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Raceway Flame Temperature With Multiple Injectants
C H A P T E R
39 Raceway Flame Temperature With Multiple Injectants O U T L I N E 39.1 Calculating the Raceway Flame Temperature With Tuyere Injectants 39.2 Raceway Matrix 39.2.1 Mass of Al2O3 in Falling Coke Particles 39.2.2 Mass of SiO2 in Falling Coke Particles 39.3 Calculation of Raceway Input Enthalpy, Output Enthalpy, and Flame Temperature
345
349
39.4 Results
352
346
39.5 List of Raceway Equations of This Chapter in Table 39.2
353
349
39.6 Summary
354
Exercises
354
Reference
354
349
• H2O(g)-in-blast (from humidity and steam), and • natural gas.
In this chapter, we automatically calculate tuyere raceway flame temperatures with simultaneous tuyere injection of;
Blast Furnace Ironmaking DOI: https://doi.org/10.1016/B978-0-12-814227-1.00039-7
349
346
39.1 CALCULATING THE RACEWAY FLAME TEMPERATURE WITH TUYERE INJECTANTS
• pulverized coal, • pure oxygen,
39.3.1 Raceway Output Enthalpy 39.3.2 Flame Temperature Calculation
Fig. 39.1 shows a raceway with these injectants plus falling CAl2O3SiO2 coke particles. Raceway flame temperature must be kept within a narrow range B2000 C to 2300 C while blast furnace’s inputs are being varied to
345
© 2020 Elsevier Inc. All rights reserved.
346
39. RACEWAY FLAME TEMPERATURE WITH MULTIPLE INJECTANTS
Table 39.2 (split for clarity) is the flame temperature matrix of this chapter with the bottom-segment inputs and outputs of Table 39.1. It consists of;
FIGURE 39.1 Sketch of blast furnace raceway with simultaneous tuyere injection of coal, oxygen, H2O(g), and natural gas. Note that the falling coke and tuyere-injected coal both contain Al2O3 and SiO2. Raceway matrix Table 39.1 and Eqs. (39.3), (39.5), and (39.6) calculate the temperature of the departing gases and solids, that is, the raceway flame temperature. Note that the raceway output gas contains only CO(g) and H2(g), that is, no CO2(g) or H2O(g). This is discussed in Chapter 14, Raceway Flame Temperature.
optimize a blast furnace operation, for example, to minimize molten iron production cost. The flame must be; 1. hot enough to ensure that the blast furnace’s product iron and slag are completely molten at 1500 C, but 2. not so hot as to impact the reduction and melting behavior of the ferrous raw materials. This can lead to irregular burden descent characterized by the burden hanging and slipping.
1. steady-state raceway input O2 and N2-inblast air masses, expressed by Eqs. (39.7) and (39.8); 2. injected coal, oxygen, H2O(g), and natural gas raceway input masses of Chapter 38, Bottom-Segment Calculations With Multiple Injectants, expressed by Eqs. (39.15)(39.18); 3. raceway C, O, N, H, Al2O3, and SiO2 mass balance Eqs. (39.9)(39.14); and 4. masses of Al2O3-in-coke and SiO2-in-coke falling into raceway of Fig. 39.1, described below Eqs. (39.1)(39.2).
39.2.1 Mass of Al2O3 in Falling Coke Particles The amount of Al2O3 falling into the raceway is described by; "
"
coke particles mass C in falling
#
" 5
mass% Al2 O3 "
coke particles
in coke mass% C
#
#
in coke
or "
mass Al2 O3 in falling coke particles
or subtracting both sides;
39.2 RACEWAY MATRIX
#
3 mass% Al2 O3 in coke 5 0:0333 5 90 mass% C in coke
The objectives of this chapter are to; 1. build a spreadsheet that will automatically calculate raceway flame temperatures from bottom-segment calculated inputs and outputs, with multiple injectants, and 2. plot and discuss the effect of injectant amounts on raceway flame temperature.
mass Al2 O3 in falling
052 1
The bottom-segment inputs for multiple injectants are provided in Table 39.1, all values are per 1000 kg of Fe in product molten iron.
