Reasons for unstable current in pellet machine
1. In the pellet machine, the feeding amount is adjusted when working.
As long as the thickness of the material in the feeding zone is less than the maximum starting point of the pressing zone, it will directly affect the length of the effective working interval of the pressing zone and extruding zone, causing fluctuations in the current and changes in the hourly output.
If the thickness of the feed zone is greater than the starting point of the pressing zone, it will have no effect on the hourly output and the energy consumption per unit of time, except for increasing the thickness of the material layer in the feed zone. It will not cause a change in current or output.
2. If the thickness of the material layer in the feed zone exceeds the maximum starting point of the press zone, the interval between the press zone and the extrusion zone is constant and does not change. The entrainment angle of the zone in which the feed is located is greater than the critical friction angle, so the material is not caught in the compaction zone. When the feed volume increases, the balance between inlet and outlet will be broken, the inlet is larger than the outlet, and the layer of material in the inlet zone will get thicker and thicker until it fills all the gaps. The inlet will become clogged, resulting in the pelletizer not functioning properly (or overflowing from the feed cover auxiliary inlet). At this point, the current will increase.
3. In the actual operation of the pellet mill as the feed rate is constantly changing, the instantaneous output and main motor current will also change. When the thickness of the feed does not exceed the maximum starting point of the pressing zone, the increase in the amount of powder fed does not result in more and more layers of material in the feeding zone. Once the amount of feed is too large and exceeds the thickness of the maximum starting point of the press zone, the layer of material will build up and gradually increase, and the pelletizer will not work properly. The current will fluctuate and become unstable.
4. Assume that the main motor power is high or the motor is not overloaded after the feed thickness exceeds the maximum starting point thickness of the press zone due to a combination of variables. At this point, the additional supply of powder cannot increase the hourly output and will not cause an increase in the main motor current. Rather, it can only keep increasing the pile of powder that accumulates in the machine until the inner chamber of the pelletizer is clogged, resulting in the pelletizer being unable to work properly. Of course, this particular phenomenon is rare in actual production (e.g., raw material moisture content is too large, effective length-to-diameter ratio is too small, the pressure roller is badly worn, the gap is not properly adjusted, and the raw material is changed. This phenomenon may occur), which is a working condition we do not want to appear.
When the power of the main motor is not large enough compared with the corresponding ball-making parameters, our feeding thickness is adjusted between the end point of the extrusion zone and the maximum starting point of the compaction zone (the point will change accordingly with the combined changes of different raw materials, compression ratio, effective length and diameter ratio, humidity, pressure roller and other variable factors). , generally not exceeding the maximum starting point.
With the increase of feeding quantity, the interval length of compression area will be shortened, while the interval length of extrusion area will be gradually increased, and the current of main motor will gradually become larger until it reaches the larger permissible value. If the current reaches the protection value we set, but the thickness of the feeding material does not exceed the thickness of the maximum starting point of the compression zone, then increasing the amount of feeding material will cause the system action to trip will make the biomass pellet machine can not work normally.
