4 -Description of Plant
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HAPTER 4 DESCRIPTION OF PLANT
4.1 General Description of Process
4.1.1 Limestone Crushing & Transportation
Limestone taken from quarry is transported via dump trucks toconcrete feeding hopper, and then transported to hammer crusherwith a rated capacity of 1500t/h by variable speed apron feeder(1600tph). The crushed limestone which is less than 70 mm (95%) istransported by long belt conveyors to pre-blending yard. A cranebeam is equipped for crusher overhaul.
4.1.2 Limestone Preblending
Limestone from the crushing department is transported via beltconveyor into plant site and is stored in a longitudinal preblendingbed. The stacking capacity is 1500tph and reclaiming capacity is 900tph. Longitudinal preblending bed reserves 2x35000t. Steel roof isconstructed to against dust and rain.
4.1.3 Clay, Coal, Bauxite and Laterite Crushing and Transportation
Clay, coal, bauxite and laterite taken from their quarries are fed intoconcrete feeding hopper respectively by dump trucks and thentransported into their crusher for crushing. Clay crusher Capacity is400tph with variable speed apron feeders(400tph). The crushedmaterials, which are less than 80mm (90%), are transported by beltconveyors to the pre-blending yard.
4.1.4 Clay, Coal, Bauxite and Laterite Preblending and Storage
Clay, coal, bauxite and laterite from the crushing departments aretransported via belt conveyors into the plant site and stored in twolongitudinal preblending bed. Materiel reserve will be decidedaccording to blend proportion. Steel roof is constructed to againstdust and rain.
4.1.5 Raw Material Regulation and Transportation
Four bins are set in the raw materials proportioning stationrespectively for limestone, clay, bauxite and laterite. Each material isdischarged from bin via weighing feeder (Schenck China) accordingto certain proportion, and then fed into roller mill via belt conveyor
(VVVF).
4.1.6 Raw Material Grinding & EGT
A vertical roller mill from European (Loesche, F.L. Smith, atox,Pfeiffer or plusius) is proposed to use for drying and grinding of rawmaterials. Under the condition that 1) feeding size 80 mm (95%),2) feeding material moisture 6%, and 3) the residue of raw meal on90m< 12%; the output of the mill reaches 430+3.49%t/h. The
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grinded material is collected by cyclones and sent to the raw mealsilo via air slide and bucket elevator (Aumund). Part of exhaust gasout of the mill will be drafted back to mill for circulation, the rest willbe dedusted by E.P.
Part of the waste gas from the condition tower will be drafted to the
mill for raw material drying, the rest will go into E.P.
Raw mill Fan and Raw mill EP fan (VVVF) will be Venti/SolyventEruopean origin.
4.1.7 Raw Meal Silo & Kiln Feeding System
A raw meal homogenizing silo (IBAU type) of 22.5 x62m (22000t) isbuilt for raw meal homogenizing. Raw meal extracted from the silo istransported to a standard bin which is equipped with flow controlvalves and motor controlled valve. Then the raw meal that is takenout of the bin through the valves and weighed by the impacting flowmeter will be conveyed to the inlet duct of the first stage cyclones ofthe preheater via air slide and bucket elevator (Aumund).
4.1.8 Clinker Burning System
The clinker burning system is mainly composed of a low pressuredrop 5-stage double string suspension preheater and a TSD
precalciner, a tertiary air duct, a rotary kiln of 4.872m and a third
generation grate cooler. At the outlet of the grate cooler, there is ahammer crusher. Its designed production capacity is 5700+6.14%t/dclinker. Heat consumption of the burning system is700Kcal/kg.clinker(coal), 710Kcal/kg.clinker(Oil),725Kcal/kg.clinker(Natural Gas) respectively.
Refractory bricks for kiln burning zone will be Europe origin. Burnersof kiln and precalciner will be European origin, Multiply burners (coal,gas and oil) will be used.
The Raw meal is sent to the gas riser duct between the stage C1 andC2 by bucket elevator(Aumund) and air slide. TCDRIs preheaterwith its new generation of cyclones have a very high efficient heatexchange rate and low-pressure drop. The decarbonation degree ofthe raw meal at inlet of kiln is up to about 90%. The clinker from therotary kiln is cooled by grate- cooler and crushed by the clinkercrusher. The temperature of the clinker at outlet of the cooler is about
65C plus ambient temperature. The cooled clinker is transported to
the clinker shed by pan conveyor with weighing scale.
A passenger lift will be installed for going up and down the preheater.
Cooler EP Fan (VVVF) and kiln ID Fan (VVVF) will be Venti/SolyventEruopean origin.
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4.1.9 Clinker Storage and Transportation
A circular shed (appox.90m, 100000t, 20days) is used for clinkerstorage.
Clinker is discharged from the silo bottom by arc valves, and then
transported to the dosing silo via belt conveyor.In keeping view of unburned clinker, an unburned clinker silo withcapacity of 1000tons is considered.
4.1.10 Gypsum Crushing and Transportation
Gypsum is transported to plant by trucks and stored in open yard, fedto the feeding hopper by wheel loader. A hammer crusher of 70t/h isused for gypsum crushing, and crushed material will be sent tocement proportioning bin.
4.1.11 Proportioning Station For Cement GrindingThree silos are set in the cement proportioning station respectivelyfor clinker Additive and gypsum. Each material is discharged from silovia weighing feeder (Schenck China) according to certain proportion,and then fed into cement mill via belt conveyor and bucket elevator.
4.1.12 Cement Grinding (2150t/h, 3200cm2/g)
Two sets of closed circuit tube mill (2-4.213, 2x150t/h) with roller
press will be used for cement grinding.