BLAST FURNACE IRONMAKING
#
" 15
mass C in falling coke particles
# 0:0333
mass Al2 O3 in falling 1 coke particles
mass Al2 O3 in falling coke particles mass C in falling coke particles
from
1
0:0333
(39.1)
TABLE 39.1
Bottom-Segment Inputs and Outputs as Calculated by Bottom-Segment Matrix Table 38.1
This is a copy of Table 38.2.
TABLE 39.2 Raceway Matrix With Simultaneous Tuyere Injection of Coal, Oxygen, H2O(g), and Natural Gas (Matrix is Split for Clarity)
All its equations are given at the end of this chapter. Column C’s numerical values are from Table 39.1. For continuity with these values: Cell C68 5 C36, Cell C69 5 C37, Cell C78 5 C59, Cell C79 5 C60, Cell C80 5 C61, Cell C81 5 C62, and Cell C82 5 C63.
39.3 CALCULATION OF RACEWAY INPUT ENTHALPY, OUTPUT ENTHALPY, AND FLAME TEMPERATURE
39.2.2 Mass of SiO2 in Falling Coke Particles Likewise, the amount of SiO2 falling into the raceway is described by;
mass SiO2 in
where the numerical values are the enthalpies (H /MW) of the substances at the temperatures of Fig. 39.1. Eq. (39.3) is given in Table 39.4 as;
5 C95 1:239 1 C96 1:339
1 falling coke particles mass C in falling 7 mass% SiO2 in coke 1 90 mass% C in coke coke particles
052
1 C97 2:488 1 C98 ð214:67Þ 1 C99 ð213:44Þ 1 C105 ð21:2Þ 1 C106 1:239 1 C107 ð210:81Þ 1 C108 ð24:52Þ 1 C109 0
or 052
mass SiO2 in
1 falling coke particles mass C in falling 1 0:0778 coke particles
349
(39.4)
Eq. (39.4) is like Eq. (30.6) with additional terms for; (39.2)
The raceway matrix with these equations is shown in Table 39.2. Its calculated values are shown in Table 39.3.
39.3 CALCULATION OF RACEWAY INPUT ENTHALPY, OUTPUT ENTHALPY, AND FLAME TEMPERATURE Raceway input enthalpy with coal, oxygen, H2O(g), and natural gas injection is given by the following equation;
1. falling 1500 C Al2O3(s)-in-coke and SiO2(s)in-coke, and 2. injected coal, oxygen, and H2O(g).
39.3.1 Raceway Output Enthalpy Chapter 14, Raceway Flame Temperature, specifies that there is no conductive, convective, and radiative heat loss from the raceway, that is; ½total raceway output enthalpy 1 ½zero 5 ½total raceway input enthalpy
½total raceway input enthalpy 5 ½mass O2 entering raceway in blast air 1:239
(14.13)
so that;
1 ½mass N2 entering raceway in blast air 1:339 1 ½mass C entering raceway in falling coke particles 2:488 1 ½mass Al2 O3 entering raceway in falling coke particles 2 14:67 1 ½mass SiO2 entering raceway in falling coke particles
½total raceway output enthalpy 5 ½total raceway input enthalpy
(39.5)
as shown in Table 39.4.
2 13:44 1 ½mass tuyere-injected coal entering raceway 2 1:2 1 ½mass O2 entering raceway in tuyere-injected oxygen 1:239
1 ½mass through-tuyere H2 O g entering raceway 2 10:81 1 ½mass injected natural gas entering raceway 2 4:52 1 ½mass additional tuyere injectant 0
39.3.2 Flame Temperature Calculation Chapter 18, Raceway Flame Temperature With CH4(g) Tuyere Injection, shows that raceway flame temperature with H entering the blast furnace is;
(39.3)
BLAST FURNACE IRONMAKING
TABLE 39.3 Raceway Calculated Values with Tuyere Injection of 60 kg of Coal, 30 kg of Oxygen, and 18 kg of H2O(g), Calculated by Eq. (19.2), and 60 kg of Natural Gas
Eqs. (39.4), (39.5), and (39.6) use these values to calculate raceway input enthalpy, output enthalpy, and raceway adiabatic flame temperature.
