The gradient of values of water activity of the product and the corresponding humidity of the environment is the driving force of mass moisture exchange in various thermal and hydrothermal processes, as well as during storage, data on the water activity index are important. This indicator shows the amount of moisture retained in the test specimens, which may bind other compounds and affect the shape and structure of the test specimens, as well as the storage efficiency. Given the growing interest in fuel pellets, it is important to determine the rate of water activity.

Composite granules based on obsolete sludge, peat and biomass (sawdust and buckwheat husks) were investigated. Measurement of thermodynamic parameters of the test samples was performed on a Hygrolab-2 instrument. Microscopic measurements were performed using a Delta Optimal Genetic Pro microscope connected to a computer.

According to the generally accepted classification, fuel pellets belong to the tested samples with low humidity and brittle structure, which indicates a high calorific value. It is noted that the effect on the water activity index of sawdust content, which does not impair the quality of the studied samples but indicates a better ability to absorb moisture than its counterparts. Microphotographs of the granule samples show a significant pore space and a high sorption area, which can adsorb compounds both on the surface of the granules and in micro and mesopores.

For the first time, the water activity index was determined for technical products, such as fuel pellets, the range of values of which is 0.224-0.231. Correlation coefficients are obtained, which have the same value for all types of granules. It is determined that the conditions of the technological process of obtaining fuel granules contributed to the formation of a porous structure, brittle and suitable for adsorption of compounds. This affects the storage conditions of the pellets and their mandatory observance.


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How to Cite
Petrova, Z., KuznietsovaІ., MyryninА., & Novikova, Y. (2022). RESEARCH OF WATER ACTIVITY INDICATOR FOR MULOTORPHONE GRANULES. Thermophysics and Thermal Power Engineering, 44(1), 14-19.
Heat and Mass Transfer Processes and Equipment, Theory and Practice of Drying