Kiln Start Up Procedures

PC-KILN START-UP PROCEDURE

(7000 TPD KILN)

1.0 Recommended Checks Prior to Kiln Start-Up (Feed On)

1.1. Kiln Feed systems

♦ The kiln feed system should be run in a recirculation operation and calibrated

♦ Test run the dust evacuation system including elevators, screws, pumps etc.

Continue to run this system throughout the warm up.

1.2. Cooler and Clinker Handling

♦ Test run all cooler drives and inspect for tracks after running. Continue to run the

system for at least 12 hours to ensure its mechanical integrity.

♦ The following equipment should also be run and checked: Clinker Roll crusher,

Vent Fan, Cooler Fans, and all downstream clinker handling equipment.

(I.e.: drag conveyors, belts, pan conveyors, gates etc.) Ensure that fan dampers or

variable speed motors can operate at full range.

♦ Ensure the calibration of all pressure and flow transmitters for the cooler fans.

1.3. I.D. Fan

♦ Test run the I.D. fan and test for proper rotation, controls from the field and

CCR/DCS as well as check for leaks.

1.4. Coal Conveying system

♦ Test run of coal conveying system should be taken Viz: calibration of Rotoscale

to be done

1.5. Kiln Bag house or ESP.

Please refer respective supplier’s manual

1.6. Pre-heater System (These items to be done well before start up)

♦ Ensure all locks are removed from the system

♦ Verify all hoses and connections are in place for the fuel and air supply systems

♦ All compressed air line valves in their proper positions for operation

♦ Ignition source ready and available at kiln hood

♦ Test run burner axial, swirl and transport air systems and check filters

1.7. Material Flow Check for Preheater Plant

♦ Verify all Cyclone Flap chutes are clear by dropping mill ball/fire ball through

cyclone and chutes

♦ Verify all Cyclone tipping valves are working properly. Open and close manually.

1.8. Common Pre-checks

♦ Ensure the proper direction or rotation of all fans, screws, conveyors, clinker Roll

crushers. Auxiliary kiln drive motor function

Check airflows on all Cooler fans

Kiln Preheat Preparation:

1.9. Kiln Refractory preparation

Purpose: To properly manage the installation of refractory during a scheduled or

Unscheduled shutdown, and to follow established procedures for preheating

the kiln system for maximum brick life.

The refractory best practice should be consulted to determine proper method

of preparation.

♦ The proper installation of refractory cannot be over emphasized as it plays a key role

in the longevity of the lining. During a major turnaround it would be well for plants to

consider hiring an experienced refractory installation specialist to supervise the

ongoing lining replacement or ensure that the installer is familiar with the various

installation techniques that are available.

2. Kiln Preheat Schedule:

2.1. Parameters to be tracked during preheat

It is essential that plants have a preheating schedule determined prior to the start up. The

start-up program, which mainly determines the kiln temperature increase per unit time

and the timing of the introduction of raw feed, must consider a number of factors such

as the type of refractory material, design of the kiln system, mechanical systems etc.

The following points should be recorded during the preheating of pyro- system

2.1.1. Preheater/Precalciner

♦ stage #2 exit oxygen

♦ Precalciner temperature

♦ kiln exit temperature

♦ kiln exit oxygen

♦ Burning zone temperature

♦ Shell temperature and tyres temperature

♦ Tyre Creep

♦ Bearing temperatures

♦ Kiln hood pressure

♦ Fuel consumption

♦ Kiln turning schedule

♦ Monitor Bag house (including gas & opacity analyzers) – turn on as soon as

possible

2.2. Turning Schedules:

The purpose of a turning schedule is to ensure slow, uniform heating of the kiln and its

refractories. Turning schedules are based on an increase in temperature over time. A

good turning schedule will allow for the expansion of the refractory and kiln shell so that

the brick remain in place and the shell expands uniformly along its longitudinal axis.

Turning Schedule: Too Slow

Overheating of the refractory and the kiln shell

Duck-nesting or sporadic gouging of the refractory

Shell and refractory damage.