TABLE 39.4
Equations for Calculating Raceway Input Enthalpy, Output Enthalpy, and Flame Temperature
The equations are like those in Table 30.1 but with more terms.
352 (
39. RACEWAY FLAME TEMPERATURE WITH MULTIPLE INJECTANTS
raceway output
ðflameÞ enthalpy mass CO in raceway 2 ð 24:183Þ output gas mass N2 in raceway ð 20:2448Þ 2 output gas ) mass H2 in raceway 2 ð2 4:130Þ output gas (" # 5 Tflame (18.9) mass CO in raceway 0:001310 output gas " # mass N2 in raceway 1 0:001301 output gas " # ) mass H2 in raceway 0:01756 1 output gas
where the numerical values are from 1800 C to 2300 C enthalpy equations of Table J.4. The flame temperature of this chapter is calculated similarly, but with additional terms for the raceway’s output Al2O3(s) and SiO2(s), which are; mass Al2 O3 in raceway ð16:72Þ output gas
and
2
39.4 RESULTS Table 39.4 shows that the raceway temperature with; • 60 kg of injected pulverized coal, • 30 kg of injected pure oxygen, • 18 kg H2O(g)-in-blast (Cell C61, Table 39.1), and • 60 kg of natural gas is 1923 C. The flame temperatures with other combinations of injectants are shown in Fig. 39.2. Our calculations confirm that; • oxygen injection increases raceway flame temperature, but • coal injection, H2O(g)-in-blast, and natural gas injection decrease flame temperature. These same conclusions are reached in; • Chapter 17, Raceway Flame Temperature with Oxygen Enrichment; • Chapter 16, Raceway Flame Temperature with Pulverized Carbon Injection;
mass SiO2 in raceway ð15:47Þ output gas
on the top of Eq. (18.9), and;
and
mass Al2 O3 in raceway ð0:001887Þ output gas
mass SiO2 in raceway ð0:001427Þ output gas
on the bottom of Eq. (18.9) where the numerical values are from Appendix J. In spreadsheet form, the equation is fJ116 2 C100 ð2 4:183Þ 2 C101 ð2 0:2448Þ 2 C102 ð2 4:13Þ 2 C103 ð2 16:72Þ 2 C104 ð2 15:47Þg Tflame 5 fC100 0:00131 1 C101 0:001301 1 C102 0:01756 1 C103 0:001887 1 C104 0:001427g
(39.6)
FIGURE 39.2 Effect of increasing individual tuyere input quantities on raceway flame temperature while holding the others injectants constant. Oxygen increases flame temperature. Coal, H2O(g), and natural gas decrease flame temperature.
BLAST FURNACE IRONMAKING
353
39.5 LIST OF RACEWAY EQUATIONS OF THIS CHAPTER
• Chapter 19, Raceway Flame Temperature with Moisture in Blast Air; and • Chapter 30, Raceway Flame Temperature with Natural Gas Injection. Fig. 39.2 also shows that 25 C natural gas is more effective at lowering flame temperature than 1200 C H2O(g).
