US2412709A - Briquetting means - Google Patents

Description

Dec. 17 1946. R. 1-.BowLlNG 2,412,709

`BRIQUMTING MEANS Filed Agg. 24, 1945 3 sheets-sheet 2 nventor mam ai Hamme R. T. BowLnNG 2,4l`2,709

BRIQUET'TING MEANS Filed Aug. 24, 1945 I5A Sheets-Sheet 3 Srwentor RGBERT T. BOWLLNQ, Bs

Patented Dec. 17, 1946 @if BRIQUETTIN G MEANS Robert T. Bowling, Lewiston,

Idaho, assignor to Wood Briquettes, Inc., Lewiston, Idaho Application August 24, 1943, Serial No. 499,794

This invention relates to improvements in briquetting means in which finely comminuted vegetable fibers are compressed into a homogenecus mass of a size and density suitable for burning as fuel.

It is well known in the prior art that finely divided wood and other fibers have been compressed under the action of an inclined plane, such as a screw, into a dense briquette having great inherent structural strength and suitable for burning as a wooden log. These developments are fully disclosed in my prior Patents No. 1,990,631, issued February 12, 1935; No. 1,990,632, issued February 12, 1935; and No. 2,018,026, issued September 3, 1935. In these earlier developments the comminuted material is fed to a rotating tapered screw in a gradually decreasing chamber and thence in the form of a laminated ribbon to a cylindrical chamber terminating in a rotating screw segment which divides the ribbon from the following mass and passes it into the final compression chamber where, against a receding force, the finished laminated briquette is produced. In these earlier developments high heats were incident to the briquette formation and cooling means were necessitated to permit the setting of the briquetted material in the solid and linal form. The practical applications of my prior inventions produced briquettes of approximately four inches diameter and having a length of about twelve inches. In this form the fuel simulated logs and were useful for fireplace, stove or furnace burning. Many attempts have been made to -produce in a similar manner smaller briquettes suitable for Stoker feeding. I have sliced the larger briquettes to produce the proper size but such attempts have not proven fully satisfactory due to the labor involved, the slowness of the operation, and other circumstances that could not be surmounted.

In accordance with my present invention I feed comminuted wood ber to a tapered screw in a close fitting chamber for initial compression, then deliver the partially compressed material to a die head that comprises a vsegment of screw thread where the material is intermediately compressed before passage to a similar second die head that delivers the material to a plurality of pressure producing dies that divide the stream of material and from which simultaneously extrucle several strings of briquettes that are severed periodically into fragments of the desired length for stoker feeding. By so doing I am permitted to eliminate the receding back pressure formerly used and to also avoid the di cultic-s of slicing the larger briquette.

Claims. (Cl. 18-12) One of the results of the high pressures and the periods to allow setting'in the former practices was that finished briquettes adhered together due to the binding action of the resin and other fluid constituents in the material. It was previously deemed necessary that these high pressures produced by mechanical means, which approached 40,000 pounds to the square inch, were an absolute'requirement that could not be avoided in briquetting. Naturally the production of such pressure necessitated elaborate equipment and massive structures. I have now devised means forming a part of this invention that produce comparable results without utilizing such high pressures in the production of Stoker fuel.

Thus it can be seen that among the objects of this invention are the production of briquettes at relative high speed in large quantities, to do so with relatively simple equipment that can operate in an economical manner; to continuously receive and divide for compression a large stream of partially compressed material into several smaller streams while avoiding the difficulties of splitting previously encountered; and to periodically sever the smaller streams into many frag-` ments in-a rapid and economical manner.

The accompanying drawings illustrate a preferred embodiment of my invention as wellas certain modifications of detail that may variously be employed.

In the drawings:

Figure 1 is a view in side elevation showing my briquetting machine, with portions in section for convenience of illustration;y

Figure 2 is an end elevational view of the machine of Figure 1;

Figure 3 is an enlarged sectional view of the compression means of Figure 1;

Figure 4 is an end view of the extrusion die;

Figure 5 is a side view with portion in sections of the die;

Figure 6 is a fragmentary end view of a modiiieol form of die; I

Figure 7 is a detailed sectional view of a die passage of Figure 6;

Figure 8 is an enlarged detail view of cut-olf mechanism shown in Figure 1;

Figure 9 is an enlarged end view of the same cut-off mechanism;

Figures `l0 and 1l are, respectively, details of a guide element of the cut-olf mechanism;

Figure 12 is fragmentary perspective view cut-olf knife, and

Figure 13 shows the knife grip and securing means.

of the afname I mount my briquetting mechanism upon a base I which supports the superstructural housing I2 that provides bearings I3 to mount for As can be seen in Figure 3, the screw has al forward extension shank 28 which rotates there- K with and carries the initial die head 3! and the terminal die head 32. H

The screw it and the heads 3l and 32 are enclosed in a suitable compression housing 3i), which has a tapered portion eli and a cylindrical portion 35. An opening 3d permits the introduction of a comminuted fibre into the housing 34 to which it is conducted by a feed tube de.

In line with and closely adjacent the delivery end of the die head 32, is a die 42 which has a plurality of passages te through which the com pressed material being discharged by the die head 32 is extruded. As can be seen in Figure 5, the passages l flare gradually from the receiving ends to the delivery ends dii.

The delivery end of the die 42 has an annular shoulder 38, which is engaged by a retainer plate 5t that is secured by bolts 52, 5.2 to the casing 54, which encloses the feed screw and die head housing 3G.

