CRUSHING
&MILLING
®
® A member of the F.L.Smidth-Fuller Engineering Group
Fuller.
Building from
Strength.
structured for
Service.
Customer Satisfaction
Cost Effectiveness
Technologicl Leadership
INTRODUCTION
F
uller is one of the largest and most comprehensive designers of
process equipment for the cement industry, with over 100 years of
experience in milling technology. Fuller’s experience includes the design
of nearly all types of mills, separators and auxiliary equipment, plus
the process design of the systems in which they are used. The Fuller
design of roller mills has evolved over many years, based on operational
experience with the harder, more abrasive materials found in certain
areas of the U.S., India, China and Korea, and the high-moisture raw
materials found in Indonesia and the Philippines. Experience with these
difficult materials has led to many refinements in the mill design,
resulting in a more reliable and efficient mill for any application.
Fuller has extensive experience in testing raw materials to determine
the correct mill selection and process design for any situation. Our
laboratory testing capabilities include a variety of standard testing, as
well as the equipment and process knowledge for pilot testing new
developments.
An 1800 kW roller mill with a 3.8mØ table installed in Mexico
grinding a hard, dry raw material.
Cover: A Fuller Roller Mill (FRM) with a 5.9mØ table and a rated
capacity of 750 tph on average raw material. 2
Vertical roller mills are widely accepted as the
most efficient means of preparing kiln feed for the
production of cement clinker. They are capable of
preparing a wide range of feed materials to the
required fineness in an energy-efficient process.
Although cement raw materials vary considerably
in grindability, drying requirements and abrasion,
the roller mill has the flexibility to be adapted to
these variations, as well as other specific site
requirements. The Fuller Roller Mill (FRM™) ranks
as one of the most technically advanced and efficient
mills available today.
The FRM system uses the friction and pressure
generated between a roller and the rotating table
to crush and grind cement raw material. Feed
material is directed onto the center of the table by
the feed chute. The rotation of the table distributes
material and passes it under the rollers. The height
of the dam ring is adjustable and sets the depth of
the grinding bed on the table. Partially ground
material spills over the dam ring into the hot gas
stream coming from the nozzle ring, and the
moisture in the material is immediately evaporated.
The finer portion of material is carried by the gas
stream to the separator while the coarser portion is
deflected directly back to the table. The separator
allows material that has reached the specified size
to leave the mill, while it rejects oversized material
and sends it back to the table for further grinding
by way of the rejects cone.
A roller mill with a 5.9mØ table operating in Indonesia
at 640 tpd and designed for 18% maximum feed moisture.
FULLER ROLLER MILL
F E AT U R E S
Roller swing-out mechanism permits
quick replacement of wear parts in a
safe, accessible position.
Table liners and tires are made from
highly wear-resistant materials and
designed for long life.
Seal bin feeder is the standard
air lock for reduced leakage
and improved reliability as
compared to a triple gate feeder.
Optional central feed point is
available for very high feed moisture.
Components are designed using
Finite Element Analysis (FEA) and
Computational Fluid Dynamics (CFD)
for high design reliability.
Four-roller design provides low roller
mass for a given capacity with
independent suspension to reduce
dynamic shocks.
External circulating lubrication system
is used to protect roller bearings and
provide filtrating and temperature
conditioning of the oil.
Low pressure drop mill design is
achieved by reducing body velocities.
Proprietary roller bearing preload
technology ensures maximum bearing
life.
High-efficiency separator design is
incorporated to easily control particle
top size to improve burn-ability of kiln
feed.
Independent roller loading system
improves operating stability.
Adjustable guide vanes on separator
control product size distribution and
provide operating flexibility.
Dual hydraulic loading system allows
mill capacity to be matched to the kiln
capacity for maximum SO2 scrubbing.
External material recirculation system
provides smooth starts, lower pressure
drop and a cleaner mill area.
One-piece tires are used as roller
wear elements for easy replacement
and reduced maintenance time.
Adjustable dam ring allows
optimization of the bed depth.
Sliding face seal on the roller protects
bearings from contamination.
Liner design permits high utilization
of wear parts.
