US2222250A - Fuel briquette - Google Patents

Description

Nov, 19, 1940. R. T. BOWLING FUEL BEI QUETTE Filed March 18, 1959 ROBERT T. BOWLING Snvcmor F'G'?" W Jn l Cmomegl txamner Patented Nov. 19, 1940 UNITED STATES txaminer PATENT OFFICE FUEL BRIQUETTE Application Marchy 18,

4 Claims.

My present invention relates to an improved fuel briquette which may be manufactured from any vegetable ber, such as wood, bagasse, or the like.

5 My briquette is in the form of a solid cylinder of a convenient length and diameter for handling, and is highly suitable for heating and cooking purposes. Through the principles involved in the construction of my fuel briquette I am able to produce a durable article of manufacture which may be readily transported great distances and will stand all manner of conditions met in the usual course of such transportation. Hithertofore briquetted fuel has tended to disintegrate in the 16 presence of heat and humidity as well as from the shocks received through being handled in shipment.

It is a characteristic of my briquette that it is bound into a substantially sized, uniform unit by n means of inherent resins, lignins, gums, and moisture so that a foreign binding or bonding agent is unnecessary. It has, however, proved advisable in certain instances as when forming decomposed vegetable matter, such as coal and the il like, to bond the material, due to the extreme dry condition of the raw material. Another characteristic of my fuel briquette is the hard, smooth, glazed combustible jacket that is presented and is apparent in the briquette when it has been 80 formed according to the principles of my invention, as shown in Patent No. 1,990,632. This jacket is relatively non-hygroscopic and therefore the briquette may be subjected to a high degree of humidity without any effect whatsoever upon $5 the log. 'Ihis jacket further serves to make more easy the handling of briquettes during the stages of shipment and in delivery to the ultimate consumer. The smooth, hard surface permits the handlers to convey the briquettes from one eleva- 40 tion to another by sliding them along troughs.

Another essential characteristic of my briquette is the construction of the artificial log by the formation of a continuous helically spiral lamination which under the extreme pressure to which I 45 subject the material closely adheres together to present a homogeneous article.

More particularly am I concerned herein in the manner by which I form these. laminations so that they are distorted to form corrugations 50 which nest one upon the other more securely than has heretofore been possible. In earlier efforts to produce the laminated briquettes the usual form of the lamination was flat or ribbon-like in cross section, thus producing an article which,

55. due to its Weight, had a multitude of lines of 1939., Serial N0. 262,754

cleavage so that if the article should ever come to rest upon an uneven surface either violently during handling or be under a great weight due to stacking for storage, the article would separate on these natural lines of cleavage into two or more smaller pieces. Such breakage is naturally undesirable and the solution of the problem by eliminating such breakage or cleavage will greatly open the market for such artificially formed fuel briquettes.

The manufacturing operation of forming fuel briquettes according to my invention comprises the use of dry or seasoned fibers cast off as refuse from many manufacturing operations. In the woodworking industry great quantities wdust wood shavings, and waste woods normally are discarded by the manufacturer who has no further use for them. In the sugar industry the fiber, bagasse, presents a refuse problem that is difficult for the sugar manufacturer to cope with and the same is true in many other industries.

One of the early steps usually necessary in the formation of briquettes is to dry the bers so that the moisture content forms a relatively low percentage of the entire mass of raw material. This material is then reduced in suitable grinding machinery so that it is finely comminuted and of a uniform size. The material is then conveyed to suitable machinery and undergoes the steps of my process which briefly consists of pressing, heating, and cooling to the result that a solid cylindrical product suitable for fuel purposes is produced.

For the purposes of further description it will be assumed that I am speaking entirely of,wood fiber but it is to be understood that in this manner I do not intend to limit my invention in any way.

In the pressing stage of my process the bers are subjected to gradually increasing pressure through mechanical means, whereby the bulk of raw material fed to the machinery is formed into gradually more dense laminations in the form of a helically spiral ribbon of material. With the increase of the pressure upon the material a high degree of heat is produced which converts or changes the inherent gums, resins, lignins, and moisture into a highly efficacious bonding agent. During this pressing stage the spiral ribbon referred to above may be distorted by the formation of corrugations which follow the conformation of the helically spiral laminations.

When the spiral laminations have been pressed into a suitable die in the presence of a high degree of heat, they are permitted to cool during a stage of the process and are later extruded from' the die in the form of a solid cylindrical fuel log or briquette. During the heating and subsequent cooling stages of my process the bonding materials thoroughly impregnate the fibers and bind them together and, to a considerable extent, are driven to the outside of the cylinder Where, upon cooling, they present, along with the fibers therein, a hard, glazed, durable surface.

It should be apparent through the pressure and the heat generated that the cylindrical briquette is composed of a quantity of wood fibers from which practically all of the elasticity has been expelled and the material is reduced to its barest structural matter. Fuel briquettes formed with the hard, glazed outer surface and of the spirally corrugated spiral laminations are also extremely slow burning and therefore highly desirable for fuel purposes.

Disintegration which formerly took place in burning the ordinary spirally laminated briquette is not present in the article herein described with the consequence that re does not have ready access to the interior of the laminations and must burn slowly and evenly over the entire outer surface. The quantity of the bonding material present in the outer jacket of the cylinder also assists the ignition of my briquettes in use.

In the accompanying drawing, forming a part of this specification and in which like numerals are employed to designate like parts throughout the same,

Figure 1 is a view in elevation showing my briquette;

Figure 2 is an end view of one of my fuel briquettes;

Figure 3 is a diametric sectional view through a portion of a fuel briquette of my invention.

