Kiln Performance & Efficiency Formulas
| Kiln Performance & Efficiency | ||||||||
| S. | Description | Symbol | Formula | Example | ||||
| No. | ||||||||
| 1 | Degree of filling | DF | 3.2 * P | P | 5500 | |||
| % | Deff 3 * n * s | Deff | 4.15 | |||||
| P | Clinker production, tpd | n | 3.8 | |||||
| Deff | Burning zone effective diameter, mts | S | 4 | |||||
| n | Kiln speed, rpm | DF | 16.20 | |||||
| s | Kiln slope, % | Target | 14-16 | |||||
| 2 | Thermal loading | TL | Formula-1 | F | 10000 | |||
| or | Gcal/hr/m2 | F * NCV | NCV | 6500 | ||||
| Burning zone loading | A * 1000 * 1000 | A | 13.52 | |||||
| F | Fuel rate in kiln, kg/hr | TL | 4.81 | |||||
| NCV | Net calorific value of fuel, kcal/kg-fuel | Target | 4.0-5.0 | |||||
| A | Burning zone cross-sectional area, m2 | |||||||
| Formula-2 | P | 5500 | ||||||
| P * H | H | 280 | ||||||
| A * 24 * 1000 | A | 13.52 | ||||||
| P | Clinker production, tpd | TL | 4.75 | |||||
| H | Specific heat consumption in kiln, kcal/kg-clinker | Target | 4.0-5.0 | |||||
| A | Burning zone cross-sectional area, m2 | |||||||
| 3 | Volumetric loading | VL | P | P | 5500 | |||
| tpd/m3 | A * L | A | 13.52 | |||||
| P | Clinker production, tpd | L | 68 | |||||
| A | Burning zone cross-sectional area, m2 | VL | 5.98 | |||||
| L | Kiln length, mts | Target | 5.0-5.5 | |||||
| 4 | Material residence time in kiln | RTK | 19 * L | L | 68 | |||
| min | Deff * n * s | Deff | 4.15 | |||||
| L | Kiln length, mts | n | 3.8 | |||||
| Deff | Burning zone effective diameter, mts | S | 4 | |||||
| n | Kiln speed, rpm | RTK | 20.5 | |||||
| s | Kiln slope, % | Target | 20-25 | |||||
| 5 | Clinker residence time in cooler | RTC | 1.55 * A * Ps | A | 100 | |||
| (Empirical relationship from | min | P | Ps | 700 | ||||
| F.L. Smidth) | A | Cooler grate cross-sectional area, m2 | P | 5500 | ||||
| Ps | Static pressure at clinker droping area, mmWg | RTC | 19.7 | |||||
| P | Clinker production, tpd | Target | 20-25 | |||||
| 6 | True CO2 in kiln exit gas | TCO2 | 100 * ( CO2 + CO ) | CO2 | 36.5 | |||
| vol% | 100 + ( 1.89 * CO ) – ( 4.78 * O2 ) | CO | 0.002 | |||||
| CO2 | Kiln exit gas CO2, vol% | O2 | 4.2 | |||||
| CO2 | Kiln exit gas CO, vol% | TCO2 | 45.7 | |||||
| O2 | Kiln exit gas O2, vol% | Target | – | |||||
| 7 | Excess air | EA | 79 * O2 | O2 | 2.8 | |||
| % | 0.21 * ( 100 – CO2 ) – O2 | CO2 | 26.5 | |||||
| O2 | O2 content in gas, vol% | EA | 17.5 | |||||
| CO2 | CO2 content in gas, vol% | Target | 10-15 | |||||
| 8 | Radiation heat losses | RHL | 4 * 10-8 * ( T4 – t4 ) | T | 517 | |||
| kcal/hr/m2 | T | Radiating body temperature, K | t | 305 | ||||
| t | Ambient air temperature, K | RHL | 2512 | |||||
| Target | – | |||||||
| 9 | Convection heat losses | CHL | 80.33 * ( ( T + t ) / 2 )-0.724 * ( T – t )1.333 | T | 443 | |||
| kcal/hr/m2 | T | Radiating body temperature, K | t | 308 | ||||
| t | Ambient air temperature, K | CHL | 760 | |||||
| Target | – | |||||||
| 10 | Forced convection heat losses | FCHL | 28.03 * ( ( T + t ) / 2 )-0.351 * v0.805 * D-0.195 * ( T – t ) | T | 525 | |||
| (when wind speed > 3.0 m/s) | kcal/hr/m2 | T | Radiating body temperature, K | t | 302 | |||
| t | Ambient air temperature, K | v | 5 | |||||
| v | Wind speed, m/s | D | 4.15 | |||||
| D | Radiating body diameter, mts | FCHL | 2088 | |||||
| Target | – | |||||||
| 11 | %Ash absorption in clinker | %AA | CC * Ash | CC | 26 | |||
| % | P | Ash | 15 | |||||
| CC | Coal consumption, tph | P | 208 | |||||
| Ash | Ash content in fuel (as fired basis), % | %AA | 1.88 | |||||
| P | Clinker production, tph | Target | – | |||||
| 12 | Raw Mix:Clinker ratio | RMCK | 100 – %AA | %AA | 1.74 | |||
| (dust to kiln) | – | 100 – LOI | LOI | 35.58 | ||||
| %AA | %Ash absorption, % | RMCK | 1.525 | |||||
| LOI | Loss on ignition of raw mix, % | Target | – | |||||
| 13 | Raw Mix:Clinker ratio | RMCS | ( 100 – %AA ) * 100 | %AA | 1.74 | |||
| (dust to silo) | – | ( 100 – LOI ) * ( 100 – DL ) | LOI | 35.5 | ||||
