US1499532A - Furnace - Google Patents

Description

FURNACE Filed July 19. 1923 3 Sheets-Sheet 1 a I l I I I I I I I I I l I I I l l l l l I I w\W///K\ Wm\\% Filed July 19. 1923 3 Sheets-Sheet. 2

l I l I I l l l l l l l l i July 1 1924. v 1.499.532

c. J. HUBER FURNACE Filed July 19 .1923 3 Sheets-She L 3 Patented July 1, 1924.

UNITED STATES I 1,499,532 PATENT OFFICE.

CHARLES J. HUBER, 0F BALTIMORE, MARYLAND.

FURNACE.

To all whom it may concern:

Be it known that I, Cr ARLEs J. HUBER, a citizen of the United States of America, residing in the city of Baltimore, State of Maryland, have invented certain new and useful Improvements in Furnaces, of which the following is a specification.

In the present existing furnace practice in which coal is fed directly to the top of the fire, being either spread over the grate surface by means of a shovel, or carried to and through the combustion area by some more elaborate stoking apparatus, great difliculty is encountered in obtaining complete combustion.

Ordinarily there is a very considerable loss of fuel in the form of smoke and gas, which being formed or generated well forward or toward the center of the furnace, does not become sufiiciently mixed with air in its passage from this point to the bridge wall to form a combustible mixture and therefore it escapes and passes up the chimney without being consumed. Failure to achieve complete combustion with consequent discharge of gas and smoke not only results in the loss of a large number of heat units otherwise obtainable from the coal, but also in the creation of a nuisance to those located in the vicinity of the furnace on account of the unpleasant and harmful effect of the gases and smoke on human beings as well as furniture, buildings, clothes, etc.

The object of the present invention is to achieve increased economy by providing for complete combustion of the coal eliminating smoke and unconsumed gases by complete combustion thereof. The result thus outlined is obtained by coking the coal at the front of the furnace after it enters the furnace but before it is fed to the fire, the vapors from the coal being thus generated or driven off from the coal at the front of the furnace are mixed with air and burned completely before they reach the bridge wall, with the result that not only are the heat values of these vapors consisting of combustible gases and smoke made available, but the harmful effects of mixing these gases and smoke with the outside air are avoided.

In the form of the invention shown, cok ing of the coal is accomplished by means of a coking shelf of refractory material, as fire brick at the front of the furnace above the fire together with a reflecting and heat Application filed July 19,

storing member of refractory material above the shelf, and means for admittin air at the front of the furnace beneath the shelf and forward of the coal dropped from the shelf so as not to be choked by the fuel, and so the smoke and gases released in the coking of the coal are mingled with air and burned as they pass over the fire toward the bridge wall. In other words, all the volatile elements are driven off from the coal at the front of the furnace and mingled with air freely admitted in front of the coal on the grate and burned before they reach the bridge wall. Every provision is made for subjecting the coal on the coking shelf to the most intense heat so as to coke each charge completely before it is fed to the fire, thus releasing the distillable portions and burning them completely by mixing with air at the high furnace temperatures, obtaining the greatest possible amount of heat from the fuel and preventing smoke.

The invention has been developed in connection with a furnace having an ordinary hopper feed. The hopper feed includes a pusher, the operation of which first places a charge of coal on the shelf to be coked and then when it has been coked, pushes it from the shelf so that it drops ontothe grate after all the volatile matter has been driven oil.

The pusher may be timed and operated in any suitable manner as by power or by hand. In the fo'rm shown, it is intended to be manually actuated and timed.

In the accompanying drawing,Ihave illustrated a furnace embodying the coking and smoke-consuming feature of my invention.

In the drawing:

Figure l is a vertical, central, longitudinal section of a furnace constructed and equipped in accordance with my invention.

Figure 2 is an elevation looking at the outside of the furnace from the front.

Figure 3 is a transverse section taken on the line 33 of Figure 1 and looking at the front of the furnace, coking shelf,'etc., from inside the furnace. The observer is looking in the direction of the arrow in Figure 1.

Figure 4 is a section corresponding to Figure 1 in thatit is taken in the same vertical, longitudinal plane, showing the coking shelf, the bridge wall and the hopper, the pusher being in advanced position.