Figure 4 is a side elevational view of the present die head employed in connection with the general structure disclosed in Patent No. 1,990,632 to produce the fuel briquette of this invention,

Figure 5 is a Vertical sectional view through the die head taken along lines 5-5 of Figure 6; and

Figure 6 is a front elevational view of the die head.

The briquette as a whole is indicated by the numeral I and is composed of a continuous series of helically spirally wound laminations II which are highly and successively compressed to form a unit of fuel and the common center I2 of the laminations provides a solid zone extended throughout the length of the cylinder along its longitudinal axis. Each cross section of a lamination is distorted as may best be seen in Figures 2 and 3 so that corrugations I3, I4, and I5 are produced in the laminations I I immediately following the formation of the helically spiral laminations. The corrugations in each successively formed spiral layer register with those of the preceding layer and are securely compressed together under from twenty to forty thousand pounds pressure per square inch. Under this high compression the bonding materials bind the fibers, as well as the successive laminations, together into a homogeneous mass as uniformly dense throughout a possible.

Because, however, the succeeding laminations must be compressed upon the preceding laminations, a tendency to cleave or shear along the lines of the laminations has existed. The interlocking or nesting together of the corrugations in the laminations effectively removes this objection and the ultimate of homogeneity results. In the earlier stage of the compression the material from which the briquettes is to be formed is compressed into laminations substantially wider and thicker than the laminations I I and these previously formed laminations are subsequently compressed into the relatively thin laminations II shown in Figure 3.

In the process of forming the briquette, the comminuted material in a substantially dry or seasoned state is laid in a continuous spiral ribbon and subjected to high pressures. This presure creates internal heat and the heat thus produced liquidizes the natural rosins, etc. in the material and permeates the entire fibrous mass.

The briquette of Figure 1 is formed in a cylindrical mold which is supported along with other similar molds in a die wheel. The entire series of molds is enclosed by suitable jackets and Water for cooling purposes is circulated therethrough.

When the ultimate compression is reached and the cylindrical die is lled with spirally laminated material the water around the outside of the die in which the material is formed, cools and sets the binding or bonding materials and forms the hard, smooth, glazed surface I6 of the briquette. While this glazed surface is highly combustile it is also non-hygroscopic, thus serving to protect the outer faces of the briquette froml deterioration due to moisture, such as humidity in the air, and it also serves as an envelope for the laminated structure within.

Briquettes formed in my machine are usually of a convenient size for handling, being approximately twelve inches long and four inches in diameter and having an approximate weight of eight pounds each. Bulk shipments and bulk sales are the customary manner of delivering the article to the market. In certain instances these briquettes may be conveniently packaged in cartons of any desirable number for delivery in smaller quantities.

The presence of the converted lignins, resins, gums, etc., as binding and bonding agents makes the log relatively easy to ignite and I have found by chipping portions of the lamination from an end of a log, that they can be readily ignited from an ordinary match which will produce sufficient heat to ignite the bulk of the log.

The die head shown in Figures 4, 5, and 6 is identical with the die head shown and described in my copending patent application, Serial No. 262,753, filed March 18, 1939. It has a spindle or shank I1, which supports the head I8 that is a portion of a screw and has the cam face I9. The cutting edge 20 extends in a radial direction from the periphery of the head to the periphery of the spindle in the usual manner.

The head also has the slot 2I through which the material passes to be iinally compressed by the cam face I9. Upon the face I9 I form one or more ribs 22, which, as the ribbon of compressible vegetable matter passes through the slot 2l, act upon the ribbon to form the corrugations I3, I4, and I in the helically spiral ribbon. These corrugations conform to the lay of the ribbon in the cylindrical briquette and function as elsewhere described in this specification.

Because of the uniformity of the size and weight of my briquettes, the normal heat values per unit of length of the article are readily determined. It is thus possible to predetermine the heat content of the complete briquette or any given portion and relatively critical temperatures can be obtatined for cooking and burning. It should be apparent that many economies can be effected through the use of my briquettes as fuel.

The high degree of compression to which the material from my briquette has been subjected expels all the air, due to the fact that the cellular structure present in all fibers is destroyed. When the fuel is burned the danger of ying sparks common with many fuels is eliminated as Well as the self-destruction of the fuel. Dispersion of unburned parts of the log throughout the fireplace or furnace, whereby a considerable portion would be discarded as ash, is also eliminated.

Because the laminations and their corrugations restrain the separation of the log through expansion, oxygen is not permitted access to the interior of the laminations and the ame area is confined o the outer surfaces of the log.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A solid cylindrical briquette formed of helically spiral ribbon laminations of compressed vegetable matter that is characterized by having Lxaminer corrugations conforming to the lay of said spiral laminations.

2.- A solid cylindrical briquette formed of helically spiral ribbonI laminations of compressed vegetable matter that is characterized by having corrugations conforming to the lay of said spiral laminations, the corrugation of one coil of the helically spiral ribbon laminations nesting in the corrugation of the preceding coil.

3. A solid cylindrical briquette formed of helically spiral ribbon laminations of compressed vegetable matter that is characterized by being ridged on one face of said spiral ribbon laminations and grooved on the opposite face thereof, said ridged and grooved faces conforming to the lay of the spiral laminations.

4. A solid cylindrical briquette formed of helically spiral ribbon laminations of compressed vegetable matter that is characterized byr being ridged on one face of said spiral ribbon laminations and grooved on the opposite face thereof. said ridged and grooved faces conforming to the lay of the spiral laminations, and the ridged face of one lamination nesting against the grooved face of the preceding lamination.

ROBERT T. BOWLING.

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