Sheet 4200-1 page 3
11. Install seal ring, rope gasket or bolt hole tape as specified on the burner and reaction chamber assembly drawing. See Item #4 for tips on proper installation.
12. Consult appropriate assembly drawing to determine proper orientation of saddle pads, locator pins or any other attachment and support mechanisms. Look for a yellow “x” to ensure proper alignment of the sections.
13. After securing the reaction chamber, lift and place burner assembly in the proper location as illustrated on the assembly drawing.
14. Apply thread lubricant to bolt or stud threads. Use washers and nuts as specified on the burner and reaction chamber assembly drawing. Be sure the entire assembly is adequately supported prior to removing the lifting mechanism.
15. All piping must be clean and free of debris prior to connecting to burner.
16. All piping must be clean and free of debris prior to connecting to burner.
17. If no permanent temperature measuring equipment is installed, temporary instrumentation is recommended for dryout.
INITIAL FIRING INFORMATION:
Measuring the reaction chamber refractory temperature is recommended during the initial firing of the system and for subsequent cold restarts if feasible. It is recommended that a bare wire thermocouple junction be placed on the refractory surface near the reac- tion chamber exit. The exposed thermocouple junction should be covered with a small piece of insulating blanket to shield it from direct flame. The insulation must be weighted to remain in place during firing. Alternately, a removable thermocouple may be inserted through a sample port near the exit of the reaction chamber. The probe should be long enough to measure the temperature of the combustion products hot mix at the chamber exit. If the temperature of the inside surface of the refractory or the hot mix near the discharge of the reaction chamber cannot be measured, a defined procedure including excess air rates and length of time is required for at least the first heat up. The Combustion Hot Mix method may be used when flame lengths will exceed the length of the reaction chamber. This includes LE and GLE assemblies, or LEx burners having standard or short reaction chambers. A chamber that has been fired, either by the optional factory pre-firing or having been in service, and has not been exposed to sig- nificant moisture should follow the “Cold Restart” instructions below. If a pre-fired assembly has been exposed to significant moisture before or after installation, or during maintenance, follow the instructions for ramp and hold at 300°F and 500°F described in the Initial Firing process. When in doubt, the slow ramp and hold process should be followed.
Using Combustion Hot Mix Temperatures as an alternative to Measurement of Hot Face Temperature:
The excess air values and corresponding hot mix temperatures listed below are based on 120°F combustion air and Natural Gas. These can be used for prefiring the burner and reaction chamber as recommended where: the excess air measured is for burner air and fuel only (no process air); and if the combustion system air and fuel flow measurement instrumentation’s correct function and accuracy has been verified. Obtaining hot mix temperatures below 600°F may require operation with pilot only. Values not listed as “hold” tempera- tures are included for reference to assist with ramp rates.reference to assist with ramp rates.
Percent Excess Air
Approximate Hot Mix Temperature
300°F 500°F 700°F 900°F
2750% 1230%
750% 510% 325% 225% 160% 130%
1200°F 1500°F 1800°F 2000°F
WARNING: Situations dangerous to personnel and property may exist with the operation and maintenance of any combustion equipment. The presence of fuels, oxidants, hot and cold combustion products, hot surfaces, electrical power in control and ignition circuits, etc., are inherent with any combustion application. Components in combustion systems may exceed 160°F (71°C) surface temperatures and present hot surface contact hazard. Fives North American Combustion, Inc. suggests the use of combustion systems that are in compliance with all Safety Codes, Standards, Regulations and Directives; and care in operation.
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