Resources
December 8, 2017

Best Practice No. 48 – Combustion Flame Visual Reviews for Performance

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Combustion Flame Visual Inspection

  • 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

Combustion Flame Visual Reviews for Performance

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

Combustion Flame Visual Reviews for Performance

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

Combustion Flame Visual Reviews for Performance

Burner Flame Deficiency

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

Combustion Flame Visual Reviews for Performance

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

Combustion Flame Visual Reviews for Performance

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

Combustion Flame Visual Reviews for Performance

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

Combustion Flame Visual Reviews for Performance

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

Combustion Flame Visual Reviews for Performance

Another View of the Combustion Flame

  • Front view
    – More difficult to see the total operation

Combustion Flame Visual Reviews for Performance

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

Combustion Flame Visual Reviews for Performance