A Research on drying of various medicinal and aromatic plants in farm scale

In this research, two tray dryer named Çukurova I and Çukurova II was designed and manufactured for drying of various medicinal and aromatic plants like peppermint (Mentha piperita L.), St. John's Wort [Hypericum perforatum L.) and oil rose (Rosa damescena Miller). To determine the optimum working condition of these dryers, Six, three, and eight drying tests with varying loading capacity were conducted with peppermint, St. John's Wort and oil rose, respectively. Dryer technical and economic performance factors such as, drying time, fuel consumption, dryer efficiency, specific heat and electrical energy consumption, annual drying capacity, clasical payback period and net present value were used to determine the optimum drying capacity. After the drying experiments made by Çukurova I dryer at 46±4°C drying air temperature, optimum drying capacity for peppermint and St. John's Wort were determined as 145 and 120 kg of per batch, respectively. Classical pay back period and net present value of the Çukurova I dryer by working at optimum drying capacity were determined as 0.10 year and $ 179985 for peppermint drying, and 0.0283 year and $ 669410 for St John's Wort drying. After the drying experiments made by Çukurova II dryer with oil rose, optimum drying conditions for oil rose were obtained at 52-53°C drying air temperature and 320 kg of per batch. By working at optimum capacity, classical pay back period and net present value of the Çukurova II dryer for oil rose drying were determined as 0.16 year and $ 471405. Results showed that relativelly low cost this type of dryers made by locally available materials were economicaly profitable drying systems. It is expected that the non-seasonal use of the dryers for other crops increases the profitability of the drying systems considerably. KeyWords: Tray Dryer, Dryer Efficiency, Specific Heat Energy Consumption, Economic Analysis, Medicinal and Aromatic plants II