Podmorazhivanie myasa morozil'noy plitoy

A mathematical description of the process of a substance phase state change at freezing of any body is presented. It is shown that the duration of the process is defined by the position of the interface between frozen and not frozen parts of the body that is not evidently specified and is displaced in time. The subfreezing is considered as a process of interrupted freezing that is used in many technologies of foodstuffs cold treatment. The analytical solution of the body freezing problem was obtained by Stefan when admitting a great intensity of external heat that should be confirmed experimentally in respect to a concrete technology. An experimental research of the meat subfreezing process at the contact with a freezing plate was carried out. A tolerable matching of results obtained by analytical and experimental methods was established. This allows calculating the thickness of the subfrozen layer or the duration of the subfreezing process as well as defining the temperature field in the body for any moment of time. The possibility of using Stefan’s mathematical model assumes a principal character when the solutions of heat conductivity problems are used as intermediate results for the solutions of other tasks that are more complicated, for example, giving proof of the storage conditions of subfrozen NOR/DFD meat taking into account the quantity of water frozen out. Keywords: meat subfreezing, phase state change at freezing, Stefan’ problem, freezing plate

подмораживание мяса, изменение фазового состояния при замораживании, задача Стефана, морозильная плита