Mill is designed by experienced
engineers utilizing the latest
computerized design tools.
Adjustable nozzle ring area adds
flexibility in air handling capability.
Mill is started smoothly without the
need for an auxiliary drive.
Components are of a proven design
and based on years of experience
with vertical roller mills.
FULLER ROLLER
Seal Bin Airlock
Material Inlet
Seal Bin
Feed Material
Pingate
Apron Feed
Spillage Conveyor
Mill Feed Chute
The Central Feed is shown in the photo above.
MILL COMPONENTS
SEPARATOR DRIVE SHAFT
MILL OUTLET
RARTM SEPARATOR
SEPARATOR
GUIDE VANES
SEPARATOR
ROTOR
FEED CHUTE
REJECTS CONE
MILL BODY
TIRE
GRINDING
ROLLER
ROCKER ARM
LEVER
ROCKER ARM
FORT
GRINDING
TABLE
MILL STAND
MAIN DRIVE
REDUCER
REJECTS
SCRAPER
ROLLER
LOADING
SYSTEM
SYSTEM
DESIGN
T
he Fuller Roller Mill (FRM) performs several functions. The FRM is a
crusher, grinder, flash dryer, material conveyor and particle separator
contained in one housing. In contrast to a ball mill system, the FRM eliminates
the need to install many separate pieces of equipment, thus minimizing
space, foundation and building requirements.
MECHANICAL RECIRCULATION
THREE-FAN SYSTEM
BYPASS OR RECIRCULATION
There are two basic system arrangements for cement raw grinding. A
three-fan system uses cyclones to dedust the mill exit gases. This
arrangement reduces the dust collector operating suction and provides
better operational control. A two-fan system uses a dust collector which
takes the mill exhaust gases directly, reducing the number of drives and
simplifying the circuit. The type of system is selected based on customer
preference and specific plant conditions; however, the three-fan system
is usually chosen due to its operational advantages.
An optional feature of an FRM system is a mechanical recirculation
system that externally conveys material which falls through the nozzle
ring back to the mill feed point. This feature allows a lower gas velocity
in the nozzle ring and a lower mill pressure drop, which ultimately reduces
the system’s power consumption, provides cleaner mill area conditions,
and improves the operational stability.
P R O C E S S F E AT U R E S
F
or classifying the final product, the Fuller Roller Mill includes
a well-proven, high-efficiency RAR™ separator. RAR technology
not only provides the highest separation efficiency available,
but also allows the steepness of the particle size distribution to
be controlled through a change in the guide vane openings.
Fuller selects the best system arrangement and process design for each plant based on over 25 years of experience in the
design and operation of more than 100 roller mill systems. As a
complete plant designer, Fuller considers all functional requirements when engineering roller mill systems. Fuller has the operating experience to optimize both the raw mill and the entire
cement manufacturing process.
The short residence time in the mill allows rapid particle size
and chemistry adjustments. This provides better product quality
control and positively affects kiln performance with a more consistent kiln feed.
The system controls for an FRM are designed to hold the operating conditions stable to maximize system performance and
product quality. The mill exit gas temperature, exit gas volume,
and inlet suction are held constant, while the mill feed rate is
controlled to hold mill loading constant, according to its pressure drop. Fuller has proven experience in roller mill control
logic, the design of required hardware and software, and the
integration of the mill system controls into the plant’s central
Sizing based on material grindability by Fuller FRM test method.
THE FULLER ROLLER MILL
Mechanical Description of the Fuller Roller Mill
Mill Support and Drive
The Fuller Roller Mill is supported by a series of independent
stands connected to form a rigid frame. Inside this frame is the gas
duct that channels gas into the nozzle ring. The hot process gases
used in drying and conveying the material in the mill are directed
from the kiln process into the gas duct and nozzle ring. The mill
stands support the majority of the mill weight and transmit the
roller forces to the foundation.
The standard main drive reducer includes bevel/planetary rightangle gearing which transmits the grinding power at a high efficiency It includes a thrust bearing specifically designed to support
the grinding loads that are transmitted through the table.
