8-105.07e

Compact and EfficientRotary Kilns

www.khdhumboldt.comwww.khdhumboldt.com

It all started with a revolutionKiln plants from KHD Humboldt Wedag are top of the line. One reason: highly efficient precalcining systems,which were developed by KHD Humboldt Wedag, revolutionizing the clinkering process. Rotary kilns no longerhave to function as calciners which mean that they can be substantially smaller in size.The advantage for customers is lower investment and operating costs. No wonder these systems quickly gainedexcellent reputations among our customers.

This is what you can saveThe main criteria for rotary kilns arehigh availability, considerable flexi-bility and cost-effectiveness. Theymust also meet all process techno-logy requirements for the clinkeringprocess. The KHD PYRORAPID® ro-tary kiln fulfills all of these require-ments. With two tire stations, lengthto diameter ratio of approx. 11:1to 12:1 and a statically defined be-aring arrangement, the PYRORAPID®

kiln offers superior advantages overa two/ three station kiln with agreater length to diameter ratios.

In addition the PYRORAPID® kiln offers:• Investment costs approx. 15% lower than three station kilns.• The lower space requirements and lower weights lead to morefavorable construction costs.

• Mechanical overloading is impossible. This results in higher levelsof operational reliability and lower maintenance costs.

• Lower consumption of refractory lining.• The reduced required power and lower radiation losses reducesenergy costs.

• The tire at the kiln discharge isoutside the sintering zone.

Convincing arguments for thebenefit of our customers.

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PYRORAPID® kiln

All good thingsFrom time to time, special circum-stances necessitate a kiln with agreater length to diameter ratiowhich means that a three-stationkiln is needed. The three-stationkiln from KHD Humboldt Wedagis a classic kiln which has beenthoroughly tried and tested overthe decades. Its proven standardi-zed parts are also used in thePYRORAPID® kiln. Regular optimi-zation of standardized parts leadsto even greater operational reliabi-lity and efficiency. The interactionof all components ensures theoverall problem-free continuousoperation of the kiln.

For example• optimized kilnconfigurationensures even loadand force distribution

• the low shell stresses ensures lowshell deformation and low con-sumption of refractory material

• the floating tire fastening systemensures optimal load transmissionto the rollers supported in doubleslide bearings

• the large service factor of the kilndrive ensures extremely flexibleplant operation

• the repeatedly proven kiln inletand outlet seals ensure minimumfalse air infiltration.

These kiln com-ponents, essential

for ensuring maximumavailability, are furnished

with high levels of safety andservice factors. Further informationabout these kiln components are onthe following pages.

Thermal plant with PYRORAPID® kiln

3-station-kiln

It’s what’s inside that countsIn order to ensure a long servicelife of the refractory lining, the kilnshell is optimized for minimumstress and deformation. The shellplate thickness changes with corre-sponding shell stresses, whichare determined from bending andtangential shell stress loads. Thisensures optimal safety to materialelasticity limits at operating tempe-rature. Elastic shell deformationsremain within narrow limits.

Put it all inPrecalcined raw meal is fed fromthe inlet chamber via the refractorylined and air-cooled brick retainingring into the kiln. The simultane-ously rotating scoop ring safelyreturns any hot meal backspill intothe inlet chamber.

What comes outThe outlet end of the rotary kiln isprotected by heat-resistant outletsegments. The air cooling of thislarge surface ensures long life ofthe segments. Their bracket moun-ting prevents flaring of the kilnshell. The kiln hood is supplied withmonitoring and sampling openings,connections for the burner and forthe control and measuring equip-

ment. Depending on the layout,there is a tertiary air take-off oneither the front or back side of thekiln hood. A large door openingpermits easy access to the kiln andenables the use of portable convey-ors for servicing.