Too Fast

Poor heat distribution

Longer preheat time due to poor transfer of heat

Potential for spiraling of brick.

An example of the turning schedules for a kiln is shown below:

TEMPERATURE OF GAS AT KILN INLET KILN TURNING PROCEDURE WITH

AUXILIARY DRIVE

UP TO 120°C KEEP THE KILN STOPPED

120°C TO 210°C TURN 90° TO 120° EVERY 45 MINUTES




750°C UP TO FEEDING CONTINUOUS TURNING

As a compromise, the kiln should be periodically turned i.e.: rotated a fraction of a turn,

During the initial phase until the sintering zone temperature reaches approximately

900°C (1650 °F). After this phase, the kiln can be rotated continuously in a normal

manner through the auxiliary drive.

2.3. Kiln Preheat Schedule

The following is a guideline for preheating Kiln refractory brick linings after

a major shutdown and a short shutdown (Repair works)

0

100

200

300

400

500

600

700

800

900

1000

0 3 6 9 12 15 18 21 24 27 30 33 36 39 42

HEATING-UP GRAPH FOR ROTARY CEMENT KILNS

Kil

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ratu

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t in

let

are

a

Heating-up Time, hours

º

C

xSTART OF MATERIAL FEED ACCORDING TO

xKILN TYPE AND OPERATING PROCESS

1300*

1200*

900*

600*

300*

* Lining Temperature under the Flame

HEATING-UP CONDITION

CURVE 1: HEATING-UP AFTER LIMITED REPAIRS/STOPPAGE THERMAL GRADIENT - 30 TO 35°C/h.

CURVE 2: HEATING-UP AFTER COMPLETE RE-LINING THERMAL GRADIENT - 20 TO 25°C/h.

Most suppliers of refractory materials recommend for the start up of kilns after

majorturnarounds with monolithic linings, a maximum heating –up rate of approximately

25 °C /h in the sintering zone up to a temperature of 900 °C. After reaching 900 °C,

heating up can continue at a rate of 50 °C up to the working temperature. After a minor

shutdown (less than 24 hours) where no major lining is replaced,

refractory suppliers recommend a heating-up rate of 50 °C /h. There should be a

holding pattern on the temperatures in the kiln system in at least two separate

temperature ranges. The first holding pattern should be made in the initial stages of the

heat up procedure. This means that when the sintering zone

temperature reaches approximately 300 °C, the temperature should be held constant for

approximately 3 hours. This procedure should be repeated again once the sintering zone

temperature reaches approximately 500 to 550 °C. This procedure allows the refractory

material to “catch up” with the gas temperature. The heat penetrates the refractory

material as well as the metal casings and reduces the

Possibility of non-uniform expansion and tyre creep problems. This procedure can of

course be modified based on the amount of refractory work that has been completed

during the shutdown.

3. Feeding of Raw Materials 3.1. Preheaters/Precalciners: Raw material feed can be started when the temperature curve in the kiln system

approaches operational conditions or as soon as the precalciner and preheater

temperatures profile is ready for feed. The period between the start of the kiln feed and

its arrival at the sintering zone is the most critical with respect to tyre creep because the

fuel supply must be increased rapidly to compensate for the heat

absorbed by the processing of the raw material. Close attention must be made at this

phase so that slip is continuously present. If slip of the tyre ceases, counter measures

must be taken to correct the situation. Feed may be introduced into the kiln system prior

to arriving at optimal temperature as a measure to coat the refractory linings. Only small

amounts can be introduced so that there is not a deterioration of the heat gradient.

4. Guide lines for Start up of Pyro processing system :( 7000 TPD)

1. Start Bag House Fan and run at minimum Speed.

2. Open Pre-heater Fan damper 5%

3. Start Oil Firing For oil firing the following initial settings must be selected,

a) Swirl: 25 -30°

b) Divergence: 3 ̊

c) Primary air flow rate: approx. 3000-3500 Nm3/h (pressure indication 30 – 50mbar

d) Cooling air flow, rate in coal dust channel: 25- 50% open (flap position)

For the start-up process with oil it may be necessary to further adapt both the primary

air and the swirl angle.