39.5 LIST OF RACEWAY EQUATIONS OF THIS CHAPTER IN TABLE 39.2 A number of new equations were added to the raceway matrix to allow for RAFT calculation with multiple injectants. These equations are: Row 68. O2 entering raceway in blast air:
347 5
mass O2 entering raceway 1 in blast air
(39.7)
Row 69. N2 entering raceway in blast air:
1145 5
mass N2 entering raceway 1 in blast air
(39.8)
Row 70. Raceway oxygen balance:
mass O2 entering raceway 1 in blast air " # mass tuyere-injected coal 0:046 entering raceway
052
" 2
mass O2 entering raceway
" " 2
mass tuyere-injected natural
#
gas entering raceway "
1
mass through-tuyere input 0:888 H2 O g entering raceway
mass CO in raceway output gas
#
0:01
2
mass C entering raceway
in falling coke particles mass tuyere-injected coal
1
0:810 entering raceway mass tuyere-injected natural 2 0:734 gas entering raceway mass CO in raceway 1 0:429 output gas
(39.10)
Row 72. Raceway nitrogen balance: 052
mass N2 entering raceway
in blast air mass tuyere-injected coal
1
0:009 entering raceway mass tuyere-injected natural 2 0:017 gas entering raceway mass N2 in raceway 1 1 output gas
(39.11)
Row 73. Raceway hydrogen balance: mass tuyere-injected coal 052 0:055 entering raceway " # mass through-tuyere input 0:112 H2 O g entering raceway mass tuyere-injected natural 2 0:240 gas entering raceway mass H2 in raceway 1 1 output gas
1
#
05 2
(39.12)
Row 74. Al2O3(s) entering raceway in falling coke:
#
in tuyere-injected pure oxygen
Row 71. Raceway carbon balance:
052
(39.9) 1
mass Al2 O3 entering raceway in falling coke particles mass C entering raceway in falling coke particles
Row 75. falling coke:
SiO2
entering
1
0:0333
raceway
mass SiO2 entering raceway 1 in falling coke particles mass C entering raceway 1 0:0778 in falling coke particles
(39.1)
in
052 0:571
BLAST FURNACE IRONMAKING
(39.2)
354
39. RACEWAY FLAME TEMPERATURE WITH MULTIPLE INJECTANTS
39.6 SUMMARY
Row 76. Raceway Al2O3 balance: 052
mass Al2 O3 entering raceway
1
in falling coke particles mass tuyere-injected coal
0:024 entering raceway mass Al2 O3 ðsÞ in raceway 1 1 output gas
(39.13)
Row 77. Raceway SiO2 balance:
mass SiO2 entering raceway
052
in falling coke particles mass tuyere-injected coal
entering raceway mass SiO2 ðsÞ in raceway
1
output gas
1
0:056
1
(39.14)
Row 78. Mass tuyere-injected coal entering raceway: 60 5
mass tuyere-injected coal 1 entering raceway
(39.15)
This chapter shows how to automatically calculate tuyere raceway flame temperatures from bottom-segment calculated values with multiple injectants. It also shows how to set up the raceway matrix and equations for additional tuyere injectants. Matrix calculations of this chapter show that; 1. oxygen injection increases flame temperature, and 2. pulverized coal, H2O(g), and natural gas injection decrease flame temperature as reported by Geerdes et al. (p 115).1 Chapter 40, Top-Segment Calculations With Multiple Injectants, will show how to similarly calculate top gas temperatures.
Row 79. Mass O2 in tuyere-injected pure oxygen entering raceway: mass O2 entering raceway 1 30 5 in tuyere-injected pure oxygen
EXERCISES
(39.16)
Row 80. Mass through-tuyere input H2O(g) entering raceway:
mass through-tuyere input 18 5 1 H2 O g entering raceway
(39.17)
Row 81. Mass tuyere-injected natural gas entering raceway: 60 5
mass tuyere-injected natural 1 gas entering raceway
(39.18)
Row 82. Mass additional tuyere injectant entering raceway: 05
mass additional tuyere 1 injectant entering raceway
All masses in this exercise are kg per 1000 kg of Fe in product molten iron. 39.1. The blast furnace management team of Fig. 39.1 is planning to inject 20 kg of oil into their furnace along with all of the existing through-tuyere injectants of Table 38.2. They wish to know how this oil will affect their raceway flame temperature. Please predict the effect and then calculate it. Use the oil composition of your results in Exercise 38.1.
Reference (39.19)
1. Geerdes M, Chaigneqeau R, Kurunov I, Lingiardi O, Ricketts J. Modern blast furnace ironmaking (an introduction). 3rd ed. Amsterdam: IOS Press BV; 2015. p. 115.
