Many feed mills have failed to meet the expected design requirements due to the process arrangement and operation technology of the pellet machine, and the pellet surface is not smooth, the hardness is low, it is easy to break, and the powder content is high. The following explains the factors that affect the production and processing of feed machinery.
1. Raw material factors
Raw material factors directly affect the effect of granulation. Materials with higher starch content are easy to be steam gelatinized. After quenching and tempering, these raw materials have a certain viscosity, which is conducive to particle formation. For raw materials with high crude fiber content, add a certain amount of Grease can reduce the friction between the material and the ring die during granulation, which is conducive to the material passing through the ring die, and the appearance of the particles after forming is smoother.
From the perspective of granulation, the crushing is fine and the granulating strength is high, but if you add more steam, it is easy to block the machine if you don't pay attention to it, and the raw material is crushed too fine, which causes the crushing power consumption to be too high. In addition, pay attention to the uniformity of mixing before granulation. Because of the complex composition of the feed formula, the proportion of various raw materials varies greatly. For different formulas and different varieties, different mixing times are used to make the coefficient of variation of mixing uniformity reach about 5%.
2. Feed flow control
In order to make the granulator work at full load in a balanced manner without stopping, the material flow entering the granulator must meet the granulation needs, and the feeding structure must effectively eliminate the intermittent feeding caused by agglomeration. The material flow rate should not be less than 10T/H, and the material flow of the feeder should be stabilized in actual production. It is more reasonable to install a buffer bin directly above the granulator. If the buffer bin is not set, or the buffer bin is There is a long connecting pipe between the feeding and it is difficult to ensure the stability of the incoming material.
When the production efficiency of many feed machinery is abnormal, they are just busy looking for the cause in the feed machinery itself, and ignore the incoming material factors. In fact, many times the production efficiency decline is caused by the instability of the incoming material flow. Generally speaking, when the feed machinery is running It is stable and normal, the steam supply is sufficient, the feed gates are all opened, the feeder speed is adjusted to the rated value and the main motor does not always reach the rated electrical value, it can be judged that the incoming material flow is insufficient, and the reason should be investigated at this time. Symptoms are treated.
3. Production operation
Correctly control the gap between the pressure roller and the pressure mold. The gap between the pressure roller and the pressure mold is too small, the pressure mold and the pressure roller are easy to wear, and the super noise is large. The gap is too large, which affects the extrusion of the material. The feeler gauge can be used to measure when adjusting, and the feeler gauge can also be used for visual inspection. Yes. Take the new mold and the new roller as an example. Visually inspect the pressure mold pressure roller, but when there is no material, it is advisable that the main machine rotates the pressure mold and cannot drive the pressure roller. It is especially emphasized that the new mold should be equipped with a new roller and the gap should be smaller. Add enough butter to the roller to avoid burning the bearing due to excessive temperature. At the same time, adjust the feeding scraper, otherwise it will be difficult for the material to enter between the pressure roller and the pressure mold, and some of the material will be strung out from the pressure mold cover. The formation of particles is high, and the front end of the scraper should not extend beyond the sinking groove of the inner hole of the die.
In order to prevent the debris from entering the press mold, the external discharge door on the operating door should be opened to drain the material mixed with debris in the machine. After the miscellaneous materials are clean, the materials can be introduced into the press mold. For caution. For the sake of simplicity, your hand should hold the handle of the discharge door outside the machine, first let part of the material enter the mold, and then observe whether there are particles smoothly out of the mold, and pay attention to the current changes. If the particles can be produced normally, the current is relatively stable and the fluctuation range is not If the rated current is not reached, the material flow can be increased, and the steam volume can be increased at the same time.
4. Ring die
Whether the material can be squeezed during the granulation process depends on the pressure and friction that can be generated in the die hole. This is related to the friction coefficient between the material and the die wall, moisture content, raw material particle size, and temperature. , The buffer time of the plastic deformation part of the material is related to the compressibility of the material, and these characteristics are closely related to the depth and diameter of the die hole.
Generally speaking, the compression ratio of the die diameter should be 1:8~1:13, the compression ratio of the die is small, the effective length of the die hole is short, the pressure formed by the material in the die hole is small, and it is easy to extrude the ring die. Therefore, the output is high, but the produced particles are loose, the powder content is high, and the appearance is not smooth. Therefore, when the feed machinery produces different specifications and varieties of pellets, the selected ring die aperture ratio will be different.