US788098A - Roasting-furnace. - Google Patents

Description

PATENTED APR. 25, 1905.

P. J. FALDING.

R0 ASTING FURNAGE.

APPLIOATION HLBD MAR. 5, 1904.

2 SHEETS-SHEET 1,

Smog/mko@ No. 788,098. PATENTED APR. 25, 1905. P. J. FALDING.

ROASTING FURNACE.

APPLIOATION FILED MAB. 5, 1904.

A 2 SHEETS-SHEET z, Z.

UNITED STATES Patented April 25, 1905.

ATENT FFICE.

ROASTlNG-FURNACE.

SPECIFICATION forming part of Letters Patent No. 788,098, dated April 25, 1905.

Application filed March 5,1904. Serial No. 196,695.

To r/J/ /r/mnt it '1m/y concern:

Be it known that I, Femenino J. FALnINe, a subject of the King' ofGreat Britain and lreland, residing' at New York, county of New York, and State of New York, have invented certain new and useful Improvements in Roasting'- Furnaces, fully described and represented in the following; specification and the accompanying' drawings, forming' a partof the same.

This invention relates to improvements in roasting'- furnaces, and particularly to that type of roasting-furnaces in which there are a series of superimposed hearths and which employ a series of rotating' stirring-arms arranged above the hearths andcarried by a central shaft.

An object of this invention is to provide means for cooling' the shaft and the stirring'- arms, so that the deterioration of the stirring'- arms and that portion of the shaft to which they are secured, caused by the intense heat necessary in the operation ofI the furnace, may be reduced to a minimum.

It is a further object of the invention to provide means for securing' the stirring-arms to the shaft, so that in case of any deterioration they may be drawn from the furnace and another arm inserted more quickly than has` heretofore been possible and without necessitating' the cooling' down of the furnace. such cooling' being' a slow and expensive operation.

lt isa further object of the invention to provide means for securing' the stirring-arms to the shaft, by which the necessity of removing' the central shaft from the furnace, owing' to the unavoidable deterioration of that portion of the shaft which carries the arms, is largely done away with.

A Vfurther object of the invention is to provide an improved sti rring'arm which shall be stronger and more thoroughly cooled than arms heretofore employed.

Fora better understanding' of the invention reference will now be had to the accompanying' drawings, in which Fig-ure I is a vertical section of a furnace embodying' the invention in a preferred form. Fig'. 2 is a cross-section, on a larg'er scale, showing' the means employed for cooling' the arms and the shaft and for securing' the arms on the shaft. Fig'. 3 is a view on line 3 3 of Fig'. 2, partly in section. Fig'. i is a section on line t t of Fig'. i2. Figs. and 6 are sections taken on lines 5 and G 6 of Fig'. 2, showing' details of the improved stirring'- arms. Fig'. T is a view similar to Fig'. 2, but on the scale ofFig'. I, showing' a mo lilied construction embodying' certain features of the invention.

Referring' now to the drawings illustrating' one embodiment of the invention, A represents a furnace of the type heretofore mentioned, comprising' a cylindrical shell or casing' formed of a lire-brick wall B, inclosed by a steel shell C. Within the shell are arranged a series of superimposed hearths E and E, the hearths E having` central openings e0 to enable the ore or other material to be fed onto the hearths IC', the latter having' openings at their outer edge, as at Il, to enable the ore to be fed to the hearths E. These hearths E and E are arranged alternately above each other, as shown in Fig'. l, and have concentric central openings through which a shaft D is passed. This shaft l), which carries the stirring-arms F, is preferably of the downwardlytapering' form now used in this type of furnace and is revolubly mounted in a hollow standard I. The shaft is fitted to thchearths by being' provided with downwardly-extendingl liang'es 4Q, adapted to eng'ag'e upwardlyextending' liang'es '-IB, provided on the hearths E'. By this means the shaft is secu rely mounted and at the same time left free to rotate. The roof H o'f the furnace, which is preferably of cast metal, is provided with a feedopening' and another opening, 45, preferably at the other side of the furnace for the escape of the products of combustion, which pass out through the stand-pipe 11. A 'further openingl is provided in the center of the roof, concentric with the openings of the hearths, through which the shaft is passed. The roof about this opening' is provided with a liang'e 43, similar to the flanges carried by the hcarths IC', hereinbefore described, and the shaft is provided with the downwardlyextending' flang'e 4t2, whereby the shaft is snugly fitted and at the same time allowed to rotate in the opening'. Any suitable means for rotatingthe shaft maybe provided. Preferably, however, and as shown a circular plate 2 is secured to the shaft below the lowest hearth. This plate 2 is provided on its under face with a circular rack or gear which is adapted to engage with a pinion 3 on the shaft 4, driven by any suitable power means.

