIONS, WITH SUPPLEMENTARY EX- TERNAL PLAN (TOP) VIEW, SHOWING DIR- ECTIONS TO USER VIEW, SHOWING DIRECTIONS TO USER l I SUPPLEMENTARY EXTERNAL PLAN (TOP) I l 1/ SCALE:

BEFORE LIGHTING COVER u MAIN BODY OF LIGHTER -4 WITH CHARCOAL APPLY MATCH THIS SIDE 93 FIG. 5

IN VEN TOR.

United States Patent 3,252,770 LIGHTER FOR CHARCOAL AND LIKE MATERIAL Robert E. Fear-on, Tulsa, Okla., assiguor to Electro Chemical Laboratories Corporation, Tulsa, Okla., a corporation of Delaware Filed July 3, 1962, Scr. No. 210,290 9 Claims. (Cl. 44-40) This application is a continuation-inpart of United States patent application Serial No. 34,601, filed May 25, 1960, now abandoned.

This invention relates to lighters for fires and, more particularly, to such a lighter for lighting fires from charcoal, wood, coal and similar materials.

In lighting fires of charcoal, wood, coal and similar materials, the essential requirement is that the fuel substance to be ignited, or a sufficient portion of it, be raised to temperature above the kindling temperature of the material which itis desired to ignite, and that, concurrently with the existence of the high temperature, there be available a sufficient amount of air to furnish adequate oxygen to commence the combustion of the material to be lit. The availability of air must then continue after the main fuel material is first ignited, and be sufficient in amount to support the combustion from the moment of ignition onward.

kindling substance does not concurrently provide both the necessary heat and sufiicient oxygen or air to support the combustion of the material which it is desired to light.

-Thehottest flame from the kindling will be the flame which corresponds exactly with the complete and full use of the air passing over the kindling. Thus, the hottest flame affords a de-oxygenated region of space in its vicinity, in which the kindling temperature of the material to be ignited may be far exceeded, but in which there is no available unspent air to support combustion of suchmaterial. Therefore, in this instance, such material cannot catch fire while the heat is being delivered.

it the fire from the kindling dies down sufficiently quickly as the kindling is depleted, it may be that the temperature of the material to be ignited will remain hot enough during the process of dying down of the kindling, and will catch fire in the stream of unspent air which becomes available, as the kindling disappears. In the case of charcoal the probability of holding enough heat when the kindling dies down is poor for the reason that the charcoal is not well adapted to hold heat on its' surface, it being a thermally insulating material. Coal likewise is diflicult fuel, which presents other problems. Coal has I an endothermic destructive distillation (coking) which constantly lowers its temperature, making the achievement of kindling conditions difiicult. For this reason,

when kindling has been consumed underneath the coal,

the tendency is for the temperature of the coal to fall very rapidly.

In general, ignition occurs, as a consequence of the use of kindling substances, mainly along the boundary of the flame which such substances deliver or occurs chiefly during the time when the fire of the kindling substance is rapidly dying down. These consequences of the lack of ability of kindling'to concurrently meet the necessary conditions for lighting a fire, result in capricious performance of kindling, particularly so when the fuel to be lit 3,252,770 Patented May 24, 1966 ice is a difliculty i-gnitable substance, such as coal, charcoal 0r coke. The capricious behavior of common igniting procedures leads to inconvenience, uncertainties in the ignition of fires and creates danger to persons adding further kindling materials, such as hydrocarbon, on fires which supposedly have gone out, but which may have a small zone of ignition that is undetected. These uncertainties and diificulties of the classical igniting processes are avoided, and salutary advantages are conferred in the instant invention.

The instant invention provides a .fire lighter in which there is an excess of oxygen available, an excess above and beyond the amount required by the lighter. Thus, in the use of the instant lighter, the material to be ignited is raised. to the kindling temperature and, simultaneously, hot gas rich in oxygen is delivered to the heated material. temperature, the gas does not cool the heated material. Thus, the lighter 'may be characterized as a hot oxygen device. The oxygen yielding portion of the lighter in general is in itself a noncombustible component. fact, it is a salutary distinction of several of the preferred forms, that the principal ingredients are in themselves noncombustible.

In operation of the instant fire lighter, the advantages are secured by delivering a stream of oxygen or oxygenrich products from the lighter to the material to the ignited at a temperature above the kindling point of the material. The igniting which occurs is orderly, and is continuous and occurs over the entire surface of the material exposed to the stream of oxygen-rich gases at high temperature. Because the ignition takes place over the entire zone of the general vicinity of performance of the tfire lighter, a coherent nest of coals results. There is therefore .a rapid and orderly growth of the fire.

