Why does Screw Conveyor Occur Material Backflow

As we all know, screw conveyor has widely application in various industries, such as building materials, chemicals, power, metallurgy, coal carbon, food and other industries, and could be suitable for horizontal or inclined conveying. During operation of screw conveyor, once there are materials blocked in hanging bearing, which is called material backflow. If screw conveyor always occurs the phenomenon of backflow, then it will cause screw conveyor throughput greatly decrease. With regard to large capacity screw conveyor, the material backed flow is likely to undermine reducer, and result in reducer overburn as well as economic losses.

If it is seen from transportation process of screw conveyor, the speed of controller and slipping material determines the speed of material which is conveyed from screw conveyor. What’s more, conveyor filling coefficient determines the discharge time, and the speed is large or small depends on the size of screw arbor and motor. Therefore raise these two components size can successfully address the material backflow problem.

What is the working preparation for screw conveyor installation?

1.The screw conveyor foundation should be completed before installation for 20 days which will make the foundation secure and reliable,and will prevent screw conveyor from sinking and deformation to ensure screw conveyor with enough stability when running.
2.The casing installation should accord with following stipulation:
(1)Allowed longitudinal straightness error is 1/1000 of length,total length error is 3mm.
(2)Allowed horizontal straightness error is 1/5000 of width.
(3)The inner wall of the casing is equal to the two sides of the screw blade,and the error is allowed to be 2 mm,the bottom interval error is ±2 mm.
(4)The connection of casing should be closely,and no interval is allowed.
(5)The casing should be fully contacted with structure support.
3.Allowed overlap error of center line between shaft and bearing is 0.5mm.
4.There should be no apparent height difference between two adjacent casings.
5.Please adjust and steady casing before tightening foundation bolts.
6.Output shaft of driven device should be in the same axis line with screw conveyor shaft.
7.If the inlet and outlet need to be installed on site,please weld them after fixing the total machine.

If you operate like this, the screw conveyor will become a pile of scrap metal soon

Are you complaining that your screw conveyor always have problems and you feel you bought a bad quality conveyor? After reading this article you will change your opinion.
Based our investigation, we find that many users operate the screw conveyor in the way. It will not only result in conveyor damage, but also harm to the operating personnel. Please avoid the following wrong operating methods in order to hope utilize the screw conveyor reasonably.
1.Open the upper cover plate during conveyor running.
Users always open the upper cover in order to observe running situation easily, however, this behavior is forbidden. During running ,if sundries fall into conveyor, the conveyor will break down, such as screw blade deformation, shaft cracking, casing damage, etc.
2.Do not clean the residual material timely after using conveyor .
If the residual material is sticky and corrosive, the blade and shaft will be corroded which will lead to a shorter service life.
3.Motor is overloaded heavily.
It can make motor temperature become too high even it will lead to motor overburning. Please control the feeding flow strictly, vibrating feeder will be a good choice.
4.Do not add lubricating oil for bearing.
The dust can make the lubricating oil become viscous, thus it will influence shaft rotating, so please add oil regularly.
5.The temperature of reducer is too high.
The reason is reducer lack of lubricating oil, please check the oil amount before conveyor running.
6.After shutting down the conveyor, the shaft is forced to stop rotating.
This behavior is very dangerous, it will harm the screw blade, shaft and motor. We should stop the screw conveyor naturally.

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