Combustion And Ten Golden Rules
This document was uploaded by user and they confirmed that they have the permission to share it. If you are author or own the copyright of this book, please report to us by using this DMCA report form. Report DMCA
Overview
Download & View Combustion And Ten Golden Rules as PDF for free.
More details
- Words: 860
- Pages: 30
COMBUSTION AND TEN GOLDEN RULES Murat SOYLU October 2012
RULE 1 • Obtaining finer material on 90 and 200 µ residues decreases the burning heat and cement grinding specific energy. • This also makes the strength higher. • Decrease the residue amount from 20% to 10% on 100 µ mesh, gain 4 kWh/t energy.
By Producing Finer Meal • Saving for: – Burning fuel energy, – Cement grinding energy Is obtained…
Finer Meal = kW
25
kWh/t
y = - 0.4267 x + 29.759
y = -0.4267x + 29.759 2 R = 0.9145
24
23
22
21
(%) > 100 µm of raw mix
20 12
14
16
18
20
22
Finer Meal = Energy Saving
%Free lime 8.00
15%>100 Microns- Industrial as it is 6.00
5%>100
- lab grinding of residue
5%>100
- complete grinding
4.00
2.00
0.00 1400
1450
1500
1550
Temperature °C 1600
Finer Meal = Saving on Grinding Energy
Rule 2 • Short burning zone effects the grindability and strength development positively.
Hot and Short Burning Zone • Makes the clinker easily grindable.
Short Burning Zone = Better Grindability 75 70
BB10 (kWh/t)
65 60 55 50
Nm
45 600
700
800
900
1000
Kiln Motor
1100
1200
1300
1400
1500
Short Burning Zone = Better Grindability
Kiln motor current, A
(Grindability and Burning Zone Length)
500
80
450
75
Increasing grindability
400
70
350
65
300
60
250
Decreasing kiln motor current
55
200 30/05/1995 04:00
50 30/05/1995 12:00
30/05/1995 20:00
31/05/1995 04:00
31/05/1995 12:00
Rule 3
• Stable conditions requires oxidizing environment. • Reducing environment increases the volatile cycle. • This causes the fluctuations of alkali sulphate and circulating elements. • Thus, bad clinker is produced.
Let the Kiln Breathe • With the reduction of volatile matter; – Stable kiln operation, – Stable clinker quality Are achieved.
Rule 4 • Increase of clinker free lime content decreases the initial and final setting time. • Limestone addition accelerates the initial and final setting time. – Key Values; • Increase of free lime from 0.5% to 1.5%, initial and final setting time decreases for 40-50 minutes.
Addition of small amount of free lime • Makes the clinker
Decrease of Free Lime and Setting Time
Initial Setting ( min. )
180
160 140 120 %
100 0.2
0.4
0.6
0.8
1
Free Lime in Clinker
1.2
1.4
1.6
Rule 5 • Increasing the C3S proportion of clinker develops the 1,2,3 and 7 day strength. After 28 days, strength development may be less because of C2S effect. – Key Values; • +10% C3S development.
+2 to 5 MPa early strength
In short and middle term,
C3S increase 10% -10% C2S
+ 5 to 6 MPa.
STRENGTH (C3S)
60.0
R-28d
55.0 50.0
R-7d
N/mm
2
45.0 40.0 35.0
R-2d
30.0 25.0
R-1d
20.0 15.0 45.0
50.0
55.0
C3 S
60.0
Rule 6 Hard to Grind…
C 2S + 10 % C2S
+ 4 kWh/t
Grindability
Case 1
Case 2
D
94,50
98,60
+ 4,10
C3 S
56
64
+8
C2 S
22
15
-7
C3 A
10,20
9,60
=
C4 A F
8,20
8,00
=
Free. CaO
1,27
1,30
=
kWh/t BB10
46,70
44,40
- 2,30
SSB BB10 ( cm2/g )
3680
3710
=
kWh/t Industrial
53,10
51,60
- 1,50
28 d. Industrial
32,0
35,5
+ 3,5
% LSF Clinker
Rule 7 • Whatever the formation is, alkalis do not affect the 28 days strength positively. – Key Values; • +0.1% increase in equivalent Na2O
• -1 N/mm2 at 28 days
Effect of Alkalis
70
28 –days strength (MPa)
65 60 55 50 45 0
0.2
0.4
0.6
0.8
1
% Total Alkalis
1.2
1.4
1.6
1.8
2
Rule 8 • Regarding early strength, with the optimum sulphate content, soluble alkalis, especially alkali sulphates develops the early strength. – Key Values; – +0.1% Equivalent Na2O – +0.5 to 1.5 N/mm2 @ 1 day strength
ALKALI
1 K2O and 1 SO3 (MOLAR)
SULPHATES
1 K2SO4 (Soluble)
These soluble alkalis are good for 1-2 days strength.