| %AA | %Ash absorption, % | DL | 8.1 | |||||
| LOI | Loss on ignition of raw mix, % | RMCS | 1.658 | |||||
| DL | Dust losses from preheater, % | Target | – | |||||
| 14 | Heat of reaction | HR | ( 4.282 * CaCO3 * RMCK ) + ( 3.085 * MgCO3 * RMCK ) | CaCO3 | 75.1 | |||
| or | kcal/ | + ( 222 * Al2O3 / ( 100 – LOI ) ) + ( 11.6 * CH2O * RMCK ) | RMCK | 1.53 | ||||
| Theoretical heat required to | kg-clinker | – ( 511.6 * SiO2 / ( 100 – LOI ) ) – ( 59 * Fe2O3 / ( 100 – LOI ) ) | MgCO3 | 1.6 | ||||
| produce 1 kg of clinker | – ( 1000 * ( K2O + Na2O ) / ( 100 – LOI ) ) | LOI | 34.5 | |||||
| or | – ( 79 * C * RMCK ) – ( 32 * S * RMCK ) | Al2O3 | 4.17 | |||||
| Clinkerisation heat | CaCO3 | CaCO3 content in kiln feed, % | CH2O | 1.05 | ||||
| RMCK | Kiln feed:Clinker ratio, – | SiO2 | 13.47 | |||||
| (including Heat of combustibles) | MgCO3 | MgCO3 content in kiln feed, % | Fe2O3 | 2.41 | ||||
| LOI | LOI content in kiln feed, % | K2O | 0.38 | |||||
| Al2O3 | Al2O3 content in clinker, % | Na2O | 0.27 | |||||
| CH2O | Water of crystalisation in kiln feed, % | C | 0.2 | |||||
| SiO2 | SiO2 content in clinker, % | S | 0.04 | |||||
| Fe2O3 | Fe2O3 content in clinker, % | HR | 389 | |||||
| K2O | K2O content in clinker, % | Target | – | |||||
| Na2O | Na2O content in clinker, % | |||||||
| C | Carbon content in kiln feed, % | |||||||
| S | Sulphur as pyrites in kiln feed, % | |||||||
| 15 | False air w.r.t. mix | FAMO | ( O2mix – O2gas ) * 100 | O2mix | 3.6 | |||
| (based on O2 analysis) | % | 21 – O2gas | O2gas | 2.8 | ||||
| O2mix | O2 content in mixture of gas, vol% | FAMO | 4.4 | |||||
| O2gas | O2 content in unmixed gas, vol% | Target | 5-7 | |||||
| 16 | False air w.r.t. gas | FAGO | ( O2mix – O2gas ) * 100 | O2mix | 3.6 | |||
| (based on O2 analysis) | % | 21 – O2mix | O2gas | 2.8 | ||||
| O2mix | O2 content in mixture of gas, vol% | FAGO | 4.6 | |||||
| O2gas | O2 content in unmixed gas, vol% | Target | 5-7 | |||||
| 17 | False air w.r.t. mix | FAMC | ( CO2gas – CO2mix ) * 100 | CO2mix | 32.1 | |||
| (based on CO2 analysis) | % | CO2gas | CO2gas | 34.5 | ||||
| CO2mix | CO2 content in mixture of gas, vol% | FAMC | 7.0 | |||||
| CO2gas | CO2 content in unmixed gas, vol% | Target | 5-7 | |||||
| 18 | False air w.r.t. gas | FAGC | ( CO2gas – CO2mix ) * 100 | CO2mix | 32.1 | |||
| (based on CO2 analysis) | % | CO2mix | CO2gas | 34.5 | ||||
| CO2mix | CO2 content in mixture of gas, vol% | FAMC | 7.5 | |||||
| CO2gas | CO2 content in unmixed gas, vol% | Target | 5-7
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Services
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Contact
Use the quote path if you need a direct business inquiry or supplier introduction.
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Kiln Performance & Efficiency Formulas is one of the public technical pages. The complete package and services page give you the deeper reference layer, commercial support path, and quote route.
Services
Use the support path for plant support, buyer inquiries, and specialist help.
Contact
Use the quote path if you need a direct business inquiry or supplier introduction.
Need a deeper reference base?
Kiln Performance & Efficiency Formulas is one of the public technical pages. The complete package and services page give you the deeper reference layer, commercial support path, and quote route.
Services
Use the support path for plant support, buyer inquiries, and specialist help.
Contact
Use the quote path if you need a direct business inquiry or supplier introduction.
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Kiln Performance & Efficiency Formulas is one of the public technical pages. The complete package and services page give you the deeper reference layer, commercial support path, and quote route.
Services
Use the support path for plant support, buyer inquiries, and specialist help.
Contact
Use the quote path if you need a direct business inquiry or supplier introduction.