Investigation of fermentation chamber thermal condition parameters
2021
Tereshchuk, M., Polissia National Univ., Zhytomyr (Ukraine) | Mykhailovych, Ya., National Univ. of Life and Environmental Sciences of Ukraine, Kiev (Ukraine) | Tsyvenkova, N., Polissia National Univ., Zhytomyr (Ukraine;National Univ. of Life and Environmental Sciences of Ukraine, Kiev (Ukraine) | Holubenko, A., Polissia National Univ., Zhytomyr (Ukraine)
The paper presents mathematical modelling and experimental results of thermal condition parameters of the fermentation process of substrate from organic materials, which consisted of 30% manure, 20% chopped straw, 20% poultry dung, 15% peat and 15% deciduous trees sawdust with the moisture content 62% and particle size less than 1 cm. The design of the fermentation chamber for bio-compost production is presented. To prevent heat losses in the composting process the fermentation chamber was thermoinsulated by polystyrene based composite. The ambient temperature was between –10 ºС to + 10 ºС. The aeration air temperature was changing from + 20 to + 60 ºС. A mathematical model is presented based on the thermal balance equation. The model connects the heat quantity, needed to maintain the temperature mode of the thermophilic phase of the fermentation process, with the aeration air temperature, the ambient temperature and the chamber insulation layer thickness. Experiments were done by the method of a multifactor experiment. It was established that at the ambient temperature –10 ºС, and aeration air temperature + 20 ºС the use of the thermoinsulation reduces the heat losses from 289.4 MJ for no insulation to 190.47 MJ for 50 mm insulation and to 53.91 MJ for 100 mm, respectively. When the aeration air temperature and ambient temperature rise, the expend for maintaining the temperature mode of the thermophilic phase reduces, and with 50 mm of insulation there was an excessive heat produced in the amount of 134.77 MJ, and with 100 mm – nearly 151.84 MJ. The energy autonomous composting process is achieved at the insulation layer thickness 100 mm, ambient temperature + 1… + 5 ºС and the aeration air temperature + 24… + 18 ºС. The obtained measured results are in high correlation with the calculations. The coefficient of determination is 0.99.
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