US708107A - Furnace. - Google Patents

Description

No. 708',ID7. Patented Sept. 2, |902.

' G. W-ESTINGHOUSE. f

FURNACE.l @application med Mar. 25, 1'901.) (No Model.) 3 sheets-sheet .1

WITNESSE'G:

Patented sept. *2, |902. G.. wEs TmaHousE. V

' F UR N A GE.

(Applicimon medusa'. 2s, 1901.)

(No Mode'l.)

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UNITED" STATES 'PATENT OFFICE.

GEORGE WESTINGHOUSE, OF PITT-SBRG, PENNSYLVANIA.

FURNACE.

SPECIFICATION forming part of Letters Patent No. 708,107, dated September 2, 1902.

Application led March 25. 1901. Serial No. 52,684. y(No model.)

To a/ZZ whom it may concern:

Be it' known that I, GEORGE WESTING- HOUSE, a citizen offthevUrit'edStatesand a:

resident of Pittsburg, inthe county of Allegheny and VState of Pennsylvania, have invented certain new and useful Improvements in Furnaces, of which the following is a specification. j

My invention relates to improvements in the class of apparatus employed for smelting ores and other materials, and particularly to that form of apparatus commonly referred to as cupola-furnaces. y

The object of the invention is to providea furnace in which the heat which is usually wasted shall be conserved and usefully applied in the smelting operation and at the same time the furnace itself made more convenient and economical as to itsconstruction and operation.: In the -ordinaryl practice it has been customary to provide such furnaces with walls of refractory material or with water-cooled jackets, the heat radiated by the refractory material or absorbed by the-water being for the most part wasted. It has heretofore been suggested also that it is practicable to use air instead of water for cooling blast-furnace jackets and forheating theblast. On this point James Douglas, in ya paper on the Metallurgy of Copper, read in England before the Society for the Encouragement of Arts, Manufactures and Commerce on May 5, 1895, said: A real improvement would be devising lan air-jacketed furnace which would not buckle and in which the blast could be raised to a much higher degree than could be done by simply air-jacketing the crucible. It has also been proposed to cool the furnace by means of an air-jacket vin which streams of air are to be directed against the wall of the furnace. So far as I am aware, however,

Vno means haveheretofore been devised for securing such a circulation of air with such an intimate contact thereof with su fcient radiating-surface on the part of the inner walls of the furnace to secure sufficient eective cooling of those walls to prevent them from becoming overheated and at the same time to impart the requisite heat to the air, nor has there, so far as I am aware, been produced prior to my inventionan air-jacket for such a furnace havingsuch mechanical strength and construction as to vprevent injurious buckling under the influence of the varying temperatures to Awhich it is subjected. It is important to observe also that the mere directing of air against a relatively smoothsurface of a furnace-wall is not sufficient to abstract the heat therefrom with sufficient rapidity, for such a wall does not possess suihcient radiating-surface to communicate to the particlesof air the necessary heat in order to maintain the wall at'a safe temperature.

I have devised an air-jacket of such form and internal structure as to have great strengh and the necessary characteristics to prevent injurious buckling and at the same time insure that practically all of the air as it passes therethrough shall impinge against heat-radiating surfaces in intimate relation to the wall of the furnace, particularly that portion adjacent to the smelting zone. For this purpose the jacket is provided with numerous closely-arranged heat-radiating ribs in intimate relation to or mechanically united with the wall of the furnace jacket, and means are provided for directing the air continuously/.against these ribs and through the spaces about them.

My invention further contemplates certain special constructions of the furnace in which an air-jacket incloses the crucible and in which those portions which are liable to be injured or destroyed by continuous use are made replaceable.

The invention will be more particularly described in connection with the accompanying drawings, in which- Figure 1 is an elevation, partly in section, of a complete furnace. Fig. 2 is an enlarged view of a portion of the furnace-wall; Fig. 3, a perspective view of a portion of the wall; Fig. 4, a transverse section of a portion of the furnace, and Fig. 5 a section of a modified form of jacket. Figs. 6 and 7 illustrate a method of employing the invention in connection with certain other apparatus.4

Referring to the figures, l represents the lining of the crucible of the furnace, composed of any suitable refractory material. This lining is contained within and embraced by a Wall 2, constructed with suitable airpassages into which air is forced through an opening 3. The portion of the furnace above IOO the crucible is fortned or built of hollow boxes 4, constituting both a wall and an air-jacket, and of air-heating passages 14, which conimunicate with the air-space 3, inclosing the crucible.

