The so-called grain dryer is a machine for drying grain in plain language. The efficiency of drying grain is much higher than that of manual drying. It is conservatively estimated that a grain dryer can meet 100 tons of high moisture per day. Demand for drying of grain. The moisture content of the grains harvested in different regions and different time periods will be different. If you use a grain dryer to dry, you must choose a suitable drying process according to the moisture content of the grain, otherwise it will affect the final drying effect. Here today, we will introduce the four drying processes commonly used in grain dryers in full detail.
Low-speed drying process
Grain drying too fast or cooling too fast is easy to produce burst waist, but the relationship between the rate of cereal burst waist and drying speed is different due to different wind temperature. Compared with the high temperature and small air volume, the increase in the rate of waist burst is not much between low temperature and large air volume, but under the premise of ensuring that the increase in grain burst rate is less than 3%, the low temperature and large air volume can increase the drying rate from 1%/hour to 8%/ hour. In general, in order to ensure the drying quality of grain, the drying speed should not be too fast, and should generally be controlled below 1.5%/hour.
Drying slow drying process
That is, the grain is dried first, and then the grain is kept warm for a period of time, so that the moisture inside the grain is diffused to the surface, and the moisture gradient inside the grain is reduced, and then the second drying is carried out, which can reduce the burst rate. However, adding a slow-down process in the drying process is bound to reduce the productivity of the dryer. Therefore, a reasonable choice of time to slow down has become a key issue.
Low temperature drying process of grain dryer
According to the research of agricultural experts, the rate of waist burst during the grain drying process is not only related to the temperature of the hot air, but also related to the moisture content of the hot air. When the air humidity content is higher under the same temperature conditions, the grain burst rate is lower. In order to make the burst rate less than 5%, the hot air temperature should be below 40°C. Depending on the type of grain dryer, the hot air temperature is also different. Such as downstream drying, the hot air temperature can reach above 100℃; cross-flow and mixed flow can reach 45℃～60℃; countercurrent drying should be lower, about 40℃, and the use effect is better. In order to ensure the quality of the grain after baking and reduce the rate of bursting, a lower medium temperature must be used, generally below 50°C. The drying process of 200 tons of grain per day researched by xxx Machinery uses a hot air temperature of 38°C to 40°C, and the increase in the burst rate is less than 2%.
High temperature rapid drying process of grain dryer
The grain drying process is put forward on the basis of ensuring the grain quality (the grain burst rate is less than 3%), but in the grain harvest season, the time is tight, and the high temperature rapid drying process can also be considered. The high-temperature rapid drying process is a drying process that uses a higher hot air temperature (above 100°C) to quickly process high-humidity grains (within 5 minutes), so that the grain moisture is quickly reduced by 3% to 5%, and then heat preservation and cooling. The moisture reduced during the drying process plus the approximately 1% moisture reduced during the cooling process can make the grain basically reach safe moisture, which can ensure that there is no mold for a period of time. The result of processing grain in this way is that the increase in the rate of grain bursting may exceed the standard, but the processing capacity of the grain dryer is increased and time is gained.
Yutung Industrial produce conveyor and elevator parts for grain storage, grain handling, grain transportation and grain drying. Website: www.ytconveyor.com Email:sales@ytconveyor.com
