The grain dryer is composed of four parts: heat source, fan, control system and drying tower. The fan is the heart of the grain dryer. It mainly sends heat to the drying layer and the grain for convective heat transfer, so that the moisture is gasified and the grain is separated. Therefore, the performance parameters of the fan determine the drying efficiency and energy consumption of the dryer. And the drying quality of grain. The fan can affect the transmission and distribution energy consumption of the entire drying system and is a very critical part of the grain dryer.

It is worth noting that according to the national relevant equipment quality supervision and inspection center for many years, many fans have problems under rated conditions. Therefore, in the grain dryer drying operation, often encounter such as fan high temperature trip fault, in order to solve the grain dryer under normal condition due to fan failure caused by the loss, we will summarize the following experience.

First, when the grain dryer equipment system enters the working state, the fan should be started in turn. At the beginning of the work, the vibration of the bearing part is very small. However, with the increase of the running time, the dust in the fan will adhere to the impeller unevenly, gradually destroying the dynamic balance of the fan and gradually increasing the vibration of the bearing. Once the vibration reaches the allowable value of 11 mm/s, the fan will be stopped for repair (dust accumulation will be removed, redo the dynamic balance). Because it is very dangerous at this time, users must not use it forcibly.

Two: the bearing temperature of the fan is normal when it is ≤ 70 ℃, if it rises to 70 ℃, the electrical control cabinet should alarm. At this time should find the reason, first check whether the cooling water is normal, bearing oil level is normal?

Three: fan startup, shutdown or operation process, if found abnormal phenomenon (such as abnormal sound, abnormal vibration, abnormal temperature rise) should be immediately checked, check the small fault should be found in time to find out the cause and try to eliminate. If a major fault is found (such as severe vibration of the fan, impact, bearing temperature rise, etc.) should be immediately stopped for inspection.

Four: master the correct way to open the fan with the air door, due to the operation of the air door careless failure phenomenon is also common.