Pressed material together with blending material is fed to V-separator. After separation the coarse material goes to the rollerpress and the fine material goes to the cyclone separator then to themill.
Material after grinding is introduced to an O-SEPA separator forclassifying. The coarse material recycled into the mill for regrindingwhile the fine product is collected by bag filter and sent to cementsilos by air slides and bucket elevators (Aumund).
Cement mill system Fan will be Venti/Solyvent Eruopean origin.
4.1.13 Cement Silo & Transportation
Four circular silos (18x44.5 m, 11700tx4) are used for cement
storage.
4.1.14 Cement Packing & Dispatching
Six sets of cement packer (8-spout rotary packer, 6x100t/h) will befitted in the packing plant building.
4.1.15 Coal Grinding
A vertical roller mill From European (Loesche, F.L. Smith, atox,
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Pfeiffer or plusius) is proposed for drying and grinding of coal. Underthe condition that 1) feeding size
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5 Low Voltage (LV) Distribution : 415V, 3 Phase+PE
6 LV Motors400V, 3 Phase+PE,(P
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In order to reduce power transmission losses and to save capacity oftransformers, cables, etc., the compensation equipment shall bedesigned to apply directly at the source.
The capacitors are used to compensate for the reactive power of themain transformer.
The large constant speed motors equal to or above 400kW shall beequipped with adequately sized individual capacitor banks connectedto the motor feeder.
The LV main distribution boards shall be equipped self-adjustablereactive power compensation. Corresponding capacitors banks shallbe located in the separated cabinet.
The improved power factor shall be over 0.95
4.2.1.6 Protection and Measurement
The comprehensive protection devices have following functions:
1 6.3kV incoming line protection: three phase timing over current,over current trip, single-phase earthling.
2 Main transformer protection: differential protection, timing overcurrent, over current trip, overload, gas and temperatureprotection, single-phase earthling.
3 6.3kV incoming line protection: three phase timing over current,over current trip, single-phase earthling.
4 6.3kV motor protection: inverse over current, over current trip,under voltage and single-phase earthling.
5 Capacitor compensator protection: three phase over current trip.
6 The protection system will be SIEMENS / ABB make.7 Medium voltage protection will be preferably MRM make SEGGermany
4.2.1.7 Emergency Power
800kW/415VAC/50Hz emergency power supply shall be fed to coolerelectrical room for safety of the equipment during a power failure.
4.2.1.8 LV distribution
The low voltage power distribution shall comprise the following basic
equipment:8 Incoming circuit breaker with protective relaying9 Outgoing feeders for capacitor banks10 Outlets for auxiliary power distribution (i.e. lighting)11 Outgoing feeder to cranes12 Outgoing feeder to welding power switch13 Spare outlets for future use
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The panels shall be of a strong steel construction, metal enclosed,free standing. The protection degree shall be IP40.
4.2.1.8.1 LV Distribution Electrical Room and Motor Control Centers (MCC)
The electrical rooms are as follows:
Limestone crushing electrical room
Power supply scope:
14 Limestone crushing
Limestone storage & reclaiming
Clay, Coal, Bauxite and Laterite Crushing
Power supply scope:
Clay, Coal, Bauxite and Laterite Crushing
Auxiliary material preblending
Raw coal Preblending
Raw material proportioning
Power supply scope:
Raw material proportioning hoppers
Raw material grinding electrical room
Power supply scope:
Raw material grinding
Exhaust gas treatment
Top of raw meal silos
Pre-heater electrical room
Power supply scope:
Bottom of raw meal silos
Raw meal feeding system
Pre-heater
Kiln
Compressor air station
Central control room (spare power supply)
Kiln cooler electrical room
Power supply scope:
Cooler
Central control room
Top of clinker storage
Coal grinding electrical room
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Power supply scope:
Coal grinding
Cement grinding electrical room
Power supply scope:
Cement grindings
Bottom of clinker storage
Top of Cement Silo
Gypsum crushing
Packing plant
Cement packing
Bottom of cement silos
Bulk cement loading for truck
4.2.1.8.2 MCC Control Signals
15 Protective motor interlocking is hard wired to the main contactor16All other interlocking are realized by means of the PLC17All signals are collected at the module18 Basic Signals Circuit breaker status, voltage and overload control DI; Main contactor status DI; Start command DO; Local start command DI;
Local stop command DI;
4.2.1.8.3 Local Control Switch Box
All push/ pull buttons for process motors, valves, dampers, gates,solenoids etc. will be located near the field equipment for local controlof equipment. Emergency stop will be arranged for MV motors.
Push buttons for start/stop, position, etc., shall be clearly andpermanently marked, equal in whole plant.
The degree of protection for local control box is IP54.
4.2.1.9 Motor
1) Motor selection and starting
Motors with a power capacity of equal and above 250 kW will adopt6.3kV, below 250 kW will be 415V. According to start-up condition, thewound rotor winding motor and squirrel-cage motor should beadopted. MV motor will be ABB/SIEMENS make and comply with IECstandard. MV motors will be totally enclosed, dust proof, with forced
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cooling and air to air-cooling type having Insulation class F &protection class IP 54. The accessories such as winding temperaturemonitoring , bearing temperature monitoring , anti-condensationheater are included for MV motors.
Liquid Starter for the MV motors will be of European origin equipped
with temperature limit observation devices, liquid level detector andautomatic setting range limiting; the squirrel-cage motor less than75kW will be directly started under rate-voltage; the LV motor equaland above 75kW shall be started by soft starter.