Any desired means for feeding the ore or other material to the furnace may be employed. As shown, however, and preferably there is provided a hopper 5, arranged on the top of the furnace, which is provided with the screw-feed 6 on the shaft 7, driven by the same power means which operates the shaft 4 through the sprocket-wheels 8 and 8 and the chain 9. A valve 10 may be provided to regulate the feed of the ore or other material and is operated from without the furnace.

The stirring-arms F are secured to the shaft to rotate `with it, and there is provided, preferably, a pair of stirring-arms for each of the hearthsE E', secured to the shaft diametrically opposite each other. The means for securing the arms to the shaft and for cooling both the shaft and the arms will now be described.

The shaft D is internally provided with longitudinally-extending inlet and outlet passages for the circulation of a cooling fluid, preferably air, being for this purpose preferably provided with longitudinal partitions 12, separated from each other to form a central inlet-passage 12 and an outlet-passage 12b on each side of the passage 12, the passage 12 opening at the lower end of the shaft to the interior of the hollow standard 1, to which may be connected any suitable air or other suitable cooling fluid supply. The sides of the shaft at the points where it is desired to secure the stirring-arms are perforated, the perforations for each pair of arms being opposite each other and corresponding perforations being formed in the partitions 12. In these perforations are secured fittings 13 for receiving the ends of the stirring-arms and which are formed to direct the cooling medium through the stirring-arms. These fittings 13 are preferably in the form of hollow cylindrical sleeves, as shown, which may be formed with circumferential bosses 14 to engage and secure a snug fit with the sides and partitions of the shaft when the sleeves are set in the shaft. To aid in setting the fittings in the openings in the shaft and in removing them, they are preferably of slightly-tapering form externally. When the surface of the fitting is cut away to leave the bosses 14 for engaging the walls and partitions of the shaft, the bosses determine the shape of the fitting so far as its engagement with the shaft is concerned and are of such relative diameter as to secure the desired tapering form. Suitable means are provided for holding the fittings against turning in the shaft. W hen of cylindrical form, as shown, studs or screws 15 .air-passages, the upper of which is again divided midway of its length by a partition 19. The lower passage 18 has a port 20, which opens to the passage 12 of the shaft, and the upper passages 18b have ports 21, which open into the passages 12b of the shaft. The stirring-arms are hollow and have a longitudinallyextending partition 22, which forms within the arms an outwardly-extending passage 22 and a return-passage 22b for the cooling fluid, said passages connecting at or near the outer end of the arm. At the inner ends of the arms the partitions 22 extend in position to abut against the partitions 18 of the fittings 13 when the arms are in position. The passage 22 of each arm will thus be in communication through the passage 18 of the fitting with the inlet-passage 12 of the shaft, and the return-passage 22b of each arm will bein communication through a passage 18D with one of the passages 12b of the shaft. The air or other cooling fluid passing' upward through the shaft passage 12, part of it will pass through the port 2O of each of the several fittings 13 and then flow in both directions outward through the passage 18 and the passages 22 of the oppositely-extending arms and then back through the return-passages 22b of the arms to the passages 13b of the fitting and thence through the ports 21 to the outlet-passages 12" of the shaft. The cooling fluid will thus be caused to fiow through the length of both the shaft and the stirring-arms, and these parts being thus cooled deterioration will be reduced to a minimum. To secure a better cooling of the part of the arm which rests in the sockets formed in the ends of the fittings 13, that part of the arm is provided with a plurality of grooves 24 and perforations 25, as shown in Fig. 5. By the ernployment of these grooves and perforations the air is allowed to circulate between the arms and the sockets, thereby cooling them and preventing to a large extent the deterioration of that part of the arm and of the projecting ends of the fittings 13. Any suitable means may be provided for securing the arms in the sockets. Preferably, however, and as shown, in order to enable the arms to be removed as rapidly as possible from the sockets the projecting ends 17 of the fittings are per- .forated and there is a corresponding perforation in the end of the arm which enters the socket, and the arms are held in place by pins 26, placed in such perforations. The arms may thus be removed from the socket with IOO IlO

