Thermal oxidizers, like those used by Intellishare Environmental are utilized as air pollution control systems for industrial processes. The process unit for air pollution control destroys hazardous air pollutants (HAPS), volatile organic compounds (VOCs), and odorous emissions that are discharged from industrial or manufacturing air flows. To improve a thermal oxidizer's efficiency, one can design a thermal oxidizer such that the waste heat recovery unit utilizes a regenerative process. These types of thermal oxidizers are known as regenerative thermal oxidizers (RTO), and a RTO is the most widely used emission abatement technology. The point of a RTO is the repurposing of generated thermal energy from industrial or manufacturing operations, and the benefit of a RTO is reduced operating costs and energy consumption.
How does a regenerative thermal oxidizer work?
Regenerative thermal oxidizers operate in two phases, namely the pollutant destruction phase and the clean air cycle. In what follows we describe the input to the regenerative thermal oxidizer process, transformation of polluted waste into an innocuous mixture of carbon dioxide, water, and heat, and the output purified air.
Pollutant destruction phase
The pollutant destruction phase commences the regenerative thermal oxidation process, whereby a high-pressure supply fan forces exhaust fumes from industrial processes into the oxidizer as the input. The input pollutant laden airstream is guided into an energy recovery canister by an inlet switch valve. Afterwards the airstream continues on a path from the valve assembly to the first heat exchanger. Due to thermodynamic and chemical effects energy is transferred to the airstream from the ceramic media, causing the particles in the airstream to move with great velocities. This increase in temperature is regarded as airstream preheating before arrival to the combustion chamber. As the air moves into the combustion chamber it becomes trapped, and the temperature of the air increases leading to a chemical reaction known as thermal oxidation. Thereby the contaminants in the air are destroyed, while in the combustion chamber.
Clean air cycle
In the second phase of the thermal oxidizing process the purified air is directed out of the combustion chamber and into a second energy recovery canister. The air is at a higher temperature than the ceramic media in the canister, thus the media acts as a heat reservoir. In other words, energy in the form of heat is transferred from the air to the ceramic media. The last step involves reemission of the purified air into the atmosphere. An outlet switch valve directs the clean air through an exhaust stack and back into the atmosphere. The regenerative thermal oxidizer process has the advantageous property of achieving high and reliable thermal energy efficiencies, as well as optimal destruction efficiencies over 99%.
SOURCE: Intellishare Environmental