Grinding Elements
The grinding table consists of a large casting with provisions for
attaching wear liners, dam ring, and reject scrapers. The dam ring
can be easily adjusted to set the grinding bed at its optimum level.
The grinding rollers are evenly spaced around the grinding table.
The rollers consist of a hub with a one-piece wear liner that rotates
on a stationary shaft and is supported by roller bearings. The roller
Pictured above are
the finite element stress analysis
results obtained from a grinding
table composed of solid parabolic
elements. The model was loaded
with theoretical loads and
compared to field data to verify
the design technique and results.
The world’s largest grinding table (6mØ), installed in Indonesia.
hub has been designed to enhance the life
of the roller bearings, using Finite Element
Analysis (FEA) to determine the placement
of the bearings, and select the optimum
bearing size and preload.
The forged roller shaft is connected to
the rocker arm with tapered surfaces that
allow easy installation and removal.
The roller shaft’s design permits access
for the bearing circulation lubrication system
and the maintenance of the roller oil level.
The oil is continuously conditioned by
filtration and cooling, and is then supplied
to the grinding roller bearings by a
lubrication pumping unit mounted near the
mill. The roller lubrication oil is sealed by a
sliding face seal designed specifically for
harsh environments.
The rocker arm holds the roller shaft, transmits the grinding forces
from the loading system to the roller, and pivots in a set of antifriction bearings to accommodate changes in bed depth. The rocker
arm assembly’s lever and fork can be separated for roller swing
out which aids when servicing the rollers. The rocker arm bearings
and thrust plates are lubricated by an automatic grease system.
Pictured are results from a
model analysis of a rocker arm and
roller with a simulated roller loading
system. The model was used to determine the natural frequency of the system, which is used as input to a System Dynamics Model to predict the
unit’s response to grinding bed excitations and to determine bearing loads.
Loading System
The rocker arm is connected to a hydraulic cylinder via a spring
rod, clamping nut, and spherical bearings. To ensure long life, the
spherical bearings receive lubrication from the automatic grease
system. The hydraulic cylinder is pressurized by a hydraulic-pneumatic loading system which controls the grinding force.
Roller loading system with accumulator allows smooth
operation while keeping constant force on material bed.
The loading system maintains a uniform
grinding force while allowing the roller to follow
the grinding bed. This system consists of hydraulic
cylinders, pump, accumulators, valves and a
control circuit. The hydraulic-pneumatic spring unit
has an intermittent running pump to keep the
grinding pressure within a specified range.
As the roller follows the profile of the grinding
bed, hydraulic fluid is exchanged between the
cylinder and the accumulators. The compressed
accumulator gases absorb shock in the hydraulic
system to make the mill operation smooth. The
grinding system is designed with sufficient
accumulator volume so that the grinding pressure
remains relatively constant as the roller moves.
The ample sizing and operating pressures of these
accumulators enable the Fuller Roller Mill to
operate with low vibrations and long cylinder and
spring rod life. The position of the rollers is
monitored during operation and, if the rollers
travel too close to the table, the roller loading
system lifts them to avoid contact. When the rollers
are raised, the grinding pressure is stored in the
accumulators and maintained by the spring unitto quickly achieve stable operation upon startup
(usually within one minute). The roller position is
also monitored in the raised position to ensure
that they remain above the table.
selected to give long operating life and
designed for low scrap loss.
The rocker arm’s design allows the roller to
be swung out of the mill for easy replacement
of the roller liner. To swing the roller, the mill’s
body covers are removed, the lever is
disconnected from the fork, and a hydraulic
cylinder is used to pull the roller out of the mill.
An experienced crew can change a complete
set of tires and table liners in one day.
Maintenance
The Fuller Roller Mill is designed for easy
maintenance. The components of all auxiliary
systems are located in convenient, accessible
areas near the mill. The liner materials are
Simple replacement of grinding parts is achieved by
rotating rollers out of the mill using the swing-out cylinder.
Mill Housing and Auxiliaries
Drying and material transport are performed by hot gases
entering the mill gas inlet and flowing through the nozzle ring
located around the perimeter of the table. The nozzle ring is
designed to direct and increase the velocity of the gases for efficient
material transport. The nozzle ring can be easily adjusted to finetune mill performance and pressure loss. A portion of the material
passes through the nozzle ring and exits the mill via chutes. The
material is then transported back to the mill inlet by the mechanical
recirculation system.
