Air Heater Service Life
Service life of air heaters The service life of heaters cannot be predicted easily as many factors are involved.
The expected life for the heating element based on the temperature during usage is as given below. However, it is rare for burn-out to occur with normal consumption in practice, in many cases burn-out occurs due to overheating caused by control errors while using the heaters.
The temperature of the heating element will be approximately 572ºF (300ºC) to 752ºF (400ºC) higher than the hot air temperature. Therefore, Hot air temperature 1562ºF (850ºC) --> Heating element 2102ºF (1150ºC) - 2282ºF (1250ºC) --> Service life is 0 - 300 hours based on the above graph Hot air temperature 1472ºF (800ºC) --> Heating element 2012ºF (1100ºC) - 2192ºF (1200ºC) --> Service life is 1000 - 50 hours based on the above graph Hot air temperature 1292ºF (700ºC) --> Heating element 2012ºF (1000ºC) - 2012ºF (1100ºC) --> Service life is 8 - 1000 hours based on the above graph The difference between the hot air temperature and the heating element temperature will vary depending on the flow rate. The difference increases with the increase in the flow rate, but on the other hand, the difference is also higher if the flow rate is very less. The trend is that a larger difference results in shorter service life for the same hot air temperature.