2) Speed regulation motor and its control
Large drives will be MV frequency drives. All the variable drives willbe Master Drives (Victor Control) Siemens Germany make.Motors for larger variable speed drives & kiln drive will be ABB /Siemens make. Input Reactor & Output Reactor for > 100 Kilowatt
rating will be incorporated in the drive. Drive of Classifier will beequipped with Brake Resistors.For larger drives like Pre-heater ID Fan drive and Kiln DC drive etc.separate (isolate ) transformer will be used.
3) The basic technical specification
severe duty, continuous maximum running duty of S1 in accordance withIEC 34
motor insulation shall be Class F, with temperature rise limited to ClassB
(80 oC), in accordance with IEC 85The terminal box shall be IP54, equipped with feeder cable glands with
grounding conductor.For motors rated 500 kW and above: 6 x PT100.Degree of Protection for MV motor is IP54Degree of Protection for LV motor is IP54
4.2.1.10 Cabling
4.2.1.10.1 Cable installation
Cable installation is on cable trays.
Power and signal cables on the cable trays will be separated.
Cable tray constructions, supports etc., will be hot dip galvanized.
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4.2.1.10.2 Cable types
The main characteristics of the cable are indicated below:
General data (MV cable)
Type Multi-core screen
Rated voltage 6kVInsulation XLPE
Minimum section power circuits 50 mm2
Conductor Copper General data (LV cable)
Type 0,6/1 kV multicoreRated voltage 0,6/1 kV
Insulation PVC
Minimum section for power circuits 1,5 mm2
Minimum section for auxiliarycircuits
1,5 mm2
Minimum section for control circuits 1,0 mm2
Conductor Copper
The cable laying outdoors within the plant is done by cable tray. Thelaying of cable trays may go along the process pipeline or beltconveyor corridor to save investment.
4.2.1.11 Thunder Protection and Earthing
The thunder and earthing protection of this project is done accordingto the regulations of the state thunder protection.
All the earthing units for the whole plant shall be connected into anearthing network by copper flat strip or copper conductor. Doubleearthing of all the electrical equipment (transformers, panels, motors)will be done.
4.2.1.12 Lighting System
Lighting intensity levels are indicated in the following table. Thelighting intensity is measured in lx (Lux).
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AreaLightingIntensity
Method of Lighting
Plant Roads 20 lx High Pressure Sodium
Open Yard, Conveyors, Platforms 30 lx High Pressure Sodium
Remote controlled process areas 50 lx High Pressure Sodium
Staircases, walkways 50 lx Mercury-vapor LampElectrical Equipment Rooms 150 Lux Fluorescent
Central control room 300 lx Fluorescent
Stores for various diverse goods 100 lx Mercury-vapor LampContinuously occupied working places inprocess area
100 lx High Pressure Sodium
Some of lights will be with battery pack for emergency lighting insubstations and electrical rooms.
Lighting fixtures outdoor is IP65
4.2.1.13 Maintenance Power SupplySocket outlets will be provided at strategic locations throughout theplant and shall comprise:
Three phase outlets for welding machine as well as for portablemachines application, 3 pole + E, rated for 63 A
Single phase outlets, 2 pole + E, each rated for 16A with residual-current circuit breakers.
4.2.2.1 Instrumentation
4.2.2.1 Instrument Requirements
All housings for instruments located outside of the electrical equipment
room shall be minimum IP65.
All transmitters shall be of electronic design with electronic analog output,
similarly final control elements shall respond to electrical analog signals.
Analog Electronic Signals: 4-20 mA DC
Electrical & Control part of the weighing system should be of Schenkmake.Damper actuator for big fans should be from ABB/ Siemens and smallfans from Youkogawa /Yamato Japan
Infrared Pyrometer of reputed Western make shall be provided for the
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monitoring of the following temperature.19 Kiln Burning Zone20 Kiln Back End21 Clinker cooler ( at inlet)22 Clinker cooler ( at out let)
4.2.2.2 Field Instrument
According to the requirements for process production it is necessary to
have measuring units as for temperature, pressure, flow rate, level,
speed and so on to detect and monitor the production situation of the
process line and equipments.
4.2.2.3 Instrumentation Selection
Speed Monitor will be proximity switch, 2-wires.
Limit Switch will be proximity switch with plastic enclosure and fast
connector, 2-wires.
Pressure Transmitters will be diaphragm type, the accuracy of the
transmitter will be within 1 % of full scale with less than 0.1 % resolution.
2-wires.
Temperature
Thermocouples will be flanged with an adjustable setscrew and
type K.
RTD ' s will be 3-wire type with 100 Ohm platinum PT.
Temperature transmitter will be linearizing programmable type.
They will have a 0.2 % resolution and a repeatability of < 0.5 %.
Flow
Flow meters. The accuracy will be < 1 % of full range.
Electromagnetic type will be used for liquid; the accuracy will be
0.5%.
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Level for continuous indication
Load cells
Radar measurement
Ultra sonic
Level switches
Capacitor type
Field devices and instrumentation shall be of proven design. All the
instruments like Pressure Transducer, Diff. Pressure Transducer,
Resistance Thermometer, Speed Sensors, V/I Convertor, R/I
Convertor, Current Transducer, Power Transducer, Pull Cord
Switches, Drifft Switches & Thermocouple will be of Siemens, Fuji,Phoenix, Telemechanic or E&H make. Level measurement sensors
and Transmitter will be of E&H make of western origin.
4.2.2.4 Gas Analyzers
Gas analysis system will be of integrated design, purpose built for each
specific application. Including Sample probes and interconnecting pipe
work, fittings, gas processing equipment, etc.