The general object of the invention is to cause the air used for blast purposes to abstract the jacket-heat resulting from smelting operations in such an efiicient manner as to keep the interior wall of the furnace Within reasonable and safe temperature limits and at the saine time utilize the heat so abstracted for producing more efficient smelting operations in the furnace. This is accomplished by causing theair to pass downward around the ribbed fu rnace-wall, in such intimate contact therewith as to abstract a relatively large amount of heat therefrom and to be then passed through suitable openings into the stnelting zone. The air, therefore, when it. is admitted through the passage 3 passes through the space beneath and around the crucible and contained within the boxes 6. The air then passes through the air-passages 14 to the top of the furnace. The upper ends of these air-passages communicate with the upper ends of the upper tier of vboxes 4. The airpassa`ges 14 may be conveniently formed in castings which constitute the outer walls of the air-jacket, the inner walls consisting of the boxes 4, which are removably att-ached to the plates 15, constituting the outer wall. The plates 15 are formed into rectangular boxes by means of corner-posts 15, to which they are bolted.

The construction of the boxes 4 is more clearlyillustrated in Fig. 3. By referring to this ligure it will be seen that there are two series of vertical ribs 16 and 18. The ribs 16 maybe cast integral with the supporting-wall 14:L ot' the box, or they may be of soft iron placed in the mold in such manner as to beconie integral with the walls 14n when the box is cast. The vertical ribs 18 are also cast integral with the wall 14, and intervening inclined battle-plates 17 are cast between the ribs 1S, and these also serve to strengthen the whole structure. The battle-plates 17 are inclined toward the inner surface of the boxes, so that air descending from the top of the furnace-wail will be directed against that wall and the surfaces of the heat-radiating ribs 16 and 1b'. In practice it is convenient to construct the furnace with two or more such boxes 4, to be fastened to each outer plate 15, one box being placed above the other. They are fastened to the outer plate by bolts 30 or in any other convenient manner for permitting their removal and replacement. The upper box is bolted against an angle iron or plate l5", which forms the top portion of the furnace. It is important that the space constituting the air-jacket should be thus provided with very great heat-radiatingsurface, for I have found in practice that unless there be a large amountof metal in actual mechanical contact with the inner wall of the furnace the heat cannot be carried away with sufficient rapidity, and this metal should be so organized and arranged as to present very great heat-radiatin g surface, and the ai r-blast should be circulated in such tnanner as to bring it into close contact therewith. The arrangement described brings the ribs into such relation, they being integral with the wall 14a. For the purpose of delivering the heated air to the furnace the lower ends of the lower jackets 4 are open through the inner wall 14, so that the air may pass directly therefrom into the furnace. The passages 14 are shown as being rectangular longitudinal boxes cast integral with the outer wall 15, and at the upper end they are closed by the plates 15b, which surround the upperportion of the furnace. The upper ends of the upper boxes are closed by the same plates, and the upper ends of the ribs 1S are cutaway, as shown in Fig. 3, topermit the ready entrance and distribution of air therethrough. In the drawings I have shown dampers or regulating-valves 21 in the passages 14, and for the purpose of affording access to the bottom of the furnace openings 2O are provided at the lower ends of the outer plates 15, these openings being closed normally by weighted lids 22. A convenient construction is to enlarge the distance between the bottom of the plates 15 and `the lower ends of the boxes 4, as shown, for instance, by the dotted lines 20, Fig. 2. These weighted lids serve also as a convenient means for stopping the blast operations by permitting the air to escape from the bottom of the furnace after passing through the air-jacket.

Suitable spouts 24 and 36'may be provided for drawing olf the contents of the crucible, when desired, in a well-known manner.

