US247333A - Feeding fuel to puddling and other furnaces - Google Patents

Description

(no Model.) 2 Sheets-Sheet 1.

U. GEARING.

FEEDING FUEL TO PUDDLING AND OTHER FURNACES. No. 247,333. Patented Sept. 20,1881.

1' ine).

(No Model.) 2 SheetsSheet 2.

G. GEAIRING'.

FEEDING FUEL T0 PUDDLING AND OTHER FURNACES.

No. 247,333. Patented Sept. 20,1881.-

v UNITED STATES PATENT OFFICE.

CHARLES GEARING, or rrrrseuae, PENNSYLVANIA.

FEEDING FUEL TO PUDDLING AND OTHER FURNACES.

SPECIFICATION forming part of Letters Patent No. 247,333, dated September 20, 1881.

Application filed August 25,1881. (No model.) I

To all whom it may concern.-

Be it known that I, CHARLES GEARING, a

burg, Allegheny county, Pennsylvania, have invented new and useful Improvements in Feeding Fuel to Puddlin g and other Furnaces, of which the following is a specification.

My invention relates to improvements inheating and puddling furnaces for iron-manufacture, and in furnaces generally, and in the method of effecting an economical and perfect combustion of the fuel employed.

The difficulty and expensive waste of coal incident to the production and maintenance of the high heats required in certain branches of manufacture have led to various attempts in the direction of economy, among which the pulverization of the coal with a view to its more rapid combustion has been resorted to, and is based on correct principles, and the failure of this method of combustion to obtain commercial recognition is believed to rest in the want of proper conditions in the methods and apparatus heretofore employed.

The object of'my invention is to provide a suitable method and apparatus for the complete and efficient combustion of coal used in a finelydivided state, and to provide, also, a simple and economical apparatus therefor which is easily adapted to a furnace of any kind, and particularly to heating and puddlin g furnaces, where highest heats are required.

After very many experiments, extending through many years and involving great expense, I have ascertained that the most, if not the only, successful mode of utilizing the pulverized fuel for high heats is to project it forciblyinto a combustion-chamber under conditions substantially such as are hereinafter pointed out, and at the same time supply air in sufficient quantity forits combustion already heated to a high temperature; and,further, to effect the preliminary combustion or gasification of the particles as near as possible to the point where the resulting flame is to be utilized.

The main principles of-my inventio there fore involve, first, pulverization of thecoal, preferably, though not necessarily, at the point where it is projected into the furnace; second, it-sprojection into the furnace by means of or in connection with a jet of superheated steam,

7 together with heated air sufficient to effect a preliminary combustion; and, third,causing it to impinge against highly-heated surfaces such as balls of refractory fire-clay or bats of fire-brickupon the grate-bars; and,lastly,supplying the additional heated air required for complete combustion preferably by means of a counter-blast projected upward from beneath the grate bars through the interstices of the balls.

My invention consists, therefore, in the method or process by which the above-indicated principles are carried out, and also in the means and apparatus employed, and as more fully described hereinafter, including certain details of construetiou'of the furnace as a whole.

Referring generally to the accompanying drawings, which exhibit my invention as applied toaheating or puddlingfurnaee, Figure l is a sectional elevationin acentrallongitudinal plane; Fig. 2, a plan view of the grate-bed; Fig. 3, a sectional elevation, on a larger scale, ofa form of grinding-mill which it has been found advantageous to use in direct connection with the furnace; Fig. 4, a plan section of the mill in the plane of w m,Fig. 3; Fig.5,a detached perspective view of the lower part of the hollow grinding-shaft; and Fig. 6, asectional elevation of the rear end of the furnace, showing the regulating damper or val-ve.

A in the drawings designates the combustion or fuel chamber of the furnace; B, the grate; G, the ash-pit; D, the bridge-wall; E, the covering-wall or reverberatory arch above the heating-chamber; F, a grinding and feeding mill; G, the upper blast-pipe, and H the lower blast-pipe.

