Research On The Process And Quality Of The Duly Drying Rough Rice, And The Drying Machine Design

A duly drying mode was defined as the dried immediately implemented within8h for the paddy rice after harvest threshing, which may keep the flavor and nutrients of rice, reduce microbial growth, in particular, can improve the taste quality of rice. This drying mode is necessary process for the production of high-quality rice.Duly drying characteristics of different processes were analyzed in this study the. Experimental procedure were deterimined based on the development of test programs variation of grain temperature, moisture content and precipitation rate. Single factor experimental methods was employed to investigate the delay drying rice drying and timely quality. The effects of hot-air speed and temper ratio on the drying rate in duly drying were analyzed to obtain the optimal drying process in a paddy rice dryer, according to meet the requirements of duly drying proces, a paddy rice mobile dryer with fuzzy control system was design for the duly drying process. Through the above experimental study research results were obtained as follows:(1) In the stacking process of paddy rice after harvesting, the aroma lost,and microbial growth may occur due to the changes of physical properties and chemical composition. Duly drying of paddy rice improve the hardness, elasticity, smell, taste and palatability of rice.(2) Fresh paddy rice contains the high moisture content with uneven distribution. Duly drying process, the crack generation within paddy rice obviously increase when the moisture content down to18percent (moisture content of3.25%deviation).(3) The optimal parameters of highest taste value for duly drying technology in a small mobile dryer was optimized as air temperature45℃, ratio of air volume to grain mass of7m3/h· kg dried to18%(w.b.), tempering treatment to setting time, followed by the1:5tempering treatment and ratio of air volume to grain mass of4m3/h·kg, till the14%(w.b.).(4) A mobile dryer was developed considering duly drying mode for the paddy rice with loaded mass capacity of3t, which may dry the wet fresh paddy rice from the initial moisture content of25%-30%down to14%moisture in drying time of10h. Heating system of designed dryer contain double spiral fin with rapid elevation temperature and high stabilization of heating system, which is suitable for the drying environment in the northern of China.(5) According to paddy drying process and timely experience for grain dryer, a designed fuzzy control system may automatically adjusts the input amount of hot-air. When the full amount of wind dried to a moisture content of paddy to18%, the fuzzy controller based on fuzzy control rules established by the ratio of air volume to grain mass is adjusted to4m3/kg· h. Air flow is controlled by using an EV2000inverte fuzzy controller using STC89C58RD+microcontroller wth fuzzy control algorithm.