Agricultural rice dryers have several drying techniques

Release time: 2022-12-07

The principle of agricultural dryers is similar, but the drying process may vary, mainly because the moisture content of rice harvested in different regions and periods of time may vary. Appropriate drying processes should be selected based on the grain situation. There are four main drying processes for agricultural dryers, namely:
1. Low speed drying process
"Agricultural drying too fast or cooling too fast can easily lead to bursting. Compared to high temperature and low air volume, the increase in bursting rate is not much. However, on the premise of ensuring that the increase in bursting rate of rice is less than 3%, low temperature and high air volume can increase the drying rate from 1%/hour to 1.8%/hour.".
2. Soothing baking technique
That is, first dry the rice, and then keep the rice warm for a period of time to allow the internal moisture of the grain to diffuse to the surface, reducing the internal moisture gradient of the grain, and then conduct a second or third drying, which can reduce the burst rate. This process requires a reasonable selection of thawing time.
3. Low temperature drying technology
The burst rate of rice during drying is related to the hot air moisture content. When the air moisture content is high at the same temperature, the burst rate of rice is low. In order to ensure the quality of rice after drying and reduce the burst rate, a lower medium temperature must be used, typically below 50 ° C; In addition, depending on the type of grain dryer, the temperature of the hot air varies, such as downstream drying, where the temperature of the hot air can reach over 100 ° C; Cross flow and mixed flow can reach 45 ° C to 60 ° C; Countercurrent drying should be lower, around 40 ° C.
4. High temperature fast drying technology
During the rice harvest season, when time is relatively urgent, it is also possible to consider using a high-temperature rapid drying process, using a rice dryer, and using a high hot air temperature (above 100 ° C) to quickly (within 5 minutes) process high humidity rice, rapidly reducing the moisture content of the rice by 3% to 5%, and then maintaining heat for cooling. The disadvantage of this process is that the increase in waist burst rate may exceed the standard.