Understanding Kiln Efficiency

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Understanding Kiln Efficiency

• Dan OBrien
• Harrop Industries, Inc.
• Columbus, Ohio

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Purpose

• Identify and quantify the specific areas
  effecting the energy consumption required to
  produce a product

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Definition of Kiln Efficiency

• The theoretical energy required to dry/heat a
  product compared to the actual measured energy to
  dry/fire the product

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Units of Measure

• BTU per Pound of Fired Ware
• Pounds of Air per Pound of Fired Ware

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Get the Facts
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Focus on the Vital Signs
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Vital Signs Contributing to Energy Consumption

• Live Load/Dead Load
• Temperature Profile
• Pressure Profile
• Oxygen Profile
• Air Injected
• Air Infiltration
• Gas Injected
• Energy Exhausted
• Radiation Losses

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Live LoadMass of Ware being Fired (Pounds
per Hour)
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Live LoadMass of Ware being Fired

• Dead Load
• Mass of Car Furniture/Car Top
• (Pounds per Hour)

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Temperature Profile
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Hand Held Pyrometer
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Optical Pyrometer
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Traveling Thermocouple
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TemperaturePressure
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ld Manometer
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TemperaturePressureOxygen
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Oxygen Analyzer w/ Ceramic Lance
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TemperaturePressureOxygenAir Flow
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Velometer
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Pitot Tube
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Temperatures to Collect

• Traveling thermocouple data

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(No Transcript)
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Temperatures to Collect

• Traveling thermocouple data
• Exhaust gas temperatures

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Temperatures to Collect

• Traveling thermocouple data
• Exhaust gas temperatures
• Ware exit temperature

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Temperatures to Collect

• Traveling thermocouple data
• Exhaust gas temperatures
• Ware exit temperature
• Under car temperature

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Temperatures to Collect

• Traveling thermocouple data
• Exhaust gas temperatures
• Ware exit temperature
• Under car temperature
• Exterior Surface temperatures

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Pressure

• Measure interior kiln pressure profile
• from entrance to exit of kiln

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Oxygen Monitoring Sites Exhaust
FanPreheat Section FirezoneEarly Cooling
Waste Heatoxygen
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Vital Signs
Kiln
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FlowMeasure pounds or cubic feet of all gases
injected into or exhausted from the kiln system

• Combustion Air
• Combustion Gas
• Cooling Air
• Air for Jets
• Dilution Air

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Vital Signs
Kiln
Dryer
Dryer
Kiln
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The System Leak Factor is Applied to Balance
the System Mass Flow
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(No Transcript)
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Thermal Balance Diagram
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How are the Results Used?

• Benchmarking Against Other Kilns
• Monitoring the Process over Time
• Gauging the Effect of Recommended or Actual
  Process Changes or Kiln Modifications

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DRYING AND FIRINGPROCESS
EXHAUST
EXHAUST
EXHAUST
SUPPLY
SUPPLY
RELIEF PORTS
AIR SUPPLY
DRYER
KILN
PREDRY
AIR AND GAS
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DRYING AND FIRING PROCESSSYSTEM LOSSES
2
5
EXHAUST
AIR SUPPLY
2
DUCTING
50
20
SUPPLY
EXHAU
EXHAU
EXHAUST
EXHAUST
SUPPLY
RELIEF PORTS
KILN
PREDRY
DRYER
.5
.5
GAS INPUT
100
20
RADIATION
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DRYING AND FIRING PROCESSHYPOTHETICAL DOLLAR
LOSSES
75,000
30,000
30,000
AIR SUPPLY
DUCTING
EXHAUST
750,000
300,000
EXHAU
EXHAUST
EXHAUST
SUPPLY
RELIEF PORTS
SUPPLY
DRYER
PREDRY
KILN
7,500
7,500
GAS INPUT
1,500,000 / year
300,000
RADIATION
39
Thank You