BLAST FURNACE IRONMAKING
39 Raceway Flame Temperature With Multiple Injectants O U T L I N E 39.1 Calculating the Raceway Flame Temperature With Tuyere Injectants 39.2 Raceway Matrix 39.2.1 Mass of Al2O3 in Falling Coke Particles 39.2.2 Mass of SiO2 in Falling Coke Particles 39.3 Calculation of Raceway Input Enthalpy, Output Enthalpy, and Flame Temperature
345
349
39.4 Results
352
346
39.5 List of Raceway Equations of This Chapter in Table 39.2
353
349
39.6 Summary
354
Exercises
354
Reference
354
349
• H2O(g)-in-blast (from humidity and steam), and • natural gas.
In this chapter, we automatically calculate tuyere raceway flame temperatures with simultaneous tuyere injection of;
Blast Furnace Ironmaking DOI: https://doi.org/10.1016/B978-0-12-814227-1.00039-7
349
346
39.1 CALCULATING THE RACEWAY FLAME TEMPERATURE WITH TUYERE INJECTANTS
• pulverized coal, • pure oxygen,
39.3.1 Raceway Output Enthalpy 39.3.2 Flame Temperature Calculation
Fig. 39.1 shows a raceway with these injectants plus falling CAl2O3SiO2 coke particles. Raceway flame temperature must be kept within a narrow range B2000 C to 2300 C while blast furnace’s inputs are being varied to
345
© 2020 Elsevier Inc. All rights reserved.
346
39. RACEWAY FLAME TEMPERATURE WITH MULTIPLE INJECTANTS
Table 39.2 (split for clarity) is the flame temperature matrix of this chapter with the bottom-segment inputs and outputs of Table 39.1. It consists of;
FIGURE 39.1 Sketch of blast furnace raceway with simultaneous tuyere injection of coal, oxygen, H2O(g), and natural gas. Note that the falling coke and tuyere-injected coal both contain Al2O3 and SiO2. Raceway matrix Table 39.1 and Eqs. (39.3), (39.5), and (39.6) calculate the temperature of the departing gases and solids, that is, the raceway flame temperature. Note that the raceway output gas contains only CO(g) and H2(g), that is, no CO2(g) or H2O(g). This is discussed in Chapter 14, Raceway Flame Temperature.
optimize a blast furnace operation, for example, to minimize molten iron production cost. The flame must be; 1. hot enough to ensure that the blast furnace’s product iron and slag are completely molten at 1500 C, but 2. not so hot as to impact the reduction and melting behavior of the ferrous raw materials. This can lead to irregular burden descent characterized by the burden hanging and slipping.
1. steady-state raceway input O2 and N2-inblast air masses, expressed by Eqs. (39.7) and (39.8); 2. injected coal, oxygen, H2O(g), and natural gas raceway input masses of Chapter 38, Bottom-Segment Calculations With Multiple Injectants, expressed by Eqs. (39.15)(39.18); 3. raceway C, O, N, H, Al2O3, and SiO2 mass balance Eqs. (39.9)(39.14); and 4. masses of Al2O3-in-coke and SiO2-in-coke falling into raceway of Fig. 39.1, described below Eqs. (39.1)(39.2).
39.2.1 Mass of Al2O3 in Falling Coke Particles The amount of Al2O3 falling into the raceway is described by; "
"
coke particles mass C in falling
#
" 5
mass% Al2 O3 "
coke particles
in coke mass% C
#
#
in coke
or "
mass Al2 O3 in falling coke particles
or subtracting both sides;
39.2 RACEWAY MATRIX
#
3 mass% Al2 O3 in coke 5 0:0333 5 90 mass% C in coke
The objectives of this chapter are to; 1. build a spreadsheet that will automatically calculate raceway flame temperatures from bottom-segment calculated inputs and outputs, with multiple injectants, and 2. plot and discuss the effect of injectant amounts on raceway flame temperature.
mass Al2 O3 in falling
052 1
The bottom-segment inputs for multiple injectants are provided in Table 39.1, all values are per 1000 kg of Fe in product molten iron.