-As material is gradually compressed by the screw l5, relatively thick laminations of material are formed in the chamber surrounding that portion of shaft 38 between the screw I6 and the head 3i. This material is divided according to these laminations by the pointed cutting end 33 of the head 3l, and pass through the slot that may be seen in Figure 3 to the space between the heads il and 32. Due to the action of the inclined face of head 3|, an additional compression is produced in the material. Similarily, the material is again divided by the pointed cutting end 35 of head 32,. and it passes through the i;

slot of the head S2. Under the force of the inclined planar face of' head 32 the material is immediately delivered to the passages 44 of the die ft2. Additional compression takes place in these passages due to the cross-sectional area of the entire group of passages e4 being slightly less than the cross-sectional area of the material being delivered thereto. The material under this high compression is in a semi-fluid state and is wiped into the various openings lill in a continuous manner. As it passes through these passages dit, the material is extruded outwardly and permitted to gradually expand due to the reduction of the pressure permitted by the increased crosssection of the individual passages.

It is extremely important that resistance" of the passage of this material through an opening dll be accurately proportioned with respect to the delivery rate from the die head 32. I have found that, since a perfectly cylindrical shape in the finished product is unimportant, that I can regulateV the back pressures applied to the material in the die 42 by either applying by welding a bead 54 shownI in the passage 56 of Figure 6, or by slotting the wall of the passage as 53, and placing in that slot a keymember Eid, The sizeof the bead 5ft or of the key E!) governs the dimension of the cross-sectional area of the passages and in increase or decrease controls the backpressure, applied to the incoming nfiaterial.`

In Figures 8 and 9 I illustrate a cut-off mechanism useful to periodically shear the extruding streams of compressed material as they leave the die 42. This cut-off mechanism comprises a reciprocal guide member 62 which has a knife blade 64 secured in its upper end by means of bolts or set screws 66. Member 62y is slotted 1ongitudi'nallyl as at 68, and both sides of the slot are provided with guide ways lil, which engage on opposed flat surfaces on the pivoted guide pin 12. A washer 'I3 and nut 14 secure this assembly in position and pin 12 is mounted to swivel in the base I0 where it is secured by the bolt 16.

Ori its lower end member 62 is connected to crank that is rotated by shaft 32 in suitable bearings 84,` 84 in the base HJ. Shaft 82 is driven in rotation by power taken olf the arbor I4 by means of sprocket 86, belt 88 and the driven sprocket Si) in a manner timed to operate and swing the knife 64 in a certain and predetermined cyclic operation, during which it is wiped across the discharge end of die 42 in a sweeping motion, and then withdrawn downwardly therefrom, swung under the extruding material, and again brought up into a position where it can sweep and shear the material as it comes out of the die 42.

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

l. A briquetting mechanism, comprising: a tapered feed screw adapted to receive and gradually compress material for briquetting, a shank on said feed screw in extension thereof, a die head having front and back spiral faces and a radial slot on said shank and spaced from the screw end, a second similar die' head on said shank spaced in advance of the rst mentioned die head, and a die having an end face perpene dlcular to the shank axis and in juxtaposition to the face of the second die head whereby the material advanced through the second die head is compressed in a thin stream between the die head and the end face, the die' having separate passages leading therethrough from said end face and positioned to` receive material under compression from said second mentioned die head to divide and conductA the briquetting material outwardly.

A briquetting mechanism, comprising: a taperedl feed screw adapted to receive and gradually compress material for briquetting, a shank on said feed` screw in extension'thereof, a die head having trout and back spiral faces and a radial slot on Said shank and spacedfrom the screw end, a second similar die head on said shank spaced in advance of the iirst mentioned die head,A and a die having an end face perpendicular to the shank axisand in juxtaposition to the face of the second die head whereby the material advanced through the second die head is compressed in a thin stream between the die head and the end face, the die having separate passages leading therethrough from said end face and positioned to receivematerial underV compression from said second mentioned die to divide and conduct the briquetting material outwardly, the passages oi said die being flared from their receiving toward their discharge ends.

3. A briquetting mechanism, comprising, a tapered feed screw adapted to receive and gradually compress material for briquetting, a shank on said feed screw in extension thereof, a die head having. front and back spiral facesy and a radial slot on said shank and spaced from the screw end, a second similar die head on said shank spaced in advance of the rst mentioned die head, a die having an end face perpendicular to the shank axis and in juxtaposition tothe face of the second die head whereby the material advanced through the second die head is compressed in a thin stream between the die head and the end face, the die having separate passages leading therethrough from said end face and positioned to receive material under compression from said second mentioned die to divide and conduct the briquetting materia] outwardly, and means to sweep the face of the die to sever the streams of material as it is extruded therefrom. y

4. In a briquetting mechanism of the screw type wherein a, compressed stream of material being briquetted is pressed forwardly for extrusion, a die to receive said material and comprising a member having a plurality of outwardly ared extrusion passages, the cross-sectional area of the forwardly pressed stream being greater than the total cross-sectional area of the several extrusion passages, and a rib longitudinally of the extrusion passages.

5. In a briquetting mechanism of the type employing a tapered feed screw; die head compression means, comprising: a shank supported in advance o5 said screw and having a head comprising a screw segment slotted from the rear to the front face, a secondsimilar die head supported in advance of said first mentioned die head, and a die to receive material from said last mentioned die head and including a plurality of extrusion passages.

ROBERT T. BOWLING.

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