Thermal Oxidizer and Its Types

A thermal oxidizer is responsible for reducing air pollution produced in industries by destroying hazardous pollutants at very high temperatures. In this way, only clean air passes into the atmosphere. However, the dangerous air pollutants and volatile organic compounds are dangerous for the environment and humans.

The thermal oxidizers work to deplete these from the airstream through a reaction between oxygen and these compounds, which causes them to break down into substances like water vapors, heat, and carbon dioxide. Thermal oxidizers can destroy around 99% of pollutants. There are different types of oxidizers and the way they work. If you wonder, “how does a regenerative thermal oxidizer work?” then continue reading below.

What factors affect the effectiveness of thermal oxidizers?

Three main factors determine the effectiveness of any thermal oxidizer. These include:

1) Temperature

High temperatures are required to combust the organic compounds present in the unclean airstream. Most of the organic compounds combust at temperatures around 580 to 650℃. To ensure that all the hazardous gases are destroyed, the units need to be set at temperatures much higher than these.

2) Time

It is also important to ensure that enough time is given for the chemical reaction to occur and the combustion of compounds to occur.

3) Turbulence

Turbulence refers to the mixing of ignited air with harmful gases.

Types of thermal Oxidizer

1) Oxidizer with no heat recovery system

The simplest one is the direct-fired Thermal Oxidizer. This unit does not consist of a heat recovery system. It is also the cheapest option in the market. However, this thermal Oxidizer has high fuel consumption and high operating costs compared to other thermal oxidizers.

2) Oxidizer with heat recovery system

Advanced thermal oxidizers have heat recovery systems that recover the heat produced during the combustion process and reuse it again. This saves on the fuel needed for the oxidation and working of thermal oxidizers. In addition to this, they are much more efficient in reducing harmful organic compounds. There are two types of thermal oxidizers under this category.

a) Regenerative thermal oxidizers (RTOs)

These are the most popular and used systems with a thermal efficiency of 95%. You might ask how do regenerative thermal oxidizers work? Well, they start by preheating the gases in a ceramic bed, then the preheated and partially oxidized gases are passed to the combustion chamber, where they are completely oxidized. The ceramic beds utilize the heat from the previous oxidation, making these units efficient and effective, allowing to cut down on operating costs and fuel.

b) Recuperative heat thermal oxidizers (RCOs)

These are not used that often, but you must wonder how a regenerative thermal oxidizer works? The answer is simple. They recover heat by using the hot exhaust gas and making it go through primary and secondary heat exchangers. This component heats the input air, thus reducing operating costs.