Rule 9 • Change of crystal formation of C3A from cubic to orthorhombic, – – – –
Bad burnability, Process problems, Sensitivity to aging Decrease in 28 days strength.
Alkalis more than sulphates • Excess alkalis go into the crystal structure
Na2O, C3A
NC8A3
K2O, C2S
KC23S12
DECREASE IN 28 DAYS STRENGTH
Rule 10 • If the clinker SO3 amount is more the molar saturation rate, a significant increase is observed on clinker fineness and grindability. – Key Values; • +1% excess SO3
+5 kWh/t
SO3 > Na2O , K2O Dusty Clinker, More kWh/t Cement Grinding
+ 1% Excess SO3
+ 5 kWh / t
( @ 350 m2 / kg )
Excess Sulphates * Finer Clinker 100
% Passing
80 60
0,1 % S03
40
1,3 % SO3
20 0 0
5
10
15
Screen ( mm )
20
25
Excess Sulphates 100
60
0,1 % SO3 2,9 % SO3
40 20 0 5
10
15
20
25
30
35
Screen( mm )
* Finer Clinker
100 80
Passing
0
%
% Passing
80
60
0,1 % SO3
40
1,2 % SO3
20 0 0
10
20
30
40
Screen( mm )
50
60
RULE 1 • Obtaining finer material on 90 and 200 µ residues decreases the burning heat and cement grinding specific energy. • This also makes the strength higher. • Decrease the residue amount from 20% to 10% on 100 µ mesh, gain 4 kWh/t energy.
By Producing Finer Meal • Saving for: – Burning fuel energy, – Cement grinding energy Is obtained…
Finer Meal = kW
25
kWh/t
y = - 0.4267 x + 29.759
y = -0.4267x + 29.759 2 R = 0.9145
24
23
22
21
(%) > 100 µm of raw mix
20 12
14
16
18
20
22
Finer Meal = Energy Saving
%Free lime 8.00
15%>100 Microns- Industrial as it is 6.00
5%>100
- lab grinding of residue
5%>100
- complete grinding
4.00
2.00
0.00 1400
1450
1500
1550
Temperature °C 1600
Finer Meal = Saving on Grinding Energy
Rule 2 • Short burning zone effects the grindability and strength development positively.
Hot and Short Burning Zone • Makes the clinker easily grindable.
Short Burning Zone = Better Grindability 75 70
BB10 (kWh/t)
65 60 55 50
Nm
45 600
700
800
900
1000
Kiln Motor
1100
1200
1300
1400
1500
Short Burning Zone = Better Grindability
Kiln motor current, A
(Grindability and Burning Zone Length)
500
80
450
75
Increasing grindability
400
70
350
65
300
60
250
Decreasing kiln motor current
55
200 30/05/1995 04:00
50 30/05/1995 12:00
30/05/1995 20:00
31/05/1995 04:00
31/05/1995 12:00
Rule 3
• Stable conditions requires oxidizing environment. • Reducing environment increases the volatile cycle. • This causes the fluctuations of alkali sulphate and circulating elements. • Thus, bad clinker is produced.
Let the Kiln Breathe • With the reduction of volatile matter; – Stable kiln operation, – Stable clinker quality Are achieved.
Rule 4 • Increase of clinker free lime content decreases the initial and final setting time. • Limestone addition accelerates the initial and final setting time. – Key Values; • Increase of free lime from 0.5% to 1.5%, initial and final setting time decreases for 40-50 minutes.
