Burner Design Review on New Installations
The operating representative, design representative, design contractor, heater designer, and burner designer should meet together to review and agree on all aspects of the burner design. For future maintenance work, it is essential that good drawings clearly showing all essential tip orientations, tip and tile clearances, etc., are provided as part of the vendor’s package.
Burner Tile Position. Typically the tile or burner block is supplied by the burner designer but it is installed in the heater. The rest of the burner is later bolted to the casing. Improper positioning of the burner may affect the fuel-air mixing in raw gas burners. If the burner position is critical, a positive positioning design should be worked out between the heater and burner designers. In no case should the burner be mounted to air plenums; rather, it should be through-bolted to the heater casing.
Burner Gun Removal. Gas and oil tips must be easily removable for cleaning. Parts should be easily carried by one man. In a preheated air system, the operator should not get a blast of hot air when he pulls a gun.
Burner Gun Position. There should be a foolproof way to return the burner gun to its proper position after it has been removed for maintenance. There should be no way to install it wrong. If a gas gun is positioned improperly, fuel-air mixing may not be adequate. If an oil gun is positioned improperly, oil may spray onto the burner refractory, depositing coke and restricting burner operation.
Air Registers. Butterfly-damper type are preferred. The sliding-can type may warp as the result of process upsets. Plate should be of 10-gage minimum thickness to provide resistance to warpage. Additional stiffness can be had by breaking the edges of sheet metal registers and welding gussets in the corners. Roller bearings should be used to provide easy register movement.
Air Register Controls. Since many air registers are contained within plenum chambers, position indicators are needed on the register controls. Also, if the air register resists warpage and moves as easily as we would like, vibration may change the register position. So a positive locking feature is needed.
Lighting and Sighting Ports. It should be easy to light burners through the lighting port and verify ignition through the sighting port. Closures should be tight and foolproof. Lighting and sighting ports should be positioned so that the position of the burner register can be visually checked from the firing platform.