Recuperators and Dilution Air Supply Maintenance

Recuperator heat exchangers need regular inspection for cracked, torn, or broken tubes or tube sheets. 

Flue gas temperature measurement needs scheduled inspection to be sure the T-sensor does not see the cold tubes, which will fool the overtemperature control into letting flue gases gef too hot. 

Minimum airflow should be at least 10% of maximum air flow, and this must be maintained 100% of the time—not 98% of the time. The maximum flow should 

Inspect the dilution air system to be sure that it has adequate capacity to cool the flue gas for protection of recuperators and other equipment. Perform this check regularly and especially after delays, when all zones will be at maximum input, with the loads hot all the way back to the charge door, thereby raising flue gas exit temperatures considerably above normal. 

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