The screening equipment of domestic Xinjiang coal transport system adopts the variable inclination coal roller screen produced by foreign import companies. Since the coal transport system has been put into operation, there are many defects in the coal roller screen, and the output is often reduced, the shaft is broken, the motor is burned, the coal is blocked and so on. In view of this situation, our factory has carried out a number of transformations in the overhaul of the coal roller screen in 2023, and achieved good results. Technical parameters of coal roller screen before transformation:
Capacity: 630t/h screen surface width: 1000mm
Number of sieve shafts: 9 Feeding size: less than 300mm
Discharge size: 30mm Power: 1.5KW
Motor reducer model No. : R6
To this end, for the coal roller screen of the variable inclination coal roller screen of our coal transport system, the output often becomes smaller, the shaft is broken, the motor is burned, and the phenomenon of blocking and breaking coal is analyzed in detail and comprehensively before the overhaul, the main reasons are as follows:
1) The whole coal conveying system is not designed and installed with a large material distributor, and all large materials enter the coal roller screen, often resulting in equipment overload operation.
2) The motor power selection is small. The phenomenon of burning the motor often occurs.
3) The shape of the roller teeth is unreasonable. It is easy to cause coal blockage.
In view of the reasons analyzed above, we have mainly made the following improvements:
1) The transformation is carried out on the original variable Angle coal roller screen, and the grid-type distributor is added on the upper part of the equipment and under the coal hopper of the belt head. The grid-type distributor is a single-sided grid-type tee, and the grid-type clearance is less than 30mm.
2) Add the corresponding arc guide plate and manual adjustment mechanism, by adjusting the arc guide plate, so that the coal can fall on the grid of the grid-type distributor well, so that the coal particles less than 30mm can pass the grid of the grid-type distributor and enter the next belt through the coal roller screen bypass and coal drop pipe.
3) Transform the coal drop pipe and tail corresponding to the grid-type distributor, install the separator and manhole door in the corresponding position for maintenance and inspection of the grid-type distributor.
4) Remove the emergency reversing device and electric actuator of the original coal roller screen, and move the power supply and control system there to the grid type distributor. In the normal operation, the raw coal is adjusted by the head coal hopper and the arc guide plate, and falls onto the grid-type distributor grid-type. The coal particles less than 30mm fall into the coal pipe bypass through the grid-type distributor grid-type distributor, and the remaining ones enter the variable Angle coal roller screen for screening, and enter the coal crusher for crushing after screening; In the case of failure of crusher and variable inclination coal roller screen, the electric actuator of grid-type distributor is operated to the other side baffle surface, so that raw coal enters the coal drop pipe bypass through the head coal hopper and the other side baffle surface of grid-type distributor.
5) Modify the original motor and reducer, the motor power is increased to 3KW, but the motor speed is unchanged, the reducer model is changed, the shaft is increased, to prevent the shaft from breaking, the speed ratio of the reducer is unchanged, and the corresponding support base is modified and installed.
6) Change the tooth shape of the original coal roller screen. That is, the roller changes the shape of the teeth and the thickness is unchanged.
7) Remove the original roller group cleaning board, make and install the corresponding cleaning board with the reformed roller group, and the clearance between the cleaning board and the roller is 8~10mm.
8) The renovated equipment fully considers the maintenance and replacement of the equipment is convenient, the internal bucket of the grid-type distributor and the (unilateral) grid-swinging bucket are easy to replace, and the wear resistance of the equipment is considered (the wear-resistant lining plate is often installed at the place where the raw coal is often passed) and the flow smoothness (stainless steel material is used in the place with a large Angle).
After the coal roller screen is put into operation, the phenomenon of coal sticking rarely occurs because the gap between the rollers is changed. The grid-type distributor is added to reduce the load of the coal roller screen, effectively improve the efficiency, and rarely appear coal blocking phenomenon; Replace the motor, increase the shaft, there is no broken shaft, burning the motor phenomenon, completely reversed the passive situation of frequent failure of coal roller screen.
