Cleaning Our Factories, Cleaning Our Air

General Article

Hazardous air pollutants (HAPs) and volatile organic compounds (VOCs) are an unfortunate by product of the factories we rely on today. These pollutants and compounds need to be removed from the air that we breathe if we are to stay safe and healthy while still producing the goods that our society requires. Thermal oxidizers are one of the ways that we can prevent too many HAPs and VOCs from getting into the environment. The way that these air quality cleaners work is by destroying the pollutants and compounds from the air streams used in industrial fabrication plants. They use thermal combustion to remove impurities from the air and burn up the unwanted chemical compounds, resulting in a creation of both C02 and H20. This is why these machines can also be referred to as “thermal incinerators“. These air quality cleaners are used frequently in mines, as well as in smelting and manufacturing industries such as pesticides, plastics, and other miscellaneous chemical manufacturing endeavors.

There are multiple types of thermal air quality cleaners to be discussed. However, they all have three basic considerations in common. To dispose of fumes, air quality cleaner designs must include a temperature element. This temperature needs to be hot enough to combust the HAPs and VOCs that are produced by the plant. This element is extremely hot in order to combust the fumes. Another factor is known as turbulence, which refers to the waste gas mixing with the combustion air. Finally, any of these machines require what is known as “residence time” to function properly. Residence time is the sufficient amount of time the oxidizer needs to create the combustion reaction.

With all types of industrial air quality cleaners, fuel conservation is extremely important. To do this, there are two types of techniques to employ. One is known as regenerative heat recovery. This involves the heated exhaust gas and the cooler inlet gas to be passed alternatively through a fixed ceramic bed in the oxidizer. Recuperative heat recovery is slightly more complicated. Recuperative heat recovery occurs when hot exhaust gases are passed through a non-contact air-to-air heat exchanger. This then heats the air incoming to the cleaner. These thermal recuperative incinerators are less commonly used in the industry.

The different types of air quality cleaners are as follows. All six of these air quality cleaners have different applications regarding disposal of hazardous waste fumes. The most common of the technology is the afterburner. This type of air quality cleaner uses a high concentration VOCs as a fuel source to combust the hazardous waste gases. As well as being the least capital intensive for companies, this basic type can be upgraded with different fuel conservation technologies such as heat exchangers. RTOs are also very common due to their efficiency and versatility. Unlike the afterburner which requires a high concentration of VOCs to function, RTOs can be efficient in both low and high VOC concentration environments. RTOs are usually used to get rid of unwanted and hazardous fumes, odors, and other pollutants.