US1469178A - Apparatus for supplying heat - Google Patents

Description

Sept. 25, 1923 I C. ELLES APPARATUS FOR SUPPLYING/HEAT Original Filed Nov. 4, 1912 ATTORNEY.

cc through the furnace chamber ifatentecl Sept. 25,1923

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CABL'E'ION ELLIS, F MONTCLAIR, NEW? JERSEY, ASSIGNOR, BY MESNE ASSIGNMENTS, '10 SURFACE COMBUSTION, INC., 016 WILMINGTON, DELAWARE, Ii CORPORATION OE nnnnurnnn.

- AIPEARATUS FOR SUPPLYING HEAT.

Original application filed November 4!, 1912, Serial No. 729,316. Divided and this application filed August 9, 1917. 'Serial No. 185,390. Renewed January 31, 1923.

To (ZZZ whom it may concern:

Be it known that 1, CABLETON ELLIS, a citizen of the United States, residing at Montclair, in the county ofEssex and State 5 of New Jersey, have invented certain new.

and useful Improvements in Apparatus for Supplying Heat, fully described and represented in the following specification and the accompanying drawings,-'forming a part of the same. 1

, Thisinvention relates to burners or apparatus for the development and supply of heat by theburning of explosive gaseous mixtures. More particularly the invention has todo with burners of that class in which a ranular bed of refractory material is provi ed into which the explosive gaseous mixture is injected with a velocity in excess of the speed of backfiring, the mixture'being caused to spread out and have its velocity rapidly reduced as it advances through the bed until it reaches a surface or zone at which the velocity of the mixture equals the rate ofbackfiring and at which surface or zone combustion takes place, the combustion being thus localizedwithin or at the surface of the bed, as more fully described in U. S. patents of Lucke No. 755,376, and of Bone, Wilson & McCourt No. 1,015,261.

The object of the present invention is to secure substantial uniformity of heating ,over the working face of the combustion bed of such a burner of considerable superficial extent, and for this purpose, in accordance as with the present invention, the explosive mixture is injected into the combustion bed through a plurality of apertures spaced apart at suitable distances between centers to so distribute the mixture through the bedso as to secure the desired substantially uniform heating thereof.

i The invention is capable of general application, and is Well adapted to furnaces for heating sheets or plates or other articles fedpast the burner or burners, as for example, a furnace such as is shown in U. S; Patent. No.

1,238,011 granted on my application Serial No. 7 29,316, filed November 4:, 1912, of which so this application is a division.

In the accompanying drawings 2- Fig. 1 is a somewhat diagrammatic sectional elevation of the sheet heating furnace illustrated in my said application No. 729,316; I a

Fig. 2 is an enlarged sectional view of one of the heating devices or burners;

Fig. 3 is a plan view of the burner shown in Fig. 2;

Fig. 4: is a diagrammatic view on aflarger scale illustrating an arrangement of injecting apertures and heat zones; and

1g. 5 is a corresponding enlarged sectional View through a part of the combustion bed. 1

Referring to the drawings the furnace as illustrated comprises a, suitable furnace chamber 1 havingw'alls of refractory material and provided with a flue connection 10 adjacent one end. A" suitable conveyor 2 is arranged'topass through the furnace to carry steel plates or other articles 3, being shown as mounted on and, driven by sprocket wheels 4 and 5. Swinging doors or gates 11 and 12 are provided at the ends of the furnace chamber to cooperate with the conveyor and make more or less tight joints while permitting the passage ofthe conveyor and articles carrledthereby. 1

The burners or heating devices comprise combustion beds of granular material mounted with their workingr'facesclosely adjacent the path of the articles" on the c0nveyor. The explosive gaseous mixture-1s in-'- jected into each of these combustion beds through a plurality of injecting orifices s0.

that combustion takes place as'described in the Luoke and Bone, Wilson & McCourt patents before referred to, that-is, the explosives gaseous mixture entering the refractory bed with a velocity in excess of the speed of backfiringis caused to spread out v and have its velocity rapidly reduced as it advances through the bed until it reaches a surface or zone at which the velocity of the mixture equals the rate of backfiring and at which surface or zone combustion takes place, the combustion being thus localized within or at the surface of the bed. The lower bed 8 may be formed of substantially uniformly sized granules of refractory material such as alumina, magnesite,-or even refractory fireclay for the lower heats, of,

for example, about one-half or three-quarter i inch mesh and arranged Within a suitable refractory lining 6 so that the upper or working face of the bed which is heated to incandescence under operating conditions is preferably relatively closer than indicated in Fig. 1. of the drawing to-the articles to be heated and arranged Within a few inches of the path of the articles for most rap d Work. The upper combustion bed 28, if provided, may also be formedof granules of refractory material permanently secured in position. in the refractory bed lining 26 as bv coating the particles with a small amount of relatively fusible or fluxing material and then calcining the bed and lining at an intensely high temperature so as to. cause the refractory granules to permanently unite together and to the bed lining by fusing or fluxing together their contacting portions at" heats considerably in excess of any Working temperatures to Which they are subsequently subjected. In this \va v, as indicated in Figs. 1 and 5, the granules are permanently secured together in such Way as to. leave numerous tortuous passages between them substantially similar to the passages through a bed of loose granules.

