US983563A - Cement-kiln. - Google Patents

Description

R. J. NASH.

, CEMENT KILN.

Ammon-mw rmzn Aun. w. um.

Patented Feb.v 7 um.

Fill

- elnimlier, mechanically operated.

ROBERT JOHN. NASH, F MAYLAWN, MITClllLDlAN. ENGLAND.

Specification of Letters Patent.

CEMENT-KILN.

lntented Fel). 7, 19H.

Application tiled August 19. i910. Serial No. 578.059.

I'o all whom il may concern:

lle it known that l, ltoiuzn'r Jolis Naim,

eenient-works chemist. reoiding at .\laylawn.

invented certain new and useful liiiproveint-nts in Cement-Kilos and l do here y deelare the followingr to lie a t'ull, clear, and e.\act description of the invention, auch an will eniihlc others killed in the art to which il' nppertains to inakc and use the cime.

As is well known, cement kiln as at present employed are cliielly of two types, viz., the continuous shaft kiln, and the rotary kiln, furthermore, the fuel economy dcriied l'i'oiii thc use of the shaft kiln andthe lullin' Having properties nl' the rotary kiln are w'dl uuderttmd, a-i are also the attendant disadvantages tn eitlit'l type.

Now llic object ol' the present invention is to provide a kiln which .shall conihine the adianta ,en derived l'roiii hoili the known einen ol1 kiln, and generally io provide a more eilieient kiln tlitili hitherto.

la order that this invention may he falli' ninei'rtood, it `will now he thnweriheil with reference to the aeeoinpanyiinr drawings in whiclrz Figure 1 is a vertical cross rerton of a kiln constructed according to this invention. Fig. 2 ifi :i cross section on line :n w (Fig. l). Figa. tt to 'i' are details hereiinittcr re feried to.

'lhokiln is essentially of the vertical shaft type connected with a horizontal drying The dryin;r elianilier consists of one or more conveyei' of the paddle hliide ty ic, (u) working toward the kiln proper ainl against the hot gases issuing therefrom. The conveyers arc arranged one nhoi'e the other as shown in Fig. :l which iny a crmei section on line y t/ (Fig. l) the hot gasses pai-sing through the lower b, and under and through the upper ehainhei' L', to an outlet or cxhaiisttlne (not chown) the draft boing produced hy a ouetion fan arranged in the part of the exhaust tine.` lhc dischai' e end of the lower conveyer is conneetei to a slightly converged iron cylinder c carried by two tires c on roller hctiringii o', which letti as a hearing for this end of thc coiweyer (sce sectional end eleviition Fig. 5). The kiln end of the cylinder is inclosod b a hood dfixed upon t ie kiln proper, and hereby forming a connection with thedr ing chambers 1:,5. The conveyors are worred hy gear wheels c and the extended drying drinn r: is revolved hy niennnl' its connection with the lower ron- I iii'er shaft o' through a spider u.A 'lhe eine .\liti fheldean7 (iloneestershii'e, lungland, haie and l-liiipe of the eonieiei' blades i'ai'y at intervals along the Shaft and are so designed im to liest snit the condition of the iiiateriiil atany particular point along,r the line of conveyance. 'llie dat;| ol the, revolving cyl inder i' i-1 to forni the half dried .slurry or dill' png,r into rounded linups, thereby facilitating thenction of hiii'ning in the kiln. The kiln is provided willi chopper i for tho main supply of l'iiel. 'l'his hopper is arranged directly-over the veitieal portion of the kiln, and it is provided with a lclidablc door or l'cedin -dei'iee i'. ,'lhil vertical portion of the ki n may he' divided into t'oui' stages or parts, (l) seasoning or smoking, (2) ealcining. (3) elinkcring, (4) cooling. The seusoning or smoking chamber (l) is for the reception of the green material from the drying eliainhera h l" and ifi no constructed that hy ineaiin ot' a perforated iron cylinder y the hot gases are allowed t0 reach the drier without snhjceting thc hud of green nnseasoned slurry to anv great heat. The ealeining ehaiuher (Q) alioi'e.tlie clinkering zone is' where the expulsion of carbon dioxid is all'ected, followed hy the intense lienting previon to elinkering.' The clinkering zone (it) which iii mudo to rotate, thereby nullifyiug the tendency on the part of any semi-molten clinker to adhere to its surface, is where combustion is completed, and vitriiieation of the. material takes platz., ..nd the cooling chamber (4) at the base of the structure is where the. hot elinkor is made to iinpiirt its heat to the air passing through it for combustion.