BLAST FURNACE IRONMAKING
#
" 15
mass C in falling coke particles
# 0:0333
mass Al2 O3 in falling 1 coke particles
mass Al2 O3 in falling coke particles mass C in falling coke particles
from
1
0:0333
(39.1)
TABLE 39.1
Bottom-Segment Inputs and Outputs as Calculated by Bottom-Segment Matrix Table 38.1
This is a copy of Table 38.2.
TABLE 39.2 Raceway Matrix With Simultaneous Tuyere Injection of Coal, Oxygen, H2O(g), and Natural Gas (Matrix is Split for Clarity)
All its equations are given at the end of this chapter. Column C’s numerical values are from Table 39.1. For continuity with these values: Cell C68 5 C36, Cell C69 5 C37, Cell C78 5 C59, Cell C79 5 C60, Cell C80 5 C61, Cell C81 5 C62, and Cell C82 5 C63.
39.3 CALCULATION OF RACEWAY INPUT ENTHALPY, OUTPUT ENTHALPY, AND FLAME TEMPERATURE
39.2.2 Mass of SiO2 in Falling Coke Particles Likewise, the amount of SiO2 falling into the raceway is described by;
mass SiO2 in
where the numerical values are the enthalpies (H /MW) of the substances at the temperatures of Fig. 39.1. Eq. (39.3) is given in Table 39.4 as;
5 C95 1:239 1 C96 1:339
1 falling coke particles mass C in falling 7 mass% SiO2 in coke 1 90 mass% C in coke coke particles
052
1 C97 2:488 1 C98 ð214:67Þ 1 C99 ð213:44Þ 1 C105 ð21:2Þ 1 C106 1:239 1 C107 ð210:81Þ 1 C108 ð24:52Þ 1 C109 0
or 052
mass SiO2 in
1 falling coke particles mass C in falling 1 0:0778 coke particles
349
(39.4)
Eq. (39.4) is like Eq. (30.6) with additional terms for; (39.2)
The raceway matrix with these equations is shown in Table 39.2. Its calculated values are shown in Table 39.3.
39.3 CALCULATION OF RACEWAY INPUT ENTHALPY, OUTPUT ENTHALPY, AND FLAME TEMPERATURE Raceway input enthalpy with coal, oxygen, H2O(g), and natural gas injection is given by the following equation;
1. falling 1500 C Al2O3(s)-in-coke and SiO2(s)in-coke, and 2. injected coal, oxygen, and H2O(g).
39.3.1 Raceway Output Enthalpy Chapter 14, Raceway Flame Temperature, specifies that there is no conductive, convective, and radiative heat loss from the raceway, that is; ½total raceway output enthalpy 1 ½zero 5 ½total raceway input enthalpy
½total raceway input enthalpy 5 ½mass O2 entering raceway in blast air 1:239
(14.13)
so that;
1 ½mass N2 entering raceway in blast air 1:339 1 ½mass C entering raceway in falling coke particles 2:488 1 ½mass Al2 O3 entering raceway in falling coke particles 2 14:67 1 ½mass SiO2 entering raceway in falling coke particles
½total raceway output enthalpy 5 ½total raceway input enthalpy
(39.5)
as shown in Table 39.4.
2 13:44 1 ½mass tuyere-injected coal entering raceway 2 1:2 1 ½mass O2 entering raceway in tuyere-injected oxygen 1:239
1 ½mass through-tuyere H2 O g entering raceway 2 10:81 1 ½mass injected natural gas entering raceway 2 4:52 1 ½mass additional tuyere injectant 0
39.3.2 Flame Temperature Calculation Chapter 18, Raceway Flame Temperature With CH4(g) Tuyere Injection, shows that raceway flame temperature with H entering the blast furnace is;
(39.3)
BLAST FURNACE IRONMAKING
TABLE 39.3 Raceway Calculated Values with Tuyere Injection of 60 kg of Coal, 30 kg of Oxygen, and 18 kg of H2O(g), Calculated by Eq. (19.2), and 60 kg of Natural Gas
Eqs. (39.4), (39.5), and (39.6) use these values to calculate raceway input enthalpy, output enthalpy, and raceway adiabatic flame temperature.
