Pumpkin Slices Using Heat Pump Dryer for Farmers

Abstract

This research aimed to investigate the use of a heat pump drying system powered by a 5.5 kW electric compressor and a 7.8 kW heating coil. The system delivered an air flow rate of 12,800 –23,600 m³/h within a drying chamber sized 200×400×200 cm (W×L×H). The dryer structure included a drying chamber, product trays, and a heat pump system integrated with an electric heating coil. The maximum controllable drying temperature was 75 °C. Drying experiments of 300 kg were conducted using sliced pumpkin, evaluating parameters such as energy consumption, drying time, moisture content, water evaporation rate, and color quality of the dried product. The system efficiently transferred heat from the evaporator to the condenser using compressor energy, while also removing moisture from the chamber without requiring external ventilation. This allowed for stable drying conditions independent of ambient temperature drying at 60 °C effectively reduced moisture content in thin pumpkin slices to the required standard within 7 hours. The energy consumption was recorded at 85.16 kWh, with a specific energy consumption of 1.51 MJ/kg of evaporated water.