Your efficient partner for modern and effective bulk material handling

PLANT DESIGN - ENGINEERING - EPC-CONTRACTING

� + 49 (0)40 36 13 090 info@ibauhamburg.dewww.ibauhamburg.de

I BAU HAMBURG

CEMENT - THERMAL POWER - MINERALS

Single silos. Ring silos.

Multicompart-ment silos. From 2 to

22 chambers,diameters:

14 to 27 m.

Advanced technology for

self-discharging Cement Carriers

including the Midship tunnel.

Marine Cement Terminals

Central Cone Silos EPC-Contracting

Silo Conversions

Components

Spare Parts

Cement Carriers

Ship Unloaders

Floating terminals.

Mini terminals.Silo systems.

Dome systems.Flat storage

terminals.

Stationary ormobile types:

From the5,000 class

up to the60,000 class.

Piling. Civil works. Steel structure, supply/erection. Electrical/mechanical supply and erection.

Economic modifications with advanced cutting-edge technology.

The key for a well functioning plant: Components, all made to measure.

High stock availability:Just-in-time supply of spare parts.After-sales Service.

I BAU HAMBURG

I BAU HAMBURGMulti-Compartment Silos

Compact Terminalsfor the Cement Industry

A HAVER & BOECKER CompanyZ/1

2/15

/Mul

ti-C

ompa

rtm

ent

Silo

s

3

Information

2

Multi-Compartment Silos with Central Cone

SPENNER ZEMENT Multi-compartment silo with 15 compartments, silo diameter 20,0 m for Spenner Zement, Erwitte Works, Germany

Multi-compartment silos evolved from single cell and ring silo references dated Jan. 2008

Dyckerhoff Mark IIZementwerk Lauffen

CBR HarmigniesHolcim (Espana)

Carboneras

Johann Schäfer KalkwerkeNatal Portland Cement

Atlacim, Maroc

RohrbachDotternhausen

LafargeKarsdorf

Spenner ZementGermany

Andre Büechl

ZementwerkBerlin

TCEC/USCC TaiwanDyckerhoff Mark II

Hornos Ibéricos Alba, S.A.Unicem Vernasca

Diamond Cement DamohRKW Wülfrath Schwelgern

Italcementi SalernoPolysius AG Cape Portland

Bateman LTD. LethaboItalcementi Vibo Valencia

Schencking KG LienenPanUnited Singapore

Ciments Français Bussac

Perlmooser MannersdorfTaiwan Cement NankangKedah Cement Langkawi

Yura S.A.Tasek Cement

Asia Cement SingaporeKedah Cement Johor Port2 x Dyckerhoff LengerichUnited Cement PTE LTDAlsen Breitenburg, Hansa

Bremen

Unicem VernascaItalcementi Vibo Valencia

Cementeria Adriatico PescaraPerlmooser Mannersdorf

Ciments de la Loire,Villiers au Bouin

KRC Umwelttechnik, WalheimItalcementi Salerno

Ciments Français BeaucaireTaiwan Cement Nankang

Uniland Los Monjos

Castle Cement ClitheroeKedah Cement Port Prai

Cementos LemonaHOLCIM (France) S.A.,

DunkerqueCham Pha Cement Plant

Usine de MarakechCementos Occidentales

Cementval S.L.United Cement Pte. Ltd.

Heidelberg SchelklingenAnneliese Zementwerke

Cimento ItambeCimento Rio Branco

Dyckerhoff AmöneburgAlpha Cement

2 x Ciments Vicat MontalieuDeuna Cement

Readymix DortmundENCI MaastrichtCCB Ramecroix

CBR Lixhe

Central Cone Ring Silo

Groupe Obourg OrignyUsine Lumbres

DyckerhoffLengerich

CBR Cement, GentDyckerhoff Neuwied

Cimento MinasVotorantim Cimentos

Juan Minetti S.A.