We know what we’retalking about when itcomes to sealsThe high effi-ciency and lowwear rates ofKHD kiln sealsmake importantcontributions toeconomical kilnoperation. Theproven spring-loa-ded segmented seals,which were developed byKHD Humboldt Wedag, are fittedto the kiln inlet and outlet. The pres-sure elements, springs and levers,rotate with the kiln, so they can beeasily accessed at any time. KHDrotary kilns can also be suppliedwith pneumatically operated seals.Pressure is applied to the movablesuspended sealing ring by a num-ber of stationary mounted pneuma-tic cylinders.

Both types of seals are designed toensure a continuous seal despiteshifts in the position of the kiln dueto the influence of temperature andlongitudinal movement, as well asany possible "deformations" to thekiln shell. This also prevents false

air infiltration in the kiln.The pressure forces

are adjustableon either typeof seal.

The kiln inletarea with pneu-matically-opera-ted seal ...

Outlet segmentsBracketBrick retaining ringKiln tubeCooling ringKiln hoodSpring-loaded segment seal

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...or with spring-loaded segment seal.

The kiln outlet areawith spring-loadedsegment seal.

Inlet chamberBrick retaining dish, air - cooledKiln tubeConical inlet ringScoop ring, air - cooledSpring-loaded segment sealSpringLever

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contact pattern between the tireand rollers.

The sophisti-cated andthousand-fold provenKHD rollerbearingsoffer optimalreliability.They are dimen-sioned to ensurethey are not affected byany types of load resulting from va-rious operating conditions. Howe-ver, in the event that it is necessaryto straighten a bent shell of a three-

Based on a very simple principlewith nearly no weld seams:the tyre fastening.

The forged rollers and cast tireshave solid rectangular profiles.They are manufactured withoutrelief or drilled holes to ensure thatno notch stresses or stress concen-trations occur. The tires of the kilnare designed according to Niesfor maximum ovality of 0.15 to 0.2percent of the nominal kiln diame-ter. This guarantees the rigidity ofthe tires.

One special feature is the constraintfree and low-maintenance tire faste-ning system, which reliably transmitsall loads via large contact surfacesat low surface pressure from the kilnshell to the tire. This also appliesto the driving torque if the kiln ispowered by a friction drive. Thisconnection also maintains a perfect

Always up to datestation kiln during operation, thesystem is equipped to do so. The

extremely robust and solidconstruction of the be-

aring arrangement,with double slidebearing blockswhich remainaligned, is desi-gned to ensurethat the rollerstations havea centering

effect on the kiln.They absorb the re-

establishing forces ofthe distorted kiln and do

not deflect as flexible or movingbearings would. The axial for-ces are also effectively con-trolled and do not result

The pressure’s on the hydraulic thrust roller mechanism

The roller bearing

in indefinable changes to the ratioof forces. This controlled absorptionof the axial forces is easy to recog-nize at all times. It helps to preci-sely adjust the bearing position andto make any necessary correctionsduring operation. One special ad-vantage is that it offers the opportu-nity, in the event of changed linearexpansion of the kiln shell, to return

the roller to an optimal position inrelation to the tire by way of thelinear adjustment of the bearingblock.

No fear of contactIn order to ensure uniform use ofthe contact surfaces between tiresand supporting rollers, as well asthe girth gear and pinion, the axial

motion of the rotary kiln is hydrauli-cally controlled. The hydraulic thrustroller mechanism counteracts theforces which are generated bythe slope of the kiln. It operatesautomatically and is controlled bynon-contact measurement.

This is our driveThe drives for all kilns are designed for the reliable operation of the kiln underany operating conditions. This means that even greater safety factors andtorque reserve, are installed for nominal operation. All drive componentsare designed for the installed motor torque plus all safety factors andnot only for effective torque generated at nominal capacity.

The installed reserves and safety factors ensure the extremelyflexible operation of the kiln, including higher clinker throughput,without overloading the drive.