Owing to immediate ignition in the near vicinity of the lighter, the material being ignited cooperates in the perform-ance of the lighter, particularly when the fuel is packed around the lighter. Since unburned gases are not evolved by the fire lighter, but only gases rich in oxygen, the fire lighter cannot produce a voluminous flame that reaches out into the surrounding air. In general, the lighter will not produce a flame larger than that which would be expected from the material being lit. The characteristics of the flame therefore are those of the combustion of the material, and are not related to the lighter.

From the foregoing it can be seen that the use of the instant lighter represents a different procedure, conferring large and unexpected advantages over previous fire lighting procedures. The advantages lie chiefly in (l) the straighforward operation of the lighter; (2) synergistic performance with the material being lit; (3) extremely fast and powerful performance; (4) absence of explosive characteristics; (5) absence of voluminous or dangerous flame; and as will appear later, (6) absence of undesirable fume characteristics or poisonous products or objectionable residue.

It is an object of the present invention to provide a safe,-rapid, non-explosive means for quickly igniting a fire in charcoal, wood, coal and similar materials.

It is a further object to provide such a lighter which avoids dangerously high flame and which does produce explosive vapors during ignition or beforehand.

A still further object of the invention is to provide such a lighter which is independent of the surrounding air to initiate and support combustion during the early stages of the fire.

A still further object of the invention is to provide such a lighter which is compact and etficient and can be stored without hazard,

These and other objects will become more apparent Since the oxygen-rich gas is, likewise, at elevated 3 from the following description and attached drawings in which:

FIG. 1 is a top plan view of an embodiment of the invention;

FIG. 2 is a top plan view showing the device of the invention diagrammatically as employed in the lighting of a fire;

FIG. 3 is a top plan view, partly in section, of a further embodiment of the invention;

FIG. 4 is a top plan view, partly in section, of a still further embodiment of the invention; and

FIG. 5 is a top, side, bottom and end view, in orthogonal projections, of still a further embodiment of the invention.

The fire lighter of the instant invention includes a noncombustible, oxygen-rich material encased in a combustible, envelope or casing. The envelope or casing may be of paper, wood, cloth or any similar material which may be easily ignited and, if desired, may be treated to regulate the combustion rate. In addition, if desired, the casing may be treated to render the fire lighter waterproof. The oxygen-rich material or filler may be any material which, when heated, releases a substantial amount of oxygen. Such material must, however, be nonexplosive and one which will release oxygen only while the material is being heated. Once the heat is removed, the liberation of oxygen should terminate.

The oxygen-rich material or filler of the lighter of the instant invention is selected so that, when the container is lighted, the temperature to the metal is elevated and a gas, rich in oxygen, is released. Should the temperature of the filler be lowered, the release of oxygen stops. Thus, the release of oxygen is controlled by temperature only and is not dependent upon a specific energy absorption by the oxidizing agent undergoing pyrolysis. This characteristic of the filler material is characterized by zero energy.

For instant purposes, zero energy is defined as energy of pyrolysis limited to plus or minus kilocalories per gram atom of oxygen released from the solid being decomposed. This yield is sufficiently small in the positive direction that explosion or self-propagating reaction cannot occur in the filling material. Thus, pyrolysis of the fi-l- :ler material is dependent upon the supply of heat from the burning surface of the container in contact with the filler. When the burning surface of the container is extinguished, the release of oxygen from the filler will stop, unless, of is at a sufiicient temperature to maintain the temperature of the filler at the oxygen releasing level.

The zero energy concept of the instant invention is of considerable importance from the standpoint of safety, In the first instance, the possibility of explosion'is removed. Explosion is, of course, one of the hazards of hydrocarbon lighter materials. In the second instance, the operation of the instant lighter can be stopped at any time merely by extinguishing the container. This is not the case with hydrocarbon lighters of other types which, once lighted, cannot readily be stopped. Thirdly and of equal importance, because the filling material is nonexplosive and will not, in itself, release oxygen, the lighter of the instant invention may be more safely stored and shipped.

Some of the fillers found to be useful in the instant invention, and described in more detail hereinafter, conit is preferred to use materials which, while releasing oxygen, do not give off toxic gases.

Turning now to FIG. 1, there is shown a casing 1 of relatively coarse absorbent cotton fabric having a thickness of between approximately .005 to .010 inch. At its opposite ends 2, 2, casing 1 is tied or sewed to form an inner cavity 3, cavity 3 being filled with an oxygen-rich material before the ends of casing 1 are closed. One composition of zero energy, oxygen-rich material which may be employed, for purposes of illustration, is a granular mixture composed of by weight agricultural grade sodium chlorate and 10% by weight finely powdered, native mineral, manganese dioxide. The manganese dioxide is preferred in a very fine grind. The ingredients were mixed and loosely packed in casing 1.