The combustion-ch amber A is located immediate] y adjacent to the heating-chamber or puddling-loasin, and differs from the ordinary fire-' box only in its lesser size, and in being extended upward beyond the usual limit into a somewhat contracted throat or dome, a, into which the upper blast-pipe, G, enters above, opening vertically downward in its center over the grate B. The nozzle-section g of the upper blast-pipe extends through and may be utilized as the crusher-shaft, and the steam and air connection may be formed directly with it; or the blast-pipe Gmay be extended through it by an independent pipe inserted therein. It is desirable to arrange the mouth of the upper blast-pipe at such an elevation and give it such a form as to expand the blast uniformly and distributeit evenly over the grate below, and in some cases to extend the mouth of the feeding hopper around and below the mouth of the blast-pipe by a suitable flange, in order to control more perfectly the particles of coal fed through the mill and project them downward upon the grate. The projecting force for both blasts is a jet of steam first superheated by passin g through coils of pipe located at any convenient point where the waste heat of the furnace may be utilized. I have shown the steam-superheatin g coils in the present case at a in the wall surrounding the upper'part of the chamber A. The coil should be somewhat larger than the supply-pipe h, leading from the boiler, and the delivery-pipe t, supplying the blasts, in order that the steam shall not pass through too rapidly, but may be in the coil a sufficient time to attain a high temperature. The air for the blasts is heated by being drawn through flues located in the walls of the furnace, where most convenient. In ordinary constructions, where an existing hea'tin g or puddlin g furnace is to be adapted to my invention,I obtain room for the heating-fines in the interior walls, which I place within the fire-box in reducing the size, in which case the-fines are located at the sides of and just above the grate B, one side sup-- stood that the pipes m and m connect with theair-heating flues, and that by the action of siphons or air-injectors s s, operated by snper-- heated steam through pipes t and j, the air is drawn through these lines, heated, and projected into the furnace, the force of the blasts being regulated by suitable valves, as v 'v.

The grate B isforined in sections mounted on a common pivot, 11, and provided with extensions b for shaking, as occasion may require. I find it desirable to use balls L, made of refractory fire-clay, in order to assist in retaining a layer of the fuel upon the grate, and also to form an irregular surface of highlyheated material, against which the down Ward ly-projected fuel impinges. They also serve to modify to a certain extent the action of the lower blast, which is projected upward from a rose-nozzle, N, located beneath the grate, by separating the blast and forming eddies tending to the more complete combustion of the particles of coal. Round balls are preferable; but brickbats may be used in an emergency with good results.

The ash-pit G is closed by a closely-fitting door, cl, to prevent access of cold air, and an ordinary fire-door opening, 0, with suitable door, is provided above the grate for putting iufucl to start the furnace in operation and for occasional access. A peep-hole, o, suitably stoppered, is also provided in the throatwall, as shown, for observation purposes.

I have not deemed it necessary to show A damper, c, is arranged to slide insuitable guides immediately beneath the hopper F, across the throat a. It is preferably a refractory tile of fire-clay, and is used to protect the hopper from the intense heat below when first heating up the combustion-chamber, but is withdrawn, when the mill is in operation, by the handle 0.

The crushing or grinding apparatus F here shown consists of a funnel-shaped hopper, F, in which is arranged a central vertical shaft, g, driven by gearing from the line-shaftin g of theestablishment,orby anindependentengine. In the present case a worm-gear is employed, driven by a belt, M, from the line-shafting. The lower end of the hopperis contractedinto an inverted conical mouth, which, in connection with the central shaft, forms the grindingmill. The inner surface of the conical mouth is formed into spiral ribs n,ratchet-shaped and regularly disposed, as shown in Fig. 4. The corresponding portion of the shaft 9 is also provided with a conical head, d, Fig. 5, externally ribbed in the same manner as shown; and immediately above the head dthe shaft is provided with a series of spurs, 0, disposed radially and graduated in length to correspond with the conical form of the discharge-mouth, in which the shaft operates. The shaft is supported by a collar, w, at its upper extremity, rest-ing upon an arm, 1", adjustably secured to a standard, 8,011 which it may be raised or lowered, in order to increase or diminish the annular opening between the lower end of the shaft and the feeding-mouth of the hopper, and thus regulate the size of the particles of coal ground and also the amount fed. The shaft is held to its proper alignment by passing through two yokes or spiders,p 19, secured at convenient intervals to the inner sides of the hopper F, and is further provided with radial arms or stirrers t, by which packing of the coal in the hopper is prevented.

