US1399970A - Furnace - Google Patents

Description

C. I. LANE.

-FURNACE. APPLICATION FILED uGJi. 1920.

Patented Dec. 13,1921,

3 SHEETS-SHEET 3.

lllil Arat cHAELEs JOSHUA LANE, or LONDON, ENGLAND, AssieNon To CYRIL. EEANK ELWELL,

'or LONDON-E. c. 1, ENGLAND.

'Specification of Letters Patent. 'i Patint-ed Dec, 13,

' Application led August 6, 1920. Serial No. 401,769. l

cation.

rlhis invention is for limprovements in or relating to furnaces of the type used for galvanizing or otherwise coating articles, and comprising va 'drum to receive the ya1'- ticles and the material wherewith they are to becoated, which drum is arrangedV to'be yrotated -while it is heated externally to bring 1t to the temperature required for the particular vprocess thatis jbeing used.

According to thevpresent invention there is provided in `furnacesof the type described the combination with a long and narrow horizontal combustion' chamber,` of

`a removable cover therefor, a rotatable drumsupportedV within the chamber on half bearings, so as to be removable upward when` the said cover isA removed, and a'series of Itwyers spaced apart along a 'combustion chamber, said drumbeing interposed in the direct path from the twyers yto the outlet iue from the combustion chamber; Preferably the lremovable cover combustion chamber is hinged-'to it along one side.

According to yanother feature of ythe k'invention the combustion chamber is fsubstantially cylindrical, the twyers yare disposedI in .a linealong the lowermostrpartl thereof, and the rotatable drum, is `disposed eccen trically in theupper portion 'of 'the cylindrical chamber', such construction-oeringgvarh ous advantages hereinaftersetforth.

According to yet anotherfeature of the invention the whole formation is constructed as a self-contained unit whichcomprises` the combustion chamber, rotatable drum, driving gear for the drum, and a fan supplying injector twyers and driven from said driving gear, all these parts being mounted on a framework and preferably arranged above described. f

.In the Vaccompanying drawings, vwhich illustrate one embodiment kof this invention,

for. theground level for` the purpose hereinafter.

Fig.' 3-,is1an end elevation lookingfrom the right-hand sideof Fig. 1, and

Fig. l shows a detail. -i VLike referencef characters indicate like parts throughout vthese drawings., Referring to these'drawings thecomplete furnace is mounted upon a suitablel framework 10, which also comprises pillars. or

Alegs 11, whereby the various partsof the furnace 'are supportedabove theground. level. y

The' furnacev proper is constitutedchy a substantially cylindrical vessel 12, whichv is lined with lfire-brick or other suitable heatresisting andV insulating -material; The 1g shown at 13 constitutes ra lidnfor thelower' half of the casing, being hinged :thereto as at 14. VSuitable handles are provided at 15 on the ends of the coveror lid 13 to. provide for convenientlyopemng and closlt. M The outlet passage from the combustion. chamber-12l is provided by 'arched openings 16towardthe top of. the rear wall thereof, such openings communicating 'with a; `chamf ber' 17 which -'s in [direct communication with the Voutlet flues 18.

These fines maybe provided with `dampers 19 in the usual'manner. A ldoor 2O is provided in the end wall:

' of the chamber 17 sothat the .said chamber can be easily cleaned or cleared.

The cylindrical combustion Vch mber'121is Vprovided in its end walls .with-semi1cylindrical bearings 21 constituting the lower half of an ordinary bearing to support a roe tatable drum 22 mounted Aonthein. This drum is used to containA the articles which are to be coatedwhile they 4arebe'ing heattreated. l l 1 l a suitably lowspeed, al worm drum 22 at is mountedon the 4framework of the-shaft, within the casing. 26 (s eeFig. 3) engages a worinwheelv i'nv af casing 27.

The shaft for .this worm-wheel is shown as 28 in Fig. 2, and any convenient means may be usedv forcouplingthe shaft ofthe wormwheel. to the trunnion-shafts of the drum: 22. In theconstruction illustrated', .-tl ie .said trunnion-shaft 29 s provided with a diamupper half of this cylindrical chamber,` as

fl 595 In order to provide for the rotation of the fof thefurnace12. vThedrive f etral slot 30, and the worm-wheel shaft 2.8

is provided with a similar slot 31 which is however of reater axial length. key or dog 32 of suitable rectangular section to fit 5 these slots 30, 31 is mounted on an endwise movable rod 52 which projects from the outer end of the worm-wheel shaft 28 and 1s fitted with any suitable striking device 33` whereby the key 32 may be moved into the position shown in Fig. 2, to couple the shafts 28 and 29 together, or may be withdrawn into the slot 31 and thereby free the shaft 29 of the drum.