AZE Mühendislik,Müsavirlik ve Ticaret

BelapatfalvaDenizli Cimento

Karcim S.A.Italcementi Collefero

2 x Rajashree Cement2 x Grasim Cement

ENCI Maastricht

Ciments LuxembourgeoisCiments d’Origny

AltkirchCBR Lixhe

Phoenix CementCementos Chihuahua

Heidelberg Schelklingen3 x Alamo Cement

Rüdersdorfer CementHeidelberg MoldanCementos Caribe

Holcim (Espana) Carboneras

2 x La Cemento Nacional2 x Ciments LuxembourgeoisDyckerhoff Mark II / Geseke

Dyckerhoff AmöneburgUnicem Vernasca

Cementownia NowinyCementos Hispania SA. Yeles

Many Thousands of IBAU Silos

CBR Gent

Central Cone Silo

5

Information

4

shape, which also hasstatic-structural advan-tages, is used from theprocess engineering pointof view, because itforms a slip surface anddisplaces the bulkmaterial outwards in agravity-induced flow.

The annular fluidizingbase at the foot of thecone together with theoptimum span widthsallow for the fluidizationof the bulk material overthe full surface. Bulkflows of 3 to 500 t/h can be controlled andextracted absolutely continuously from thesesections.

If the outer ring silo isnot divided into compart-ments, the flow-controlgates positioned along acircular base line areopened individually inturn or simultaneously tosuit the level of thebulk flow. The geometryof the silo floor,the arrangement of theextraction openingsat the foot of the inclinedconical slip surface anda variable level offluidization of the bulkmaterial enable the massflow of the bulk material.

In many ways the undi-vided silo with a centralcone already fulfils theseconditions, so additionalpressure-relievinginternal chambers withconnected venting sys-tems are not needed inmulti-compartment silosof this basic design.It is possible to derivevery different compart-ment cross-sections fromthe circular shape of thesilo to suit the flow cha-Fig. 2: Ring silo

Multi-Compartment Silos with Central Cone

1. Introduction

Intensive developmentduring the last few deca-des in the field of silotechnology has producedpneumatic emptying andblending systems whichprovide reliable storageand good homogenizationof the powdered bulkmaterials.

Changes in the productionof binders and fillers, forexample by grinding themixing components sepa-rately or utilizing wastematerials, fly ash, etc.,have had an effect on silotechnology, the prepara-tion of the bulk materialsand ultimately the dis-patch technology.

The concentration of storage, blending and dispatch for a greatlyincreased number of bulkmaterials, intergroundadditives and mixed products has eventuallyled to the concept of amulti-compartment, high-capacity silo systemwith integral positivemixer and dispatch station.

2. Design and processtechnology ofmulti-compartment silos

The internal compartmentdivisions result in clearexternal diameters of 14to 27 metres, recognizableoutwardly as cylindricalsilo units. The base of theentire silo floor is formedby the central cone whichhas proved its worth overmany years in single-cell,cylindrical silos (Fig. 1)and ring silos (Fig. 2).The cantilevered conicalFig. 1: Central cone silo

7

Information

6

Multi-Compartment Silos with Central Cone

Fig. 5: Ring silo with ring compartment subdivided into 8 sections, and one inner silo cellFig. 3: 4-chamber Central cone silo Fig. 4: 5-chamber Central cone silo

9

Information

8

Multi-Compartment Silos with Central Cone

cement, limestone meal,fly ash, etc. are only flu-idized to a limited extenton part of the silo basezone so that the restrictedoutlet cross-sectionsachieve air saturation ofthe mixture with verylow extraction quantitiesand sharply reduced per-centages of air. A self-regulating air overflowsystem which depends onthe set pressure is inoperation under theseconditions; this reducesthe air supply in therespective fluidizing sec-tion without changing thestate of fluidization.

The utilization of spacein the compartments isvirtually 100 % becauseof their comparativelysmall horizontal dimen-sions, thus plannedchanges of the type ofmaterial cause no problems. The samegeometrical conditionsand the intermittentextraction operationwhich normally occur,result in mass flowswith turbulent mixingwhich further improvesthe quality of the bulkmaterial.

3. Separation andmixing of typesof material and thedispatch system

Measures to keep thetypes separated apply tothe silo and compartmentfeeding system andto the interconnectedconveyors below the silocompartments. Pneumaticconveying systemswith pipes are preferredfor providing absolutelyresidue-free silo feeding

racteristic of fluidizablebulk materials. Fig. 4, forinstance, shows a centralcone silo with 5 compart-ments. Appropriate back-filling and secondaryslopes at the base areused to avoid trappingthe bulk material atacute-angled walljunctions which canoccur in the central silocompartments.

