RTOs: The Media Matters

Regenerative thermal oxidizers (RTOs) and other types of thermal oxidation systems have proven to be a highly effective and energy-efficient method of abating volatile organic compounds (VOCs) and other pollutants emitted by finishing industry applications. However, particulate matter in the emission stream can be a particularly vexing problem, resulting in the fouling and plugging of media beds. Careful attention should be given to selecting the shape and material of the heat exchange media to mitigate potential problems with particulate matter and to ensure reliable, economical and safe operation of thermal oxidation systems.

Multi-layer ceramic media(MLM) is a type of structured packing which designed for VOC emission reduction equipment——Regenerative Thermal Oxidation (RTO). MLM is made of ceramic plate with prong. MLM obtained US patent for invention and Chinese patent for utility models because of its special structure design.

      The product has been exported to Europe, the United States, Southeast Asia,more than 30 countries and is the first choice of heat exchange media for RTO system which used for the VOCs emission of chemical, metallurgy, painting and so on.

The advantage of MLM as following:

 High specific surface area

 High specific heat capacity

 Excellent heat conductivity

 Low pressure drop

 Plugging resistent

 Low price with high performance 

Regenerative Thermal Oxidation

Thermal oxidizers are essentially incinerators that thermally or catalytically convert pollutant-laden emissions into carbon dioxide and water vapor. The oxidation process typically achieves better than 99% destruction/removal efficiency (DRE) levels for VOCs, hazardous air pollutants (HAPs) and odors.

Regenerative thermal oxidizers minimize fuel consumption by “regenerating” or reusing heat generated by the system. Fans draw air from paint-booth collection systems and other sources, and the air is preheated by heat exchanger media to the thermal oxidation temperature, typically 1,400 to 1,600°F (760 to 871°C). The air then moves into a combustion chamber for the specified residence time (0.5 to 2.0 seconds), where an exothermic reaction takes place, converting the VOCs to carbon dioxide and water vapor. Prior to being exhausted to the atmosphere, the hot, purified air passes through a media bed to capture heat energy that will be used to preheat incoming air. Valves continually alternate the flow between media beds: a cycle with incoming cool air into a media bed that has just been heated by hot exhaust, followed by a cycle with hot exhaust air flowing through the media bed to reheat it.

RTOs can operate at thermal efficiencies of 85 to 99%, reducing or eliminating the need to burn natural gas in the combustion chamber. RTOs are particularly effective for process streams with low to moderate solvent loading, as typically found in many finishing industry applications. In fact, RTOs can be self-sustaining at moderate lower explosive limit (LEL) levels. In other words, once the system is sufficiently heated, the natural gas burners can be turned off if enough flammable gas is present in the exhaust stream