The kiln itself as shown is built. of three A sect ions. 'lhc bottoni section 4 is constructed of hrick work and is nominally s. clinker hopper with .-i large mechanically oscillating shaker discharge device j (Figs. 1 und 2) at thc haue. A numher ot porta m consisting of short iron ihres, are huilt at intervals in thc walls. 'liese ports together with the discharge aperture n't oi'in the entrances or the necessary air supply. The discharge il of .'.utlieent.tiw.a to para clinkar of connideriihlc hulk and is largo enough to clear any cliuker produced under ordinary conditionerI 'lhe capacity of this chaniher is suicient to enable the elinaer to he discharged in a worin to moderately cool condition. The discharge of the dei-ice is regulated by the 2a mixture is eleva speed of the rau' material feed and drier conveyor, thereby keeping the level of niaterialin the kiln constant.

n n are six perpendicular girder supports upon which the sections l and 2 are carried and the sections are built of substantial steel shells lined with tre brick. In order to facilitate the lining with refractory brick, the

shells are constructed conically as mach as is lo possible 'the whole weight of the brickwork bein taken by the conical pai-t of tlie shell and ign the case of the calcinini chamber 2 with this further advantage, tiat the lower ring or rings of tire brick may bei'ei5 placed without interferin with those above.

From the principle of t ie kiln,.previeusly set forth, it will be obvious that considerable advantage is gained by working a number of kilns in a battery. It will therefore be necl 2c celery ln dealing with the construction and work g of the kiln to mention certain points common-to a battery only.

The raw miterial, either slurry, or pa is mixed with a proteiortion of breeze, w ach if necessary to a con ve er feedingrthe line of hoppers over the ki n driers. his conveyer has a capacity, greater than that of the united hopper extraction screws, h thus insuring a return tlow of the mixture to thebrceze' and slurry mixer. By this arrangement, the hop rs, which are only of comparatively ama l size, are always kept full and the .feed of any articular kiln may be increased or diminished Awithout inconvenience. The extrac- 1 tion screw h is driven from the extended shaftab of the to drier conveyor and its peed is re ated y that of the drier. The rier sha ts are driven through the gear 4a wheels e from a small'inotor, or a line of shafting throu h a variable speed controller. The drying c embers are constructed of substantial iron tho desi being shown in the sectional diagram ig. 8). The top 4.', part of the upper chamber is reinovablc,.as

is also theside ofthe bottom chamber, there` by givin access to the shafting and conveyer bla sfor repairs or adjustment. At.

,the discharge end of 'the to conveyor, tl'ie 5o chamber is made with a sliding bottom A: the adjustment of which alters the distance of conveyance through both chambers. 'lhe vslide bottom moves u in ledgesattached to the vertical sides of c lower chamber, and is ad'usted by means of a screw `rod k passing.t rou 4h the drier end, and worked by a convenien hand wheel. The ends of the chambers are covered by, suitable iron lates or l"endaf k bolted .to angle iron anges e0 attached to and surrounding the drier. 'lo

these plates are tixcd bearings l for the conveyer shafts, but the late la at. the kiln end of thc drier (Fig. p only closes the top chamber, leaving. a c ear passage from the This cylinder c is attached to the conve el'.

