vertical ball mill

Tanjung Jati B TrainingVERTICAL BALL MILL

REAGENT PREPARATIONVERTICAL BALL MILL

Tanjung Jati B Training


PT Central Java PowerTanjung Jati B Units 1 & 2Flue Gas Desulfurization (FGD) System

Absorber Area DewateringArea

Reagent PreparationArea

Limestone JettyAnd Conveyor


THE INTENT OF THIS SECTION IS TO DISCUSS BASICPROCEDURES FOR STARTING UP THE VERTICAL BALLSYSTEM.

THIS SECTION, BY NO MEANS ESTABLISHES OPERATINGPROCEDURES, THEREFORE IT IS THE RESPONSIBILITYOF THE OPERATORS TO FULLY UNDERSTAND THEOPERATING PROCEDURES PROVIDED IN THEOPERATION & MAINTENANCE MANUALS.

Reagent PreparationVertical Ball Mill

Prior to starting the Vertical Ball Mill section, letsfirst review the Reagent Preparation flow paths andrelated components.




LimestoneSilo

Bin Activator

LimestoneFeeder Limestone

Pre-Crusher

VerticalBall Mill

MillHydroclone

MillRecirculation

Sump

Limestone SlurryStorage Tank

Mill OutletSump

Mill RecyclePump

Seawater


The function of Reagent Preparation is toprocess raw limestone stored in the LimestoneSilos into a limestone slurry which is ultimatelystored in the Limestone Slurry Storage Tank.

Limestone Slurry, produced by the Vertical Ball Millsand classified by the Hydroclones, will have a solidscontent of 30%.

95% of those solids will pass through a 325 meshscreen.




LimestoneSilo

Bin Activator


Pre-Crusher

VerticalBall Mill

MillHydroclone

MillRecirculation

Sump


Mill OutletSump

Mill RecyclePump

Seawater30%

SOLIDS

95% of solidsthrough a 325 mesh screen


The Limestone Slurry produced by the ReagentPreparation System, by design, will have asolids content of 30%.

Control of the Reagent Preparation Systemis from the main control room. The system isoperated most efficiently as a batch processwith a constant design feed rate of limestoneto the vertical ball mills.





The Hydroclone is an integral part of the ReagentPreparation system as well as being integral to theoperation of the Vertical Ball Mill.

Lets first take a look at the Vertical Ball Millcomponents.



BALL FILL

DRIVEMOTOR

MILLRECIRCULATION

SUMP

GEARREDUCER

RAWMATERIAL

INLET

SCREW

TO MILLOUTLET SUMP

TO MILLRECIRCULATION

PUMP



DRAIN

WASH CONNECTION

SLURRY FEED

BALLDISCHARGE

LOW LEVELSWITCH



AGITATOR

AGITATOR(300 RPM)

MILL RECYCLE SUMP(PLAN VIEW)

AGITATORMOTOR

SLURRYOUTLET

AIRVENT

CLAMPASSY

BLADES



RAWMATERIAL

INLET SLURRY OUTLETTO RECIRC SUMP

RECYCLE SLURRYFROM RECIRC PUMP

VERTICAL BALLMILL FLOW PATH


VERTICAL BALL MILL INTERNALS @ TJ-B




An Oil Lubrication Unit is required for the operationBall Mills Gear Reducer. This Lube Oil Unit requiresa cooling water source and has instrumentation formeasuring oil flow, temperature and differentialpressure.

The source of cooling water is Service Water. Thecooling water exiting the Lube Oil Unit goes tothe drain (trench).