Addition of small amount of free lime • Makes the clinker
Decrease of Free Lime and Setting Time
Initial Setting ( min. )
180
160 140 120 %
100 0.2
0.4
0.6
0.8
1
Free Lime in Clinker
1.2
1.4
1.6
Rule 5 • Increasing the C3S proportion of clinker develops the 1,2,3 and 7 day strength. After 28 days, strength development may be less because of C2S effect. – Key Values; • +10% C3S development.
+2 to 5 MPa early strength
In short and middle term,
C3S increase 10% -10% C2S
+ 5 to 6 MPa.
STRENGTH (C3S)
60.0
R-28d
55.0 50.0
R-7d
N/mm
2
45.0 40.0 35.0
R-2d
30.0 25.0
R-1d
20.0 15.0 45.0
50.0
55.0
C3 S
60.0
Rule 6 Hard to Grind…
C 2S + 10 % C2S
+ 4 kWh/t
Grindability
Case 1
Case 2
D
94,50
98,60
+ 4,10
C3 S
56
64
+8
C2 S
22
15
-7
C3 A
10,20
9,60
=
C4 A F
8,20
8,00
=
Free. CaO
1,27
1,30
=
kWh/t BB10
46,70
44,40
- 2,30
SSB BB10 ( cm2/g )
3680
3710
=
kWh/t Industrial
53,10
51,60
- 1,50
28 d. Industrial
32,0
35,5
+ 3,5
% LSF Clinker
Rule 7 • Whatever the formation is, alkalis do not affect the 28 days strength positively. – Key Values; • +0.1% increase in equivalent Na2O
• -1 N/mm2 at 28 days
Effect of Alkalis
70
28 –days strength (MPa)
65 60 55 50 45 0
0.2
0.4
0.6
0.8
1
% Total Alkalis
1.2
1.4
1.6
1.8
2
Rule 8 • Regarding early strength, with the optimum sulphate content, soluble alkalis, especially alkali sulphates develops the early strength. – Key Values; – +0.1% Equivalent Na2O – +0.5 to 1.5 N/mm2 @ 1 day strength
ALKALI
1 K2O and 1 SO3 (MOLAR)
SULPHATES
1 K2SO4 (Soluble)
These soluble alkalis are good for 1-2 days strength.
Rule 9 • Change of crystal formation of C3A from cubic to orthorhombic, – – – –
Bad burnability, Process problems, Sensitivity to aging Decrease in 28 days strength.
Alkalis more than sulphates • Excess alkalis go into the crystal structure
Na2O, C3A
NC8A3
K2O, C2S
KC23S12
DECREASE IN 28 DAYS STRENGTH
Rule 10 • If the clinker SO3 amount is more the molar saturation rate, a significant increase is observed on clinker fineness and grindability. – Key Values; • +1% excess SO3
+5 kWh/t
SO3 > Na2O , K2O Dusty Clinker, More kWh/t Cement Grinding
+ 1% Excess SO3
+ 5 kWh / t
( @ 350 m2 / kg )
Excess Sulphates * Finer Clinker 100
% Passing
80 60
0,1 % S03
40
1,3 % SO3
20 0 0
5
10
15
Screen ( mm )
20
25
Excess Sulphates 100
60
0,1 % SO3 2,9 % SO3
40 20 0 5
10
15
20
25
30
35
Screen( mm )
* Finer Clinker
100 80
Passing
0
%
% Passing
80
60
0,1 % SO3
40
1,2 % SO3
20 0 0
10
20
30
40
Screen( mm )
50
60
Related Documents
Combustion And Ten Golden Rules
June 2020 6
Golden Rules Of Life
May 2020 8
100 Golden Grammar Rules
June 2020 9
100 Golden Grammar Rules
June 2020 15
Golden Rules Ceremony
June 2020 7
Combustion
April 2020 18More Documents from ""
Analysis Toolpak- Exponential Smoothing.pdf
April 2020 17
Amrit Nhi Milega.pdf
April 2020 9
Pre-homogenization Factor.pdf
July 2020 5
Raw Materials Using Machine Vision.pdf
July 2020 6