Gas analyzers shall be provided as follows:
Gas Analyzer Type
Oxygen (O2) Paramagnetic
Carbon monoxide (CO) Non-dispersive infra-red absorption
Nitric Non-dispersive ultra-violet
The gas processing and analysis equipment will be housed in sheet steel
cubicle enclosures for local mounting.
Gas Analyzer System including Analyzer and sampling system will be
from Fuji Japan at following locations:-
i) Kiln Inlet for measurement of CO, O2 & NoX components.
ii) Precalciner Outlet for measurement of CO, O2 & NoX componenets
iii) EP Inlet for measurement CO,CH4 & O2.
iv) Coal mill for measurement of CO & O2.
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4.2.2.4.1 Kiln inlet Gas Analyzer
As per the specification mentioned in the annexure (electrical & I & C)
4.2.2.4.2 EP of kiln system, Coal Meal Bin Gas Analyzer
As per the specification mentioned in the annexure (electrical &
I & C)
4.2.2.5 Kiln Shell Temperature Measurement
Kits (Kiln-shell Infrared Temperature Scanning) system analyze and
process kiln shell temperature data, which collected by infrared
temperature detector, indicate the distribution of surface temperature as
well as more important information in form of image and data accurately,
quickly and intuitively.
Scanner should be of from reputed Western origin with KMS software.
4.2.2.5.1 Hardware Configuration
DELL GX260
CPUPentium IV 2.4MHz and above.
Memory512MB and above.
Hard Disk40GB and above.
21CRT
Display CardAGP (can display 24bits real color).
Network CardEthernet card with BNC connector.
Operation System
Windows NT Workstation.
4.2.2.5.2 Software Functions
Temperature Distribution Image
Two Dimension Image
Three Dimension Image
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4.2.3 Process Control System
4.2.3.1 Description of the Process Control System
The DCS configuration will be designed and made with most famous
brand products in the world, such as or SIEMENS-SIMATIC PCS7, or
ABB-industry-IT etc.
4.2.3.2 Network Concept and Hardware Specification
This DCS system is very distributed, and all computers and
controllers are linked together via several kinds of communication
network.
The network of whole system consists of 3 communication layers.23 The top layer is high speed Ethernet ring, Its information
backbone, and its communication route way between PLCs & HMI.
This architecture is an open system, could be easy connected to
other system.
24 The middle layer is real time token network Field Bus (such as:
Modbus Plus, Devices Net or Profibus). Its transfer commands, I/O
states rapidly between controller and field I/O.
25 The bottom layer is Remote I/O bus. Its a simple bus way to be
configing and extending with 10% spare capacity.
4.2.3.3 Specification of the Process Control System
4.2.3.3.1 Process Station
The offered process station system for the entire plant is based on
decentralized PLC system and distributed remote I/O modules for
motor control, alarm handling and loop control.
According to the production department arrangement in General
layout, the system configuration as:
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26 PLC1 - Limestone crushing
Comprising:
1- PLC- processor placed in limestone crushing electrical room.
1- Lot of control cabinets, incl. Internal wiring and power supply
1- Lot of I/O racks.
1- Set of digital input modules, 16 channels, 24 VDC
1- Set of digital output modules, 16 channels, 24 VDC (relay
contract)
1- Set of analog input modules, 8 channels, 4-20mA
1- Set of analog output modules, 4 channels, 4-20mA
1- Set of remote I/O modules placed separately in Clay Crushing
electrical room
1- PC Computer operator workstation
Each PC is equipped with Pentium IV processor, 512 MB memory,
40GB hard disc capacity, CD-ROM drive, , 21high resolution (1024
1280) color monitor, keyboard, monitor, keyboard, mouse, Ethernetcontroller,
1- Event/Alarm report printer
27 PLC2 - Raw meal grinding
Comprising:
1- PLC- processor placed in raw mill electrical room.
1- Lot of control cabinets, incl. Internal wiring and power supply
1- Lot of I/O racks.
1- Set of digital input modules, 16 channels, 24 VDC
1- Set of digital output modules, 16 channels, 24 VDC (relay
contract)
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1- Set of analog input modules, 8 channels, 4-20mA
1- Set of analog output modules, 4 channels, 4-20mA
1- Set of remote I/O modules placed separately in Raw material
proportioning hoppers electrical room
28 PLC3 - Preheater and kiln system Comprising:
1- PLC- processor placed in raw mill electrical room.
1- Lot of control cabinets, incl. Internal wiring and power supply
1- Lot of I/O racks.1- Set of digital input modules, 16 channels, 24 VDC
1- Set of digital output modules, 16 channels, 24 VDC (relay
contract)
1- Set of analog input modules, 8 channels, 4-20mA
1- Set of analog output modules, 4 channels, 4-20mA
29 PLC4 - Clinker cooler system
Comprising:
1- PLC- processor placed in raw mill electrical room.
1- Lot of control cabinets, incl. Internal wiring and power supply
1- Lot of I/O racks.1- Set of digital input modules, 16 channels, 24 VDC1- Set of digital output modules, 16 channels, 24 VDC (relaycontract)1- Set of analog input modules, 8 channels, 4-20mASet of analog output modules, 4 channels, 4-20mA30 PLC5 - Coal grinding
Comprising:1- PLC- processor placed in raw mill electrical room.1- Lot of control cabinets, incl. Internal wiring and power supply1- Lot of I/O racks.
1- Set of digital input modules, 16 channels, 24 VDC1- Set of digital output modules, 16 channels, 24 VDC (relaycontract)1- Set of analog input modules, 8 channels, 4-20mA1- Set of analog output modules, 4 channels, 4-20mA31 PLC6 - Cement mill system
Comprising:1- PLC- processor placed in raw mill electrical room.
