Industry Problem
Food and agricultural drying—grain, flour, starch, fruit, vegetable, herb, seafood—runs hot, humid exhaust (60–120°C) continuously. Recovering that heat to preheat incoming make-up air cuts firing cost, but the product air must stay clean.
Exhaust Conditions
Exhaust is warm and moisture-laden; the make-up air must be heated and supplied to the drying chamber. Food safety rules forbid sending exhaust back into product air.
Recovery Principle & Recommended Exchanger
Use sensible plate recovery with the two streams fully separate. Grain & food drying sensible plate recovery preheats make-up air without any exhaust recirculation. Never recirculate exhaust to the product. For very humid or odorous loads, a run-around coil keeps condensate and contaminants out of supply air.
System Configuration
- Plate core recovers sensible heat from exhaust to incoming air.
- Condensate drain pan below the exhaust side handles humidity.
- Food-grade / stainless materials where product contact is possible.
Energy-Saving Potential
Preheating make-up air by 20–35°C typically reduces dryer firing 15–35%. Examples: grain drying plate exchanger, seaweed drying, tea & shiitake drying, seafood drying.
Material & Design Considerations
Stainless steel or food-grade polymer-coated aluminium; easy-clean, drainable cores. Avoid fouling by allowing access for cleaning.
Application Example
A grain dryer preheats 30,000 m³/h make-up air from 15°C to 45°C using a stainless plate core on 110°C exhaust—saving ~25% of burner fuel with zero exhaust-to-product contact.
Related Products
Plate heat exchangers · Run-around coil · Drying heat recovery pillar
FAQ
Can exhaust air be recirculated to the product?
No for food and agriculture—use sensible plate recovery so supply air is never contaminated by exhaust.
What about condensation?
Plate cores need a drain pan on the exhaust side; high-humidity loads may prefer a run-around coil.
Size Your Dryer Recovery
Send EN159 your dryer exhaust data. Call 15753355505 or request a quote.