Figure 5 1s a similar view, the pusher be ing partly retracted;

Referring to the drawing bynumerals, the furnace'is in the main of the usual'con struction having a bridge wall, 1, an arch, 2, ash pit, 3, grate, 4, and feed hopper, 5. The feed hopper is closed at the bottom by a sliding pusher or feed piston, 6. This,

as shown, is of L-shaped cross section providing for the entrance of. the outside air into a chamber, 7, beneath the L, serving to cofolthe coal in the hopper. The pusher is actuated by a link, 8, pivotally connected thereto and in turn pivotallyconnected to a lever, arm, 9, which is rigidly secured to an actuating arm, 10, said arm, 10, and link, 9, combined having a bell crank lever action, both being pivoted at their meeting point or vertex on a stationary journal pin, 11.

The pistonor usher, 6, slides on a horizon talplate, 12, ,mown as the feed plateand extending across the furnace from side to side and being rigidly mounted in the furnac e structure, it being understood that the furnace may be of any desired width, hav ing; a corresponding number ofhoppers and p ushers depending on the number of boilers which may be set side by side in a battery thus equipped. 1

,An important feature of the invention resides in the construction and arrangement of .tl1e parts in the vicinity of the hopper feed opening, 14, and the co-operation therewith of the feeding member or pusher, 6. The coking shelf, 15, is placed with its top surface; in thehorizontal plane of the top surface ;of.the feed plate, 12, and projects into the furnace. from the feed opening. This shelf is formed of resistive material tongued' and grooved for mutual engagement, of the lateral edges as shown at 17, 18 in Figure-3, the tongues being indicated by. reference character, 17, and the grooves by reference character 18. The fire bricks forming the coking shelf are also shown as provided with longitudinal T slots, 19, dotted in cross section in Figure 3, the slots extending downwardly from the top sur- 7 faces of thebricks, the T being inverted and the portion ofthe slot corresponding to the cross arm being near or below the center and extending longitudinally thereof, cooperating with these T slots and occupying the same, I haveshown T bars, 20, secured to andiprojecting' from the feed plate, 12,

directly backward into the furnace. The

shelf is preferably builtupthe fire bricks thus formed by placing the T slots in engagement with the T irons and sliding the bricks backward against the feed plate, 12,

the T irons entering the slots, and the 7.

of the cross bar, 12, and the latter is pro vided with a depending web, 22, against which the ends of the bricks abut, whereby they are further positioned and supported and. aligned. i

The top wall of the hopper opening, 14, is formed by a depending portion, 24, of the arch 2. This depending member, 24, is composed of blocks of resistive material placed side by side, and extending across the front of the furnace. They are partially supported by ears, 30, entering apertures, 31, in the blocks. This portion; of the arch is shown as formed as to its lower innerv surface in a full, substantially circular curve, 25, which *gives the opening an increasing cross-sectional area from the entrance 26, .thereof inwardly. Beyond the depending portion, 24, of the arch, the rear portion, 27, thereof is curved and constructed in the usual manner. This formation of the depending portion of the arch, in cooperation with the flat shelf, 15, contributes to the coking action by permitting the deposit of the coal on the shelf,as illustrated, where it is permitted to become coked, the formation of the opening, i. e., its increasing taper inward by contributing to the prevention of cramping when the coke thus formed is again engaged by the pusher being broken up thereby and pushed fromthe shelf so that it drops on the front of the grate. The depending portion 24 is directly exposed to radiation from the hot test part of the fireand so becomes highly heated. The heat thus stored in this member 24 has a very important effect in heating the green or cold fuel which comes direct-ly in contact with it as it enters the furnace,the heating effect being produced both by conduction, i. e., direct contact, and by reflection and'radiatio'n. The shelf which is also of heavy fire brick or other'suitable resistive material, is alsoa very eflicient heat reservoir, receiving the radiation directly from the fire and transferring the heat to thefuel, and on account of the narrowness of the shelf, some of the fuel is also-exposed directly to radiation from the fire.

-Beneath the shelf, 15, adjacentthe front' of the grate and just forward'of the fire, I have shown a grid, 35, the openings in which lead from the ash pit to the fire box. These openings which are well forward of the rear edge, 36, of the shelf, 15, provide fora-the admission of air at a pointand in a manner'which permits it to combine in combustible proportions with the smoke and gases resulting from the coking of the.

- is almost completely out off when and where it is most needed. As'the raw coal gives off practically all the gas and smoke generated in the furnace, it will be apparent that, under the conditions described, the discharge of smoke and unconsumed gases from the chimney can hardly be prevented for the air which is admitted to the fire box enters well back in the furnace and it is not suflicient in quantity and there is not sufficient opportunity for it to become heated and mixed with smoke and gas generated at the front of the furnace, while these products of partial combustion are in the heated zone to provide for their further and complete combustion.