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1- Lot of control cabinets, incl. Internal wiring and power supply1- Lot of I/O racks.1- Set of digital input modules, 16 channels, 24 VDC1- Set of digital output modules, 16 channels, 24 VDC (relaycontract)
1- Set of analog input modules, 8 channels, 4-20mA1- Set of analog output modules, 4 channels, 4-20mA32 PLC7 - Cement packing system
Comprising:1- PLC- processor placed in raw mill electrical room.1- Lot of control cabinets, incl. Internal wiring and power supply1- Lot of I/O racks.1- Set of digital input modules, 16 channels, 24 VDC1- Set of digital output modules, 16 channels, 24 VDC (relaycontract)1- Set of analog input modules, 8 channels, 4-20mA
Set of analog output modules, 4 channels, 4-20mA1- PC Computer operator workstationEach PC is equipped with Pentium IV processor, 512 MBmemory, 40GB hard disc capacity, CD-ROM drive, , 21highresolution (10241280) color monitor, keyboard, monitor,keyboard, mouse, Ethernet controller,
33 Event/Alarm report printer
4.2.3.3.2 Operator Station
One operator computer hardware system, for operator human-
machine interface and for central control of mainmachineries/departments, located in the central control room,consisting of:
34 PC computer Server stations (redundant data servers).Each PC is equipped PIV/4G CPU,512M RAM,80G HARDDISK,48xcd,100M Ethernet Card, 8 GB tape backup unit , 21high resolution (10241280) color monitor,32M DISPLAY
ADATPTER, keyboard, mouse.1set -Network equipment4 - PC Computer operator workstations
Each PC is equipped with Pentium IV processor, 256 MB
memory, 40GB hard disc capacity, CD-ROM drive, , 21highresolution (10241280) color monitor, keyboard, monitor,keyboard, mouse, Ethernet controller,
1- HP Laser 13001- Event/Alarm report printer35 Hard copy HP 3820c
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4.2.3.4 Functional Description
The process control and automation system comprise of operatorworkstations for the man-machine interface and programmable logiccontrollers (PLCs) for motor control and alarm handling, loop controland process value acquisition. Production management information
system and kiln control system(KCS).
A. Operator stations
The basic functions are as follows:
36 Supervision37 Control38Alarm-handling39 Reporting
All these functions can be performed via any of the operatorworkstations.
For each plant department, the following screens are defined:
40 Mimic displays:41
4243
44
45
4647 Start-Up displays:48 PID loop displays:
49Alarm/event Surveys:50 Trend curves:51 Reports:52 On-line creation and modification of screens, reports and trend
curves groups.
B. Engineering workstation
The basic engineering includes the choice and configuration ofthe hardware, its interconnection and start-up, the installation ofthe software modules, and the tests for correct operation.
The application engineering includes programming of thesoftware modules in accordance with the project requirementsand with the available plant specifications, as well as allcorresponding tests.
For each department, it consists among others of:
53 Creation of system data base.54 Creation of process displays.55 Creation of start-up displays.
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56 Dynamic animation of displays for start/stop sequences, PIDloop, analog and digital values.
57 Configuration of alarms.58 Configuration of trend curves.59 Configuration of reports.
C. Process Station (PLC)
The basic functions are as follows:
60 Motors & devices control (individual & group)61 Process values acquisition62 PID loops63Alarm handling64 Communication with operator station65 Communication with other PLCsNote: The automation system will be as per specificationsmentioned in the Annexure (electrical, I & C)
4.2.4 Quality Control System
4.2.4.1 General
The automatic quality control system TRAWMIX consists of:
66Automatic continuous sampling with manual transport system forraw meal.
67 Semi-automatic sample preparation in the laboratory with manualinsertion into the X-ray analyzer.
68Automatic analyzing of the samples in a multi-channel X-ray
fluorescent quantometer69Automatic quality control of raw meal including calculation of raw
materials and on/off-line setting of the weighing feeders of the rawmaterial grinding plant.
The samples of raw meal and kiln feed shall be carried by manuallyto the sample preparation room.
The supplied equipments and software shall have enough capacitywith flexibility and easiness for the expansion of production line infuture.
4.2.4.2 Automatic Sample Analyzing SystemThe automatic sample analyzing system shall consist of:
4.2.4.2.1 Simultaneous X-Ray Analyser
The X-ray analyzer shall be included X-ray florescent quantometer.The model of X-ray analyzer shall be Shimadzu XRF & XRD orPHILIPS twin type Cubix.
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Description of PHILIPS twin type Cubix:
70 Cubix FAST XRD for cement
Complete ultra fast industrial XRD system consisting of console, fastsample loader, high precision sample spinner, Ni filter, to sets of PW
1812/35 press rings, programmable divergence slits, 0.04 rad sollerslits, X celerator detector, X pert industry, profit software & Xperthigh score software (with complete pakage).
71 Cubix-CEM XRF cement Package
Compact cubix 14 Channel x-ray spectrometer with sample surfaceup, equipped with fixed Channels for Na, Mg, Al, Si, S, K, Ca, Fe &Cl. The package includes detector gas system, SuperQ analyticalsoftware and internal cooling system (with complete pakage).
Main components shall be including:
72 Multichannel spectrometer unit
73 X-ray tube74 X-ray generator75 Vacuum system76 X-ray tube cooling water system77 Pneumatic system78 9 fixed measuring channels for elements Si, Al, Fe, Ca, Mg, K, Na,
S, Cl79 Pre-calibration standard reference sample for the 9 elements.
