The wall of the ring die is too thin, so that the strength of the ring die is not enough, and the phenomenon of die explosion will occur during production. At this time, the thickness of the ring die and the pressure relief hole should be increased under the premise of ensuring the effective length of the die hole. Generally speaking, the compression ratio between 8-12.5 should be selected for compound feed with high grain content; the compression ratio between 5-8 should be selected for heat-sensitive feed and urea feed; The compression ratio between 11; the suitable compression ratio between 7 and 15 for dairy cow compound feed. In addition, after considering the basic formula of the feed, the specific compression ratio can be adjusted according to the feed quality required by the producer. For example, choosing a slightly lower compression ratio is beneficial to increase production, reduce energy consumption, and reduce wear of the ring die. However, such a If the pellets are not firm enough, the appearance is loose and the length is different, the pulverization rate of the feed is high. On the contrary, it is beneficial to the quality of the pellets (the pellets are smooth and shiny, and the pulverization rate is small), but it will increase The production cost of the product.

Secondly, whether the working gap between the ring die and the pressure roller is reasonable or not has an important influence on the effective use of the ring die. Generally speaking, the gap between the ring die and the pressure roller is between 0.1 and 0.3. According to practical experience, it is better for the pressure roller to reach a state of seemingly rotating but not rotating while the ring die is rotated by hand. So, how to adjust the gap between the ring die and the pressure roller? According to our practical experience, when a new mold is installed, firstly, loosen the pressure roller adjustment bolts to adjust the pressure roller to the state where the outer surface of the pressure roller is close to the inner surface of the ring die; secondly, adjust the eccentric shaft of the pressure roller in order to The gap between each pressure roller and the ring die is appropriate, pre-tighten the adjustment bolts, pull the ring die, gradually adjust the gap, so that the pressure rollers can reach the working state of turning and non-rotation, and finally tighten the adjustment bolts. When the new die is installed, it is usually required that the gap between the ring die and the pressure roller is slightly larger than what you need, which is conducive to the smooth transition between the new ring die and the old roller, and the new die and the old roller complete a certain running-in period Later, the gap can be adjusted to your desired gap. In use, the pressure roller is sacrificed to the environmental protection mold, because the price of the ring die is more than ten times or even dozens of times the price of the pressure roller, so in use, under the condition of choosing a reasonable gap, the hardness of the pressure roller cannot Too high, that is to say, the wear resistance of the pressure roller cannot be higher than that of the ring die.

During the production process of the ring die, it is required to clean up the materials used to prevent the materials from being mixed with hard particles such as large sandstones, sand grains, iron blocks, bolts and iron filings. Because these inclusions accelerate the wear of the ring die, and a large number of large and hard inclusions will cause the ring die to be stressed many times, causing fatigue to the ring die. When a certain force exceeds the strength limit of the ring die, the ring die will explode. model phenomenon.

Finally, when the operator installs or replaces the ring die, for the ring die assembled through the cone surface, when installing the new mold, it is required to avoid the bumps and scratches on the cone surface, and to ensure that the cone surface and its matching drive rim The conical surface should be cleaned as necessary and assembled with oil. When replacing the ring die, dismantle it without bumping or scratching the cone surface, and apply oil for protection. For pellet mills that often need to replace the ring die, it is required to check the drive wheel rim regularly to prevent excessive wear and cause the centering pin of the mold to break, because excessive wear will affect the fit between the ring die and the wheel rim , the fit is not tight. When the ring die is working, it will generate shear force on the centering pin of the mold and cause breakage. When this happens, do not mistakenly think that the pin is not strong enough and replace it with a high-strength pin. It can only lead to ring die damage and frequent breakage of safety pins. Therefore, it is quite necessary to protect and regularly check the matching cone surface of the ring die and the matching drive wheel rim. For the hoop-type assembled ring die, the protection and inspection of its assembly surface and its matching components are also quite necessary. When the pressure roller is used for a period of time, it will wear and tear, which will affect the matching precision with the ring die, thereby affecting the production output of the ring die, and it should be repaired or replaced with a new ring die.

3. Basic maintenance of ring die

As the saying goes, sharpening a knife is not a mistake in chopping wood. Reasonable maintenance of the ring die is part of the economical and effective use of the ring die.

In the production process, the operator often finds that during the use of the ring die, there are usually phenomena such as blockage, wear, sealing and inversion. At this time, if the necessary maintenance is not carried out, the output will decrease and the energy consumption will increase. Not even the expected phenomenon. At this time, the method for basic maintenance of the ring die is to first grind the working inner circular surface of the ring die, and then chamfer.

When replacing the ring die, it is required to fill the die hole with oil-containing material while the die is hot, so that the ring die can reach the best state in the next production.

To sum up, only the correct selection, reasonable use and effective maintenance of the ring die can reduce costs, improve efficiency, create particle quality, enhance product market competitiveness, meet challenges, and create more economic benefits for enterprises.

For reference only!