Kiln Audit ATC
SMO / 02/09/2008 - 1
Kiln Audit - ATC
Kiln Audit : What it means? •
Review • • • • •
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Establish equipment / system performance • • • •
•
Production Heat Consumption Power Consumption Efficiency
Benchmark • • • •
•
Present operation philosophy Operating parameters Operation / Quality targets Present Constraints Status of PID control loop operation
Past performance Supplier guarantees Type of equipment / system Anticipated performance
Recommend for performance improvement • Changes in operation philosophy, operating parameters, operation / quality Targets • Modifications to individual equipment / system
SMO / 4-Jun-2007 - 2
Kiln Audit - ATC
Kiln Audit : Steps involved • Pre-audit information checklist.
• Plant base information (Flow sheet, equipment details). • Past performance data (Run / production / reliability factor, energy consumption, quality). • Type of fuels used and products manufactured. • Present problems faced by plant.
• Measurement / sampling tools
• Instruments (availability, suitability, functioning, calibration)
• Measurement / sampling plan
• Measurements / sampling / analysis requirments with priority level. • Frequency of measurement / sampling.
• Calculation tools • Data from other plant audits • Result Interpretations. • Report writing • Reference documents
SMO / 4-Jun-2007 - 3
Kiln Audit - ATC
Kiln Audit : Pre-audit information • The Plant • • • • •
Location (place, nearest city, MSL, Ambient temperatures, % RH) Local line No. (if any) Supplier Year supplied Supplier guarantees (Production, heat consumption, power consumption etc).
• Preheater & Pre-Calciner • • • • • • •
No. of stages No. of strings Whether In line calciner / separate calciner / AS / AT Type of calciner: Low NOx / hot point etc. Cyclone sizes Calciner dimensions with sketch (showing firing / feed /Tertiary air entry point locations) Feeding arrangement (air lift / bucket elevator)
• Kiln • • • • • •
Size (Diameter x Length) No. of supports (2 / 3) Slope (3.5 / 4%) Maximum speed, rpm Lining thickness, mm Installed motor power
SMO / 4-Jun-2007 - 4
Kiln Audit - ATC
Kiln Audit : Pre-audit information • Cooler • • • • • • • • • • • • • • • • •
Supplier Supplier product code (e.g. FLS COOLAX 1284) Type (Conventional chamber aerated / Beam aeration etc.) Type of inlet (e.g. Fixed) No. of Grates Dimensions (width x Length) Effective Grate area No. of compartments No. of fans (Specify v-belt / direct drive, variable / fixed speed) Enclose sketch showing grate plate layout with aeration arrangement Vent air de-dusting arrangement (ESP, Heat exchanger + Bag filter) Emergency cooling arrangements (fresh air / water spray) Cooling air & Vent air fan specifications Tertiary air take-off point (through kiln hood / separate) Dust Settling Chamber in tertiary air line? Any hot air tapping (for raw / coal / cement mill) Under-grate dust collection arrangement (drag chain / hoppers with pneumatic gates) SMO / 4-Jun-2007 - 5
Kiln Audit - ATC
Kiln Audit : Pre-audit information • Burner • Supplier • Supplier product code (e.g. FLS Duoflex) • Type (Uni-flow / Multi-channel?)
• Miscellaneous • • • • • •
Fuels used (with proportions, way of preparation) Sketch showing gas & material flows Present performance (Production, heat / power consumption) Present constraints Sketch indicating measurement / sampling point locations Modifications done w.r.t. original supply (e.g. changed to Lafarge Burner, installation of Hurrivanes in preheater cyclone)
SMO / 4-Jun-2007 - 6
Kiln Audit - ATC
Kiln Audit : Samples & analysis •
Inputs • Kiln Feed • • • • • • • • • • • • •
Fineness (Residues on 90 and 212µ) Temperature Moisture Uniformity (KFUI), Homogenization (Standard deviation of CaO/CaCO3/RC3S at silo exit) Burnability (K1450) Coarse quartz and calcite content LOI Chemical analysis (incl. minor oxides and chlorine) Organic carbon Water of crystallization / hydration Sulfur as pyrites TC
• Fuel, as fired • • • • • •
Moisture Fineness (Residues on 90 and 212µ) Temperature Heat value Proximate analysis Ultimate analysis SMO / 4-Jun-2007 - 7
Kiln Audit - ATC
Kiln Audit : Samples & analysis •
Outputs • Clinker • • • • • • •
Temperature Sieve analysis Free lime Liter weight LOI Chemical analysis (incl. Minor oxides) Microscopy
• Dust from Preheater • PSD • LOI • Chemical analysis (incl. Minor oxides)
•
With in Process • Bottom stage exit material • • • •
LOI Temperature Chemical analysis (incl. minor oxides) Un-burnt Carbon SMO / 4-Jun-2007 - 8
Kiln Audit - ATC
Kiln Audit : Sampling frequency
• Sample • • • • •
Kiln Feed Fuel Clinker Dust from Preheater PH bottom stage cyclone exit material
collection frequency Every 2 hour Every 2 hour Hourly 2 samples 2 samples
Note: Except temperature, fineness, moisture, free lime and liter weight, the detailed analysis could be performed on composite samples. From the composite sample, 3 sets to be prepared. Set-1 To ARL Set-2 To Plant Laboratory Set-3 To be preserved by plant laboratory (till final report is released) SMO / 4-Jun-2007 - 9
