KilnLine Operation

5/20/2018 KilnLine Operation

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Page 1 Training THALOFA

Operation of the kiln lineTraining

Klaus Grittner

Polysius Services

Polysius Headquarters / Germany

19. May 13. June 2008


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S ilzR 13 Jun 2008 S:\Team\Training\TH ALOFA\CD-for-Customer\05-04-K ilnLine-Operation.pptPage 2

Heating UpStarting Sequence

Start Up

Increasing Performance

Normal Operation

Optimisation

Main Control Loops

Normal Shut Down

Emergency Power Consumers

Operation of the Kiln Line


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Rotary kiln

Clinker cooler

Preheater

Calciner

Tertiary Air Duct

1400 C

Clinker Production LineClinker Production Line

1700 C 280 C; to EP

900 C

340 C; to raw mill

and / or EP

80 C

fuel

55 60 %

fuel

40 45 %860 C

80 - 100 C

Ambient air temp.

350 C


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Heating up the kiln line

The fuel burns with the smallest possible amount of combustion air.

There is no CO, or only slightly formation of CO at the kiln inlet

Most of the heat remains in the clinkering zone

The flame is short and compact.

for the new kiln heating up takes approx.

-- 48 hrs. (with new brick lining)

-- 30 36 hrs. (after normal maintenance shut down)


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Example for 1st heating up the kiln line

Continuous turningor heavy fuel oil


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Tilting and turning the kiln

During the heating up the kiln should be continuously inched and turned,the guide values for a new kiln are :

0 12 h: 1/3 revolution with auxiliary drive every 30 minutes

12- 24 h: 1/3 revolution with auxiliary drive every 20 minutes



46 - 46 h: continuous rotation with auxiliary drive

0,1 rpm

from 48 h: turn kiln with main drive app. 0,6 rpm

and start feed


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Starting-up Sequence of the Kiln Line

Filter dust transport

De-dusting plant

De-dusting filter fan

Kiln waste gas fan (ID-fan)

Remarks:

Control air compressors,

cooling water system.Auxiliaries of the kiln line

with closed damper

with closed damper

rapping system


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Remarks:

Clinker transport

Cooler waste air filter dust transport

Bull Nose cooling fan

Fuel supply (fuel oil or coal)CO < min.

- analyser behind cyclone 2- analyser before bag house

Primary air fan for MB With damper closed

cooler roof protection


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Cooling for roller crusher

Remarks:

Cooler exhaust air fan

Cooler de-dusting filter

Roller crusher

Cooling air fans for

recuperation zoneWith damper closed

With damper closed


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Remarks:

Cooler grates

Kiln main drive

Cooling fans for kiln outlet

Cooling fans for kiln shell

Main burner many preconditions (CO, T.)

slow speed 0.6 rpm

only if main drive is running


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Kiln feed

Remarks:

Pre-heater cleaning systems

Open tertiary air dampers

Calciner burners

Cooling tower

app. 20 %

Fuel MIN


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Start of the Kiln Line / Kiln Feed

For kiln feed start sufficient personnel has to be in thepre-heater to watch the function of the pendulum flaps

and material flow!!!

1. Cooler Grates: ~ 3 - 5 stroke/min, (minimum speed)

2. Kiln main drive : 0,6 0,8 rpm

3. Cooler Fans : ~ 30% of the nominal quantity

kiln hood pressure: -1 to -2 mm WG (Automatic control)

4. Main burner fuel: Heavy oil: ~1.000 Nm/h

Coal / Pet coke: ~ 6.000 kg/h

5. Start Kiln Feed : ~30 to 35% of nominal feed rate (new kiln, no coating)

att.: there is a time delay between kiln feed group start

and real kiln feed.

6. Adjust draft after : - 12 to -15 mbar by ID-fan/ dampers exhaust gas duct.

cyclone pre-heater

!


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Start of the Kiln Line / Kiln Feed

7. Main burner : Increasing of the fuel quantity to specificheat consumption 1300 ...1500 kcal/kg clinker

Att. ! : Its only a guide value!!!

8. Start PC-burner : Sufficient Oxygen - after cyclone stage 2: > 2,5 %

- after DOPOL: > 4,0 %

Fuel distribution: MB ~70-75%, PC ~25-30%.

