US1804362A - Kiln for manufacturing lime or the like - Google Patents

Description

May 5, 1931- G. MARTIN KILN FOR= MANUFACTURING LIME OR THE LIKE Filed April y2s; 1927 Patented May 5, 1931 i i i Y 1,804,362 y y i UNITED; STATES! PATENT OFFICE Application filed April 28, 1927, Serial No. 187,332, and in Great Britain May 17, 1926.

rllhis invention relates to kilns particularly to flow over oneof its longer walls, and by inadapted for use in the manufacture of lime, troducing the cold raw material through one gypsum, calcareous and/or aluminiferous eeor more openings in the opposite Wall. The ments, the calcination of ores and kilns therehot gases thus impinge eccentrically upon the fon slower and cooler gases in the deearbonating 55 The object of the invention is to improve or preheatiiig chamber, causing the gases on kilns of the shaft type into the upper end the colder, or inlet side to sink and helping to of which raw materials in powdered form are Carry down the fine particles just introduced, introduced and permitted to fall against an instead of allowingthem to be swept upwards ascending streamof hot gases. and through the exhaust flue by the rising 60 According to this invention the average gases. y speed of the gases in the clinkering or siiiteihe -ijaW materials may be introduced 1n Wet ing zone is' maintained at least four times OI'I'TI, aS a Spray, or in dry granular or pulgreater than that of the gases in the preliniverized form by a blower, worm feed orother inary heating` or decarbonating zone. In this kHOWHIDSMlS, the Particle Sizes being so pre- @5 Way the fine particles do not leave the predetermined that-'on the one hand fine dust is liininary heating Zoneluiitil a sufficient nuin- 110i? Carrled awa-y by the hot gases and on the ber of them fuse together or coalesce and can OhGI. hand the raw material does not at one@ thus overcome the higher speed of the gases fail 111120 the Sntering zonekorA shaft,

2o in the sintering Zone and so fall through this One f orm of kiln for carrying out the 73 zone and pass into the cooling shaft or cham- Present Invention is diagrammatically. illusbei. formed beloWit. f Y f tlted in f the accompanying drawings, in

'As a result, the' fine particles form a baiiie Whihi i y and soprevent internal radiation losses in the Flglll l 1S EL Vertical section through a upper or deearbor'ating kzone and sintering quarry faCo ShOWng a shaft kiln, 75

rapidly takes place 'in the, 'lower Zone 0f the Figure 2 is a vertical section on the line kiln after these partielesare properly cal- 2--2 0f Flgpl@ l, and

@ined and preheate@ Figure 3 is a cross-seetion on the line 3 8 The heating gases are preferably main- 0f Flgue 2- i gaingd at 'bha r'equilgd' relative Spgeds Th@ kllll. dllgl'nlllltlCillly llluStI'lGd S forming the cross-sectional area of the deexcavated 111 the ground and comprises 2111 carbonating zone at least four times greater Upper P'I'ehhatihg and declhohitihg Ohhh* than that'of the Snterng Zolm ber portion A, a lower narrower portion cou- Further, to prevent internal radiationv Stlthtlhg the Clihkeihg 01' Sihiihihg Z011@ 01' losses and to facilitate the heating of the kiln Shaft B, and @Cooling Shaft 01` Chamber C 85 '140 Shape in (gyogggectojthus bringing the longtures El With the lOWel Bild Of the CllIllQland the roofing of the upper chamber,both the Which comhiiiliihiies With the gI'OlllCl level sinteringand'decarbonating portions areconthrough ah adii' D- n Y y veniently formed of elongated elliptical or Th? burners E WhlCh Suppi7 hot gases iO 0f narrow and Substantially ,rectangular thS klln COn'lll'lUlllCtte through lateral @p61*- er opposite walls close to one another.V 111g Shaft B and are Supplied With liquid? Moreover to ensure thorough preheating of Powdered Orga-Semis fllei in any iIlOWll maiithe raw powdered materials in the decarbon- 1161', 1H the particular @Xalnple illustrated a ating zone or chamber and to redueethelength hopper F for pOWd-@led illei bGiIlg (iiglmi5 of this portion of the kiln, the gases are made HltiCaiiy iiuStrated on one side only. 95

o follow a; rotary 0r Circulatory path in the The preliminary heating or decarboiiating vdecarbonating chamber. This result i556- chamber is of at least four times the crosscuredby introducing the hot gases from the sectional area of the sintering shaft, and in elinkering zone eccentrically or asymmetrithe 1331110111211' @Xaliipie diaglmlliltoally 50 cally into the decarbonating chamber, so as ShOWhi the fieCiihOhi-Jihg Chamber A iS 0f ing a large heating surface'which meets with` considerable resistance on encountering the descendingparticles. As a result the heating gases can be quickly brought to rest thus reducing the height of the kiln and its cousequent cost of construction. Further, the

narrow substantially rectangular cross-sec-V tion of the upper portion of the kiln facili! tates'the formation of roof `iviich, inthe case of large kilns, would present ditliculties were the kiln of circular cross-section.

The raw materials are introduced laterally into the upper aortion of the chamber A through a suitable number of openings G, being introduced by means of a fan or blower or by worm conveyers as diagrammatically illustrated in the drawing. l

A suitable co'nveyer H is also furnished in the working adit D through which' the hot clinker can be withdrawn from the cooling shafty C, the air to support combustion being introduced to the burners throu i the 'mass of hot clinker in the cooling shaft thro" i one or more suitable supply pipes as inflicatedat J. "f 'f It will beseen from Figures l and that the decarbonating or preheating chamber portion A of the shaft is arranged asynnnetrically with relation to ther sinte o' shaft B, and further that the lateral op through which the powdered mat l troduced into the kiln are formed in the wall furthest from and opposite to that with which Vthe sintering shaft is in alignment.

