To optimise product drying such as biltong we can reduce the trial and error time by providing a drying approach which tackles key parameters in drying food. Temperature, Humidity, airflow and handling methods are key considerations.
Air flow 2-4m/s recommended Velocity through product between 2m/s and 4m/s for turbulence on product skin for faster drying. Re-circulation in room with false ceiling and 1.8mH hanging trays
H 1800 of racking W 2300L 6000Face area = 4m2
Max airflow 4x4m/2 16,000l/s ESP 200Pa est
2000kg/day product, Moisture removal 10%
EST Drying time 24hrs
Capacity average – 2000 x 1.2 x 24= 8.3kg (L)/h
Heat load from DST R061R Dehumidifier to room 7kW – (0- 5.6kW average cooking from 8.3kg/h evaporation. Max est 7kW)
Cooling load 7kW desiccant heat generation from drying 8.3kg/h (plus summer heat gain 2kW)
Method- Product drying with Desiccant Dehumidifier – Batch drying
The use of desiccant dehumidifiers for product drying in a bypass to recirculated air. The heat given off by the desiccant is adequate for heating the room and therefore cooling equipment is needed to avoid over cooling. As different products each have their own drying characteristics, it is important to know their drying profile to make an initial selection. Initial evaporation rates are usually substantially more than the calculated average.
Simple measurements in the change in weight over time will allow for oversizing, where some drying trend and initial moisture loss test will help reduce the equipment sizing.
*SAMPLE ONLY time profile of product moisture content and suggested
room temperature control, cooler at end of cycle to avoid
overheating dry product.