Bucket Elevator Holdback Problems during Operation

While using bucket elevator, sometimes there is abnormal holdback operation phenomenon during operation, do you know the reason?
In fact, during the operation of bucket elevator, sometimes there will be operation stopping inevitably due to malfunction or heavy-loading, even the breakage of link chain or belt could occur, then cause reversal. The reverse operating can cause collision of the bucket and material that remain in the bottom, this could easily cause deformation of bucket and will not function well due to severe damage. Overloading situation is easy to occur if not pay attention to feeding capacity.
Under normal circumstances, the bucket of bucket elevator will lift the material from the bottom to the discharge port which is located on top of bucket elevator and then throw out. In order to ensure the production, when designing and manufacturing equipment, manufacturers just consider that the equipment will not reverse under the non-load condition, because bucket of lower part is two more than upper part, which will be much heavier than the upper. In order to prevent the breakage of belt or link chain or reversal occur in the bucket and link chain, especially when the bucket elevator is under the overload condition, the backstop should be installed at the external of bucket elevator in order to avoid the problem of overload.

 

The bucket elevator holdback consists of reverse rod, revolving shaft, retracting spring and dowel pin etc. In the process of normal operation of bucket elevator, the reverse rod will be upswing after hit by the sleeve, it will fall under the action of retracting spring force, then upswing after hit by another sleeve, not affecting the normal operation of equipment. If there is reversal of bucket elevator, the dowel pin will halt the reverse rod, so it will no longer swing down, and the sleeve will also be blocked by the reverse rod, hence the whole link chain could not reverse. If there is too much material spilled inside the body of machine and fall on the reverse rod, it will cause the failure of holdback. 

If there is too much materials outside the bucket elevator, it will affect the rotation axis of screw. We may see there will be stacked with material in the pit of bucket elevator on the user’s site, which will seriously affect the operation of the relevant parts of holdback.

Five Phenomenon will Lead to Bucket Elevator Dust Explosion

Bucket elevator is widely applied in industrial and agricultural production. In the process of loading materials, the buckets of bucket elevator will strike on the material at a higher speed, which causes a great friction and impulsive force on materials, and will result friction between materials. Hence, the dust material dust will be blown out. When unloading the materials, materials will be thrown from the bucket, which also cause the dust blowing out.
In order to control the dust leakage, bucket elevator works under the condition of completely sealed, the enclosed space virtually increased the risk of explosion. Although the bucket elevator is worked in a sealed condition, the casing is not very tight, the air can enter through the connector and inlet port. Therefore, there is presence of large amounts of oxygen in the internal. When there is a fire, it can generate dust explosions. Bucket elevator can create dust explosion may be due to undesirable of machine operation, where there is high possibility of creating a spark. The main reason is as follows:
(1) if particle flow contains metallic impurities, it may collide and rub with the bucket in the process of the flowing, this will create spark.
(2) if belt deviation occurs and rubs with casing, it may produce spark, so in order to prevent the sparks, it is better to use the chain bucket elevator.
(3) when buckets or screw fall off, it can produces sparks when rub with other components.
(4) when bearing overheats or belt skid for a long period, it can achieve ignition point of dust explosion.
(5) the open flames enters, igniting dust explosion etc..