Inspecting the Burner
Once the burner has been removed, check it against the manufacturing and installation tolerances shown on the burner manufacturers drawing. In addition, review the burner tip alignment and height. Note and adjust any discrepancies prior to reinstallation. This is much easier to do during a plant turnaround from inside the furnace
but it can also be done by taking the difference between the height of the riser with
the gas tip and the burner tile.
The flame angle can also be checked by placing drill bits in the gas tip drillings. The tolerance of the fuel port angle is plus or minus four degrees. After the burner alignment has been checked, inspect the gas tips for the following conditions:
Plugging. Burner plugging is caused by solids in the fuel gas line which are larger than the holes in the burner tip or fuel orifice. With severe burner plugging, the burner tip can become extremely hot and melt due to loss of fuel gas flow. Coking. Coking is caused by a combination of liquid in the fuel and high temperature at the burner tip. Liquid can be removed by installing local fuel gas knockout pots or filter coalescers or by steam tracing the fuel lines.
Corrosion and erosion. Corrosive materials in the fuel gas can also damage burner tips. In this case, the metallurgy can be improved to prevent corrosion. Scored and elongated. Solids in the fuel traveling at high velocities across the burner tip will cause scored and elongated holes. Again, the solids and liquids should be removed with fuel gas coalescers.
When inspecting the burner, you must also determine when to replace worn parts. Replace the burner tip if any of the burner tip holes are damaged or the holes are enlarged beyond the manufactures tolerances. The same holds true for restriction orifices.
When the burner is taken out of service, inspect all flex hoses for wear. Replace all damaged flex hoses.