DUPLEXFILTER

MOTOR

THERMOMETER(WITH SWITCH)

OILPUMP

FLOWMETER

OILCOOLER

DIFFERENTIALSWITCH

OILINLET

OILOUTLET



Prior to discussing the start-up of the Vertical BallMill, lets look at the Alarms Mill Trip Recycle Pump Trip Recirculation Sump Agitator Trip Mill Liquid Level Low Mill & Mill Motor Bearing & Winding Temperatures High Mill Motor Current (amps) High Gear Reducer Lube Oil Pump Trip Gear Reducer & Bearing Temperatures High Gear Reducer Lube Oil Flow Low Gear Reducer Lube Oil Temperature High



The Reagent Preparation System is started in thefollowing sequence. Note, the Limestone SlurryStorage Tank must be ready to receive slurry

1. Mill Outlet Sump, Agitator & Pump

2. Tower Mill System Lube Oil System Mill Main Drive Mill Recycle Pump & Recirc Sump Agitator Limestone Pre-Crusher Limestone Weigh Feeder & Silo Gate Valve Limestone Bin Activator



The Reagent Preparation System is started in thefollowing sequence

3. Limestone Slurry Storage System

Slurry Storage Tank (Level not Hi-Hi) Tank Agitator Limestone Slurry Feed Pumps



We have discussed system alarms and the start-upsequence, now lets look at the basic steps for startingthe Vertical Mill and related equipment

Please consult the O&M Manuals for the details forstarting and stopping the Vertical Mill and relatedequipment.



Starting the Ball Mill System (Mill Outlet Sump)

Open the Mill Outlet Sump Recycle Valve

Close Sump Pump Common Discharge Valve

Open manual Feed Valve to the Hydroclone

Verify that the manual Flushing Valve to theHydroclone Overflow is closed

Verify that the manual seawater Flushing Valve isclosed


From Vertical MillRecirculating Sump

(Flush Water)

Seawater Flush

MillHydroclone

FLUSH

FEED

Pumps A & B

To Vertical MillRecirculating Sump

To LimestoneSlurry Tank C

O

CO

C


Seawater Fill C*

SUMP VALVEARRANGEMENT

DURING START-UP

* Open Valve if sumplevel is low

C



Starting the Ball Mill System (Mill Outlet Sump)

Place the Mill Outlet Sump Pump in Automatic

Place the Mill Outlet Sump Agitator in Automatic

Once Sump level is achieved, the Pump & Agitatorwill start.

The Sump Pump discharge flow will remain in theRecycle Mode until the entire mill system is in operation.



(Flush Water)

Seawater Flush

MillHydroclone

FLUSH

FEED

Pumps A & B


To LimestoneSlurry Tank C

O

CO

C


Seawater Fill C

SUMP PUMP ANDAGITATOR TO AUTO(SHORT RECYCLE)

C



Starting the Ball Mill System (Hydroclone)

Verify that 4 of 5 Cyclone Isolation Valves are open

Mill Hydroclone Recycle Valve to manual and open

Open Sump Pump Common Discharge Valve

Close Mill Outlet Sump Pump Recycle Valve

Mill Hydroclone Recycle Valve to automatic



(Flush Water)

Seawater Flush

MillHydroclone

FLUSH

FEED

Pumps A & B


To LimestoneSlurry Tank O

O

CO

C


Seawater Fill C

MILL HYDROCLONEIN THE

RECYCLE MODE

O



MILL HYDROCLONEMILL HYDROCLONE

(PLAN VIEW)

CYCLONES

CYCLONE

4 of 5 Cyclones openfor normal operation



INLET

UNDERFLOW

OVERFLOW

MILL HYDROCLONE


MILLHYDROCLONE

orCLASSIFIER

KREBS U.S.A.

LOWERLAUNDER

UPPERLAUNDER

CYCLONESReagent PreparationVertical Ball Mill



Starting the Ball Mill System (Lube Oil Unit)

Verify Lube Oil Shutoff Valves are Open

Verify Cooling Water Shutoff Valve is Open(Observe cooling water discharging into trench)

Start the Lube Oil Pump

Verify Lube Oil Flow is above minimum, temperaturebelow maximum and differential pressure belowmaximum



DUPLEXFILTER

MOTOR

THERMOMETER(WITH SWITCH)

OILPUMP

FLOWMETER

OILCOOLER

DIFFERENTIALSWITCH

OILINLET

OILOUTLET



Starting the Ball Mill System (Vertical Mill)

Verify Mill Flush & Drain Valves are closed

Seawater Flow Control Valve to manual and open fully

Open Seawater Make-Up Isolation Valve

If Mill is empty, open seawater isolation valve.Fill Mill until water is seen overflowing into theMill Outlet Sump

Verify Seawater Valve to Mill Hydroclone Underflowis open



MILL OUTLET SUMP

SEAWATERMAKE-UP

O

O

O

O

MILL HYDROCLONE

VERTICAL MILL



Starting the Ball Mill System (Vertical Mill)

Once water from the Mill Recirculating Sump is seendischarging into the Mill Outlet Sump, the Mill can bestarted (manually).