4.2.4.2.2 Laboratory Computer
1 - PC Computer is equipped with Pentium IV processor, 256 MBmemory, 40GB hard disc capacity, CD-ROM drive, , 17highresolution (10241280) color monitor, keyboard, monitor,keyboard, mouse.
80 Printer HP 1300
4.2.4.2.3 Software Package for Automatic Sample Analysing
Including:81 Communication with X-ray florescent spectrometer for automatic
adjusting, starting, supervision of analysis operation.82 X-ray florescent spectrometer re-calibration, including graphical
editing facilities, stability and calibration reports.83Analysis 9 specific elements for cement applications chosen from
Si, Al, Fe, Ca, Mg, K, Na, S, Cl etc. following calculation facilities: linear or quadratic calibration equations. line overlap correction. drift compensation.
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inter-element matrix corrections.
4.2.4.3 Proportioning Control
The proportioning controls will be used for automatic control of theraw-mix chemical composition based on periodical analysis of raw-mix samples compositions. Feeder set-points shall be calculated foron-line control to achieve optimization of the composition of the rawmix.
4.2.4.3.1 FunctionFunction of the proportioning control system84 Determining the quality of raw meal e by continuum accumulate of
the batch quantity of raw materials85 Product Statistic and administer86 Recording the actual quantity of the feeder87Automatically calculate the ratio between feeders88Automatically receive analysis result from X-ray florescent
spectrometer89 The new feeder set-points shall be positioned automatically by the
system or manually by the operator90 real time PI control91 batch quantity revising control
4.2.4.3.2 Specification
1 - PC ComputerPC is equipped with Pentium IV processor, 256 MB memory,40GB hard disc capacity, CD-ROM drive, , 21high resolution(10241280) color monitor, keyboard, monitor, keyboard, mouse,Ethernet controller,
1- HP Laser 1300
4.25 Intercommunication System
01 No. PABX200 digital lines telephone exchange (internal) with 15external lines (Siemens make).
Adequate public address system and paging system will be provided.
One high power master set with 30 sets of hand walkie talkie forIntercommunication between the different plant sections
4.2.6 Analysis of Standard Samples1Set of 60 standard samples for calibration of XRF & XRD will be
prepared by BCL & analyzed by CBMC from any international Lablike FLS (Denmark).
4.2.7 PLC Software Back UPThe password, Licence & back up of application software used for allPLC system and programmable remote PLCs will be provided, forany rare case, if it can not be provided, then the back upprogrammed PLC will be provided as spare.
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4.3 Introduction of Main Equipment
4.3.1 Technical Description of Preheater and TSD Precalciner
In the end of 1980s, TCDRI imported DD-furnace technique from
KOBE Steel. After carefully study, absorbing latest big eddying flowand low pressure drop technique, TCDRI developed the new pre-heater and pre-calciner system and used them for 2000t/d ~ 10000t/dcement production line from then on.
The cyclone of preheater developed by TCDRI has thecharacteristics of high efficiency and low pressure drop. The cycloneoutlet diameter - effective diameter ratio is bigger than normal type,which insures lower outlet velocity thus reduce pressure drop undersame cyclone-section velocity. There is a slope at the inlet of thecyclone which can reduce raw material pilling up, at the same time,
this slope can guide the raw material to get a higher separatingefficiency. The structure of the cyclone is simple which reduce failurepossibility. The immersion tube is round style and is hanged up at theroof of cyclone. The immersion tube is composed by many pieces ofheat-resistant steel plate or casting steel component. Flap valve isused for air-locking in the material chute of each stage cyclone. Theshaft of the valve is supported with 2 SKF roller bearings at bothsides, which make the flap swing flexibly. There is a cover on thecasing of the valve behind the flap shaft, so that the flap with shaftcan be drawn easily when removing the cover for maintenance.
The furnace is the key part of the pre-calciner system. There are
many processes such as fuel combustion, carbonate calcining,transporting of raw meal and air, etc. proceed in the furnace. For thelow volatile ingredients coal fuel, we add a pre-combustion chamberbefore the pre-calciner to extend retention time of coal powder. Thetertiary air drawn from the kiln hood has high oxygen content andhigh temperature. The temperature is above 900 at the inlet of thepre-combustion chamber. The tertiary air comes into pre-combustionchamber from tangential direction. The raw material from C4 cycloneis fed into the pre-combustion chamber from the roof of its tertiary airinlet, this position is far from the burner so that the coal powder canreach high firing temperature. The coal power, raw material and high
temperature tertiary air are mixed sufficiently at the bottom of pre-combustion chamber before going into main pre-calciner. Theretention time of the TSD Pre-calciner can reach about 6s.
Raw meal shall be fed into C2-C1 gas duct and pass through C1, C2,C3, C4 and related connection gas ducts to be heated. The heatedmaterial is fed to TDF Calciner from C4 discharge outlet. Fuel isspouted to the firing zone of TDF calciner through two horizontalspray nozzles and the tertiary air from kiln hood also flows into this
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zone through two symmetry inlets. Meanwhile, the high temperaturewaste gas from kiln end forms a boiling layer going through thebeading between the calciner and the kiln inlet chamber to enterfiring zone, which makes the fuel oil be gasified, calcined and quicklyburnt in this zone and enter the main burning zone, where the heat is
fast transfered to raw meal. After that, they enter the fully burning andcalcining zone where the raw meal is calcined rapidly. Before the rawmeal arrives at the inlet of C5 cyclone, the fuel oil/natural gas iscompletely burned out and the raw meal calcining rate reaches 90%or more. Inside the whole TSD calciner, fuel oil/natural gas, hightemperature gas and raw meal are always doing the disordermovement through the ways spraying and striking from beginning toend that promotes the gas and the meal to be mixed better in order toimprove heat sufficiently. At last, meal enters the kiln inlet chamber tobe fed into the rotary kiln by going through the discharging deviceunder C5 cyclone. During the process in pre-calciner, the raw meal
moves from lower to upper, and they exchange heat sufficiently at thesame time. In addition, a part of waste gas coming from the outlet ofC1 cyclone is through the waste gas duct conveyed to the raw mill tobe used as the heat source for drying raw material.
