US1570340A - Furnace - Google Patents

Description

Jan. 19 1926.l

H. H. DODGE FURNAGE Filed oct. so, 192s 2 sheets-santi reasonable figure.

Patented Jan. 19, 1926. y

gUNrrED #STAT-Es HARRY DODGE, OF BUFFALO, NEW YORK.

rUnNAcE.

Application filed October v30, 1923.

10 all eli/0m t may concern Be it known that I, HARRY H. DODGE, a citizen of the United States, and a resident of Buffalo, in the county ofErie'and State of New York, have invented certain new and useful Improvements in a Furnace, of which the following' is a full, clear, and exact description.

This invention appertains to certain improvements in furnaces generally, and more particularly to a typeof the same .adapted for use in the metallurgical or enamelware making industries and the like,wherein eX- tremely high and uniform temperatures are essential to the production of perfectly finished articles of manufacture.

1n the prior practice of design and operation of furnaces, particularly in the enamelware industry, serious disadvantages, difficulties andmuchtrouble has been experienced in the production of high grade enamelware, both with regard to the quality or perfection of finish to the articles as well as to keeping the cost of manufacture at a The more important of i these several disadvantages, dii'liculties and troubles, are: first, the 'high cost of fuel consumption of a furnace per pound weight of the articles produced; second, the inability to maintain a constant or maximum temperature within the furnace, especially dur-V ing the loading and unloading periods of operation thereof; third, the inability to maintain uniform temperature throughout the interior of the furnace, particularly at or along the hearth thereof; and, fourth, the

inability to obtain low velocities in the products of combustion, such as otherwise act on the molten enamel coating on ythe articles being fired to keep the same in motion in the early stages of the ring operation and frequently result in a lumpy appearance in the finished surfaces of the articles.

The principal object of the present invention therefore is to provide for a furnace construction, wherein the articles to be fired are subjected to direct contact with the products of combustion thereof, such as will readily and eiiiciently overcome the several difficulties, disadvantages and troubles, aforesaid, and which will admit of the production of smooth finished enamel coatings, free from any and all blemishes or lumpy effects either in appearance or in fact.

Another object of the invention is to pro- Siial No. 671,786.

vide for a furnace of the class mentioner, and one wherein the hot products of combustion will be evenly distributed so that a uniform temperature will be maintained throughout the interior of the furnace, and much higher temperatures will be possible with a marked reduction in fuel consumption and consequently in the cost of operation. I

A further object of the invention is to provide for a 'furnace of the character described, and one wherein the usual stack for the exhaust of the products of combustion from the interior of the furnace will be dispensed with, such as will resultin higher temperature being produced and maintained within the furnace, the products of combustion will be practically -stagnant or of extreme low velocity during the firing periods of operation, and the desired high temperatures will be quickly restored within the furnace after each loading andunloading period thereof. f

A further object of the invention is to provide for a furnace of the type set forth, and one of an extremely simplied construction and arrangement, such las will involve a much lower cost in materials, labor and time in its manufacture and installation and in maintenance and operation as compared with that of these types of furnaces now employed in the practice.

With the foregoing and other equally important objects in view, the' invention rehereinafter more fully described, set forthA in the appended claims, and illustrated in the accompanying drawings, in which Figure 1 is a fragmentary front elevation, partly in section, of a preferred embodiment of the furnace,

Figure 2 is' a side elevation thereof, Figure 3 is a vertical transverse section taken on the line SH3 of Figure 2, and,

Figure 4 is a fragmentary vertical longitudinal section taken on the line 1 -i of Figure l.

Referring to the drawing, wherein similar characters of reference designate corresponding parts throughout the several Views thereof, the preferred embodiment of the furnace comprises a supporting frame con-- sisting of vertically disposed members l0 arranged in spaced' relation at the opposite sides of the furnace, similarly disposed and arranged members 11 at the rear end thereof, and the members 12 at its front end, all of which are formed of an angle or channel iron, preferably U-sha-ped in crosssection. The frame members at each side of the furnace, and the complement-al of the front and rearwardly disposed menibers 11 and 12, are connected together by means of longitudinal bars of angle iron 13 which are spaced at an equal distance above the ground or floor level, to support thereon the furnace proper, substantially shown, while the upper ends of the rearwardly dis'- posed members 11 are connected with the front members 12 by means of longitudinal bars of angle iron lll, lthe latter extending in common plane above and parallel to the lower bars 13 and connecting the front members 12, which are of a greater height than either of the side members l() or the rear members 11, at joints below their upper ends.