Kiln Audit - ATC
Kiln Audit : Field Measurements • Preheater • Preheater Exit Gas (Downcomer duct) • • • • •
Temperature Static Pressure Flow Gas analysis (O2, CO, CO2, SO2, NOx) Dust concentration
• Calciner exit • Temperature • Static Pressure • Gas analysis (O2, CO, CO2, SO2, NOx)
• Each cyclone inlet and outlet • Temperature • Static pressure • Gas analysis (O2, CO, CO2) SMO / 4-Jun-2007 - 10
Kiln Audit - ATC
Kiln Audit : Field Measurements
• Kiln • Kiln inlet • Temperature • Static Pressure • Gas analysis (O2, CO, CO2, SO2, NOx)
• Primary Air (Kiln / Calciner Burner) • Flow • Pressure • Temperature
• Transport air for fuel • Flow • Temperature SMO / 4-Jun-2007 - 11
Kiln Audit - ATC
Kiln Audit : Field Measurements •
Cooler • Cooling air • Flow • Temperature • Pressure (at fan outlet, for each individual duct after flap damper)
• Cooler vent air • Temperature • Static pressure • Flow
• Secondary air • Temperature
• Kiln hood • Pressure
• Tertiary air (at cooler end) • Temperature • Static pressure • Flow (if possible)
SMO / 4-Jun-2007 - 12
Kiln Audit - ATC
Kiln Audit : Other Measurements •
Mass flows • • • • •
•
Power • • • • •
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Kiln Feed Clinker (by drop test) Preheater exit dust (by drop test) Fuel to Kiln Fuel to calciner Kiln main drive Preheater fan Cooler vent fan Individual cooling air fan Total shop
Surface temperatures • Kiln shell • All components of preheater (cyclones incl. risers, material pipes, smoke chamber, kiln riser pipe, calciner vessel) • Tertiary air duct • Kiln hood • Cooler walls Remember! Always specify emissivity set in pyrometer for temperature measurement SMO / 4-Jun-2007 - 13
Kiln Audit - ATC
Kiln Audit : Measurements
• Remember! • • • • • •
To cross-check CCR indications w.r.t. field measurements To have Minimum 2 sets of measurements To perform measurements during stable kiln operation To Specify measurement point locations To check suitability of flow measurement point (8D – 3D criteria) To record: • • • • •
Pitot tube constants Duct diameters at flow measurement point Emissivity used for surface temperature measurement Surface areas required for radiation loss calculation Transport air details (fuel / feed) SMO / 4-Jun-2007 - 14
Kiln Audit - ATC
Kiln Audit : Measurement tools • Gas analyzer (2 Nos.) • With CO, CO2, O2, NOx, SO2 sensor
• Digital manometer (1 each) • Low range: 0–100 mmWG for Pd measurement • High range: 0–4000 mmWG
• Thermocouple with indicator (2 Nos.) • Radiation pyrometer (1 No.) • Stroboscope / Taco meter (1 No.) • Measuring tape (2 Nos.) • Insulated container for clinker temperature measurement (1 No.) • Pitot tubes • S type, 2m long (2 Nos.) • L type for primary air flow measurement (1 No.) Make sure to have calibrated instruments!
SMO / 4-Jun-2007 - 15
Kiln Audit - ATC
Kiln Audit : Operating parameters • • • • • • • • • • • •
Kiln Speed Preheater fan speed & damper opening Tertiary air duct damper position Cooler grate speeds Cooler under-grate pressure (way of calculation) Ratios used for grate-2, 3 speed w.r.t. grate-1 speed Individual cooler fan speed, damper opening Cooler vent fan speed, damper opening If SLC kiln, feed dividing gate (at PH Top) position Material dividing gate position for material diverted to kiln riser Primary air fan speed, damper opening Any other relevant parameter
SMO / 4-Jun-2007 - 16
Kiln Audit - ATC
Kiln Audit : Miscellaneous • Check performance of PID control loops • Check adequacy Sampling / measurement frequency from quality / operation / process aspects • Look for sources of air leakages / false air entry in to the system • Understand present constraints in terms of operation / quality • Analyze Stoppages / Slow downs • Monitor safety • Record fuel and power cost
SMO / 4-Jun-2007 - 17
Kiln Audit - ATC
Kiln Audit : Calculation tools • Pitot Measurement • For gas / air flow calculation
• Air Distribution • Compare cooler flows w.r.t. recommended
• Cooler Heat Balance • • • •
K – factor Recovery ratio Cooling efficiency Cooler loss
• Kiln Shell & Preheater losses • For calculation of surface / radiation heat loss
• Heat & Mass Balance for Kiln • Overall heat balance of pyro-processing section
SMO / 4-Jun-2007 - 18
Kiln Audit - ATC
Kiln Audit : Benchmarking • Preheater Exit Gas Temperature • 4 stage preheater • 5 stage preheater • 6 stage preheater
380oC 330oC 300oC
• Kiln Feed Homogeneity • KFUI • CaO standard deviation
• Dust loss from preheater
<14 < 0.11 8% of Kiln feed
• Pressure drop across preheater cyclones • Top stage • Rest
80 mmWG 60 mmWG SMO / 4-Jun-2007 - 19
Kiln Audit - ATC
Kiln Audit : Benchmarking • Heat Consumption Kcal/Kg Cli. • 4 stage preheater • 5 stage preheater • 6 stage preheater
760 - 780 720 - 730 690 - 700
• Power Consumption kWh/t cli. • Preheater fan • Cooling air fans • Cooler vent fan
6.5 5 – 5.2 (beam aeration w/ fixed speed fans) 0.6 – 0.8
• Cooler Performance Conventional • K-Factor • Recovery ratio • Sp. cooling air (Kg/Kg cli.)
3.0
Beam aeration
Modern (cross bar)
> 1.5 > 70 2.5 – 2.6
2.3 SMO / 4-Jun-2007 - 20