After filling, and if need be, drying the entire composition in an oven, the structure is thickly painted with pyroxylin varnish 4 of the type used in coating the wings of fabric covered airplanes. The coating may be ac complished, if desired, by dipping the entire structure in a pail of the varnish and permitting the portion which does not immediately drain oflf simply to dry in place. Repeated dipping'rnay be resorted to if necessary to produce a thick coat. The varnish is made sufliciently thick that it has a total mass very much larger than the total mass of the fabric casing 1. Whatever plasticizers are needed may be included in the composition of the pyroxylin varnish to make it tough and durable, and to permit it to form a coherent layer adapted to enclose and protect the granular composition 3 from absorbing atmospheric moisture.

The manner in which the described arrangement works when it is used in lighting a charcoal fire can be understood by referring to FIG. 2. In FIG. 2 the stick shaped structure, diagrammatically illustrated at 5, is surrounded by lumps of charcoal 6. The casing is lighted by applying a lighted match to casing 1 such as at one of the ends 2. The fire propagates along the outer pyrotechnic casing and produces hot spots 7 on the charcoal. These hot spots are of a very limited extent at first. The internal composition of the fire lighting structure is released by the burning off of the pyroxylin and, at the same time, a portion of the internal composition is sufficiently heated to release some oxygen. The oxygen so released escapes in the presence of the hot spots 7, enlarging them. Radiant heat from these hot spots so enlarged, then reacts further upon the already released granular composition, decomposing more of it and driving even more oxygen against the ignited areas, whereby they are still further enlarged. The described process is of an accumulative nature, and proceeds to a conclusion corresponding with the total consumption of the granular contents which were at first released. The release of oxygen may, of course, be terminated at any time merely by extinguishing the casing or removing the remainder of the lighter from the presence of the hot coals.

There are a number of substances which would be serviceable for the practice of my invention, for the oxygen supplying function in it and which are capable of supplying oxygen more abundantly than those already mentioned. Illustrative of materials which have a richer supply of oxygen are iodine pentoxide and tetranitromethane. As is noted in the literature of chemistry, the acyl modification of nitroform is solid in the ordinary ambient range of temperature, melting at 50 C. The potassium salt of nitroform does have a degree of solid residue. This is comparatively small, considering the oxygen it has available, which is three times as much per molecule as is available from potassium nitrate. In choosing such materials for fillers, such materials are blended with other materials so that the energy level of the filler composition will be at the zero energy level as hereinabove defined. For example, sodium chlorate is capable of supplying oxygen at a richness level adequate for purposes of the instant invention. However, when used alone, sodium chlorate does not exactly fulfill zero energy though it meets our defined requirement. Hence, the energy level of the sodium chlorate is conveniently adjusted downward by adding thereto by weight of manganese dioxide. Such composition has been found to provide a rich supply a of oxygen and, at the same time, a relatively safe lighter because of its energy level. The manganese dioxide in the mixture also serves as a catalyst, aiding the release of oxygen from the sodium chlorate. 'The fact that the manganese dioxide is black favors the absorption of radiant energy from the fuel being lit, aiding the further release of oxygen.

In the particular model of the lighting device shown in FIG. 1, it is evident that more or less potassium or sodium nitrate may be incorporated in any mixture as desired. Sodium orpotassium nitrate cannot be used except in mixtures, for the reason-that decomposition of either of these substances absorbs too much energy,

violating our zero energy principle. Additives which energetically form oxides may be used tocompensate this energy loss. Oxygen yielding additives, of the class which yield energy on pyrolysis may also be used to correct the sodium or potassium nitrate energy loss. Red phosphorus will serve as a suitable additive. Variations in shape of the structure are also permissible.

The stick tends to create a linear strip of burning coals. Ammonium perchlorate is a desirable ingredient in certain mixtures. Noting that ammonium perchlorate has very abundantly available oxygen, spots containing this substance may be strategically placed along the length of a stick shaped fire lighter, to provide for strong availability of oxygen at periodic intervals of distance along its axis. For the casing, which I have suggested he made of pyroxylin, there are other equivalent compositions which will serve more or less satisfactorily. As an example, a blotting paper tube which has been saturated with a strong solution of potassium nitrate and then dried may be used. To make the tube impervious to moisture, an outer coating of any convenient varnish, including pyroxylin, may be employed.

A structure generally similar to FIG. 3 was made and provided with cardboard caps in place of the corks. Nitrated paper in the amount of approximately 6 grams of paper and 6 grams of potassium nitrate composed the tube which was 4 /2 long and 1 /8" in inside diameter. The contents which filled the interior consisted of 90% by Weight of sodium chlorate and 10% by weight of manganese dioxide.