The furnace proper consists of an outer casing, preferably of a heavy sheet metal formed of a bottom wall 15 which is supported on the upper sides of the longitudiH nal bars 13; oppositely disposed side walls 16 which abut the inner side faces of the oppositely disposed sets of side frame ineinbers 10; rear and front end walls 17 and 18 which similarly abut the inner side faces of the rear and front frame members 11 and 12, and a top wall 19 which extends directly beneath the upper longitudinal bars let. VDisposed within the outer metal casing is a lining of lire brick or the like, which formed to provide a hearth portion 2O having oppositely disposed side walls 21 rising therefrom with their top edges spaced below the upper edges of the conipleniental side walls 16 of the outer casing. The lower portions of the side walls 21 are thickened at their inner sides, as at 22, to provide an article receiving spiace between the opposed vertical walls thereof, and flat upper faces alongl the outer edges of which are supported bal'lies 23. Opening through the side walls 21 in a horizontal plane above the upper flat faces of the lower thickened portions 22 are a series of equidistantly spaced twyer or burner openings 24 which are slightly flared in an inward direction in a manner to discharge the flames from the burners 25 inserted in their outer ends directly against the baffles the spaces 23 formed between the latter and the opposed faces of the side walls 2l constituting' the combustion chambers' for effecting a uniform distribution of the products of combustion from the burners 25 into the central heating portion of the furnace. Formed longitudinally within the lower portions of the side walls 21 are fines 26 which extend :from points inwardly of the forward wall of the furnace to and open through the rear wall thereof. Opening laterally through the thickened portions 22, of the side walls 21, are outlet fines 2T through which the burnt gases or waste products of combustion pass fr in the interior of the furnace to the main outlet flues 26. rhe bottom walls of the several flues 26 and 2T are disposed in the plane of the inner surface of the hearth 26, so that the hot gases or 'produc-ts of combustion must traverse the entire interior of thev furnace fromy the upper side thereof to the hearth surface before passing outwardly of the lateral fiues 2l'. Supported on the hearth 29 in spaced parallel relation to the inner vertical walls of the thickned portions 22 of the side walls 21, and consequently to the ends of the lateral fines 27 opening through the latter, are baliles 2S which act to retard the outflow of the hot gases or products of combustion directly to and through the latter. The upper sides of the central heating space and the combustion spaces at the opposite sides thereof are enclosed by an arched top wall 29 which is keyed in proper position by means of angular stretches 36 of the lire brick interposed between the opposed side edges of the top wall 29 and outer stretches 31 of fire brick disposed along` the upper edge Vportions of the side walls 16 of the outer casing of the furnace.

As best shown in Figure El, an air space 32 may be provided beneath the top wall 19 of the outer casing, and for the purpose of allowing for a circulation of air through this space, the ripper edges of the opposite side walls 16, of the outer casing, are spaced below the top wall 19 thereof, and these edges` are disposed in the plane of the upper sides of the courses of fire brick 39 and 3l, while the highest point on the outer surface of the arched top wall 29 is spaced at a slight distance below the top metal wall 19.

The forward end of the furnare, between the frame members 12 is formed to provide a loading and unloading opening, which is normally closed by a door or closure member 33 mounted for vertical sliding movements in the opposed channelled faces of the frame members 12. ln its lowered closed position, the closure member is supported on a 'ross bar or sill 3l; extending between the frame members 12 with. its upper face disposed substantially in the plane of the upper surface of the hearth 29.

To facilitate the opening and closing operation of the furnace door or closure meni ber 33, the saine is preferably counterweighted for such purpose, and this is ac complished by suspendirm` the door or closure from one end of a cable by means ol" an eye member carried at a central point on its upper edge. and passing the other or free end of the cable i'ipwardly between the frame members 12, and then training the same laterally over an inner lpulley 37, which is our'nalled in and between a pair of cross bars 38 secured in position at the opposite sides of the upper'ends of the frame members, and from thence over a secondpulley 39, journalled between the extreme outer ends of the crossbars 38, which are ext-ended'to point slightly beyond ore side of the furnace. The Vfree end portion of thel cable 35,- depending from the outer pulley 39, is now weighted, as at -Je0,in any suitable or desired manner, and substantially as shown.

