Since the life time of the hot air heater varies depending on the usage conditions and is determined by multiple factors, it is very difficult to estimate the life time, and we do not guarantee the life time.
Multiple factors include the life time of individual parts, how to control the hot air heater, the flow rate and pressure of the compressed gas source, the amount of water vapor and oil mist mixed in the compressed gas source, impact and vibration. The factor that determines the life time of the hot air heater most is the life time of the heating element. Therefore, the approximate life time is estimated by focusing on the life time of the heating element from multiple factors. Most of the causes of hot air heater failure are related to the heating element, and rather than disconnection of the heating element due to normal wear (life time), failure due to overheat disconnection due to control error during use or no wind energization. Occupy a lot.
The life time of the heating element is also determined by multiple factors, but the biggest factor is the maximum temperature of the heating element. The temperature of the heating element varies from place to place. Since the gas temperature gradually rises from the gas supply side to the hot air outlet after passing through the heating element, the place where the maximum temperature is reached is the hot air outlet side. The important point for estimating the life time is to measure the maximum temperature. A non-contact radiation thermometer is suitable for temperature measurement. The approximate life time of the heating element can be estimated from the measurement results.
The graph below shows the relationship between heating element temperature and life time.
When the heating element becomes hot, metal atoms separate from the heating element as metal ions and are consumed.
Heating element temperature 1150 ° C → life timespan of about 300 hours from the above figure
Heating element temperature 1100 ° C → life timespan of 1000 to 2000 hours from the above figure
Heating element temperature 1000 ° C → From the above figure, almost semi-permanent life time
Measures to prevent burning of the Air Blow Heater due to excessive temperature rise
1. Please sure to supply an appropriate flow rate before applying voltage to the hot air heater. It is safer to add an interlock function to the controller.
Example) Heater controller HCAFM (heater controller with flow rate interlock)
2. Monitor and control the temperature of the heating element inside the hot air heater. When the heating element temperature is around 1200 ° C, the risk of burning the heating element increases in a short time. It is safe to set the temperature so that it does not exceed the set temperature with the temperature controller.
Example) + 2S specification heating element temperature sensor option