In Fig. 5 a ring silodesign with a central siloand 8 outer compart-ments can be seen. Fig. 6shows a different subdi-vision of the ring silocross-section with 5 compartments in thecentral silo.

The multicompartmentsilo shown in Fig. 7 isparticularly interesting.In the upper level thereare fairly large storagecompartments, i.e. 1 central silo and 6 ringcompartments, and in the lower level there are12 multi-purpose com-partments for mixedcomponents and finishedproducts.

These conditions forcontinuity were achievedboth for bulk flowsgreater than 100 t/h andfor very small flows ofless than 10 t/h. Variousrecipes for the mixedproducts which are madeup in weighing hoppersabove the positive mixerrequire correspondinglylow fine flows which areextracted and meteredby the flow-control gatesat the discharge boxes.

Under these fluidizingconditions bulk materialssuch as various types of Fig. 6: Ring silo with inner silo subdivided into 5 sections Multi-compartment ring silo during construction

11

Information

10

Multi-Compartment Silos with Central Cone

systems, especially whenseveral, chemically verydifferent bulk materialshave to pass through onetransport line in turn.

High levels of wearmake it necessary to payattention in this tech-nology to wear-resistantsealing of the conveyingdiverter. Conveyingcombinations consistingof airslides and bucketelevators or verticalpneumatic conveyorsoffer energy-saving andvirtually wear-freesolutions; here again it isimportant to seal thediverting elements andthe problem was solvedby using solid designs.

Airslides are always themost suitable means oftransport for the general-ly short interconnectingconveyors below the silocompartments. Operationof the exhaust air filtra-tion system can only becombined where thereare compatible bulkmaterials.

Otherwise decentralizedfilter installations anddust return systems are needed for the entireplant for the sake ofquality assurance.

The production of adiversity of mixedproducts has also set newtrends. Separate grindingor the use of furtherinterground additives aswell as the adaptation ofthe production processhave lead to the integra-tion of a mixing stationinto the multi-compart-ment silo plant. Recipeswhich have been checkedand combined by weigh- Material transport after mixer via I BAU Pump

Batch-type mixer with toggle lever system

Fig. 7: Ring silo (mixing system) with 7 + 12 = 19 compartments

ing hoppers are mixed inbatches in a “single shaftmixer” (Fig. 8) in theshortest possible time toform a homogenousmass. The mixer iscompactly designed, hasa trough lined withwearing tiles and a lowenergy consumption andruns extremely quietly.

Depending on the plantdesign the mixedproducts can either betransferred directly to thedispatch system orconveyed to silo com-partments provided forthe purpose (Fig. 9).

The cantilevered designof the multi-compartmentsilos ensures a generoushousing space and accessfor all the equipment andmachines for operatingthe system.

The silo cells and hencethe silo floors are normally elevated fortwo reasons: Firstly, theextraction devices andthe necessary mechanicalequipment have to behoused under the cellsand, secondly, direct lorryor rail loading is usuallyan objective to eliminateadditional transportand loading points, thusvehicle access isprovided under the silo.

The systems are veryextensively automatedand are fitted withprotective circuits andelectronic monitoringadapted to the require-ments of the operator.

13

InformationMulti-Compartment Silos with Central Cone

12

Multi-compartment silo with 6 compartments, silo diameter 26,0 m for Cementa AB HeidelbergCement Group, Malmö Sweden

15

Information

14

Multi-Compartment Silos with Central Cone

2 Multi-compartment ring silos with 2 compartments each, silo diameter 26,3 m and 24,2 mfor Pan United, Singapore

Multi-compartment silo with 5 compartments, silo diameter 28,0 m for Hatien I Cement Company, Ho Chi Minh City, Vietnam

17

Information

16

Multi-compartment silo with 7 compartments, silo diameter 21,0 m for Holcim France, Val de Seine Works, France

Multi-compartment silo with 11 compartments, silo diameter 24,0 mfor Zementwerke Berlin, Berlin, Germany

Multi-Compartment Silos with Central Cone

19

Information

18

Multi-Compartment Silos with Central Cone

Silo conversion into a multi-compartment silo with 5 compartments, silo diameter 16,0 mfor Holcim, Untervaz, Switzerland

Multi-compartment silo with 13 compartments, silo diameter 24,0 m for Lafarge Zement, Karsdorf Works, Germany