174105579-Start-Up-Procedures.pdf

7/27/2019 174105579-Start-Up-Procedures.pdf

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K i ln Start-up Procedu res Presentat ion & Instructor Notes

Operator DevelopmentKiln Control Best Practices







Pyro-processing: Kiln Control 4

Kiln Start-up Procedures

Learning Objectives

At the end of this session you should be:

fami l iar with the start-up BP

able to l ist the major steps invo lved

name the requ ired pro cess ind icators

able to explain the cus tom izat ion dif ferences w ith

you r plants SOPs



End-users: Production Operators/technicians

Content: Checks p r ior to start-up

Kiln preheat preparat ion: Bu rner pip e, Refractory

Kiln Preheat schedu le: Parameters to monitor

Tire Creep

Turning schedule

Start-up Process data sheet

Kiln lining preheat schedule Feeding raw m ix

What to do in c ase of deviat ions

Start-up Pos t-aud it

Kiln Start-up Procedures




Pre Start-up Checks

Dry run & complete check sheets

Feed Sys tem

Cooler & Clinker Handl ing

ID fan

Coal Conveying System

Ki ln Baghouse ESP

Pre-heat sy stem

Pre-heater tour

Bu rner Pipe al ignment

Common & auxi l iary equipment

Check sheets should include room for comments

& assigned responsibility


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Sample:

Pre Start-up Checks

Feed System

recirculat ion mode & cal ibrate

if no recirculation ... run briefly check operation, leaks

run dust evacuat ion (e levators, screws & pumps)

Cooler & clinker handling

run cooler dr ives & inspect for loose grates

check cooler alignment while running

run for 12 hours (mechanical integrity)

Breaker, fans, con veying equ ipment

alignment, motor direction, automation & full motion

operation & seal of all Plattco valves

calibration of all pressure transmitters



Kiln Preheat Prep

Burner pipe alignment

exact ly w here is th e pipe in relat ion to the ki ln

laser al ignm ent measu red in 3 places

Refractory preparation manage the ins tallat ion o f refractory ,

proper installation is key to longevity

fo l low p rocedu re for preheat ing to maximize br ick l i fe

Burner pipe lining

pou red castable mus t cure 24 hrs before remov ing

forms or at temp t ing bake-out



Burner Pipe Lining Preheat Schedule

Four inch refractory lining

50

100

150

200 200 200 200 200

250

300

350

400

450

500

550

600 600 600 600 600

0

100

200

300

400

500

600

700

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Temperature C

bake-out - adjust per inch of refractory



Kiln Preheat Schedule

Determined Prior to Start-up

10-14 process parameters should be recorded l ist di f fers for precalciner & long ki lns

Example list (incomplete) oxygen

back -end, BZ temperatures

tyre creep, tyre & bear ing temperature

hood pressure

fuel con sumpt ion

turn ing schedule

Kiln shell temperature ( BZ)

ESP/Baghouse



Kiln Start-up Process Data Sheet

Date: _________________ Time of Flame On:_________________ Preheat Schedule: -

_____ Hours

___________________ Hour of the

Preheat

Tyre Creep

#1 Tyre

Tyre Creep

#2 tyre

Hour of the

Day

Chain Gas

Temp

Fuel Rate Feed End

Oxygen

Swirl Air

Setting

Axial Air

Setting

Feed End

Temp

I.D. Fan

Speed



Tyre Creep Control

Minimum heating-up period

determ ined by the t ime required to s tabi l ize the

temperatur e difference, hence the clearance

shel l heats up faster than tyre

Tyre #2 is critical

too rapid heat ing w i l l constr ic t ki ln shel l

resul t in permanent shel l deform ation

excessive tyre sl ip after no rmal temp. regained

Creep should be monitored at regular intervals i f low, heat ing shou ld be slowed




Turning Schedule

Ensures slow, uniform heating of the kiln and

refractory

increase in temperature over t ime

allows for the expansion of refractory and s hel l

br ick remains in p lace and shel l expands uni form ly

along its long itudinal axis

Too Slow

overheat ing o f refracto ry and shel l

shell & refractory damage (e.g. “duck - nesting” )

Too Fast

longer preheat t imes du e to poo r heat transfer

potent ia l br ick spiral ing




Turning Schedule Example

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

210 C TO 450

C TURN 90

TO 120

EVERY 30 MINUTES



750 C UP TO FEEDING CONTINUOUS TURNING

Reference temperature (Lower

stage)




Kiln Preheat Schedule

Major & short shutdown

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

K i l n e x i t g a s t e m p e r a t u r e a t i n l e t a r e a

Heating-up Time, hours

º

{START OF MATERIAL FEED ACCORDING TO

{KILN TYPE AND OPERATING PROCESS

1300*

1200*

900*

600*

300*

curve 1:

Limited

repairs

30-35 C/h

curve 2:

Complete

relining

20-25 C/h




Kiln Preheat Schedule - Detailed

stepped to inclu de two holdin g patterns (300, 550 C)

allows refractor to “catch- up” with gas temperature

24 HOUR PREHEAT SCHEDULE

0

100

200

300

400

500

600

700

800

900

1000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28HOURS

T E M P E R A T U R E

0.0

5.0

10.0

15.0

20.0

25.0

O X Y G E N STG 4 TEMP

STG 1 TEMP

STG1 OXYGEN




Feeding of Raw Material

Raw material feed “ON”

when burning zone is ready

Start of feed and arrival in sintering (burning) zone is

critical to tyre creep

fue l supply m ust be increased

com pensate for heat absorb ed by raw mater ial

Close attention to tyre slip

i f sl ip ceases, coun ter measures m us t be taken

Limited feed may be introduced prior to optimaltemperature to assist coating




Start-up Post Audit

Analyze deviations from the planned schedule to

continuously improve operational performance

produ ct ion coo rdinator , ki ln coach & operators

ident i fy reason s for deviat ion s

make jo int recommendat ions

correct SOPs and circu late among al l operators

Develop a table of variances and explanations

Use our collective knowledge & experience to

become the world’s best cement producer!

174105579-Start-Up-Procedures.pdf

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