If the Mill is in Automatic, the Mill will start when thelevel in the Mill Recirculating Sump is above the lowlevel (switch).



MILL OUTLET SUMP

SEAWATERMAKE-UP

O

O

O

O

MILL HYDROCLONE

VERTICAL MILL



Starting the Ball Mill System (Recycle Pump & SumpAgitator)

Verify Mill Flush and Drain Valves are closed.

Verify Mill Recycle Pump Isolation Valves are open

Verify Mill Recycle Feed Valve is open

Place Pump & Agitator in automatic. Both will startif the level within the Recirculating Sump is abovethe minimum (low level switch)



MILLRECYCLE PUMP

TO MILLOUTLET SUMP

MILLRECIRCULATING

SUMP

OOO



Starting the Ball Mill System (System Dust Collector)

Verify Instrument Air Isolation Valve is open

Verify Isolation Valves at the Mill and LimestoneFeeder are open

Start the Dust Collector

Verify Differential Pressure is not excessive


LIMESTONE SLURRY TANK(UNDER CONSTRUCTION)

REAGENT PREPARATIONAREA DUST COLLECTOR




FROM TOWER MILL A

FROM LIMESTONE FEEDER A

FROM TOWER MILL B

FROM LIMESTONE FEEDER B

INSTRUMENTAIR

REAGENT PREPARATION SYSTEM DUST COLLECTOR

C

C

O

O

O



Starting the Ball Mill System (Crusher, Feeder andBin Activator)

Pre-Crusher will start after a short time delay afterthe Mill is started (automatic)

Verify Silo Discharge Gate Valve is open

Limestone Feeder will start after a short time delayafter the Pre-Crusher is started (automatic)

Bin Activator will start (if in automatic) when Feederis running and Gate Valve is open.


LimestoneSilo

Bin Activator


Pre-Crusher

VerticalBall Mill

MillHydroclone

MillRecirculation

Sump


Mill OutletSump

Mill RecyclePump

Seawater

Slide Gate



When the Limestone Slurry Storage Tank Levelreaches the high level set point, the Mill OutletSump Pump will stop.

When the Sump Pump Stops, this will stop thefollowing equipment if in automatic mode

Pre-Crusher Limestone Feeder Bin Activator

The Vertical Mill will remain in service for flushingand proper shutdown (approximately 60 minutes).



LimestoneSilo

Bin Activator (4)

LimestoneFeeder

(3)Limestone

Pre-Crusher(2)

VerticalBall Mill

(5)

MillHydroclone

MillRecirculation

Sump


Mill OutletSump Pump (1)

Mill RecyclePump

Seawater

SHUTDOWN ORDER

High LevelSet Point



The Vertical Mill is required to operate or run for60 minutes after the Mill Outlet Sump Pump hasstopped.

This is required so that the slurry within the Millwill become finer (smaller) and not settle rapidlyif the Mill were shutdown earlier.

The Mill will shutdown automatically after 60 minutesif the Mill is in Automatic.



The Mill Recycle Pump and Mill Recirculating SumpAgitator will continue to operate and slurry will berecycled back to the Vertical Mill.

It is recommended that the Vertical Mill be run for a5-minute period every 4 hours. This will prevent thecompacting of ground limestone within the Mill.




MILLRECYCLE PUMP

TO MILLOUTLET SUMP

MILLRECIRCULATING

SUMP


Emergency Shutdown of the Vertical Ball Mill

In case of emergency stop due to electrical failureor other cause, the Mill is to be drained and washedof all slurry to prevent the cementation of the hardparticles.

For next start-up, the Vertical Mill must be filled withwater until the water is seen overflowing into the MillOutlet Sump.


REAGENT PREPARATIONVERTICAL BALL MILL

(END)


vertical ball mill

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