FIG. 4shows' a structural modification of my invention illustrating a more complicated device using tetranitromethane enclosed in a long, slender, thin walled tube of glass, a substance able to contain it indefinitely. Outside the glass is a sleeve of pyrotechnic material, such as a treated wood, adapted to rapidly break up the glass when it burns, releasing the tetranitromethane. The latter sub stance falling into the fire delivers a tremendous blast of oxygen, far greater than is available from many other oxidizing agents. The tetranitromethane assembly illustrates very clearly the division of my device into separate and distinct functional parts, in view of the fact that tetranitromethane itself is neither combustible nor explosive, nor does it have any instability on long contact with glass. In this case, accordingly, the inner member of my device is, in fact, incapable of burning, but illustrates very effectively the provision of a concentrated means adapted to support the combustion of the fire first ignited by the pyrotechnic casing. As time passes, doubtless other extremely favorable oxygen providers will become available and will be developed. All such are included in the scope and intent of this disclosure, and fall within the spirit of my invention.

Materials such as tetranitromethane and iodine pentoxide are illustrated as contained in my glass enclosure bottle for the reason that these substances require an impervious enclosure. The tetranitromethane requires such an enclosure or at least requires an impervious enclosure for the reason that it is a liquid. The iodine pentoxide requires an impervious enclosure to protect it from the atmosphere for the reason that it rapidly absorbs moisture. These materials are very rich in oxygen and very powerfully effective. They are costly and their use would be particularly worthwhile in those instances where an extremely compact fire lighter is required, and where the demand for compactness would outweigh the cost argument.

Besides the above peculiarities of such substances which require an impervious envelope, there is a further point of departure which is particularly well illustrated by the tetranitromethane. Tetranitromethane can be evaporated at atmospheric pressure substantially without decomposition. The vapor produced at atmospheric pressure will support combustion. It is accordingly true that this substance may light a fire or, rather, augment one in a way different from the action of sodium chlorate, which cannot be vaporized at atmospheric pressure. In the case of the tetranitromethane, unlike that of sodium chlorate, pyrolysis is not a necessary antecedent to the action of the fire lighter. In place of pyrolysis evaporation is a requisite.

A further and different particular practice of my invention consists in the use of a baseboard of thermally nonconductive material to which the tubular structure of FIGS. 1, 3, or 4, are attached by means of a liberal smear of pyroxylin varnish. The baseboard forms a support under the structure when the fire lighter is positioned in the charcoal. The use of the baseboard is to prevent the oxygen-yielding material from falling down. onto the iron structure of the cooking apparatus or carbon burning furnace after the tube or casing is consumed during initial stages of the fire. The need to prevent this escape of oxygen-yielding material onto the iron exists for the reason that the yield of oxygen will cease when the material comes in contact with a metallically conducting substance that can cool it below the temperature at which oxygen release occurs. Thus it is seen that if a fire lighting stick was placed at the bottom of a mass of charcoal, resting on iron, and not on the charcoal, the performance for lighting fires would be less effective. As a matter of fact, in my tests it has been discovered that the fire lighting function may be altogether prevented if the user makes the mistake of putting the fire lighter at the bottom of a bed of charcoal on the cold structure of the iron support. Also, partial failures have occurred if the carbon bed underneath the fire lighting device is not sufficiently compact or permits the escape of the oxygenyielding material downward to too large an extent.

The use of a baseboard of thermally nonconducting and preferably combustible material prevents the incorrect use of my igniting device. In practice I have found that the baseboard may consist of a piece of charcoal or a loosely compacted charcoal briquette of the shape illus trated, or a piece of any kind of wood, including even resinous woods, provided the latter is slightly charred on the outside. To prevent a charred surface from being messy, it is entirely feasible to coat the charred surface with a thin layer of pyroxylin varnish. A thickness of /s for the baseboard has been found sufiicient. The ends of the baseboard should extend far enough to fall even with and underneath the tubular fire lighting device. The extension laterally is sutficient at 50% more than the diameter of the tube for total width of the base slab. Generally the tube should be cemented and approximately centered, though exact centering is certainly not critical.

Using this structure, much more consistent performance is obtained since the presentation of the oxygen-yielding material surrounded by the newly established fire is rendered uniform from one test to the next. The fact that the entire process is a kind of a chain reaction in which the newly established fire accumnlatively brings about the release of the oxygen that further increases it, adds to the importance of uniform arrangement, since chain reactions are extremely sensitive to the conditions that make their cycle grow. Thus it is seen that the base plate is not necessarily an indispensible' thing in all instances of the use of my invention, but that it frequently adds desirable results.

Another particular variation of my invention which has special merit for certain applications employs a mixture of ammonium, or potassium, perchlorate and sodium nitrate as a filler ingredient in a structure generally similar to FIG. 3. The sodium nitrate and ammonium perchlorate are ground together as a composition comprising an equal weight of each in any given quantity of mixture. Such a composition corresponds with a very slight excess of sodium nitrate over what would be an equimolar mixture. Such a filling ingredient has been found to be satisfactorily complete in itself and requires no catalyst, and

needs no separately prepared composition to energize it.

