Drying of medicinal and aromatic plants with vacuum oven operated by solar energy / [electronic resource].

Year book of Misr Society of Agricultural Engineering : The 20 th. Annual Conference of the Misr Society of Agricultural Engineering "Agricultural Engineering and Country Challenges"

Includes references.

The research aim is to drying of medicinal and aromatic plants with vacuum oven operated by solar energy. The panel of solar energy system was used to operate the 900 W vacuum oven and the 800 W vacuum pump. The theoretical calculation is done and the experiments are recognized in MariOllt Research Station, El- Amria -Alexandria- Desert Research Center. From the experiments, the parsley (Petroslinum crispwn Mill) with moisture of83 :t O.4J/o (w.b) was dried using vacuum
drying. Parsley was dried in a vacllum oven to assess the effects of material load on drying time, drying rate and energy consumption. The drying experiments were carried out under four different pressures (100, 200, 300 and 400 mbar) and three different temperatures (40, 50, and 60 0c). Mini tab 16 program (RSM) was used to analysis the data. For vacuum drying, the minimum drying periods lasted 120 minutes at 100 mba,. and 60°C and the maximum drying period lasted 1620 minutes at 400 mbar and 40°C. Energy consumptionfor vacuum drying was 576.5 Wh at 100 mbar and 60°C and 3689.2 Wh at 400 mbar and 40°C. The highest values of drying rate were obtained during the experiment at 60 °C at 100 mbar. A relative~v long constant rate perioa was observed after a short heating period The results showed that the moisture content was arrived to 17 :t 0.4% (w.b) at 100 mbar after 600, 240 and 180 min at 40, 50, and 60°C, respectively. It was also noticed that the drying at 50 °C was ideal for drying parsley regarding that color is of primary importance in dried herbs at 100 mbar.

Summary in Arabic