In Fig. 5 a modification is illustrated in which the boxes 4 are built up of outer castmetal sections 3l and intermediate rolledmetal sections 32. These latter may be rolled with ribs 1S and fitted together, as clearly shown in the drawings. The inner ends are dovetailed together and present an inner wall 14, The entire set of plates are held together by bolts 33. I

In Figs. 6 and 7 an organization is shown wherein a furnace of the character described is employed in connection with an exterior air-heating device 41. This consists of a tubular heater through which the hot products of combustion from the smelting-furnace may be passed by a pipe 42. These products pass downward around the tubes of the heater, thence through a dust-box 44 of any wellknown convenient construction to a stack 45. A by-pass 4G, provided with a damper 47, may be employed for permitting more or less of the hot products of combustion to pass direct to the dust-box in order to regulate the preliminary heating of the air. A suitable airpuinp 48 forces air through the heater and into pipes 49, leading to the air-jacket of the furnace. In this manner more or less of the IOC IIO

l. deliver air beneath the crucible to the pas-` heat which might otherwise be carried away by the products of combustion majT beim-v parted tothe air beforeitis delivered'to thel furnace-jackets. In these figures the pipes conveying the air to the furnace are shown as delivering the air directly to the passage 14; but it will be understood lthat they may sage 3, as before.

The furnace is also shown as being provided with a hood 50, which maybe closed at the top by a'damper 51 when desired.

Y `I claim as my invention- V1. In a smelting-furnace, an air-jacket consisting of wall-plates having vertical ribs and transverse baffle-plates integralwith the inner-surface ofthe plates, the baffle-plates eX- tending across they spaces between adjacent sages, an air-inlet and an air-outlet leading. yto and from said passages, and its inner wall ribs, substantially as described.

'2. Asmelting-furnacehavingits outer walls composed of vertical plates having air-pascomposed-of plates having integralheat-radiating ribs, and means for securing the same to the outer wall. i 3. A smelting-furnace consisting of a cru- `cible and vertical air-jacketed walls and air inlets and outlets leading to and from the airjacket, saidwallsconsisting of hollow independently -removable compartments, and. heat-radiating ribs integral with the inner 1 walls thereof.

4. In a smelting-furnace, an inclosing wallv consisting of wall-plates'of iron having heatradiating ribs integral with one side thereof,

and an outer wall to which the wall-plates are' independently removably attached.

5. In a smelting-furnace, an air-jacketed wall and air inlets and outlets leading toand from the air-jacket, said wall consisting of an outer supporting structure, and independ-` ently-removable sectional wall-plates having heat-radiating ribs Aintegral therewith, substantially as described.

-6. rA removable section of wall'for a furnace,'consisting of a wall-plate having vertical and transverse heat-radiating ribs, the

transverse ribs being inclined with reference to vthe vvwall.

7. -'A furnace-wall consisting Aof a series of independently-removable heat-radiating sections, each section comprising a wall-'plate having one surface presented to the reductionchamber of the furnace and having its oppositesurface constructed with heat-radiating ribs, and means for detachably securing thev wall-plates in the furnace. 4 p

8.. The combination with the wall-plate Il, of the vertical ribs 16 and 18 projecting vfrom one surface ofthe wall-plate, and the interposed baffle-platesl inclined with reference to the'surface of the wall-plate.

9. In a smelting-furnace, the combination of the outer walls, the vertical flues therein, the inner" vertical heat-radiating compartmentwith which said iiues communicate at` stituting the shell of a furnace, the vertical iiues therein, the openings at their lower ends, j

the air-heating chamber beneath the crucible, the twyers, connections between the heating chamber and. the twyers and connections from the ii-ues to'the twyers.

12.v The combination with the crucible of a furnace, of theinclosing wall, the vertical flues carried thereby, an air-jacket beneath they crucible communicating with the verticalA fines, an` airjacket ywithin the wall ofthe furnace, connections from the upper ends of the fines with 'saidl air-jacket, and openings from the lower end'of the jacket into the furnace. v

Signed atNew York, in the county of New Yori; and State of New York, this 19th day of March, A. D. 1901. l

GEo. wEsTINGHoUsE.

Vitnesses:

H. C. TENER,

WM. H.,CA1 EL.

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