4. After reaching 300 -350 ̊ C temperature at kiln inlet Coal firing to be started with

minimum coal along with oil firing

Note * before starting coal firing Start Pre-heater Fan (Maintain around -30 mmwg

at P/H Fan outlet by adjusting the Bag House fan damper/speed) and close

Pre-heater fan damper to less than5 % and open both fresh air dampers

5. Open Tertiary air damper 10%

6. For combined oil and coal firing and also for pure coal firing the primary air flow rate

then has to be increased to suit the higher quantity of fuel. Initially, there should be no

adjustment of the swirl and divergence, so that the flame remains slim and long. Note: As

soon as coal is fed cooling air flow to coal dust channel, the flap to the cooling air

channel leading into the dust channel to be closed.

Note:* If the kiln hood becomes smoky and the flame loose then increase the draft

slightly. If the flame moves away from the burner tip it might be too much draft or too

much primary air. Change one of them and see what happens.

7. Start Clinker transport System. Cooler ESP transport System, Bull Nose Cooling fan,

cooling fans of Roll crusher, Roll crusher, Cooling Fan recuperation zone (1-6fans)

8. Start Cooler ID fan and maintain hood draft around -5 mmwg.

9. Start remaining cooler fans with min. speed

10 Start Cooler drive at 1 spm speed. (maintain minimum chamber pressure)

11 Put PID loop in auto mode at set point of -5 mmwg and adjust Cooler ESP fan speed

to maintain the Hood draft.

12 Rotate Kiln continuously after Kiln inlet Temperature reaching 750 ̊C

13 Increase the Fuel in Main Firing burner

14 Maintain Primary air fan pressure at 1400 to 1500 mmwg.

15 After reaching workable temperature at kiln inlet around 1050 ̊ C

16 Change to kiln main drive from Auxiliary drive.

17 Put Kiln Coal ~ 9.0 tph

18 Make Preheater Fan speed 350 rpm and open PH Fan damper 100%.

19 Cooler Fans 1 ~1 100 rpm, 2 -3~ 1000 rpm, rest at 900 rpm.

20 Make Kiln Coal ~ 12 t/h

21 After PH Fan inlet pressure reaching above 100 mmwg, start kiln feed at 140t/h.

22 Start Calciner firing at 2.0 tph coal and increase to maintain around 860-870 ̊C at

Cyclone 1th Gas temperature.

23 Open tertiary air damper to 30 % (Adjust based on kiln inlet & P/H Exit Oxygen

content).

24 Increase the main drive speed to 0.7 rpm. Based on kiln conditions.

25 Start Cooler ESP High tension and rapping.

26 Increase Cooler fan’s speed gradually as the Clinker bed starts increasing over the

cooler grates.

27 Maintain Compartment 2 Chamber pressure around 550 mmwg

28 Increase Kiln Speed, Feed, fuel and Fan Flows based on the Pyro system conditions.

29. For Kiln inlet firing system Pre conditions: kiln inlet analyzer to be ready, kiln inlet

Temperature to be below 1200 ̊C and kiln inlet maintain o2 2- 3 %.

POLFLAME

• Normal operation

For normal nominal operation with a coal supply rate of approx. 21- 25 tph following

settings should initially be selected :( Standard Flame)

Swirl: 20°

Divergence: 5°

Primary air flow rate: approx. 8500-9000 Nm3/h (pressure indication 250– 300 mbar)

The above initial settings result in the following operating figure. Primary air rate

approx.12% related to the total primary air Primary air ratio approx. 7.5% related to the

nozzle air .Specific axial moment of approx. 7 N/MW, calculated with nozzle air, cooling air

and conveying air and coal Specific axial moment of approx. 5 N/MW, calculated with

nozzle air Swirl factor approx. 0.23

For Further optimization of Flame Please do refer Polflame burner manual.

For further optimization of Poly track cooler please do refer Poly track manual.