Also the composition of sodium nitrate and ammonium perchlorate has a further advantage in that it does not absonb water vapor appreciably from humid air. Another advantage is in a technique for placing this filling ingredient without using either corks or caps in the ends of the cylinder, whereby the filling ingredient hardens into a cylindrical mass that is suificiently solid to remain in place in the nitrated paper tubes such as are illustrated in FIG. 3. The solid mass can be produced by stirring up a paste of the equal weight mixture of sodium nitrateammonium perchlorate powders, using an addition of liquid such as denatured alcohol. The denatured alcohol is mostly composed of 2-propanol and 30% water. The effect of the water contained in the mixture is to dissolve some of the nitrate component and a very small amount of the perchlorate component of the composition. The dissolved material is regenerated in crystalline form upon evaporation and cements the remaining undissolved crystals together into a solid mass. If care is taken to use a thick paste, at least as thick as plasterers mortar, the amount of shrinkage is very small and the cylinder of solid substance produced in the nitrated paper tube by packing it with paste remains adherent to the nitrated paper tube filling it and converting the whole structure into a solid cylindrical mass. Such structure as described above, has been tested and found to be very satisfactory as a means of lighting fires.

Another way of producing a solid mass of substance in an appropriate pyrotechnic casing consists in charging the already described paste into a prepared cylinder of porous paper, the paper having not been treated with potassium or sodium nitrate beforehand. Slow drying of the resulting structure in a 135 F. oven results in deposition of nitrates in the paper during the drying process to a sufficient degree that the paper acquires the pyrotechnic characteristics indicated in FIG. 3. The usefulness of the employment of paper tubes that are not previously impregnated lies in the fact that the paper tubes can be manufactured under conditions not requiring the type of fire protection which is necessary when nitrate impregnated paper must be used. The employment of paper tubes from nonimpregnated stock thus renders the manufacture of my fire lighting device more efiicient. Quite naturally it is feasible to employ the composition which has just been recited in conjunction with the base-plate which I have described in previous paragraphs. Also it is clear that potassium nitrate could be used in place of sodium nitrate if technical or practical reasons favored such a choice.

Lastly, the cementing together of the internal contents of a cylindrical fire lighter obviously is not limited to the use of a liquid with water,ybut cementing liquids adapted to deposit an appropriately small amount of organic substance can be employed. Resinous materials, solutions of natural or artificial rubber, substances which will polymerize in place, may all be employed, the amount being restricted sufiiciently to prevent the cylindrical component from becoming explosive, i.e. maintain the zero energy level, and also sufiiciently restricted to still leave most of the oxygen available, rather than consuming it to use up the cementing substance. A very suitable cementing substance is obtained by the evaporation of thin pyroxylin solution. A concentration'of pyroxylin, as little as 2%, may be employed. The organic solvent evaporates, leaving behind a very sparsely distributed amount of cementing material which sticks the granules of nitrate-perchlorate mixture together. Sparsely distributed cellulose acetate may also be used. A very thin lacquer of polystyrene dissolved in carbon tetrachloride is feasible. The latter may be varied by the inclusion of volatile hydrocarbons to the extent that they are tolerated in a good lacquer composition. A considerable list of analogous variations in the manner of use of my sodium nitrate-ammonium perchlorate filling will be evident to the worker skilled in the art, and all such variations lie within the reasonable scope of my invention and discovery.

Particular dimensions and weight-s of material which have been found to have merit in the use of the sodium nitrate-ammonium perchlorate arrangement consists of a tube having an internal diameter of /4" and an external diameter of Vs", prepared as illustrated generally in FIG. 3, and having a total length over-all of 3". The tube so prepared and filled within of each end of solid mass of substance as has been described is cemented on a base-plate of charred yellow pine, having dimensions 1 /8" wide and 3" long and A5" thick. The cementing agent used is ipyroxylin lacquer as has been suggested. The emergent unfilled lip of the tubular structure, at each end, presents an opportunity to apply a match, for ignition. If the flame of the match plays upward on the upper portion of the extended lip of the tube, this pyrotechnic casing material easily catches fire and the fire propagates in the necessary manner to ignite charcoal and start the decomposition of the oxidizing agent. The weight of filling substance required to produce the dimensions and composition consists of 13 grams of sodium nitrate and 13 grams of ammonium perchlorate, approximately, the exact amount depending on the size, distribution of particles, and the manner in which the material is packed into the tube to produce the indicated dimensions. This exact description is given for the purpose of completeness and to illustrate an especially desirable ex perimental model which was found to serve very success- :fully. Successful results with this particular arrangement are achieved with practically all methods of cementation of contained filling substance, which may be chosen in a broad latitude of possibilities with the guidance of the preceding paragraph. Of course numerous variations of this device will be evident, to accord with the specific requirements for ignition in a given case. In fact the application of the present precisely described model is to produce a charcoal fire in which the domain of original ignition extends about 4 /2" one way by 3 /2" in the other direction as viewed from above. The domain of original ignition extends upward from the igniting device through the mass of charcoal which lies above the base-plate for a distance of about 3 toward the top of the pile of charcoal, if the pile extends further than the 3". The products of the reaction of this precisely described model comprise very largely sodium chloride, some of which is evaporated at the temperature of the ignition process. The evaporated sodium chloride condenses slightly on remote briquettes of charcoal or coke, and causes a visible white deposit on these, a deposit disappearing later on as the charcoal burns.

