METHOD TO STABILISE HEAT AND MOISTURE CHARACTERISTICS OF CEREAL AND OIL PLANT SEEDS IN PROCESS OF DRYING AND STORAGE

摘要

FIELD: agriculture.;SUBSTANCE: method of stabilisation includes control of drying processes in a shaft dryer and cooling of grain in process of its active ventilation in granaries of silo type with usage of a heat pump plant for preparation of a dried air in a working section of an evaporator and its division into two flows, one of which is supplied for active ventilation of grain into silos, and the other one - for drying of grain with subsequent recirculation in a closed contour with serial transfer into a condenser, a heater, a heat exchanger, a cyclone, a working section of an evaporator, which, alternately with a reserve section, switches from the condensation mode to the regeneration mode as the current value of heat transfer coefficient on the cooling surface of the evaporator reaches the limit permissible value, acting at the capacity of the compressor drive of the heat pump plant in process of dried air moisture and temperature control with correction by fresh air flow in the make-up line. The novelty is the fact that in order to stabilise heat and moisture characteristics of cereal and oil plants seeds, an oscillating mode of drying is used with alternation of grain heating and cooling processes in a multi-section dryer, which consists of heating and cooling sections; to realise the oscillating mode of drying, one part of cold air downstream the evaporator is sent to cool down grain in the cooling section of the multi-section dryer, and the other part - via a condenser of the heat pump plant and heaters - is sent to heat grain in each heating section of the dryer; the saturated steam is used for heating of air in the heater prior to its supply into heating sections of the dryer and for regeneration of the cooling element surface in a reserve section of the heat pump plant evaporator, besides, the saturated steam is produced in a steam generator with electric heating elements and a safety valve, at the same time the condensate of the saturated steam generated in the hearth and the reserve section of the heat pump plant evaporator is drained into a condensate collector, and then in the mode of the closed cycle it is again supplied into the steam generator to make up for water loss; dried grain prior to its laying for storage is treated with an antioxidant, besides, the used air after active ventilation of grain is supplied into the cyclone, in process of grain drying in the oscillating mode grain temperature and moisture are additionally measured in the heating sections, in the cooling sections - grain temperature, air flow, antioxidant consumption, saturated steam flow downstream the steam generator, steam pressure and condensate level in the steam generator are measured, besides, using grain temperature in the heating sections, the steam flow to heaters is established, and using grain moisture in the heating sections and grain temperature in the cooling sections, accordingly flow of hot and cold air is established by acting at the capacity of controlled drives of fans; ratio of dried grain flows and a flow of antioxidant supplied into a mixer, is maintained by variation of the antioxidant flow; the saturated steam pressure in the steam generator is used to establish the specified efficiency of the steam generator by acting at the capacity of electric heating elements, with reduction of condensate level in the steam generator below the specified value, the condensate is supplied from the condensate collector, and when the steam pressure in the steam generator achieves the upper limit value, the steam pressure is discharged via a safety valve.;EFFECT: method to stabilise heat and moisture characteristics of cereal and oil plants grain in process of its drying and storage makes it possible to increase quality of cereal and oil plants grain due to realisation of drying in oscillating modes by means of alternation of heating and cooling intervals, to increase time of grain storage as a result of its treatment prior to its laying for storage with an antioxidant in required quantities; to provide for synchronism in operation of a reserve and a working sections of the heat pump plant evaporator, and to increase quality of dried grain; to improve environmental safety of the process of grain heat and moisture characteristics stabilisation in process of drying and storage due to recirculation of used air after active ventilation of grain.;1 dwg