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4.3.2 Technical description of TC Aeration Grate Cooler
4.3.2.1 Grate Plate
The key technology of TC Aeration Beam Grate Cooler is TC Aerated
Grate Plate (Patent License: ZL99205461.3) and TC High ResistanceGrate Plate (Patent License: ZL99205460.5).
The TC Aerated Grate Plate is used in the high temperature zone.This Grate plate is made of entire casting heat resistant steel toResist Thermal Deformation. The Special Designed Air StreamChannel and Outlet of the Grate Plate get high outlet air velocity andhigh resistance. High outlet air velocity can separate the fine clinkerup to the top of the clinker bed, extend the thermal exchange wayand time, remove Red River. High grate plate resistance can bufferthe resistance vary of the clinker bed which is caused by thethickness of clinker bed or clinker grain size. The air channel islabyrinth type which avoids leakage of clinker.
TC High Resistance Grate Plate is used in the middle-hightemperature zone. This grate plate is made of entire casting heatresistant steel to Resist Thermal Deformation too. The majorpressure drop is distributed to high resistance grate plate to minimizethe influence of the clinker uneven distribution. The air streamchannel is labyrinth type too to reduce leakage of clinker. This grateplate uses chamber aerated which insure good cooling effect.
4.3.2.2 Grate
The grate of TC Aeration Beam Grate Cooler is composed with TCAerated Grate Plate and TC High Resistance Grate Plate. At thequench cooling zone and the thermal recovering zone, the TC
Aeration Beam Device is adopted, among which the first 5 row arefixed aeration beam, after that there are 4 rows movable aerationbeam and then is resistance grate. This arrangement can get highcooling efficiency and high thermal recovering efficiency and removered river. Wed like to point out that the Fixed Aeration Beam Deviceused at the inlet of the cooler can decrease the failure ratedramatically. The service life of the TC Aeration Grate Plate and TCHigh Resistance Grate Plate is more than 2 years at normally
operation.At the first chamber of the 2nd grate, there is also TC HighResistance Grate Plate and after which there is normal grate plate.
The designed thickness of clinker bed is 600-700mm. Increasing thethickness of clinker bed can extend the thermal exchange time andincrease the contact area between cooling air and clinker. So we canget a good cooling result and high secondary air temperature.
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Normally the secondary air temperature can reach 1000-1050oCwhen the tertiary air is also drawn from the kiln hood. A thick clinkerbed can also provide a cold clinker layer which can prevent the directcontact of hot clinker and grate plate thus protect the grate plate
4.3.2.3 Air Tight Device
Good air tight device guarantees that the cooling air is usedefficiently with a rational cooling air ratio. A movable air duct isadopted for the movable aeration beam and the sleeve sealing of thisduct which has the characteristic of high reliability and maintenanceconvenience. A clinker hopper with electric air tight valve in theaeration chamber lays under grate to collect leaking clinker. In thishopper, the level of leaking clinker was detected by a detector andthis detector can control the valve opening and closing intermittentlyto keep leaking clinker at a proper level to get a good air sealingeffect.
4.3.2.4 Air Cannon DeviceTo prevent the Snow Man, air cannons are installed on the front endwall above the fixed aeration grate. These cannons can be set towork in sequence.
4.3.2.5 Automatic Control for Grate Cooler
Three-component control system is installed in TC Aeration BeamGrate Cooler. Automatic control can ensure effective, stable and safeoperation of grate coolers. It is required that automatic controlsystems use corresponding variables of meter loop during process toimplement control of related equipments. The content of the three-
component control is as follows.
4.3.2.5.1 Control Loop for the Cooler Grate Drive
It is necessary to keep stable clinker thickness on grate plate asdesigned thickness to achieve designed cooling efficiency andthermal recovery rate. Because material entering into grate cooler iswaved, it is necessary to adjust travel velocity to get stable materialthickness. That is, accelerate speed as the material get too thick orreduce speed as the material get too thin. The air pressure in the 2ndcooling air chamber of the first section is taken as monitoring andcontrolling conditions. The pressure shows the clinker bed resistance
under a certain volume of air, high pressure means strong clinker bedresistance (clinker bed is thick or clinker is fine and dense); or viceversa. The reason why the second chamber of the first section istaken as monitoring basis is that the first compartment of this sectionis opposite to feed point, so it is not suitable to take first compartmentas monitoring basis because of big disturbance of material bed andirregular wave of pressure. TC Aeration Beam Grate Cooler isequipped with DC motor or VFD motor which is used to control
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driving speed of grate bed. Rectifying thickness of material bed canget the purpose of keeping certain resistance under a certain volumeof air.
4.3.2.5.2 Control Loop for the Automatic Air Flow
The cooling air flow that the grate cooler needs shall vary accordingto material amount and temperature. Under previous statedautomatic control condition, the material bed resistance should bestable. To achieve this goal in complicated working condition, coolingair flow must be controlled automatically for cooling material, heatrecovery and grate components protection.