In addition to the sodium chloride, there is produced from the NaNO -NH ClO model a residue including a small amount of sodium oxide or hydroxide, representing the molar excess of sodium nitrate over ammonium perchlorate. No offensive amounts of hydrogen chloride fumes or nitric oxide fumes have been observed during 9 the ignition process in the particular model above described. The igniting process is accompanied by a vigorous, strongly luminous yellow flame extending upward from the vicinity of the cylindrical structure to a distance of 3" or 4", such flame exhibiting the characteristic sodium color of brilliant yellow. The special use of the particularly described model outlined immediately preceding is to the ignition of relatively small charcoal fires for household cooking purposes. Another useful field of application for this specifically described structure is in the lighting of indoor fireplaces. One use of the device for this purpose proceeds by starting in the fireplace a small charcoal fire in the same manner that has been described elsewhere in this disclosure. duced charcoal fire is then employed to ignite wooden logs or other fireplace fuel. The danger of employing highly combustible kindling of unpredictable performance, or of employing explosive hydrocarbons within the house is avoided. Thus it is apparent that my device not only serves the convenience of the household user in lighting an indoor fireplace, but also increases safety and prevents accidents which may include the burning down of his house.

Although the structures have been generally described as 'havinga circular cross section, such an arr-angment is not at all indispensible. Reasonable variations include, among other choices, square cross sections of the tubular structure, hexagonal cross sections, regular pentagon cross sections, or triangular cross sections; Any such shapes are suitable and may be chosen, if reasons of convenience of manufacture or packaging indicate that they are desirable. The triangular cross section, in particular, adapts itself for compact packaging.

A very favorable yield of gases results when the ammonium perchlorate-sodium nitrate mixture is used. Therefore, during the lightening action the fuel burns more vigorously than it does in air.

The chain reaction involving release of oxygen and steadily increasing ignition of charcoal, once begun, does not require a pyrotechnic outside casingto promote it, depending only on the oxygen-source filling and the surrounding charcoal, once it has been initiated. Therefore, an alternative structure is an arrangement of briquetted salts in which the pyrotechnic material is at one end only. Even more than the other devices which have been described, this one has an interdependence with the fuel, interdependence of such a degree that, to a first approximation, it is not consumed unless surrounded by fuel.

Instead of a container of fabric as shown in FIG. 1, or paper as shown in FIG. 3, the container may be of Wood or other combustible material hollowed out at one side, such as is shown in FIG. 5, and covered with a pyrotechnic or combustible layer of material extending across the top of the container. The wood may be subjected to a treatment which superficially increases its cornbustib'ility. I have tested the treatment of the wood in two forms, both of which are successful and must be regarded as competitive ways of accomplishing the same thing. in one method of treatment of the wood, it is soaked for twenty minutes in a water solution of sodium nitrate approximately saturated at a temperature of 160 F. :to 170 F. It is understood that the figures given here are illustrative only, and that other solutions such as [for example solutions of potassium nitrate also serve.

. A rich solution is required, rich to a degree that it cannot The initially pro- 1 The alternative method of treating the wood consists in dipping it in a mixture of 50% by weight sodium nitrate and 50% by weight potassium nitrate at a temperature in the vicinity of 230 C. to 240 C. At this temperature the designated mixture of salts is liquid and the wood can be dipped in the described mixture at the temperature set out. When so dipped for a brief interval of time, of the order of a few seconds, the wood comes out with an ivory like layer of salts on it. If the salts are removed by a'sander on every side except in the cavity, the lining of sodium-potassium nitrate on the cavity serves very well to promote the combustible function of the wood along the cavity lining. This is, of course, import-ant to provide on the interior of the container, in contact with the filler, a combustible surface to release the oxygen from the zero energy level filler contacting such surface.

It is understood that the top cover of the treated wooden container has various equivalents, all of which are essentially similar provided they perform the functions of this top board. Preferably the top board is extended out, at one end, beyond the end of the wooden container and serves to contain and protect the contents, carry fire from the extension, which serves as a fuse, and deliver the ignition to the container surface zone of the wood where the inner surface of the cavity comes level with the top. Other ways of sealing the top may comprise, among other things, covering with a lacquer or paint which will harden into an impervious layer of sufficient mechanical strength. The function of the extend ing portion of the top card may also be performed by employing a fuse suitably attached to the top of the wooden structure, or in fact, to any portion of it, provided the solution method of treatment has been employed. It is noted that the solutionmethod of treatment of the wood leaves it superficially highly combustible over its entire exterior, whereas the salt plating using the molten salts technique ends up, after sanding, with the lining of the cavity only having treated characteristics.