In order to make the whole furnace a completely self-contained unit, there 1s provided a fan or blower 40, this being conveniently located on the framework underneath one end of the chamber 17. Thefan 1s driven by a belt 41 from the ycountershaft above mentioned, and itsupplies air under the necessary pressure through a pipe 42 to a delivery pipe 43 located underneath the combustion chamber 12 and extending throughout the length of that chamber. In 25 order to insure a uniform delivery of air to the pipe 43, the pipe 42 is connected to it at the middle of its length. A series of branches 44 on the upper side of the pipe 43 supply air to nozzles entering or located within the combustion chamber V12. The construction of each of these nozzles is shown in Fig. 4 which is a sectional view of a nozzle with some parts broken away.

Each of the pipes 44 has connected to it a nozzle 45, which nozzle is mounted within a suitably shaped tube 46 open at its lower end. As illustrated, the nozzle 45 is screwed into a central boss which is supported on radial ribs in the base of the tube 46. Air under pressure is delivered by the fan 40 through the open end of the nozzle 45 and it exercises an injector effect so as to draw in additional air from atmosphere through the lower end of the tube 46, all of such air then being delivered into the furnace.

In the operation of this furnace coke or other suitable fuel is fed into the combustion chamber 12 when the lid or cover 13 is open. The cover is Ythen shut down and the fan set in opera-tion to blow up the fire by means of the twyers 45, 46. Simultaneously the drum 22 is set in rotation, and this rotation with the heating is continued as long n as desired. Provision may be made for testing the extent to which the coating opera tion has taken place by means of a test-rod similar to that described in our concurrent patent application Serial No. 401,768, filed August 6, 1920, such rod being inserted through the trunnion bearing at one end of the drum 22.

When the process is completed the fan is j stopped, and simultaneously the'drum 22 isV also stopped. The cover 13 is lifted, and

'when the clutch 32 is disengaged from the drum trunnion 29, the drum can ybe lifted vertically out of its bearings 21. lAs above stated the framework 10, 11 is so arranged thatall the parts of the furnace are above ground level and the reason for this is to permit the use of a portable crane for the lifting of the drum 22, the base of the crane being run in underneath the furnace. When the drum has been emptied and recharged, it is replaced n its bearings 21 and coupled up by the dog-clutch 32 to the worm gear and the process repeated.

It will be seen, particularlyifrom F ig. 3, that the flue opening from the combustion chamber 12 is situated behind and above the drum aXis, and that the drum is itself located in the direct path from the twyers to the outlet flues, being disposed eccentrically in the 'upper portion of the chamber 12. This insures that the hot gases are caused to circulate around the drum and insure pits satisfactory heating. A f

Another advantage of this construction is that the cylindrical or long and narrow formation of the combustion chamber enables a comparatively small quantity of fuel to be used in it so that rapidkheating can be effected. Moreover the cylindrical formation of the bottom of the combustion chamber insures complete combustion of the fuel since the combustion takes place mainly around the twyers, and the unburnt fuel all tends to fall into the hot region. Y

Another important advantage of the hereinbefore described construction is that the use of injector twyers permits the use of a fan or Y blower of smaller dimensions lthan would otherwise be the case,and in addition insures that the twyers themselves are not subjected to the risk of burning, since they are efectively air-cooled by the flow of air through them. Y

Finally it will be appreciated that the yarrangement of the furnace whereby the drum is lifted vertically from itfinstead of being removed endwise through 'the end of the combustion chamber, is of considerable advantage in that the space required for a furnace of this type is reduced to a minimum.

It will be appreciated that various modications may be made in the precise details of mechanical construction and that vthe invention is not limited to the specific embodiment hereinbefore described.

VWhat I claim as my invention and desire to secure by Letters Patent is z-f 1. In a furnace for heat-treating material, the combination of a substantially cylindrical combustion chamber whereof the length is greater than the diameter, a hinged lcover extending throughout the length of saidV chamber on the upper .part thereof, a'plurality of twyersspaced apart in a line along ythe lower part of `said combustion chamber,

a closed rotatable drum supported eccentrically within the upper portion of said combustion chamber and means outside said combustion chamber adapted to to said drum to rotate it. Y

2. n a furnace for the heat-treatment of material, the combination of a self-supporting frame-work, a substantially cylindrical combustion chamber whereof the length is greater than the diameter mounted on said framework, an outlet flue-chamber supported.on said framework and communicating with the interior of the combustion chamber in the upper portion thereof, a plurality of twyers disposed in a line along the'lower part of said combustion chamber, a hinged cover on the upper part of said combustion be lcoupled chamber, half-bearings in the end wall of said combustion chamber, a Closed'rotatable drum supported in said half-bearings eccentrioally in the upper portion of said combustion chamber in the direct path from said twyers to said outlet, a worm reduction gear external to said combustion chamber for rotating said drum, said reduction gear being mounted on said framewark, a fan mounted on said framework, a pipe said fan to said twyers mounted on said from the outlet of framework, means coupling said fan to said Y worm gear, and a pulley whereby a drive can be imparted to said fan vand said worm gear. In testimonyl whereof aflix my signature.

CHARLES JOSHUA LANE.

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