The material-laden gases rise within the mill body until they
reach the separator. The mill body is constructed with wear-resistant
liners. Its access door allows for easy inspection of mill internals.
Mill feed is supplied by a totally enclosed, variable-speed apron
feeder that operates in conjunction with a material bin to provide
an air seal. This arrangement has been proven as an efficient air
lock which requires little maintenance. An optional triple gate
feeder is also available.
A 2500 kW roller mill being installed in the Philippines grinds 300
tph of raw material with 15% feed moisture 4.8mØ table.
The RAR™ Separator
The RAR is a high-efficiency separator designed
to control the fineness of the material leaving the
mill. The separator’s design includes a variablespeed motor so that the fineness can be controlled
by remotely varying the rotor speed. The rotor is
suspended within the separator by an oil- or
grease-lubricated bearing cartridge. Guide vanes
swirl the gases and material as they enter the separation zone. Beneath the rotor, a collection cone
directs rejected material to the center of the grinding table jor further grinding. Both the high-efficiency RAR and/or the standard separator can be
supplied for side feed or central feed. A central
feed option is available which can greatly reduce
the plugging problems caused by very wet feed.
The feed travels directly down through the separator shaft to the center of the table.
Summary
Since the roller mill was first introduced to the
cement industry, system capacity has continued to
increase and milling technology has continued to
evolve. The. Fuller Roller Mill incorporates the best
available technology to meet today’s operational
demands. Tomorrow, when larger and even more
efficient milling systems will be required, Fuller’s
design experience, product quality, and customer
commitment will be able to set the pace and meet
new challenges.
Pictured above is a Computational
Fluid Dynamics (CFD) model of a mill body
with the particle and air interaction fully
coupled. The CFD models are used to determine gas velocities, pressures, flow characteristics and particle trajectories in the
Fuller Roller Mill in order to reduce pressure drop, improve material transport, increase separation efficiency and reduce
wear of mill components.
WORLDWIDE OFFICES
HEADQUARTERS
Fuller Company
2040 Avenue C
Bethlehem, PA 18017-2188 USA
Tel: (610) 264-6011
Toll Free: (800) 523-9482
FAX: (610) 264-6170
Telex : 173189
http: //www.fuI lerco.corn
U.S. SALES OFFICES
Fuller Company
Eastern District Sales Office
2040 Avenue C
Bethlehem, PA 18017-2188
Tel: (610) 264-6764
FAX: (610) 264-6293
Fuller Company
Midwest District Sales Office
907 North Elm Street, Suite 203
Hinsdale.IL 60521
Tel: (630) 323-6390
FAX: (630) 323-6483
Fuller Company
Southwestern District Sales Office
11777 Kaly Freeway
Suite 375 North
Houston. TX 77079
Tel: (281) 752-0222
FAX: (281) 752-0111
Fuller Company
Western District Sales Office
16 Mifchell Boulevard
Son Rafoel, CA 94903
Tel: (415) 499-0695
FAX: (415) 499-0698
INTERNATIONAL OFFICES
INDONESIA
BRAZIL
PT Fuller International Indonesia
F.L.Smidth Comércio e Indústria Ltda. Gedung BRII, Suite 2101
Rua Nebraska, 443
Jl. Jenderal Sudirmon 44-46
Brooklin Poulista-CEP 04560
Jakarta 10210
Caixa Postal 3506
Tel: +62-21-251-2738/2739
01051 SáoPaulo-SP
FAX: +62-21-571-3354
Tel: +55-11-532-8500
ITALY
FAX: +55-11-533-9612
F.L.Smidth & C. Italiana S.r.L
CANADA
Via G. Marconi, 20
Valbrembo Bergamo
Fuller-F.L.Smidth Cement Limited
10 Thornmount Drive
Postal address:
Scarborough, Ontario M1B 3J4
P.O. Box 143
Tel: (416) 284-8200
1-24100 Bergamo
FAX: (416) 284-8348
Tel: +39-35-46-8311
FAX: +39-35-46-0838
DENMARK
JAPAN
F.L.Smidth & Co. A/S
F.L. Smidth & Co. Japan Ltd.
