Definition - What does Preheated Air mean?
Preheated air is a type of air that has undergone heating prior to another process, like combustion in boilers. The main objective of preheating the air is to enhance the thermal efficiency of heating processes.
In boilers, preheated air recovers its heat from the boiler's flue gas. This leads to the improved boiler thermal efficiency brought about by the lessened level of heat loss in the boiler’s gas. Preheated air is highly useful in boilers, air heaters as well as drying processes.
Corrosionpedia explains Preheated Air
Preheated air plays a vital role in improving the efficiency of processes like combustion. By preheating the air, all of the wastes produced by flue gases can be recovered. Preheated air also produces elevated flame temperatures, which is vital for certain processes like thermal cracking.
Furthermore, preheating the air used in combustion is typical in high-temperature industrial environments and processes like:
- Petroleum refining
- Chemical processing
- Glass and metal industries
Preheated air is also applicable in certain low-temperature industrial processes like generation of steam, heating and drying of non-metal where the levels of flue gas are very high.
By preheating the air, damage to machinery can be prevented. Additionally, it promotes higher savings in terms of energy by improving heating efficiency. By preheating the air, industrial systems that consume high amounts of energy or exhaust gases can experience significant energy savings.