TABLE 39.4
Equations for Calculating Raceway Input Enthalpy, Output Enthalpy, and Flame Temperature
The equations are like those in Table 30.1 but with more terms.
352 (
39. RACEWAY FLAME TEMPERATURE WITH MULTIPLE INJECTANTS
raceway output
ðflameÞ enthalpy mass CO in raceway 2 ð 24:183Þ output gas mass N2 in raceway ð 20:2448Þ 2 output gas ) mass H2 in raceway 2 ð2 4:130Þ output gas (" # 5 Tflame (18.9) mass CO in raceway 0:001310 output gas " # mass N2 in raceway 1 0:001301 output gas " # ) mass H2 in raceway 0:01756 1 output gas
where the numerical values are from 1800 C to 2300 C enthalpy equations of Table J.4. The flame temperature of this chapter is calculated similarly, but with additional terms for the raceway’s output Al2O3(s) and SiO2(s), which are; mass Al2 O3 in raceway ð16:72Þ output gas
and
2
39.4 RESULTS Table 39.4 shows that the raceway temperature with; • 60 kg of injected pulverized coal, • 30 kg of injected pure oxygen, • 18 kg H2O(g)-in-blast (Cell C61, Table 39.1), and • 60 kg of natural gas is 1923 C. The flame temperatures with other combinations of injectants are shown in Fig. 39.2. Our calculations confirm that; • oxygen injection increases raceway flame temperature, but • coal injection, H2O(g)-in-blast, and natural gas injection decrease flame temperature. These same conclusions are reached in; • Chapter 17, Raceway Flame Temperature with Oxygen Enrichment; • Chapter 16, Raceway Flame Temperature with Pulverized Carbon Injection;
mass SiO2 in raceway ð15:47Þ output gas
on the top of Eq. (18.9), and;
and
mass Al2 O3 in raceway ð0:001887Þ output gas
mass SiO2 in raceway ð0:001427Þ output gas
on the bottom of Eq. (18.9) where the numerical values are from Appendix J. In spreadsheet form, the equation is fJ116 2 C100 ð2 4:183Þ 2 C101 ð2 0:2448Þ 2 C102 ð2 4:13Þ 2 C103 ð2 16:72Þ 2 C104 ð2 15:47Þg Tflame 5 fC100 0:00131 1 C101 0:001301 1 C102 0:01756 1 C103 0:001887 1 C104 0:001427g
(39.6)
FIGURE 39.2 Effect of increasing individual tuyere input quantities on raceway flame temperature while holding the others injectants constant. Oxygen increases flame temperature. Coal, H2O(g), and natural gas decrease flame temperature.
BLAST FURNACE IRONMAKING
353
39.5 LIST OF RACEWAY EQUATIONS OF THIS CHAPTER
• Chapter 19, Raceway Flame Temperature with Moisture in Blast Air; and • Chapter 30, Raceway Flame Temperature with Natural Gas Injection. Fig. 39.2 also shows that 25 C natural gas is more effective at lowering flame temperature than 1200 C H2O(g).