shafts as beforcsaid by a spdtler a key to thc'shafts as before use of which the pug is worked forward in uniform iecea previous to bein" subjected to the rolling action of the cylinder. In this chamber tliercmaining moisture is further expelled, and the tlioroii h drying of the material completed. Shoal this process take place too.rapidly, the lamps or balls of material will tend to 'l burst asaiider and break up into small fra monts, which would eatl restrict t e draft and regular running o the kiln. 'In order to prevent this, a clear pasa is provided for the hot gases around th niaso terial as well as through it by employing an internal cylinder g of substantiagoierforated iron depending from the h el. B this means, the bod of material conta ned by the iron cy'lln er is not subjectedI yM to excessive heat, and by the-time it. is admitted to the hot chamber below it is in a` condition to withstand the eects of a high temperature, without tlie harmful cited. above mentioned. From the hood d inclut' au iiig the discharge end of the cylinder, a loii r or sera r dl is fixed, its pcsitionbein sach, as to i etach from the asccndin side o the cylinder aiy plastic materia which shoul tend to a here to its surface. As the 98'- draft within the kiln and drier is induced by suction, it would be detrimental to admit air at any point abovetlic burning zone and as the rotary cylinder c is situatedA with a stationary structure at either end, an air '10o passa at the junctions can not be avoided and ni ordertc exclude outside air from these passages, the cylinder is compl y inclosed by 'a sheet :iron casiig, d connected at one end to the kiln h d a I drier end at the other. ,The bearii wheels?.

c', upon which the cylinder c nv vas are also inclosed by' the casing'lbut it is so. arranged that thespindles of these wheels h are carried by bearings fixed outside the 1U psing (see Fig. 5). The. whole exterior surace of the drier andcasjng iscovered with packing of non-heat conducting properties.

The seasoning or sinokiag chamber- (l) 'which constitutes the upper part of the top ll section is so dengncd' as to allow of its eapacity bein varied and for this pnrgmse a second erlirated sleeve g* Ais telcscopicall inounte around the lower end of the cv inder y adapted to be raised or lowered by screwed rods g' enga ing extensions y' and operated by hand w ioels p. These variations iii sr/.e are iuinle at t ie ex use of the lower pre-heating chamber am the reason,

for thus altering the capacity of both chainier I bers will be'apparent when the manipula-.- tion of the kiln is lieieinafter described.

'llic shell of the rotary or cliiikeriiig cham. ber (2) widens downward, parallel with its a bottom conveyor-'to the rotary cylinder c. i interior surface, as far as thebottom ring 1W ad to them.

nannies l, n

'Ilie bottoni rouiw of lire lii'ieih ure tlii'rcl fore of more oi'lcss the yaanniihiipc as thel hist course in the pre-heating chamber and 1 :entering from the seasoning chamber (l) the weight of thc refractory lining instead of being tiikeii by the flange alone is taken by the narrowed portion of thil shell. .\.-i this chamber revolves between stationary Imdies, it is necessary to previ-nt outside air from entering at the junctions. 'lo accomplish this, a metal channel or canal o is iittached to the top of the chamber 3 within which a lian 'e o* depends from the u iper stationary cliiimbcr :2. This chaiine or canal o contains a low melting alloy or i :soms auch suitable, fluid, air being thereby etiectinilly excluded. A similar arrangement is used at the lower end of the chainbei', but with the flange and canal situated vice versa. Surrounding the shell at a suitable point ni a stron iorizontiil thing: p to the top side of w iich is bolted a ve spur wheel p wliiie to the other side is bolted a tire p". The chamber by means of the tiro is iup ioi'tcd by bearing wheels carried by brac ets q* attached to the stce u rights n (ace details in Figs. 6 and 7).

ie rotation of the chamber upon these wheels is accomplished by the engagement of suitable bevel wheel a' carin op r wheel p.. The revolution o the chumis necessarily slow and the best speed can oiil be ascertained b practice, but it is proba le that an interna surface speed of about 4 ft. to 0 ft. per minute would be suitable. l

