The "heart" of grain dryer and its failure

Grain dryer consists of four parts: heat source, fan, control system and drying tower. Fan is the heart of grain dryer. It mainly sends heat to the drying layer and carries out convective heat transfer with grain to separate moisture and grain. Therefore, the performance parameters of fan determine the drying efficiency, energy consumption and drying quality of grain dryer. The fan function affects the energy consumption of the whole drying system, which is a very important part of the grain dryer.

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

1： When the grain dryer equipment system enters the working state, the fan shall be started and operated in turn. At the beginning of the operation, the vibration of the bearing part is very small. However, with the extension of the operation time, the dust in the fan will adhere to the impeller unevenly, which will gradually destroy the dynamic balance of the fan and increase the bearing vibration. Once the vibration reaches the maximum allowable value of 11mm / s, the fan must Shut down and repair (remove dust accumulation and redo dynamic balance). Because it is very dangerous at this time, users must not use it forcibly.

2： When the bearing temperature of the fan is normal, it is ≤ 70 ℃. If it rises to 70 ℃, the electrical control cabinet shall give an alarm. At this time, the reason should be found out. First, check whether the cooling water is normal? Is the bearing oil level normal?

Three: in the process of fan startup, shutdown or operation, if abnormal phenomenon (such as abnormal sound, abnormal vibration, abnormal Wen Sheng) is found, it should be checked immediately, and the small fault found in the check should be found out in time to try to eliminate the cause. In case of major faults (such as severe vibration of fan, impact, sharp rise of bearing temperature, etc.), stop the machine immediately for inspection.

4： It is common to master the correct opening mode of the air distribution door of the fan, because of the careless operation of the air distribution door.