Kiln inlet : ~ 1050 C,

After stage I: ~ 860 C,

Hot meal 1: ~ 840 C

9. Adjustment of according to kiln feed ( ~ 2,0 Nm/kg clinker)!!!

cooling air:

10. Observing clinker visual check, kiln camera, pyrometer,

formation: observe the power consumption of the kiln drive.


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Gas analyser / Alarm set points

Gas analyser behind kiln

-- CO (max 0,8 %, Alarm)

-- O2 (min 1,0 %, Alarm)

Gas analyser behind Calciner

-- CO (max-max. 0,8 %; calciner burner)

-- O2 normal value app. 2,5 %

Gas analyser before bag house

-- CO (max-max 1,1 %; main burner)-- O2 normal value app. 4,0 %

CO > 0.6 % alarm

CO > 0.8 % shut off the calciner burners

CO > 1,1 % stop the main burner


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Increasing the kiln performance

Precondition: granulated clinker in the sintering zone and in the clinker cooler

1. Increasing the gas flow through via damper or speed of ID-fan- / filter-fan

the cyclone pre-heater Oxygen content behind cyclone

stage 5 > 4,0 % before increasing fuel.

After ID-fan: keep -50 mm WG (by EP-fan)

2. Stepwise opening of the (Oxygen at kiln inlet adjust to ~2 3 %)

tertiary flaps

3. Increasing of clinker keep kiln hood pressure -1 to -2 mm WG.

cooler air quantity (control loop)


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Increasing performance

4. increase of kiln feed and fuel target of fuel distribution:-- MB ~ 45%,

-- PC ~ 55%

5. increase of kiln speed according to the kiln feed

6. close fresh air flap (if open) depends on temp. after the pre-heater

7. operate clinker cooler with -- until a clinker bed dept ~ 500 mm

slow speed -- pressure in aeration chamber 1 ~ 40 mbar)

Same above mentioned steps for further increasing of the kiln feed!


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Increasing performance

Cooler grate velocity (watch the pressure!!!) and cooling air

quantities have to be adapted

(1,8 2 Nm/kg Clinker)!

Att.: Secondary air and tertiary air temperatures will rise! The specific heat

consumption will reduce!!! Prevent overheating the sintering zone!!!

Take attention to: the kiln inlet temperature (max. 1150C),

the hot meal temperature (max 870C),

the temperature after pre-heater

(normal 340C, max. 450C):


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Normal Operation

Preconditions of trouble-free operation:

- most homogeneous raw meal (LSF, SR, AR)

- constant kiln feed (variation < 1 % / minute)

- constant fuel rates (variation < 1 % / minute)

- constant gas flows, cooling air flows


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Optimisation of the plant

-- Process parameters

-- Typical operating parameters

-- Burner-/ Flame adjustments


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Process Parameters

1. kiln feed rate tons / h

2. Specific heat consumption, kcal / kg (calculated)

3. Total fuel rate , tons / h

4. Proportion of fuel to pre calciner / riser, %

5. Secondary air temperature , degree C

6. ID fan draft , mbar

7. Pre-heater exhaust gas temperature, degree C

8. Kiln inlet gas analyser O2 %, CO %, NOx mg

9. Cyclone stage II gas analyser O2 %, CO %, NOx mg

10. After ID.-fan gas analyser O2 %, CO %, NOx mg


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11. Water into the cooling tower l / h

12. Kiln feed material (meal chute 1) SO3 %, LoI. %, (Lab. results)

13. Kiln drive power , kW, Amps

14. Primary air pressure mbar

15. Clinker cooler ventilators, air volume Nm3/ h

16. (Primary air, Nm3/ h)

17. Pre-heater profile (Temp. Pressure) C; mbar;

18. Specific Calculations kcal/kg clinker

-- Specific kiln volume loading, tons / mday

-- Gas velocity in burning zone, m / sec

-- Specific heat loading of burning zone, Mcal / h per m2

Process Parameters


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Typical Operation Parameters

Temp.: -- gas duct 1: 860.... 880 C

-- meal chute 1: 840.... 860 C

-- tertiary air: 850.... 950 C

-- after pre heater: 320.... 340 C

Press.: -- Kiln Hood: - 0,1- 0,3 mbar

-- Kiln Inlet: - 4. .- 6 mbar

-- Gas Duct 1: -14.- 16 mbar

-- after Pre heater: - 50.- 60 mbar

Clinker cooler: -- Chamber 1 pressure 50... 60 mbar

-- Secondary air temp. 900.... 1000 C

-- Cooler exhaust air temp. 250.... 300 C

-- Clinker temperature 80... 100 C


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-- to burn a good clinker quality, but prevent damages in the refractory.