'llie inanipuiation of the'kiln is extremely simple and straightforward. This is to the fact that each of the dilerent actions which take lace under the process of cslci iiiition csa controlled at an stage, independently anil an ii whole wit the greatest etnie. As a rough exam le of the method of working with this ki n, assume the kiln rniining at its normal capacity but with ciinkcr obtained from the clin erin sone S3) showing .an c'ect of over vitri cation i ne to excoouvc temperature. The burner would immediately increase the speed of the kiln iii accordance with the degree ot overhiii-iiing to he remedied. 'lhiu would have thc ollcct of discharging thc clinker and also feeding thc kiln at a greater speed with the result of a. more rapid passa of material through the burning none. n conjunction with the increased speed the size of the smokin and pre-heating chambers 1 and 2 would iy extending the perforated cylinder yl in .the lsmoking chamber, he increased and reduced respectively. 'llie capacity of tho drying chambers Il, b may also he reduced liv manipulating the slide bottom k of the conveyer, with tbc result of an immediate with the 4 f "ases would be iiiiicli hotter owiii v lo the llitei'enec hi the wor'.' they would called upon to accomplish before their exit. A corresponda etlect would be produced in the pre-heating chamber iiii the material would much less advanced toward the completion of eliiikering therefore requiring more heat to bring it to the requisite teinpcrutnre within a given time. The eect upon the clinkei'ing zone `(3 would be found in a very short time an steps could be taken according to the degree of overburning to be rectified to bring the kiln again to itsnormal working rate. The rea: son :for taking overburning as an example of kiln manipulation is that it is the least to be desired, for the eects in the ultimate cement from this cause are nioreoften farrcaching and active in character than are the eticcts of li ht burning.

Light an under-burning would ofcourse be rectified by reversing the operations given in the foregoing example, t be in severe cases of under or over-burnilig that the coal supply would need to be vari l at least to any extent, and with a kiln o auch consistency, variations of any description would only be alight in character and y rare in occurrence.

Having now particularly described my said invention w at I claim as new and a sire to secure by v Letters Patent lai-- 1. ln a kiln, the combination, with a calcining chamber and a` cooling chamber arran clin ering chamber arrang between tl said chambers, and driving-mechanism for revolving the said rotary chamber.

2. In a kiln, the com ination, with a calcining chamber and a cooling chamber arran one above the other of a rotary clin ering chamber arran between the said chambers, air-tight oint members pro vided with tongues an grooves and arran between the rotary chamber and the sai chambers. :ind drivin mechanism for revolving the said rotary c in mber.

8. In a kiln, the combination, with a calciniii chamber of an inlet hood for receiviii t e fuel and the material to he cidcined,

sa d hood bein provided wltli a teieaco icA delivery c lin er which projects withinhe said chamber, and means for adjusting the length of the said telescopic cylinder.

4. The combination, with a kiln provided with an inlet hood for receivin the fuel and the material to be calcined, o a horizontal drying compartment connected to the nid l hood, :i rotary spiral conveyor worki in the said compartment and operating to the num-rial into the hood and a revoluble drum interposed between the said compartwoiild only one above the othizbi"i of a rotary ment and hood and driven by the said con. 65 lossI of hciit, as by those means tlie escaping l veyer. 39

5. The combination, with a kiln provided with un inlet hood for receivin the fuel and the material to be onlcined o a horizontal drying compartment connected to the said 5 hood, a rotary spiral conveye'f working i3 the said compartment and operating to tho material into tho hood, a rsecond horizontal dryin compartment arranged above tho tiret nnilcompartmont, a nlidable plaus n lwtwwn tlm said compartments for varying their eectivc length, and o second '-otury spiral coivoyer errno rml in the second said compartment and feqi ing the marinl from it into the first said com artment.

In testimon whereof aix my signature, 15

.in presence o two witnesses.

ROBERT JOHN NASH. Witnesses:

Amlu'i' \V. W msnm., SYDNEY It. 'Phnom

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