As result,-the hot gases from the shaft B impinge eccentrically upon the slower and cooler gases in the preheatin cha inher causing the gases on the materia inlet or opposite side wall to sinkand thus assisting to carry down theiine particles of raw n'iateria" which have just been introduced'instead of allowing these particles to be swept away by the exhaustl fan or its equivalent (not shown) through the shaft L. f

It will therefore be seen that the gases in the upper or decarbonating chamber A of the kiln are caused to follow a rotary .r circulatory path, thus permitting reduction of the vertical height of the kiln and further ensuring proper calcination and :ulmixture of the various powdered materials before these yparticles coalesce or fuse together sufficiently to overcome the tendency of the hot gases to resist-their fall. As soon as the particles are thus of sufficient size and weight they fall against the hot and more rapidly moving gases in the sintering shaft B and being thus properly sintered pass into the cooling shaft C whence they are removed by the conveyer H after they have given up their heat to the incoming air which supports combustion.

Itis to be appreciated -that the drawings are Vof a purely Vdiagrammatic nature and that in some cases the liln may be built up -against the quarry face. Moreover' the general layout of the kiln, the way in which the raw and sintered materials are respectively introduced and removed and the auxiliary apparatus employed, will naturally vary widely iny accordance with special circumstances without departing from this invention.

Further, the relative length of the preliminary heating and decarbonating zones and the size of the cooling zone will again be varied to suit the material under treatment and the product sought to be obtained, the relativecross-sectional area of the sintering zone and the preliminary heating zone being in all cases such that the speed of the gases in the sintering Zone is at least fourtimes as great as that of the gases in the upper or preliminary heating zone.

lVhat I claim as my invention and desire to secure by Letters Patent is l. A shaft kiln for heat treating lime, cement and the like in powdered form comprisingv a preheating chamber of elongated crosssection having its wider side walls relatively close together, a sintering shaft of relatively smaller cross-section disposed'below the preheating chamber and communicating kasymmetrically therewith through .the bottom, and means for introducing'heated fluid into the lower portion of the sintering shaft, said chamber having yan inlet for powdered raw material and a gas outlet both located at the upper endof the preheating chamber at the side remote-fromxtheupper end of the sintering shaft..

2. A shaft kiln for heat treating lime, cement and the like comprising a preheating chamber of elongated cross-section having its wider opposite sides relatively close together, a. sintering shaft of relatively smaller crosssection disposed belowthe preheatingchamber. and communicating asymmetrically `therewith through the bottom in such a way that the whole of the'said sintering shaft lies to one side of the vertical axis ofthe preheating chamber, means for maintaining an ascending stream of hot gases in the sintering shaft, a passage so connecting the upper end of the sintering shaft and the preheating chamber that the hot gases from the sintering shaft enter the preheating chamber close to one of the longer side walls of said chamber,

said chamber'havingan inlet through which powdered .raw materials are delivered into the upper end of the preheating chamber so as to fall along that side of the axis of the preheating chamber remote from the sintering shaft, and a gas outlet likewise located at the upper end of the preheating chamber at the side remote from the upper end of the sintering shaft. Y

3. A shaft kiln for heat treating lime, cement and the like in powdered forni comprising apreheating chamber of elongated crosssection having its wider side wallsrelatively close together, a sintering shaft having a cross-sectional area not exceeding onesfourth that of the preheating chamber, the said sintering shaft being disposed below the preheating chamber and communicating asymmetrically therewith through the bottom, and means for introducing heated fluid into the lower portion of the sintering shaft, said chamber having an inlet for powdered raw material and a gas outlet both located at the upper end of that side wall of the preheating chamber which is opposite to the wall in alignment with the sintering shaft.

a'. A shaft kiln for heat treating lime, cement and the like in powdered form comprising a preheating chamber of elongated crosssection having its wider side walls relatively close together, a sintering shaft having a crossesectional area not exceeding one-fourth that of the preheating chamber, the said sintering shaft being disposed below the preheating chamber and communicating asymmetrically therewith through the bottom, means for introducing heated fluid into the lower portion of the sintering shaft, an inlet 'for powdered raw material and a gas outlet both located at the upper end of the preheating chamber and at thatside wall thereof oppositeto thewall in alignment with the sintering shaft, a cooling shaft forming an eX- ment and the like in powdered form comprising a preheating chamber of elongated cross'- section havingy its wider side walls relatively close together, a sintering shaft of relatively smallercross-section disposed below the preheating chamber and communicating asymmetrically therewith through the bottom and having its upper end adjacent one of the longer side walls of said preheating chamber, and means for introducing heated iiuid into the lower portion of the sintering shaft, said chamber having aninlet forpowdered raw material and a gas outlet both located at the upper end of the side wall of the preheating chamber opposite to that to which the upper end of the sintering shaft is adjacent.

- In testimony whereof I have signed my name to this specification.

. GEOFFREY MARTIN.

tension of the sintering shaft into which the sintered vmaterial is discharged, and means for introducing air to support combustion through the kiln shaft and thereby preheating the said air as set forth.

5. A shaft kiln .for heat treating lime, cement and the like in powdered form comprising a preheating chamber of elongated crosssection having its wider side walls relatively close together, a sintering shaft of elongated cross-section having a cross-sectional area not exceeding one-,fourth ythat of the preheating chamber, the said sintering shaft being disposed belowthe preheating chamber and communicating asymmetricallyV therewith through the bottom, and means for introducing heated fluid into the lower portion of the sintering shaft, said chamber having an inlet for powdered raw material and a gas outlet both located at the upper end of that side wall of the preheating chamber which is opposite to the wall in alignment with the sintering shaft.

6. A shaft kiln for heat treating lime, ce-

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