Instruction for the action to be taken in case of power failure

a). Make sure the emergency generator starts up The generator will normally start up

automatically and

Supply power for emergency panel.

b). Start the emergency compressor. This will supply compressed air for the spray lubrication

c). Start kiln auxiliary and kiln barring. In order to be able to the start the kiln auxiliary

group.....

d). A power failure will stop the primary air fan. A stop of the primary air fan will

automatically start the emergency air fan for cooling of the burner pipe.

The following items concerning the kiln sustem are operational on emergency

power.

L I S T O F E Q U I P M E N T S R E Q U I R I N G E M E R G E N C Y P O W E R S U P P L Y

SR.

NO.

EQUIPMENT IMPERATIVE RECOMMENDED

1. Cooling water supply *

2. Cleaning device for gas sampling probe

*

3. Throttle flap before preheater fan *

4. Fresh air fan before RABH *

5. Fresh air flap in down comer duct * 6. Instrumentation and control

actuator *

7. UPS for computer and process control equipments

*

8. Aux.drive for rotary kiln * 9. Lub.oil pump for rotary kiln gear

box *

10. Grease pump for kiln girth gear *

11. Compressor for kiln girth gear lubrication

*

12. Brake lifter for kiln gear box * 13. Magnetic clutch for kiln gear box * 14. Control cabinets for firing or dosing

system *

15. P.A.fan for cooling down the burner nozzle

*

16. Cooler drive *

17. Cooler fans for static grate of cooler * 18. Clinker transport system from

cooler to stockpile *

19. CO2 flooding for fine coal bin *

Cooler operation guide lines

. Cooler operation: Guideline

Note: These guidelines are

to be

for adjustment of cooling air

adapted or revised regularly as required by

actual

conditions

Kiln feed/clinker ratio: 1 ,62 ambient temperature: 35 °C barometric pressure 980 mbar

BED HEIGHT: 600 - 800 mm Grate strokes: 5 - 7 spm at 7000 t/24 h

Kiln feed t/h 473 142 179 215 252 289 326 362 399 436 473

Clinker production t/24 h 7000 2100 2650 3190 3730 4280 4830 5360 5910 6460 7000

% 100 30,0% 37,8% 45,6% 53,3% 61,1% 68,9% 76,7% 84,4% 92,2% 100,0

Design m

3/h

Fans mbfan 1 m

3/h 84500 100 63270 64220 65170 66120 67070 68020 68970 69920 70870 71830

fan 2 m3/h 78000 100 55850 57010 58170 59330 60490 61650 62810 63970 65130 66300

fan 3 m3/h 74000 95 50560 51930 53300 54670 56040 57410 58780 60150 61520 62900

fan 4 m3/h 70500 90 45870 47430 48990 50550 52110 53670 55230 56790 58350 59930

fan 5 m3/h 67000 80 41400 43130 44860 46590 48320 50050 51780 53510 55240 56950

fan 6 m3/h 63500 70 37160 39030 40900 42770 44640 46510 48380 50250 52120 53980

fan 7 m3/h 60500 65 33430 35430 37430 39430 41430 43430 45430 47430 49430 51430

fan 8 m3/h 56500 60 29370 31440 33510 35580 37650 39720 41790 43860 45930 48030

fan 9 m3/h 53000 55 25820 27960 30100 32240 34380 36520 38660 40800 42940 45050

fan 10 m3/h 95500 50 41840 46210 50580 54950 59320 63690 68060 72430 76800 81180

fan 11 m3/h 81500 40 30380 34700 39020 43340 47660 51980 56300 60620 64940 69280

Total cooling air m

3/h 784500 45495 47849 50203 52557 54911 57265 59619 619730 643270 66686

Spec. Total cooling air m3/kg cli. 2,69 5,20 4,33 3,78 3,38 3,08 2,85 2,67 2,52 2,39 2,29

Spec. Total cooling air Nm3/kg cli. 2,31 4,46 3,72 3,24 2,90 2,64 2,44 2,29 2,16 2,05 1,96

Note: Please note that this is only basic guide lines for start up and doesn’t include start

up of every individual drive in the pyro processing system.

Kiln Start Up Procedures

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