39.5 LIST OF RACEWAY EQUATIONS OF THIS CHAPTER IN TABLE 39.2 A number of new equations were added to the raceway matrix to allow for RAFT calculation with multiple injectants. These equations are: Row 68. O2 entering raceway in blast air:
347 5
mass O2 entering raceway 1 in blast air
(39.7)
Row 69. N2 entering raceway in blast air:
1145 5
mass N2 entering raceway 1 in blast air
(39.8)
Row 70. Raceway oxygen balance:
mass O2 entering raceway 1 in blast air " # mass tuyere-injected coal 0:046 entering raceway
052
" 2
mass O2 entering raceway
" " 2
mass tuyere-injected natural
#
gas entering raceway "
1
mass through-tuyere input 0:888 H2 O g entering raceway
mass CO in raceway output gas
#
0:01
2
mass C entering raceway
in falling coke particles mass tuyere-injected coal
1
0:810 entering raceway mass tuyere-injected natural 2 0:734 gas entering raceway mass CO in raceway 1 0:429 output gas
(39.10)
Row 72. Raceway nitrogen balance: 052
mass N2 entering raceway
in blast air mass tuyere-injected coal
1
0:009 entering raceway mass tuyere-injected natural 2 0:017 gas entering raceway mass N2 in raceway 1 1 output gas
(39.11)
Row 73. Raceway hydrogen balance: mass tuyere-injected coal 052 0:055 entering raceway " # mass through-tuyere input 0:112 H2 O g entering raceway mass tuyere-injected natural 2 0:240 gas entering raceway mass H2 in raceway 1 1 output gas
1
#
05 2
(39.12)
Row 74. Al2O3(s) entering raceway in falling coke:
#
in tuyere-injected pure oxygen
Row 71. Raceway carbon balance:
052
(39.9) 1
mass Al2 O3 entering raceway in falling coke particles mass C entering raceway in falling coke particles
Row 75. falling coke:
SiO2
entering
1
0:0333
raceway
mass SiO2 entering raceway 1 in falling coke particles mass C entering raceway 1 0:0778 in falling coke particles
(39.1)
in
052 0:571
BLAST FURNACE IRONMAKING
(39.2)
354
39. RACEWAY FLAME TEMPERATURE WITH MULTIPLE INJECTANTS
39.6 SUMMARY
Row 76. Raceway Al2O3 balance: 052
mass Al2 O3 entering raceway
1
in falling coke particles mass tuyere-injected coal
0:024 entering raceway mass Al2 O3 ðsÞ in raceway 1 1 output gas
(39.13)
Row 77. Raceway SiO2 balance:
mass SiO2 entering raceway
052
in falling coke particles mass tuyere-injected coal
entering raceway mass SiO2 ðsÞ in raceway
1
output gas
1
0:056
1
(39.14)
Row 78. Mass tuyere-injected coal entering raceway: 60 5
mass tuyere-injected coal 1 entering raceway
(39.15)
This chapter shows how to automatically calculate tuyere raceway flame temperatures from bottom-segment calculated values with multiple injectants. It also shows how to set up the raceway matrix and equations for additional tuyere injectants. Matrix calculations of this chapter show that; 1. oxygen injection increases flame temperature, and 2. pulverized coal, H2O(g), and natural gas injection decrease flame temperature as reported by Geerdes et al. (p 115).1 Chapter 40, Top-Segment Calculations With Multiple Injectants, will show how to similarly calculate top gas temperatures.
Row 79. Mass O2 in tuyere-injected pure oxygen entering raceway: mass O2 entering raceway 1 30 5 in tuyere-injected pure oxygen
EXERCISES
(39.16)
Row 80. Mass through-tuyere input H2O(g) entering raceway:
mass through-tuyere input 18 5 1 H2 O g entering raceway
(39.17)
Row 81. Mass tuyere-injected natural gas entering raceway: 60 5
mass tuyere-injected natural 1 gas entering raceway
(39.18)
Row 82. Mass additional tuyere injectant entering raceway: 05
mass additional tuyere 1 injectant entering raceway
All masses in this exercise are kg per 1000 kg of Fe in product molten iron. 39.1. The blast furnace management team of Fig. 39.1 is planning to inject 20 kg of oil into their furnace along with all of the existing through-tuyere injectants of Table 38.2. They wish to know how this oil will affect their raceway flame temperature. Please predict the effect and then calculate it. Use the oil composition of your results in Exercise 38.1.
Reference (39.19)
1. Geerdes M, Chaigneqeau R, Kurunov I, Lingiardi O, Ricketts J. Modern blast furnace ironmaking (an introduction). 3rd ed. Amsterdam: IOS Press BV; 2015. p. 115.
BLAST FURNACE IRONMAKING