but a very short stopping' of the furnace, the operator having' simply to open the apertures '27 (see 1) in the wall of the furnace, insert tongs or other similar instrument, pull ont the pin` and withdraw the arms. The employment of this simple means for securing' the arms permits the apertures in the fm'- nace to be reduced to minimum size, which is an important factor, because of course the larger the aperture the greater is the amount of cold air necessary to belet into the furnace during the operation of removing' the arms. In order to obtain the requisite strength of the arms without unduly increasing' their weight, the arms are preferably formed, as shown, with a longitudinal vertically-extending swell or hollow rib Q8 on the upper side of the arm. Such form of arm is especially desirable when the arms are secured to the shaft as shown and described herein and g'ives the necessary strength and rigidity to the arms without requiring' the use of bolts extending' through the arms and without necessitating' undesirable increase of weig'ht.

ln cases where it may not be desirable or necessary to cool the arms for their entire length. but only to cool the shaft, the fitting's 13, and the connecting' ends of the arms, a construction such as is shown in Fig. T may be adopted. In this construction the hollow sleeve-fittings 13 are employed, having' the annular bosses 1l and the projecting' soclieted ends 1T extending through the sides of the shaft; but as the cooling' fluid is to flow only through the shaft and not through the arms the partitions in the shaft and in the arms and the ports and partitions in the fittings 13 are omitted and the air or other cooling fluid fiows directly through the shaft,passing' around the fittings 15. With this construction the arms are preferably provided with shoulders 29 to abut against the ends of the fittings 13 and limit the insertion of the end of the arm into the socket.

By the employment of the fittings lwhich are preferably held in place in the shaft merely by being tightly fitted and without any positive means, the sleeve when deteriorated or when not properly fitting' owing' to deterioration of the shaft may be readily withdrawn from the shaft by tong's passed through the apertures in the furnace-wall and another sleeve having' bosses l-.t of the proper dimensions inserted. By the employment of such fitting's,therefore,constructed as describeththe necessity of cooling down the furnace and withdrawing the shaft for the purpose of inserting' a new shaft is largely obviated, thus avoiding' a serious difficulty heretofore encountered in the operation of this type of furnaces.

No claim' is made in lthis application to the combination in a roasting-furnace of a series of' superimposed hearths having' concentric openings, a rotatable hollow shaft extending' through said openings and divided internally by a longitudinal partition joined at its edges to the wall of the shaft to form inlet and outlet passages for a cooling' fluid extending' long'itudinally of the shaft, and stirring-arms carried by the shaft and having a longitudinal outwardly-extending passage connecting' with the inlet-passag'e of the shaft and a returnpassage connecting' with the outlet-passag'e of the shaft.

'hat is claimed is- 1. In a roasting-furnace. the combination of a series of superimposed hearths having concentric openings, a rotatable shaft extending' through said openings, detachable fittings carried by and extending' bodily into the shaft, and stirring-arms detachably supported by said fittings, substantially as described.v

2. In a roasting-furnace, the combination of a series of superimposed hearths having concentric openings, a rotatable shaft extending' through said openings, detachable fittings carried by and extending bodily into the shaft, and stirring-arms detachably supported by said fittings, the shaft and the stirring-arms having connecting-passages for the circulation of a cooling' fiuid longitudinally through the shaft and the sti wing-arms, substantially as described.

3. In a roasting-furnace, the combination with a series of superimposed hearths having concentric openings, a rotatable hollow shaft extending through said openings, fittings detachably mounted in said shaft and extending transversely through the shaft with their ends extending' through openings in the wall of the shaft, and stirring-arms detachably supported by said fittings, substantially as described.

1. In a roasting-furnace, the combination with a series of' superimposed hearths having concentric openings, a rotatable hollow shaft extending through said openings, fittings detachably mounted in said shaft and extending transversely through the shaft with their ends extending through openings in the wall of the shaft, and stirring-arms detachably supported by said fitting', the shaft and the stirring-arms and the fittings having connecting-passag'es for the circulation of a cooling' `fluid longitudinally throug'h the shaft and thel stirringarms, substantially as described.

