US957163A - Straw-burning furnace. - Google Patents

Description

A. G. JOHNSON. STRAW BURNING PURNAGB. APPLICATION FILED APR. 12, 1909.

Patented May 3, w10.

`3 SHEETB-SHEET 1.

OOOOOOOO OOOOOOOO Wmme@ mmnzw n omwnu co. FuowMmoGnAPNsns wAsmNmnu, n

A. G. JOHNSON.

STRAW BURNING PURNGE.

APPLICATION FILED APR.12,1909.

Patented May 3, 1910.

I a SHEETS-SHEET 2. WA4-Lim*- @Mimmo Jf im Mw K )X41/@L Nnaew s :aP/mm CovPuma-LITHOGRAPHEHSwAsnmmcn,n.1:

A. G. lJOHNSON.v STRAW BURNING FURNAGB. APPLICATION FILED APR.12,1 909.l

Patented May 3, 1910.v

3 SHEETS-SBEBT 3.

ANDREW B GRAHAM au, PuoTo-LHHDGRAPNERS. wASmNGmN. Dlc

@Nrn

ANDREW G. JOHNSON, OF SUTTON, NEBRASKA.

STRAW-BURNING FUR/NACE.

Specification of Letters Patent.

Patented May 3, 31919.

Application filed April 12, 1909. Serial No. 489,272.

T o all whom it may concern:

Be it known that I, ANDREW G. JOHNSON, a citizen of the United States, residing at Sutton, in the county of Clay and State of Nebraska, have invented certain new and useful Improvements in Straw Burning Furnaces, of which the following is a specilication.

This invention relates to improvements in straw-burning furnaces of the class especially adapted for use in connection with traction engines.

The obj ect is to provide means for moving 'or agitating the straw while burning in the furnace, as an aid to combustion.

Another object is to provide a movable ash rake, useful for removing ashes from the furnace, and which by reason of its location and arrangement of parts, operates to materially assist combustion.

The invention also has reference to the form and arrangement of the grate and to certain operating devices found useful, and to a construction embodying as few parts as is consistent with reliable operation, so that manufacture may be economical.

With these and other objects in view, the invention consists of a novel combination and arrangement of parts as described herein, pointed out by the appended claims and as illustrated in the accompanying drawing, it being understood that changes in the form, proportion, size and minor details may be made within the scope of the claims without departing from the spirit or sacricing any of the advantages of the invention.

In the drawing, Figure 1 is a vertical, side view showing the body of a traction engine, parts being in section to clearly show construction of the furnace. Fig. 2 is a view sectioned on line a a of Fig. 3, showing the reverse side of the furnace, one of the supporting-bars being partly vbroken away. Fig. 3 is a plan View, on line 5 l) of Fig. 2, the platform being partly removed.

Referring now to the drawing for a more particular description, numeral 1 indicates a traction engine having a boiler 2, fire-box 3, smoke-stack 4 and provided with draftflues 5 providing communication between the fire-box and smoke stack. Within the fireboX, at 6, is shown an arch for deflecting, in a forward direction, the movement of the flames of burning material, the opening for the intake of fuel being indicated at 7.

While the hereinafter described devices are particularly useful in connection with traction engines, they may of course be used upon furnaces generally, where it is desired to employ straw or like material, as fuel.

I provide grate bars 3, preferably mounted in pairs, as pairs 9, 10 and 11, best shown in Fig. 3; they are disposed parallel with reference to each other, longitudinally of the fire-box, their front ends being mounted upon crank shaft 12, their rear ends having mountings upon crank shaft 13, these shafts having their ends mounted at 14, upon supporting-bars 15. Grate-bars 8 preferably have projections 16 formed to eXtend upwardly at intervals upon their upper edges, these projections operating to control the movement of the straw, as will be hereinafter explained. Bars 15 are disposed hori- Zontally near the lower part of the fire box at an altitude somewhat lower than the fuel opening, and have front portions 17 inclined upwardly for a support thereon of feeding-apron 18. As thus described, straw or similar material may be passed through the opening 7 upon the grate bars, and it will be understood that a movement of shafts 12 and 13 or either of them will cause a movement of the fuel. Since I employ three pairs of grate-bars, the cranks are disposed upon their respective shafts 12 and 13, intermediate arcs of 120 degrees, and therefore if a shaft movement is provided as mentioned, a movement for the bed of fuel will be provided, the preferred movement to be presently explained.

In order to provide a movement of the grate bars, rear shaft 13 is mounted as an idler, and upon front shaft 12 is loosely mounted crank-arm 19; upon shaft 12 is rigidly mounted ratchet 20, also having a seating adjacent arm 19, and upon said crank-arm is mounted the pawl 21, adapted to engage the ratchet.

At 22 is shown a horizontal shaft to be actuated from any suitable source of power, applied to pulley 23. Secured upon shaft 22 is the crank-arm 24 having the rod 24 mounted thereon at 25, this rod also having a pivotal mounting at 26 upon crank-arm 19, and a rotation shaft 22 in either direction will cause a swinging movement of arm 19. Pawl 21 will thereby cause shaft 12 to be partly rotated at each rotation of shaft 22, since ratchet 2O is rigidly mounted upon said shaft.

Each grate-bar 8 is mounted at 26 upon crank- shafts 12 and 13, said shafts being revoluble in these mountings. It will thus be seen that when the grate-bars are at their highest altitude, they are moving longitudinally toward the rear of the furnace, and this is a desired feature so that the straw will be carried rearwardly beneath arch 6 while burning. Since both of the bars of each pair are connected to the same crank upon the crank shaft 18, it follows that the movements of the bars comprising a pair will be in unison, but since the several cranks of the crank shaft 12 are set at an angle of 120O to each other, it follows that the movement of the pairs of bars with relation to each other will not be in unison, but that when one of the pairs of bars is moving forwardly, another of the pairs will be moving rearwardly. This movement will be hereinafter referred to as an alternate movement.