77 Vigerslev Allé
Shibakoen Ridge Bldg. 6F
DK-2500 Valby
1-8-21 Shibakoen Minato-Ku
Copenhagen
Tokyo 105
Tel: +45-36-18 1000
Tel. : +81-3-3578-0541
FAX: +45-36-30 1820
Fax : +81-3-3578-0548
http://www.flsmidth.com
FRANCE
F.L.Smidth-Fuller S.A.
2/4 rue Vincent van Gogh
F-93364 Neuilly-Plaisance Cédex
Tel: +33-1-4944-6800
FAX: +33-14308-5099/5188
GERMANY
F.L.Smidth-Fuller GmbH
Am Seestern 8
40547 Düsseldorf
Tel: +49-211-591-038
FAX: +49-211-593-223
INDIA
Fuller India Limited
Capital Towers
18U, Kodambakkam High Road
Nungambakkam, Chennai 600 034
Tel: +91-44-827-630/6343/9569
FAX: +91-44-827-9393
KOREA
Fuller International, Inc.
Independent Sales Office
Mace Company
502 Eunyang BIdg. 1582-3
Seocho-Dong Seochu-Ku
Seoul, 137-073
Tel: +82-2-587-8672
FAX: +82-2-587-4976
MEXICO
F.L.Smidth-Fuller Mexico, S.A. de C.V.
Ediricio F.L.S.
San Alberto #406
Residencial Santa Barbara
Gorza Garcia, N.L 66260
Tel : +52-836-33150
FAX : +52-836-33421
PAKISTAN
FLS Pakistan (Pvt.) Ltd.
House 189, Street 69
Sector F 10/3, Islamabad
Tel: +92-5129-3195
FAX: +92-5129-3196
P.R. OF CHINA
F.L.Smidth & Co. A/S
Beijing Representative Office
East Lake Office Building,
5th Floor
35 Dong Zhi Men Woi Do Jie
Beijing 100027
Tel: +86-106-4677070
FAX: +86-106-4677071
PHILIPPINES
F.L.Smidth & Co. A/S
Manila Representative Office
8 Jerusalem St., Mervilte,
Parañaque
1700 Metro Manila
Tel: +63-2-824-7676
FAX: +63-2-824-7676
THAILAND
Mr. Per Mejnert Kristensen
c/o Mitsiam International Limited
15th & 16th Floor,
Sathorn City Tower
175 South Sathorn Road
Tungmahamek
Sathorn Bangkok 10120
Postal address :
P.O. Box 870
Tel : +66-2-285-1020
Fax : +66-2-285-1968
TURKEY
F.L.Smidth & Co. A/S
Liaison Office
c/o Trakmak Traktör ve
Makine Ticaret Ltd.
Sirketi
Ismet Inönü Cad.
Mithat Pasa Han. 92-94
80090 Gumüssüyu, Istanbul
Tel: +90-212-251-1331
FAX: +90-212-249-1660
UNITED KINGDOM
SOUTH AFRICA
F.LSmidth-Fuller Ltd.
F.L.Smidth & Co.(Pty) Ltd.
Constantia Pork Lakeview House 17. Lonsdowne Road
Croydon, CR9 2JT
corner of Hendrik Potgieter &
Tel: +44-181-686-2422
14th Avenue
FAX: +44-181-681-7229
Constantia Kloof
Roodepoort
Postal address:
P.O. Box 5073
WeltevredenPark1715
Tel: +27-11-470-9700
FAX: +27-11-475-7665
SPAIN
F.L.Smidrh-Fuller &
Cio Española, S.A.
Carretera de La Coruña,
km. 17,8
E-28230 Las Rozas (Madrid)
Tel: +34-1-634-9000
FAX: +34-1-636-1150
Data in this brochure is intented for preliminary project planning only.
The Manufacturer reserves the right to modify equipment details and/or specifications without notice.