Physical and technological properties of hemp seeds

The research objective was studying physical and technological indicators of hemp seeds. General description of anatomic structure of hemp seeds was given. The data on the number of physical and technological indicators of seeds were summarized: the size, the bulk density, the nature, the mass of 1000 grains, the coefficients of external and internal friction, the angle of natural slope, the speed of soaring, borehole capacity. The influence of humidity on these characteristics was considered and corresponding mathematical dependences were given. The sorption isotherm at the temperature of 20 °C was considered in comparison with the similar dependence for flax seeds and wheat grain. The Oswin model was proposed as the model for the equilibrium moisture content of hemp seeds. It was found that the coefficient of thermal conductivity of hemp seed mass varied on average from 0.14 to 0.22 W/(m ∙ K). With increasing humidity, the coefficient of thermal conductivity of seeds increased. The coefficient of thermal conductivity of the seed mass was about 100 times less than the coefficient of thermal conductivity of the air. The equilibrium moisture content of hemp seeds was lower than that of flax and wheat seeds, which made it possible to achieve lower humidity at lower temperatures, while preserving valuable core nutrients. The adsorption potential of hemp seeds was significantly less than that of wheat grain, and, consequently, the energy consumption during their dehydration, such as drying, would be less. The presented data on the structure and physical and technological characteristics of seeds of technical hemp are of interest at the organization of their storage and development of technological schemes of processing, in particular at their collapse with receiving proteinaceous fraction. The coefficients of friction and corners of natural slope were used at calculation of bunkers and the burt formation in the warehouse. The speed of soaring served as the reference point of the top limit of the speed of the air at pneumoseparation of the mixture of whole kernels, shells, chaff (kernel particles), whole and incompletely hulled seeds and geometrical sizes - at sieve sowing.