How to adjust the gap between the pressure roller of the biomass pellet making machine and the ring die?

 

The gap between the pressure roller and the ring die is one of the important parameters adjusted during the operation of the biomass pellet making machine. The adjustment process is also one of the important adjustment steps before the operation of the biomass pellet making machine. The rationality of the gap adjustment will directly affect the use of the biomass pellet making machine.

Correct adjustment can save the cost of biomass pellet making machine and improve economic benefits. This article introduces 5 kinds of small knowledge about the adjustment of the gap between the pressure roller and the ring die of the biomass pellet machine: In general, the rotation direction of the biomass pellet mill ring die is clockwise. For a biomass pellet machine equipped with two rollers, the largest eccentric flange of the left roller should be installed in the upper left half of the ring die when the roller is installed. Zone, the largest eccentric flange of the right press roller is installed in the lower right half of the ring die; if multiple press roller biomass pellet making machines are equipped, it should also be ensured that when the eccentric adjusting block ring rotates in the opposite direction of the die rotation, the press The roller should move in the direction where it is in contact with the ring die, otherwise it means that the pressure roller is not installed correctly, and it should be reinstalled according to the above requirements.

1.       In general, the rotation direction of the biomass pellet mill ring die is clockwise. For a biomass pellet machine equipped with two rollers, the largest eccentric flange of the left roller should be installed in the upper left half of the ring die when the roller is installed. Zone, the largest eccentric flange of the right press roller is installed in the lower right half of the ring die; if multiple press roller biomass pellet making machines are equipped, it should also be ensured that when the eccentric adjusting block ring rotates in the opposite direction of the die rotation, the press The roller should move in the direction where it is in contact with the ring die, otherwise it means that the pressure roller is not installed correctly, and it should be reinstalled according to the above requirements.

2.       The gap between the pressure roller and the ring die of the biomass pellet making machine is generally 0.3mm-0.5mm. When adjusting, the outer surface of the pressure roller is usually in slight contact with the inner surface of the rotating ring die, and the ring die is driven to achieve a non-rotating rotation. Under normal circumstances, the gap between the smaller die hole is smaller, and the larger die hole is larger; the gap between the new die is smaller, and the gap between the old die is larger. If the gap between the pressure roller and the ring die is too small, the pressure roller and The ring die is easy to wear and noisy. On the contrary, too large a gap will cause difficulty in discharging.

3.       The roundness of the ring die and pressure roller will generally be slightly deformed after heat treatment. When adjusting, the maximum outer diameter of the pressure roller should be in contact with the minimum inner diameter of the ring die, and the gap is still 0.3mm-0.5mm. This adjustment is usually called It is a jump contact adjustment. If this happens, once the minimum outer diameter of the press roller and the maximum inner diameter of the ring die are in contact, additional radial force (impact load) will be generated, and abnormal metal friction sound will occur.

4.       Generally, the ring die biomass pellet making machine press roller and the ring die are installed in a cantilever beam type and are subjected to additional radial forces.

l  The cantilever support rod swayed and reacted to the ring die through the pressure roller, so that the ring die was subjected to periodic alternating stress, and the fixed ring at the root of the ring die was worn and loosened, so that the screw of the fixed ring die was subjected to shear stress and was sheared for a long time. The stress causes shear fracture at the screw root.

l  The extra radial force is transmitted to the bearing through the pressure roller. Although the tapered cylindrical bearing used to support the rotation of the pressure roller can bear a certain radial and axial load, the bearing is prone to occur under normal load for a long time due to the inner and outer rings of the bearing. Raceway, the local stress on the working surface of the ball exceeds the yield limit of the material. The deformation failure is manifested as obvious uneven wear pits on the inner and outer rings of the bearing and the ball. Once the deformation failure occurs, the bearing friction torque Increased, rotation accuracy decreases, if the amount of plastic deformation exceeds a certain value, the temperature of the bearing rises rapidly, the grease is burnt, the bearing cage is deformed, and the bearing is stuck and becomes invalid.

Because the roller bearing is fixed by the inner ring and the outer ring rotates, if the additional impact load is obvious, there will be obvious crushing phenomenon in the bearing cage after failure.

5.    The gap between the pressure roller and the biomass pellet making machine ring die not only affects the discharge of the biomass pellet machine, but also affects the life of the biomass pellet mill itself. During the operation of the pellet machine, if the ring die fixing screw breaks and the roller bearing is damaged, there is no other problem. In the case of obvious reasons, it is generally caused by the out-of-roundness of the ring die and the pressure roller and the gap between the two is too small.