These porous and permeable beds are heated by injecting thereinto an explosive gaseous mixture which may be formed of comliustible gas or vapor and air or other supporter of combustion preferably in about the proportions required to secure complete combustion of the fuel for greatest efiiciency, although by using a slight excess of the fuel gas a slightly reducing atmosphere may be maintained in thc'furnace to avoid oxida tion. The explosive gaseous mixture is injected intothe combustion bed through a plurality of injecting apertures provided bynozzlcs or short pipes 13 spaced preferably uniformly throughout the bed to secure uniformity of heating, these injecting nozzles or apertures being preferably so spaced as to secure suflicient overlapping or approximation of the heat zones produced by the mixture supplied from each of the apertures as to secure substantial uniformity of heating throughout the bed, such uniformity of heating being highly desirable for many purposes, and especially in heating thin plates or other articles in .a furnace of the kind illustrated by Fig. 1. l or moderate sized injecting apertures of, for example, three-eights of an inch to an inch or so in diameter, through which is injected an ex plosivc mixture formed from coal gas or enriched producer gas and air at a pound or so pressure, which gives suflicient velocity to prevent backfiring through the injecting apertures, the spacing of the apertures and thickness of the granular bed to give a most effective and uniform heat should apparently, as determined by an extended series of empirical. tests, hear about such ratio to the spears/e size of the apertures that D tA. and C QDzSA; Where D is the depth of the granular bed, A is the diameter of the mjecting apertures and C the distance between the centers of the apertures; that is, the distance between the center lines of adjacent apertures as indicated in Figs. 4 and 5. Under these circumstances, the heating zones extending from the several apertures, While of course somewhat irregular because of the tortuous character and irregular section of the channels through the granular bed, have approximately such boundariesas indicated by the lines 14-14 in Figs. 3, t and 5, so that there tends to be some overlapping in the areas 15 Where the heating zones approach most closely, although these reinforced areas are naturally equalized to a con siderable extent by the action of the gas pressure Within the granular bed. A substantially uniform temperature and substantially uniform incandescence is thus secured throughout the working face of a porous and permeable bed of this character; and as in a bed of this character unusual quantities of gaseous fuel may be burned in p a very restricted. space, the rate of combustion being accelerated many times beyond that occurring in ordinary flame combustion, extremely rapid as Well as uniform heating may be effected because ofthe extremely high temperatures secured in the vorkin face of the bed and the correspondingly great radiating efficiency thereof. This is of great importance, especially in a conveyor furnace such as shown.

The explosive gaseous mixture may be supplied to the combustion bed by any suitable arrangement, such for example, as the supply pipes 7 shown in Figs. 1, 2 and 3 as connecting the lines of injecting nozzles 13; and these supply pipes may be connected to a suitable supply line as 17 fed with explosive gaseous mixture Which may be supplied under the desired pressure by any suitable form of pump or other device. The supply line may, as indicated, have a suitable Y connection, the air. connection 18 leading to a suitable air pump 19 and receiving therefrom air under pressure which has been drawn from the air line 20. The gas connection 21 similarly receives the combustible gas or. vapor from afgas pump 22 which draws the gas from a gas line 23, so that in this Way a substantially uniform explosive mixture of gas and air can be conveniently secured, the mixture preferably containing a slight excess of gas Where steel plates or other steel articles are to be heated so as to maintain a slight reducing atmosphere Within the hot portion of the furnace and minimize oxidation of the metal.

T he plates or articles 3 fed along by the conveyor in the. furnace shown in Fig. -1 between the heating devices or burners are ieces the beds, it is thus not only possi ole -to secure a rapid anti uniform heating of the articles, but because o fithe eosy reguletion, and control of the mixture su ply suck the amount of fuei burneol in the be s, it is possible to eccuretel time the feed or sup ply of the heated urtic es as may be desireri, us for example, in suppiying the articles to a press or forging device so as to secure the most satisfactory results from uniformity of the forging or stamping conditions. By conducting the intensely hot combustion gases aiong the furnace chamber in the opposite direction to the articles fed towurci the combustion beds a considerable preheat ing action can be secured depenciing upon the length of the furnace chamber, and u correspomiing economy in fuei consumption thus effected.

By the term explosive gaseous mixture as used herein is meant e mixture of u suitable combustion supporting gas, either oxygen alone or air or other oxygen containing gas, with combustible mutter in a gaseous or other finely divided state in proportions such that the mixture will have the property of self-propagation of inflammation. Such proportions may be the chemicei combining proportions or there may, of course, be un'excess of either the combustible matter or the combustion supporting gas within the limits which determine the property of selifepropegution. The mixture may be varied in this respect eccorciing to the liming described invention in connection with. on, illustrutive embodiment thereof, tothe uietuils of which disclosure the invention. is not to he iimited, Whetis claimed as new is set forth in the app-linden claims,

iVhut is claimed is: p

1 Heating epparetus comprising e porous and permeable bed oi? refractory material,

and means providing it piurulity of open tures for injecting an explosive gaseous mixture into, send bed with o velocity in excess of the speed of beckfiring of the mixture, said! apertures being spaceii spurt to so elistribute the minturethrough the beol as to secure substantially uniform heating thereof 2. Heating apparatus, com rising e, po-

rous unti permenbie beci oi? re rectory mete,

rial, moons providing at plurality of 'u-p'era tures for injecting on explosive gaseous mix ture into seiol bed, and nieens for supplying the mixture uneier pressure suliicient to cause the mixture to be injected into the bed with e, velocity in excess of the speedof bee ing of the mixture, said apertures being spaced spent-to so distribute the mixture through the bed as to secure substantially uniform heating thereof,

In testimony whereof I heve hereunto set my hand inthe presence of two subscribing witnesses UAFLETON ELLKSK 1v icn see:

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