In accordance with the present invention, the coal is coked before it is fed to the grate. In coking it becomes caked into a solid mass and when broken up by the pusher, the fragments are so large that the air passes between them. Also I have provided an extra air passage beneath the coking shelf. This passage it will be noted is placed well forward of the edge of the coking shelf so as to be free of the fuel which is dropped from the shelf so that it is not choked in the normal operation of the grate providing for a free passage of the air from the ash pit to the fire box which is not true of the grate area proper. In this way, suflicient air is admitted at the front of the furnace to provide for complete combustion of the smoke and gases generated in coking, and the gases are generated at the extreme forward end of the furnace in a position which provides a long path for the gases from the point of generation to the flue. In making this passage, they become completely mixed with air admitted to the front of the fur nace, as aforesaid, the air has suflicient chance to become heated, and mixing takes place within the heated area providing for complete combustion and the elimination of smoke and raw, poisonous gases, and also for the generation of a correspondingly increased amount of heat in a position in which it .will be available for heating the boiler.

The manner of operating the coking apparatus illustrated will be easily understood. The hopper is filled with coal, usually bituminous, a large part of it being so finexthat it would tend to drop through the grate. The pusher is withdrawn as by raising the handle, 37, fitted onto the level arm, 10. On withdrawal of the pusher, a. charge of'fuel settles down from the open bottom of the hopper onto the feed plate, 12, in front of the pusher. The lever or handle, 3 i then lowered, advancing the pusher and moving it forward onto the coking shelf within the furnace, where it is subject by radiation and convexion, to the full temperature of the furnace and to conduction and radiation from the highly heated depending member 24 and from the coking shelf 15, both of which are of heavy ceramic material adapted to receive and store and radiate heat to the very best advantage. The pusher is then withdrawn, permitting a new charge to pass downward from the hopper to a position in front of the pusher, and the parts are allowed to remain in this position until coking is complete and the furnace is ready to receive a new supply of fuel. The pusher is then advanced, forcing the new charge forward through the feed opening, 14, onto the shelf, and by the pressure thus applied breaking up the coke on the shelf, causing it to fall on the forward portion of the grate, as illustrated. Coking and feeding may thus tend to follow immediately after each stok ing operation, it being apparent that stoking and feeding may be accomplished in any suitable manner, either by hand or by power, the coking and smoke consuming device illustrated being capable of use with any type of feeding and stoking apparatus.

I have thus described specifically and in detail a furnace structure embodying my invention in the preferred form, together with the operation of the same in order that my invention may be fully understood by those skilled in the art, however, the specific terms herein are used descriptively rather than in a limiting sense, the scope of the invention being defined in the claims.

What I claim and desire to secure to Letters Patent is:

1. In a furnace having a grate, a flue, a bridge wall and a feed opening, a coking shelf extending backward into the furnace at the lower side of the feed opening in front of the furnace and above the grate, the feed opening having a top wall at the front of the furnace and exposed to radiation from the fire and extending backward above the shelf and having an upward inclination towards the rear, the coking shelf and the top wall being of heavy ceramic material and serving as heat reservoirs to receive and store heat and transmit it to the fuel, and a free and unobstructed air passage beneath the shelf.

2. Ina furnace having a the box, a grate, a flue, and a feed opening at the front of the furnace. above the grate, a coking shelf extending backward into the furnace near the bottom of the feed opening, said shelf being composed of resistive, ceramic inate'rial, a heat retaining and transmitting member immediately over the shelf, thesame being exposed to the direct radiation" from the fire and being in contact with the fuel on the shelf, and an air opening leading from the ash pit into the fire box beneath the coking shelf and spaced for- Wardly from the rear edge thereof.

3. In a furnace having a grate, a feed opening, a coking shelf spaced above ther e t the f on f: the f n h opening having a top Wall extending back Ward above the shelf, both the top Wall and the, coking shelf being, directly exposed to radiation from the fire and of heavy ceramic material, constituting means for storing heat and transmitting it to the fuel, and. an air opening spaced beneath the coking shelf and forward of the rear edge thereof.

Signed by me; at Baltimore, Maryland, this 17th day of July, 1923.

CHARLES J. Witnesses: PORTER H. ELAUTT, ELIZABETH KEECH.

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