Energy demand of thermal oxidizers
RTO (regenerative thermal oxidizer) and RCO (regenerative catalytic oxidizer) units destroy VOC-laden process air at 700-900°C. Reaching that temperature for every cubic meter of incoming air is expensive, so the oxidizer’s own hot exhaust is used to preheat the cold, solvent-laden inlet stream before it enters the burner or catalyst bed.
Suitable exchanger types and how they work
Within an RTO the heat is stored in a ceramic regenerator bed, but the upstream make-up air and the downstream clean-exhaust loops are often linked by a high-temperature air-to-air plate exchanger. This recovers sensible heat from the cleaned exhaust to warm the raw inlet. Our plate core material selection guide helps pick temperature-rated alloys.
Design considerations for oxidizer loops
Temperatures are high and the exhaust can be acidic or contain catalyst fines. Specify stainless or higher-grade alloys rated for the duty, allow for thermal expansion, and design cleaning access for any particulate. Confirm the exchanger’s pressure drop fits the oxidizer’s existing fan and that no cross-leakage contaminates the clean side.
Typical Application Environments
Heat recovery is valuable wherever a building or process expels warm, stale air while drawing in cold or hot fresh air. Common sites include factory make-up air systems, commercial kitchens, paint booths, drying rooms, laboratories, and cleanrooms. In each case the exhausted air still holds usable thermal energy, and capturing it reduces the heating or cooling demand placed on the primary plant.
Matching the Unit to the Duty
The right selection starts with the air volume, the temperature difference between streams, and the cleanliness of the exhaust. Clean, steady flows suit plate exchangers; humid or dusty exhaust may need a rotary wheel with purge or a unit arranged for easy wash-down. Pressure drop must stay within the fan curve, and the core material must resist any contaminants present in the airstream.
Integration Tips
For the Heat Exchanger for VOC Abatement Exhaust (RTO/RCO) duty, position the exchanger so the exhaust is filtered before it reaches the core, and provide condensate drainage where the supply side may drop below the dew point. Balanced supply and exhaust fans keep the building neutral in pressure, which protects indoor air quality and process control. A bypass damper lets the system free-cool in mild weather.
Frequently Asked Questions
Can it handle greasy kitchen air? Yes, with a rotary wheel and a wash cycle, though the exhaust should first pass a grease filter. Will it cause condensation? Some condensate is normal in winter; provide a drain or a defrost strategy on the supply side.