In the operation vof the furnace as thus constructed and arranged and with the hearth 20 loaded in the usual manner with the articles to be heat treated or fired and the burners ignited, the hot products` of combustion from lthe latter are projected inwardly of the flared openings or passages 24: and directly against the baflies 23, where they will be first spread along the combustion chambers or spaces, formed between the opposed vertical faces of the baffles 23 and the side walls 2l of the fire brick lining of the furnace, and to either side of the openings or' passages 24, and then deflected in the upward direction to pass over the top edge of the baffles 23, and between the same and the arched top wall 29, and inwardly toward the center of the furnace and from thence downwardly toward the hearth 20, where the waste gases will exhaust outwardly of the transverse and longitudinal flues 27 and 26, passing over the lower baffles 28 from the heating space immediately above the hearth 2() for the purpose. With this arrangement of the combustion chambers or spaces along the inner side walls 2l of the furnace, ex'

.tremely hot zones are created for the entire length of the same, and the hot products of combustion are uniformly spread and distributed upwardly and inwardly over the top edges of the baffles 23. The hot gases or products of combustion from the opposite sides of the furnace thus meet and commingle together substantially in the plane of the longitudinal center of the upper part of the heating space above the hearth 20, and then pass downwardly toward the latteifin'combined volume to be effects will be obtained from the hot gases or products of combustion in their passage through the furnace from the oppositely disposed side combustion chambers' to the tlues. Also, whenthe door or closure member S3 is opened for purposes of loading and unloading articles into and from the interior of the furnace, this lack of draft effects through the flues 26 and 27 tends te prevent any serious admission of cold lair through the door opening, so that the reduction of temperature within the furnaceis minimized, and the slightly reduced temperature is quickly raised to maximum upon the completion of aloading` operation and the closing of the door or closure member. This slowness of exhaust ofthe wasteY gases or spent products of combustion, together with the efficient and uniform spreading out and distribution of the het gases'or products of combustion inwardly from the opposite sides of the furnace throughout the entire length thereof, results in the creation within the latter of extremely high and even temperatures with a comparatively low fuel consumption, and, consequently,

greatly reduces the cost of operation, as,v

compared to the otherwise excessive costs of operation of the types of furnaces now made use of in the practice; and, also a more perfect and smooth finish is produced on the articles under treatment, by reason of the extremely low velocity of the hot gases or products of combustion in their passage through the furnace, since the molten enamel or other coating on the articles being fired will not be effected thereby, as is the case of the passing of the hot gases or products of combustion therethrough at hgh velocities, when the molten coating is often disturbed or moved about on the surfaces of the articles in a manner to give to the finished coating, when hardened, a lumpy or wavy and uneven finish.

From the foregoing, it will be readily ap parent that, while a preferred embodiment of the furnace has been described and illustrated herein. in saeci'l'ic terms and details of construction and arrangement of parts, various changes in and modifications of the same may be resorted to without de- {arting from the spirit of the invention, or the scope of the claims appended hereto,

Having thus fully described the invention, what is claimed, is

l. A furnace as charactei-izedl comprising oppositely disposed parallel side walls, a lower flat hearth wall, and an upwardly arched top wall, combustion chambers extending longitudinally of the opposed faces of said walls provided with upright baille members at their inner ends, said combustion chambers being disposed intermediate said lower hearth and the arched top wall, an outlet flue formed in each side wall beneath said combustion chambers and extending longitudinally through said walls, and a plurality of lateral lues opening inwardL through said walls onto said hearth at points below said combustion chambers and conimunicating with said outlet fines.

2. A furnace as characterized, comprising oppositely disposed parallel side walls, a lower flat hearth wall, and an upwardly arched top wall, continuous inwardly thickened lateral portions formed on the lower sides of each side wall 'ull length thereof. continuous vertical bailie members disposed longitudinally ot the furnace along the in ner edges of said inwardly thickened portions whereby to form with the inner faces of said side walls coml'iustion chan'ibels said side walls being provided with burner openings extending transversely therethrough and in communication with said combus4 tion chambers7 an outlet flue disposed longitudinally through the side walls in the f bottom portions thereof, said bottom portions of said side walls being provided with lateral ues communicating from the interior of the furnace to said outlet flue on the hearth, and vertical battle members arranged. longitudinally in the furnace in front of said lateral lues and on the hearth wall to provide work supporting members.

HARRY H. DODGE.

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