4.3.2.5.3 Control for Excess Air (kiln hood draft control)
During clinker cooling, cooling air becomes hot air, the hot air drawnfrom cooler by negative pressure at kiln hood will go into kiln assecondary air. The secondary air flow is influenced by negativepressure at kiln hood. Usually, the cooling air is more than required,so an exhaust fan is used to release surplus air.
To ensure proper secondary air flow for kiln, negative pressure at kilnhood must be stable and the surplus air will be released base onrequired negative pressure value. The control method is as follows:
The pressure in kiln hood is taken as monitoring condition. Holesconnecting to pressure sensor are opened on hood for pressuremeasuring.
The set range of negative pressure at kiln hood is 10~+2.5mm WGcolumn. When kiln and grate cooler are in good operation condition,
the negative pressure at kiln hood shown by controller is mininegative pressure near zero; this mini negative pressure can betaken as set value going into automatic control.
The surplus air released by exhaust fan will be controlled by electricaldamper. If the negative pressure at kiln head is more or less than theset value, the damper actuator will adjust open-limit base on controlsignal, thus keep the kiln running smoothly.
4.3.2.6 Hammer Crusher
The hammer clinker crusher is set at the discharging end. Clinker ofsmall particle size (
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Rotary kiln is one of the most important equipment in the cementprocess. The kiln with the capacity of 5700+6.14%t/d developed byTCDRI is designed on the basis of the situation and feed back ofmany kinds of rotary kilns in use, applying latest technology andmanufacturing method.
The rotary kiln is comprised of main kiln body and accessoryequipments. The main kiln body includes kiln shell, three supportingdevices, drive station and hydraulic thrust roller. The accessoryequipment is consisting of kiln hood, air sealing device at kiln outletand kiln inlet, main gear reducer oil line system and hydraulic oil feedstation etc. Please refer to the following table for main technicalspecification.
Technical Specification
Diameter (m) 4.8
Length (m) 72
Capacity (t/d) 5700+6.14%Process pre-calcining
Slope 3.5% (sin)
Number of Supporting 3
Drive style single drive
Main driving device (r/min) 0.396~3.96
Auxiliary driving device (r/h) 11.45
Total weight (t) 831
The statements of the main parts of the rotary kiln are as thefollowing:
1). Kiln shell
The shell of kiln is rolled up with sheet of boiler steel No. 20g whichhas six mechanical characteristics and applies automatic weldingwhile welding. Generally, the thickness of kiln shell is 28mm, andthickness at sinter zone is 50mm, the thickness under tyre is75/80mm, the transition section between tyres is 42/55mm, therefore,the design of kiln shell is fairly reasonable, the rigid of cross sectioncan be ensured and the bearing condition of supporting device canbe improved as well. The heatproof and wear-resisting kiln nose
retaining ring is respectively installed at the inlet and outlet of kilnshell. Of which, a divided sleeve space is consisted by kiln noseretaining ring and cold air sleeve. The cold air is sent into from thehorn end of air sleeve and the non-work face of the kiln noseretaining ring is cooled so as to guarantee long term and safetyoperation of this part. There are three rectangular and solid tyres onthe shell. The clearance between the tyre and the shell shim isdetermined on expand. When the kiln is normally operated, the tyres
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can reduce the radial deflection of kiln body. In order to guarantee thereliable operation of the supporting device near the highertemperature kiln hood section, a special air-cooling device for shell isinstalled under the two tyres near kiln hood.
2). Supporting Device
The kiln shell is supported by 3 supporting devices through the tyresand the correct Distribution of span between individual supportingpoints makes the design for supporting devices more reasonable.The sliding bearings are mounted in the supporting devices, which islubricated by means of oil spoon. The cooling water device isinstalled inside the bearing and at the same time there is atemperature measuring instrument for every bearing. The workingtemperature of bearing bush can be checked in the central controlroom.
A hydraulic trust roller is mounted at the supporting device near thekiln inlet to bear the downward force of the kiln and push the kiln tomove upwards, therefore the kiln body can be forced move upwardsin the required speed and slide downwards under controlling, so as toguarantee the average contacting of tyre and roller.
3). Driving Device
Single driving is adopted, and the motor of driving device is a newtype frequency conversion variable speed motor, and this motors
start torque is 2.5 times to its rated torque, and the motors speedcan vary from 100r/min to 1000r/min. The speed indicatinggeneration is set at the rear of main motor to indicate the actualspeed of kiln body. The reducer which matches with the main motoris a 3 stage hard tooth surface cyclindrlical gear reducer, which has aspecial concentration circular lubrication device with a heater for oil,so it can guarantee the oil line working properly in long term. Thegirth gear of kiln is fixed on shell by the tangential elastic plate. Thegirth gear and pinion is sealed by the gear case.
The auxiliary drive connecting to the safety power supply andauxiliary drive power supply insures that the bearing operation of kiln
can still executed when main power supply failed so as to prevent theshell from deformation and be convenient for inspection andmaintenance. The elastic rubber coupling is used for the driveinstallation to increase the balance of drive.
4). Air Sealing Device at the Kilns Outlet and Inlet
The cover and casing with labyrinth and spring shim air sealing isused for the kilns outlet, the cold air is sent into through the horn
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opening to cool the kiln nose retaining plate. The heated cooling air isexhausted from the top of sealing casing to atmosphere. Theinterlock and heat-resisting steel shim is appropriately held at theshell with a air-cooling case to guarantee kiln to keep a good sealingeffect when the kiln deflects slightly.
The rotary graphite block sealing devices is used as optional sealingdevice at the kiln inlet. The device can well adapt itself to the axialmovement and the radial deflection of kiln. This device is of a goodair lock property, simple and reliable construction, and convenientoperation and maintenance.