No. 48 – Combustion Flame Visual Reviews for Performance

BEST PRACTICE NO. 48

Combustion Flame Visual Inspection

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• The following presentation is an overview of a combustion flame analysis for plant personnel for the inspection of the combustion flame for performance
• The combustion testing and adjustments should always be done with the use of combustion analyzer
• However, a daily visual inspection provides an insight into the combustion performance

What is a Good Flame Geometry

• Burner throat has a bright red/yellow color (indicating a high temperature) that is distributed through out the burner throat
• No dark spots in the burner throat area
• Flame front is in the correct position

A Good Flame Pattern

• The flame has a swirl to the operation which is mixing the fuel with the air
• End Result:
  – Low excess air
  – No carbon monoxide
  – Higher boiler efficiency

A Imperfect Flame

• The throat does not have a red/orange glow (high temperature) which is an example of the flame front
  being too far away from the burner throat
• The burner throat helps the combustion process by providing temperature to support the combustion process

Burner Flame Deficiency

• Results in high levels of carbon monoxide
• High levels of excess air Another Deficient Combustion Flame

Another Deficient Combustion Flame

• Burner throat has areas of red/orange, but does not completely cover the entire throat area
• The results was from poor air flow distribution in the burner
• Resulting in high levels of carbon monoxide Another Example of Poor Air Flow Mixture

Another Example of Poor Air Flow Mixture

• Same as the previous slide, the burner is displaying several negative features:
  – Flame front to far away from the burner throat area
  – Air flow mixture is not achieving proper mixture
  – High levels of carbon monoxide
  – High levels of excess air

Proper Combustion Flame Operation

• Throat area totally has the red/orange color which is the result of the following:
  – Proper air and fuel mixing
  – Flame front is in the correct position
  – Resulting in the following:
          › Low excess air levels
          › No carbon monoxide in the combustion process

Proper Combustion Operation

• Burner throat is red/orange (hot) which means flame front is in correct position
• Proper swirl operation to achieve air/fuel mixing Another View of the Combustion Flame

Another View of the Combustion Flame

• Front view
  – More difficult to see the total operation

Proper Combustion Efficiency

• Visual inspection is a key factor in overall boiler efficiency
• Visual inspection is only one piece of the checking the combustion efficiency
• Full testing should be performed at least every three months by a qualified person