The wooden container is ignited on its fuse, which delivers ignition to a suitable region of the surface of the wooden structure. The fire travels from whatever point is initially ignited until it reaches the boundary between wood and other substance at the top of the filled cavity. Ignition then progresses along the lining of the filled cavity. The combustion of the wood is at first supported by using the oxidizing substance which is either plated 'on the cavity surface or charged into the wood, depending on the processing of the wooden structure. The combustion which progresses along this cavity lining converts the entire cavity, in effect, into a heated crucible within which the oxidizing substance is very rapidly decomposed.

Experiments with the wooden container type of fire lighter have shown an operation time of approximately sixty seconds, during which the entire contents consisting of 16.3 grams of filling mixture is decomposed to a cinder of sodium chloride, with a little sodium carbonate. The yield of gases from the mixture employed is of a relatively large proportion of oxygen. The inert ingredients in the gas yield consist of nitrogen, and of carbon dioxide and superheated stream, the latter two gases resulting from superficial combustion of the lining of the wooden cavity. The volume of gas yield is in the general vicinity of a cubic foot, and in view of the time of release as has been noted, the rate of yield is approximately sixty cubic feet per hour, but of course this is not absolutely constant during the igniting process. It reaches a maximum about fifteen seconds after the fire propagates itself over the lining of the wooden cavity, continuing at a high and relatively constant rate until the filling material is all consumed. The temperature of the evolved gas is sufficient to appreciably sublimate the products of the decomposition. A white crust remains afterwards which is quite visible on the more remote ten sodium nitrate and ammonium perchlorate.

pieces of charcoal. Two substances Which are volatile at high temperature could produce this crust. Sodium oxide sublimes at 1275 C. and sodium chloride boils, per The Handbook of Physics and Chemistry, at 1413 C. Accordingly, it is reasonable to assert that the temperature of the evolved gases reaches a value which at least, is in the vicinity of 1000 C. in view of the volatilization of the products, which has been observed through their sublimation onto charcoal. Another clue to the high temperature of the evolved gases is the intense yellowness seen in the gas stream carrying the vapors of sodium compounds. Whether this intense yellow flame eifect is entirely caused by the original temperature of the evolvement is a matter of doubt, since of course the burning charcoal in the immediate vicinity increases the heat.

In summary of the description of gas evolvement, gases are evolved at a rate which is of the order of 60 cubic feet per hour and at a temperature of the order of 1000 C., for a period of about one minute, carrying in the appreciable quantities of vaporized sodium compounds. Repeated experience has shown that a stream of oxygen of the type described is a very effective means of starting a charcoal fire. In fact, such a stream of hot oxygen is a very effective means of building a fire involving any substance capable of burning in air.

In addition to those set fortl above, the following formulation has been found useful with the hollowed out wooden container:

Percent Sodium nitrate 42.2 Ammonium perchlorate I 54.8 Chromium sesquioxide 3 In this formulation, the oxygen donors are sodium nitrate and ammonium perchlorate, the ammonium perchlorate also serving as'an energy source. Sodium nitrate is the energy absorber. Chromium sesquioxide, the catalyst, is not effective to promote the decomposition of either the sodium nitrate or ammonium perchlorate. However, when the mixture becomes molten, exchange of ions occurs, producing some ammonium nitrate from the mol- The decomposition of the ammonium nitrate so produced is increased substantially by the chromium sesquioxide present. Chromium sesquioxide, as a catalyst in this preparation, has the desired quality that it does not detract from the stability of the mixture under storage conditions, since it is not a catalyst for the decomposition of the ingredients initially present.

In the fire lighter of the invention, the operation of the lighter is started by applying a lighted match, or the like, to the combustible container of the fire lighter. Once the combustile container starts to burn, the burning container elevates the temperature of the material to be burned and, at the same time, elevates the temperature of the oxygen-rich source within the container. As the temperature of the material is elevated to the kindling temperature, oxygen from the oxygen-rich source within the container is liberated at the kindling temperature of the material to be burned, initiating and supporting combustion in such material. Once the fire in the material to be burned is started, the heat from the fire elevates the temperature of the oxygen-rich source, increasing the oxygen yield. As the oxygen yield increases, the fire in the material -to be burned likewise increases. Thus, the combustible container triggers the reaction, elevating the temperature of the material to be burned to the kindling point and, at the same time, initiating the yield of oxygen at elevated temperature from the oxygen-rich source. Once the reaction is triggered, the fire in the burning material completes the release of oxygen from the oxygenrich source.

