Gentle, controlled drying
Traditional Chinese medicine herbs, flowers (honeysuckle, chrysanthemum), and other botanical or pharmaceutical materials are dried at controlled, often low temperatures to protect active compounds. The exhaust is warm and humid, and recovering its heat stabilizes the inlet air while cutting energy use.
Suitable exchanger types and how they work
Clean stainless plate exchangers preheat the incoming drying air using the exhaust, with the streams fully separated to avoid cross-contamination of product air. Where humidity control matters, an enthalpy wheel recovers moisture. A sensible vs latent review helps decide if latent recovery is worthwhile.
Design considerations for pharma duty
Material must be cleanable and non-reactive — stainless with smooth, accessible surfaces. Provide condensate drainage, control face velocity to protect delicate material, and allow validated cleaning. Keep pressure drop low so the existing drying fans are not overloaded, and document the recovery performance for process records.
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 Recovery for Herbal and Pharmaceutical Drying 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.