When the herein described straw-burning furnace is used in connection with a traction engine, straw may be passed over platform 27 and reaches fire-box 3 through opening 7. To assist in causing uniformity of consumption, I provide certain devices to be considered in connection with draftopening 2S; this opening is preferably located below or somewhat lower than platform 27, and is at the lowest part of the fire-box and is useful for removal of refuse as well as an aid to combustion, as will be presently described.

From the description it will be seen that the grate-bars, during operation, have movements in pairs; they are raised and lowered in alternation and these movements facilitate combustion of the bed of straw thereon, since air may circulate between the raised and lowered parts. The operation of the pawl and ratchet already described, causes intermittent rotary movements of crank shafts 12 and 13, this being a desired feature; the interruption in the rotary movements of these shafts causes vibration of the fuel upon the grate-bars which aids in combustion, and in operation a limited speed is all that is required.

I provide a carrier or means for removing ashes and non-combustible matter from the fire-box, consisting of the fieXible members or sprocket chains 29 mounted upon pulleys 30 and 31 and having, at suitable intervals, the Scrapers or bars 30 secured crosswise thereon. Pulleys 30 are rigidly mounted upon shaft 32, at the front of the fire box, pulleys 31 being rigidly mounted upon shaft 33 within and near the rear end of said fire box. Shaft 32 may be actuated by the flexible member or belt 811, mounted upon pulleys 35 and 36, these pulleys being mounted, respectively, upon shafts 22 and 82, and in operation, if shaft 22 is rotated in the direction indicated by the arrow in the drawing, ashes or other matter falling upon the bottom 37 of the fire box will be moved forwardly by the Scrapers, and may be deposited in ash receptacle 38.

In practice, any partly burned straw which falls downward between the pairs of grate-bars 9, 10 and 11, will be readily consumed in that part of the fire boX near draft opening 28, and the metallic apron 18 prevents movements of the flames in this part of the furnace from being directed upon fuel at intake 7 until the newly added fuel is moved rearwardly from the grate-bars.

The conditions met with in burning straw are so different from those existing in the consumption of coal or like fuel, that the same methods can not be employed in both cases. The compactness of straw and the large quantity of ashes left when it is burned, demand that a plentiful supply of air be supplied to the seat of combustion if the best results are to be obtained. The wide spaces left by mounting the bars in spaced pairs permits the ready escape of the ash and the ready access of air to the burning straw. In addition to this the alternate walking movement of the pairs of bars continuously shifts the body of burning straw from one angle to another, thereby opening fresh air spaces Vtherethrough and tending to separate the straw.

In the use of the herein described furnace, power can, in most cases, be conveniently obtained for moving the ash-rake and gratebars, and a single operator is sufficient for managing the same. The devices may be employed and the parts may be placed in furnaces already built in many instances, only slight changes being required for the mounting therein of the parts which have been mentioned.

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

1. In a straw burning furnace, the combination with a continuously rotating driving member, of a crank sha-ft having a plurality of cranks set at varying angles thereto, a plurality of grate bars mounted longitudinally of the furnace and in pairs, said grate bars being engaged by the crank shaft and said pairs being spaced from each other a considerably greater distance than the distance between the bars of each pair, the connection of the grate bars with the crank shaft serving to impart a walking movement to said bars, the movement of the bars of a pair being in unison, but the movement of said pairs of bars being alternate, an ash pit beneath said bars having an open rear end and a closed bottom, a rearwardly moving scraper traveling over the floor of said ash pit, connections between the driving member and the scraper, a swinging arm, a

pawl and ratchet connection between said arm and said crank shaft, and a connection between said swinging arm and said driving member whereby the movement of the crank shaft is rendered an intermittent one.

2. In a straw burning furnace, the combination with a plurality of grate bars mounted in pairs, said pairs being spaced from each other a considerably greater distance than the distance between the bars of each pair, of means for imparting a walking movement to said grate bars, the movement of the two bars of a pair being in unison, but the movement of said pairs being alternate.

3. In a straw burning furnace, the combination with a plurality of grate bars mounted in pairs, said pairs being spaced from each other a considerably greater distance than the distance between the bars of each pair, of means for imparting a walking movement to said grate bars, the movement of the two bars o a pair being in unison, but the movement of said pairs being alternate and intermittent.

4. In a straw burning furnace, the combination with a plurality of grate bars mounted in pairs, said pairs being spaced from each other a considerably greater distance than the' distance between the bars of each pair, of means :for imparting a walking movement to said grate bars, an ash pit beneath said bars having an open rear end and a closed bottom, and a rearwardly moving scraper traveling over the iioor of said ash pit to remove the ash from the straw burned on the grates.

5. In a straw burning furnace, the combination with a plurality of grate bars mounted in pairs, said pairs being spaced from each other a considerably greater distance than the distance between the bars of each pair, of means for imparting a walking movement to said grate bars, an ash pit beneath said bars having an open rear end and a closed bottom, and a rearwardly moving scraper traveling over the floor of said ash pit to remove the ash from the straw burned on the grates, said scraper comprising an endless belt and a plurality of scraper blades carried thereby.

In testimony whereof I have affixed my signature in presence of two witnesses.

ANDREW G. JOHNSON.

Witnesses:

JOHN ALLEN, M. L. KLINTBERG.

Images