5. In a roasting-furnace, the combination of a rotatable hollow shaft, a fitting' detachably mounted in said shaft and arranged transversely thereof and extending' bodily into the shaft through an opening' in the wall of the shaft, and a stirring-arm detachably support- IOO IIO

ed by said fitting', substantially as described.

6. In a roasting-furnace, the combination of a rotatable hollow shaft, a fitting' detachably mounted in said shaft and extending' transversely through the shaft with its ends extending' through openings in the wall of the shaft, and stirring-arms detachably supported by said fitting', substantially as described.

7. In a roasting-furnace, the combination of a rotatable hollow shaft, a fitting detachably mounted in said shaft and extending transversely through the shaft with its ends extending through openings in the wall of the shaft, and stirring-arms detachably supported by said fitting, the shaft and the stirringarms and the fitting having connecting-passages for the circulation of a cooling fluid longitudinally through the shaft and the stirring-arms, substantially as described.

8. In a roasting-furnace, the combination of a rotatable hollow shaft, a fitting detachably mounted in said shaft and extending transversely through the shaft with its ends extending through openings in the wall of the shaft and having sockets formed Vin its ends, and stirring-arms having ends formed to fit in the sockets in the ends of the fitting, substantially as described.

9. In a roasting-furnace, the combination of a rotatable hollow shaft divided internally to form longitudinally-extending inlet and outlet passages for a cooling fiuid, fittings detachably mounted in said shaft and extending transversely through the shaft with their ends extending through openings in the wall of the shaft, said fittings being' formed with inletpassages and ports connecting with the inletpassage of the shaft, and outlet-passages cornmunicating with the outlet-passage of the shaft, and stirring-arms detachably supported by said fittings and having longitudinal outwardly-extending passages connecting with the inlet-passages of the fittings and returnpassages connecting with the outlet-passages of the fittings, substantially as described.

10. A fitting for roasting-furnaces for connecting stirring-arms with a hollow rotating shaft, said fitting being formed of a sleeve adapted to extend transversely through the shaft and having its ends formed to connect with and support the ends of the stirring-arms, and having annular bosses to fit openings in the walls of the shaft, substantially as described. v

11. A fitting for roasting-furnaces for connecting stirring-arms with a hollow rotating shaft, said fitting being formed to extend through the shaft and having its ends formed to connect with and support the ends of the stirring-arms, substantially as described.

12. A fitting for roasting-furnaces for connecting stirring-arms with a hollow rotating shaft, said fitting being formed of a hollow sleeve adapted to extend transversely through the shaft and divided internally to form inlet and outlet passages to communicate with inlet and outlet passages of the stirring-arms and having ports for connecting its inlet and outlet passages with inlet and outlet passages of the shaft, substantially as described.

13. A fitting for roasting-furnaces for connecting stirring-arms with a hollow rotating shaft, said fitting being formed of a hollow sleeve adapted to extend transversely through the shaft and divided internally to form inlet and outlet passages to connect with the inlet and outlet passages of the stirring-arms, and havinginlet and outlet ports for said passages, substantially as described.

14. In a roasting-furnace, the combination of a rotatable shaft, a socket carried by said shaft, and a stirring-arm havingits end set in said socket, the shaft and the stirring-arm having connecting-passages for the circulation of a cooling fluid, the end of the stirring-arms being formed with perforations 25 connecting with grooves 24 for the circulation of the cooling fluid between the end of the stirring-arm and the socket, substantially as described.

15. In a roasting-furnace, the combination of a rotating shaft, and a hollow stirring-arm carried by said shaft havinga horizontally-arranged partition and having a hollow vertically-extending longitudinal strengtheningrib 28, substantially as described.

16. In a roasting-furnace, the combination of a rotatable hollow shaft, a tapering fitting detachably mounted in said shaft and extending transversely through the shaft with the ends extending through openings in the shaftwalls, and stirring-arms detachably supported by said fitting, substantially as described.

17. In a roasting-furnace, the combination of a rotatable hollow shaft, a detachable fitting carried by and extending bodily into the shaft, a stirring-arm detachably supported by said fitting, and means for causing the circulation of a cooling fluid through the shaft, substantially as described.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

FREDERIC J.'FALDING. Witnesses:

J. A. GRAVES, A. L. KENT.

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