1. Dryer Descriptions By: M Gummert J Rickman Agricultural Engineering Unit IRRI, Los Baños, Philippines

2. IRRI Flat-bed dryer Capacity1 – 2 metric tons/batch PriceUS$ 1000-2000 Drying time6-8h Grain QualityMedium quality, uneven drying of bottom and top layer HeaterDrying air temperature: 43°C A.) Kerosene burner, 2.0 l kerosene/h B.) Rice hull furnace, 3-4 kg rice hull/h FanAxial flow fan, 2200 rpm 1800 cfm at 20mm H2O A.) Electric motor, 2.5 kW B.) Gasoline engine, 0.75l gasoline/h Dimensions Weight L: 3.2m; W: 2.5m; H: 1m; bin: 220 kg; furnace: 290kg AdvantageSimple design, can be locally made, can handle very wet crop DisadvantageMoisture gradient, mixing necessary, dust when unloading, kerosene smell Kerosene burnerRice hull furnace

3. Low-cost seed dryer Capacity100-250 kg PriceUS$ 150-200 Drying time6-9h (initial MC of 22%) Grain QualityGood seed quality HeaterDrying air temperature: 43°C Rice hull stove, 1-1.5 kg rice hull/h FanCentrifugal fan, 3200 rpm 0.11 m³/s Electric motor, 220W AdvantageSimple design, can be locally made, affordable, mobile DisadvantageMoisture gradient

4. Low-cost dryer Capacity1 t/batch PriceUS$ 150-200 Drying time2-4 days Grain QualityGood, low temperature drying principle HeaterDrying air temperature: 6°C above ambient, if weather is bad A.) Coal stove, 0.9-1 kg/h B.) Electric heater, 1 kW FanAxial flow fan, 1750 rpm blowers from automotive coolers Electric motor, 0.5 kW AdvantageVery cheap, simple design, can be locally made, can utilize traditional storage structures, highly mobile DisadvantageSmall moisture gradient, long drying time

5. Re-circulating batch dryer Capacity10 metric tons/batch PriceUS$ 10,000 Drying time6-8 h, 55 min circulation period Grain QualityBest quality, continuous mixing, tempering – drying cycles HeaterDrying air temperature: adjustable, Kerosene burner, 15.4 l/h Fan2 axial flow fans, 1730 rpm 1800 cfm at 20mm H2O A.) Electric motor, 2.5 kW B.) Gasoline engine, 0.75l gasoline/h DimensionsL: 3.5 m; W: 2.5 m; H: 8.3 m; 2,110kg Electricity cons. 7.2 kW for blower, conveyors, electronic control AdvantageAutomatic operation, excellent quality, Automatic safety features DisadvantageProblems with very wet crop (>30%) Axial-flow blower Kerosene burner Control panel

6. Agridry seed dryer Capacity0.6 t/batch (1m³) PriceUS$ 1,350 Drying time3.5 hours from 21.5% to 12.5% Drying rate: 2.3%/h Grain QualitySee quality analysis HeaterLPG gas, 20 MJ/h FanCentrifugal fan Electric motor, 1.5 kW AdvantageMobile, convenient operation, automatic temperature control, high drying rate DisadvantageUneven grain bed thickness Bin needs to be totally filled Inconvenient unloading