-- to build and to keep good coating formation.

as protection of kiln bricks and reduced kiln shell temperature,

but also to avoid coatings rings etc.

-- good heat transfer to the material by radiation and convection.

Burner- / Flame Adjustment


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Burner- / Flame Adjustment

Main Burner Fuel: - Temperature of sintering zone

- Kiln inlet temperature

- Kiln main drive power (A or kW)

- Free lime (CaO) in the clinker

Total Fuel: - Specific heat consumption (kcal/kg clinker)

- Temperatures of meal and gas in the pre-heater

Fuel Calcinator: - Hot meal temperature

- Degree of calcination (92...95%)

Attention: Orientation only! Parameters/Results may overlap!!!


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Gas conditions: CO ---> to be prevented!!!min. of Oxygen is required!

Oxygen after pre-heater: ~ 4 % by damper or fan speed

Oxygen after stage II ~ 2 3 % by damper or fan speed

Kiln inlet: ~ 1,5 - 2 % by Tertiary Air Flaps

-- more open:

Oxygen stage II up / kiln inlet down!!!

-- more closed:

Oxygen stage II down / kiln inlet up!!!

Optimal Operation:


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Kiln hood pressure Target:

-0.1 mbar

Actuator: Cooler exhaust fan speed or damper

Under grate press. Target: constant at set point

(chamber 1 or 2) Actuator hydraulic drive for grates

Cooler air flow Target: constant at set pointActuator: Cooler fan speed or damper position

Press. after kiln ID fan Target: - 5 mbar

Actuator: EP-fan speed or damper position

Temp. after Target: 160-190 CCooling tower Actuator: Water valve at the return line

Main control loops of a kiln plant


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Normal shut-down of the kiln plant

Generally

-- reducing of the kiln feed in steps of app. 5%-- minimal kiln feed is about 4050%

-- an empty kiln can be easier heated-up and re-started!

Stop of PC-Burners and kiln feed

Reduce fuel at the main burner

Reduce pre-heater draft

Close the Tertiary air sliders / flaps

Stop of main burner

primary fans to be kept in operation (for cooling!!!)

Close the DOPOL-flaps to 10-15%


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Normal shut-down of the kiln plant

DOPOL-fan: dampers to be closed

Clinker cooler fans: dampers to be closed

Cooler exhaust air fan: controlled by kiln hood pressure measurement,

or set to minimum value

Kiln to be tilted! - during cooling down

- if raining continuously with auxiliary drive

- 1st and 2nd hour each 10 min 120

- 3rd hour each 15 min 120

- 4th hour each 20 min 120

- 5th till 8th hour each 25 min 120

- then... each 30 min 120

...till a kiln shell temperature (sintering zone) of about 100C is reached

cooler track units: to be operated in intervals


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Emergency power consumers

-- Emergency lighting

-- Communication systems

-- UPS unit for computer and process automation equipment

-- Control voltage for the total kiln plant

-- Cooling water supply system

-- Dampers in DOPOL exhaust gas duct-- Kiln auxiliary drive including lubrication)

-- Oil pumps for circulation lubrication system for roller bearings

-- Primary air fans for all burners including actuators

-- Protective air fan for sintering zone pyrometer

-- Actuators for damper in tertiary air duct

-- Fan for kiln outlet cooling

-- Cooling air fans for roller crusher

-- Cooling air fans for recuperation section


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StopTimer

Filter dust transport

CLINKER Transport

5 min

Stop Timer

15 min

failure of 2 or

more air fans

failure of one fan

CALCINERBURNER

Stop Timer

0,5 hour

FILTER FAN

KILN ID-FAN

STOP

STOP

STOP

STOP

STOP

STOP

STOP

STOP

STOP

MAIN DRIVE

KILN FEED

MAIN BURNER

PRIMARY AIR FAN

CO

Stage 2 > Max Max

Temperature

Preheater > Max Max

CO

Preheater > Max Max

TemperaturePreheater > Max Max

Grate 1

CLINKER

COOLER

CLINKER

COOLER

CLINKER

COOLERExhaust air

fan

STOP

STOP

StopTimer

5 min

MainPlantIn

terlock

Rotary Kiln

Grate 2


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KilnLine Operation

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