In engineering applications, mobile belt conveyors for conveying bulk materials need to be able to unload in the middle, and sometimes need to unload at multiple points in the middle or continuously unload in a certain section.
There are three main ways to choose a mobile belt conveyor unloading device
1) Plough unloader.
Plow unloader is divided into manual plow unloader and electric plow unloader. Nowadays, manual plough ship unloaders are only used in some small coal mines and power plants, and are rarely used in new coal mines. Most electric plough unloaders have variable groove angles.
Variable groove angle plow unloader is mainly composed of electric push rod, drive push rod, variable groove angle roller group, flat roller group, plough board and electric device.
Its working feature is that when the unloading plow is pushed down by an external force, under the action of the external force, the idler group supporting the conveyor belt under the plow can be synchronized with the unloading plow from a trough shape to a linear shape. At this time, the scraping plane under the unloading plough can press the upper plane of the conveyor belt to realize bilateral or unilateral unloading.
When the unloading plow is lifted by an external force, the roller group supporting the conveyor belt under the plow is restored from a flat shape to a trough shape, and the material can pass through the current plow unloader to release the unloading state.
Its advantage is that it greatly reduces the belt wear of the coal plough. The disadvantage is that the structure is more complicated, the installation and debugging are troublesome, and the actions are inflexible and stuck occasionally during use. At the same time, because the joint gap between the conveyor belt and the scraping plane under the unloading plough cannot be adjusted, the material can be unloaded cleanly.
Plow-shaped unloader is used for unloading at any point of the horizontal section of the belt conveyor. The plough unloader has two unloading methods: unilateral and bilateral. It is suitable for belt speed V=2.5m/s, material particle size below 25mm, small grindability, and mobile belt conveyor with vulcanized joints.
2) Unload the cart.
Unloading trolley is mainly composed of reversing drum, driving device, blanking hopper, driving wheel, driven wheel, frame, brake and electronic control device.
In order to improve the environmental pollution caused by dust during the unloading process, the mobile belt conveyor unloading trolley can also be equipped with a dust removal system and a tape bin sealing device. The unloading trolley drops the material through the reversing roller and puts it into the three-way funnel. Under the control of the electric flap, the material can fall into the funnel on both sides or the middle discharge hole respectively. The blanking to the middle blanking port is mainly used to adjust the position of the unloading trolley and feed the material to the tail bin.
Its advantage is that it can adapt to the working conditions of high belt speed and large processing capacity without damaging the tape. The disadvantage is that the unloading lifts the upper roller to a certain height, the unloading trolley is huge and complicated, and the body is longer. In addition, the concave arc suspension section makes it impossible to unload at least a section of the feed guide chute larger than 10m, which will limit the equipment layout. As the height and length of plants increase, investment also increases. At the same time, when the belt material moves, scattering occurs. The unloading trolley is used to unload the horizontally arranged belt conveyor. The applicable belt speed is 3.15 m/s. Under the same rated conveying capacity, the mobile trolley can choose a lower bandwidth, which can reduce the operating cost.
3) Reversible silo distribution belt conveyor.
Reversible warehouse belt conveyor is a complete mobile belt conveyor that can be turned and moved. Its function is the same as that of plow-type ship unloader and ship unloader, and can be regarded as a kind of unloading device.
Its feature is that the height of the fuselage is low, which reduces the height of the building and saves capital investment. However, the track is long and laid on the floor. It is easy to spill materials on the track when unloading, and running back and forth will jam the track. The drive is a sprocket drive, which is easy to drop the chain, severely worn, and reversible. The conveyor belt is easy to deviate and difficult to correct.
In actual use, it is prone to failures, maintenance is large and unsafe, the silo has a large opening, and it is difficult to seal and vacuum the silo. Dust is flying when unloading, and the working environment of workers is harsh.
Through the above comparison, the mobile belt conveyor with reversible silo distribution is flexible in layout and simple in structure. The unloading trolley is suitable for various materials, and the belt has a long service life. Reversible bin belt conveyors are relatively complicated. In the design, comprehensive comparison and reasonable selection should be made according to the characteristics and working conditions of the conveyed materials.