Because the oxygen-rich source is not reliant upon the heat from the combustible container to complete the release of oxygen, the weight of the combustible container in relation to the weight of the oxygen-rich source can be kept to a minimum. This, of course, increases the overall safety of the fire lighter, The weight of the combustible container, of course, depends on the particular type of container material used. Preferably, the oxygen-rich source constitutes not less than one-third of the total weight of the structure.

While the fire lighter of the invention is intended, primarily, for lighting fires from charcoal, it may also be employed for lighting fires of wood and coal. Depending on the size and type of wood or coal to be burned, one or more of the fire lighters may be used to start a fire in the wood or coal. Preferably, because the fire lighter depends on the heat radiated from the initially lighted material to complete the yield of oxygen from the oxygenrich material, when starting a fire in wood or coal with the device of the invention, it is preferred to use charcoal with the lighter. Thus, the fire lighter is employed to start a fire in the charcoal and the charcoal, in turn, to start the fire in the wood or coal. In this manner the oxygen yielded from the fire lighter may be more efliciently employed.

The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed.

What is claimed is:

1. An igniting device consisting essentially of a combustible container containing a noncombustible decomposable material, said decomposable material being a blend of a first composition selected from the group consisting of ammonium nitrate, ammonium perchlorate, potassium perchlorate, and sodium chlorate, and a second composition selected from the group consisting of sodium nitrate, potassium nitrate, iodine pentoxide, and manganese dioxide, said first and second compositions being proportioned in said blend so that, when said material is decomposed a gas rich in oxygen will evolve from said material at an energy level per gram atom of oxygen not less than l0 kilocalories and not more than +10 kilocalories.

2. An igniting device as recited in claim 1 in which said first composition consists of sodium chlorate and said second composition consists of manganese dioxide.

3. An igniting device as recited in claim 1 in which said first composition consists essentially of potassium perchlorate.

4. An igniting device ,as recited in claim 1 in which said first composition is ammonium perchlorate and said second composition is sodium nitrate, said ammonium perchlorate and said sodium nitrate together comprising by weight not substantially less than twothirds of the total weight of said igniting device.

5. An igniting device as recited in claim 1 in which said combustible container is of wood, said first composition is ammonium perchlorate and said second composition is sodium nitrate, said decomposable material containing, as a catalyst, a minor amount of chromium scsquioxide.

6. An igniting device as recited in claim 5, said sodium nitrate comprising about 42.2% by Weight of said decomposable material, said ammonium perchlorate comprising about 54.8% by weight of said decomposable material,

and said chromium sesquioxide comprising about 3% by weight of said decomposable material.

7. An igniting device as recited in claim 5 in which said wooden container is treated with anoxidizing material.

8. An igniting device as recited in claim 7, in which said oxidizing material is sodium nitrate.

9. An igniting device as recited in claim 7, in which said oxidizing material is a mixture of 50% by weight of sodium nitrate and 50% by weight of potassium nitrate.

References Cited by the Examiner UNITED STATES PATENTS Cook 44-40 Livingstone D. 44-4 Griffin 44-40 Hager 44-40 Diederiehs 44-34 10 Crecelius 44-4 Grand et a1 44-3 Taylor et a1. 149-92 Hall 149-60 FOREIGN PATENTS 11/ 1943 Denmark.

12/ 1935 Great Britain. 7/ 1937 Great Britain.

12/ 1940 Great Britain. 4/ 1950 Great Britain.

DANIEL E. WYMAN, Primary Examiner.

E. W. GOLDSTEIN, C. F. DEES, Assistant Examiners.

Claims (1)

1. AN IGNITING DEVICE CONSISTING ESSENTIALLY OF A COMBUSTIBLE CONTAINER CONTAINNG A NONCOMBUSTIBLE DECOMPOSABLE MATERIAL, SAID DECOMPOSABLE MATERIAL BEING A BLEND OF A FIRST COMPOSITION SELECTED FROM THE GROUP CONSISTING OF AMMONIUM NITRATE, AMMONIUM PERCHLORATE, POTASSIUM PERCHLORATE, AND SODIUM CHLORATE, AND A SECOND COMPOSITION SELECTED FROM THE GROUP CONSISTING OF SODIUM NITRATE, POTASSIUM NITRATE, IODINE PENTOXIDE, AND MANGANESE DIOXIDE, SAID FIRST AND SECOND COMPOSITION BEING PROPORTIONED IN SAID BLEND SO THAT, WHEN SAID MATERIAL IS DECOMPOSED A GAS RICH IN OXYGEN WILL EVLOVE FROM SAID MATERIAL AT AN ENERGY LEVEL PER GRAM ATOM OF OXYGEN NOT LESS THAN -10 KILOCALORIES AND NOT MORE THAN + 10 KILOCALORIES.

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