Determination of The Optimal Ratio Between Moisture Reduction and Energy Consumption in Superphosphate Drying

Abstract

This article investigates the optimal relationship between moisture reduction and energy consumption during the drying of superphosphate in a drum dryer equipped with three-section modified lifting flights. The drying process was evaluated using final moisture content, total heat consumption, evaporated moisture flow rate, and aerodynamic resistance. The main operating parameters were drying agent temperature, gas velocity, material productivity, and the number of lifting flights. Particular attention was given to the balance between achieving low final moisture content and avoiding excessive heat consumption. The analysis was carried out for a material productivity of 0.095 kg/s and gas velocity of 20 m/s, with drying agent temperatures of 100, 120, and 140 °C and 24, 30, and 36 lifting flights. The results showed that increasing temperature and the number of lifting flights reduced the final moisture content, but also increased total heat consumption. For example, at 140 °C, increasing the number of lifting flights from 24 to 36 reduced final moisture from 4.874% to 3.266%, while total heat consumption increased from 3046.098 to 3111.135 kJ/kg of evaporated moisture. The results indicate that 30 lifting flights at 120–140 °C provide a rational balance between moisture reduction and energy consumption.