KHD Humboldt Wedag offers various types of drives for kilns opera-tion, depending on the application. We differentiate between form-fitdrives (pinion/girth gear) for all kilns with two and three stations andfriction drives (roller/ tire) for kilns with two stations.

This is where the power isThe drive units consist of the main and auxiliary drive. Variable speed AC or DC motors are used as drivemotors. The auxiliary drive is furnished with an electric motor and/or a combustion engine. In conjunction withmulti-stage or planetary gearboxes and elastic, practically maintenance-free couplings, the drives offer maximumoperational safety and outstanding efficiency.

The gear drive

Single drive with two pinions

Either single, double or triple reduc-tion gearboxes are used, dependingon the torque to be transmitted.These are the most common typesof drive for rotary kilns becausethey have a high degree of efficiencyand long-term economical design.

Nothing can shake themThe even, smooth operation of thekiln and optimal contact patternwith the pinion is achieved bymounting the girth gear on the kilnshell using tangential springs. Thecentered action of the girth gear isadjustable.

KHD Humboldt WedagGmbHColonia -Allee 351067 Cologne/GermanyPhone +49 2216504 0

ZAB Zementanlagenbau GmbH &Industrietechnik & Service GmbHBrauereistraße 1306847 Dessau/GermanyPhone +49 340 5029 0

Humboldt Wedag India Private Ltd.Espire CampusA -41, Mohan Co -op Estate,Mathura RoadNew Delhi -110044/ IndiaPhone +91114210 1100

KHD Humboldt (Shanghai)International Industries Ltd.Office Beijing Guo Ji Da Sha 25 -A19, Jiangou Menwai DajieBeijing/PR ChinaPhone +861065004101

Humboldt Wedag, Inc.400 Technology ParkwayNorcross GA 30092/USAPhone +1770 810 7315

OOO KHD Humboldt EngineeringMjasnizkaja ul., 24/7Office 108Moscow 10100/RussiaPhone +7 495 9233480

KHD Humboldt Wedag Rep.Iran Branch Office3rd Floor, No. 244Navak Building, Africa Avenue,Tehran 15186/ I.R. IranPhone +98 218888 9880

Humboldt Wedag SA (Pty) Ltd.36 Wankel Street, Jet ParkBoksburg, 1459/South AfricaPhone +27 11397 4660

Feel free to create frictionAlternatively, it’s possible to transmit the drive torque from the rollers tothe tire. This type of drive is only suitable for two station kilns. Thecharacteristics of both types of drive are listed in the adjacent table.

Hydraulic drives – acting directly or via gears on the driven shaft – alsopermit smooth kiln operation but are less efficient. This is why they arealso considerably less economical.

One special feature of the gear drive, as a single drive with two pinions,is that it can operate with only one main motor. This type of drive is oftenused to increase productivity using the existing girth gear.This variant, which was developed by KHD Humboldt Wedag, has twopositive advantages:• no additional foundation is necessary for a second drive unit• each pinion transmits precisely half of the torque

Function

Design

Efficiency

Maintenance

Gear drive (form-fit)

Transmission of loads via tyres and rollers,transmission of torque via pinions and girth gearOptimal separation of functions withoutreciprocal influenceComponents are optimised for the relevantfunctionMaximum degree of efficiency, minimumwear and tearEnsure lubrication

Roller drive (friction-fit)

Transmission of loads and torque via tyresand rollersBearing and drive function in one unit means:functional compromiseAdditional drive forces requires stronger rollerbearingsSlipping and friction result in wear and tear totyres and rollers and impair efficiencyAscertain friction values

Main motorFlexible coupling with brake drumDouble shoe brakeMain gear boxLubricating oil systemFlexible couplingPinion gearGearwheel guard

Main drive Auxiliary drive

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1 Internal combustion engineCentrifugal clutchElectrical auxiliary motorCentrifugal clutch/brakeAuxiliary gear boxFlange pumpFree -wheelFlexible coupling

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The drive components