The operation of the grinding-mill will be readily apparent. The coal or slack, being placed in the hopper, feeds downward by gravity, and is crushed, into fragments by the action of the spurs o, and finally ground by the conical head (I in the lower mouth of the hopper.

One further important feature of my invention remains to be described. In the operation of the furnace it will be observed that the particles of coal are projected downward by means of and intermingled with the blast of superheated steam and air into a chamber already intensely heated and filled with incan descent gases, and are almostinstantaneously deprived of their volatile constituents, and on meeting the counter-blast below these gases, in a state of intense combustion, pass over the bridge-wall into the heating-chamber on their way to the stack; but in order to prevent the flame from passing too rapidly through the heating-chamber, and thereby failing to act upon the billets upon the hearth, I find it nee cssary to close the ordinary stack-opening by an adjustable damper, f, (shown in Fig.:6,)-

above the. slag-pit. The size of the stackopening can be easily determined and adjusted by observation, so as to keep the heatingchamber full of flame and secure the best effect upon the iron undergoing treatment. In constructing a furnace complete embodying my invention, I dispense with the tall stack commonly employed and build one of sufficient height only to carry off the gases without requiring the draft usually sought to be obtained through the stack.

I have shown and described herein that form of apparatus adapted to be applied to the best advantage to a single furnace of the ordinary type; but it will be apparent that the grinding of the coal may be done at any other place or by any other means than that shown, and that where several furnaces are used in the same establishment separate means should be provided for grinding; and the apparatus shown, or some other, can be used for feeding only, the coal being supplied to the feeding devices from a common source in any convenient manner.

With an apparatus such as here shown, and operated by common .slaek or cnlm, I have produced and maintained a heat amply sufficient for all the purposes of reheating scrapiron for the rolling operations with a very considerable economy of fuel and labor. The invention may also be applied to steam-boilers by placing the combustion chamberA adjacent thereto and passing the incandescent gases thence beneath the boiler as into the heating chamber.

Having described my invention, I claim and desire to secure by Letters Patent- 1. The method of heatingpuddling, heating, and otherfurnaces by projecting into and upon the grate of a vertical generator or combustionchamber adjacent to the puddling chamber or hearth pulverized coal in regulated quantity by means of and intermingled with a blast of superheated steam and air to produce a preliminary combustion, and supplying thereto additional superheated steam and air by means of a counter-blast, and passing the incandescent gases directly into the heating-chamber, where the combustion is completed, substantially as set forth.

.2. In combination with the heating-chamber of a puddling or other furnace, a vertical gen erator, A, adjoining the same, an upper blastpipe, G g, arranged, in connection with means for feeding pulverized fuel in regulated quantity, to project the fuel, by a blast of superheated steam and air, downward upon the grate, and a counter blast-pipe, H N, arranged to discharge superheated steam and air upward through the grate, substantially as and for the purpose specified.

3. In combination withthecombustiou-chamher A of a furnace such as described, a hopper, F, provided with a rotating hollow shaft for feeding pulverized coal and projecting it into the furnace by a blast of steam and air issuing through the shaft, substantially as specified.

4. In combination with thecombustion-chamber of a furnace such as described, a vertical grinding-mill having an adjustable hollow shaft, by which the grinding and feeding of the coal maybe regulated and driven into the furnace by a forced blast through the shaft, substantially as specified.

5. Thegrinding-millasconstructed,embodying the combination of a hopper with a contracted lower mouth provided with angular ribs, and a rotating hollow adjustable shaft provided with a lower head, ribbed and corresponding with the mouth of the hopper, and radial spurs above the same for crushing the coal, and adapted to be used for grinding and feeding coal to a furnace by aforced blast,

substantially as and for the purpose specified. In testimony whereof I have hereunto set my hand in the presence of two' subscribing witnesses.

CHARLES GEARING. W'itnesses:

G. P. DooLrrTLF, L. M. HOSEA.

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