METHOD FOR THE AVERAGE INTEGRAL ASSESSMENT OF THE BOND STRENGTH OF MOISTURE IN A SUBSTANCE IN ANY GIVEN RANGE OF MOISTURE CONTENTS Russian patent published in 2021 - IPC G01N25/56 

FIELD: physical chemistry.

SUBSTANCE: invention relates to methods for determining the bond strength of moisture with a substance and can be used in food, chemical and other industries, as well as in the study of hygroscopic properties of wet materials. The method for the average integral assessment of the strength of the moisture-substance bond includes preliminary construction of a graphical curve of the change in the moisture content of the substance from time to time during drying of a finely ground sample in a drying plant with constant thermodynamic parameters of the vapor-gas medium at the entrance to the installation, determination of the maximum drying speed and drying duration to moisture contents corresponding to critical and final values, and determination of the average integral value of the moisture-substance bond strength in the range of moisture contents, corresponding to the removal of bound moisture by the value of the relative equivalent moisture content, while two experiments are previously carried out on drying samples of the substance in a dryer at constant thermodynamic parameters of the process, on the basis of which two curves of changes in the moisture content of the substance from time are constructed: drying curves, and in the first experiment the sample is the starting substance, and distilled water is added to the sample for the second experiment in such a way that it contains free moisture, but the size and amount of solid particles of the substance or the evaporation surface of the paste-like substance are equal to the first sample, then the drying rate corresponding to the removal of free moisture from the sample is determined by the drying curve of the second experiment, as the tangent of the angle of inclination of the rectilinear section on the upper part of the curve of the change in the moisture content of the substance to the time axis, the duration of the process is determined by the graphical drying curve of the first sample in any considered range of moisture contents.

EFFECT: ability to determine the average integral estimate of the bond strength of moisture in the material in any range of moisture content.

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