Developing Heated Air Dryer for Food Waste Using Steam Generated from Incineration Plant

Abstract

Purpose: This study was conducted to develop and experimentally evaluate the performance of drying devices for high-moisture food waste. Methods: A drying device for an incineration plant with a drying capacity of 10,000?kg/h was constructed using heated air obtained through heat exchange. The experimental material was food waste collected from heavy industrial restaurants in the vicinity of a shipyard. The drying characteristics of the food waste was identified, and the device’s applicability was evaluated. Results: Following the experiment, it was observed that using the heated air generated from the steam heat exchanger of the incineration plant, the duration of drying food waste was extremely long, at above 50?h. This results in less than 50% efficiency in the heat exchange process and heat losses in the piping line. The temperature of the dry air supplied to the dryer was lower than 165°. Furthermore, it was found that the ratio of dry essential energy (water evaporation energy) to input steam energy, at 7%, was significantly low; therefore, drying high-moisture food waste using heated air obtained from the steam heat exchanger of the incineration plant was found to be ineffective. Conclusions: It is difficult to dry high-moisture food waste using steam heat exchange in incineration plants; however, it is more effective to use steam as a direct drying heat source in the treatment of food wastes. ? 2019, The Korean Society for Agricultural Machinery.