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Feed machinery mainly includes hammer mill, mixer, pellet mill, packaging scale and so on, we should reasonably arrange various models according to the actual needs of the whole set of production equipment, so that each equipment can fully play its production capacity. At the same time, the proper usage and maintenance of equipment make production proceed smoothly. As the key equipment in production, the usage and maintenance of pellet mill is very important.
1. General process of pelleting
Silo→feeder→conditioner→pellet mill→cooler→finished product silo.
2. Matters needing attention in the process of pelleting
1). Material should be conditioned before pelleting. The pressure of the steam must be stable (4 ~ 8bar), and the water must be removed before conditioning, if the steam contains lots of water, it will cause blockage in pelleting process. After the material is conditioned, it is matured to a certain extent, which can significantly improve the utilization rate of nutrients in feeds.
2).The humidity and temperature of the material should be checked regularly during the process of pelleting. Inspection method of humidity: material can be made into block after gently pinched. The temperature should be controlled between 75~95℃ according to different varieties.
3). Cooling of the particles after pellets can not be too fast or enough. If too fast, the surface of the pellets will be cracked. If not enough, the high temperature will make the material damp, causing mildew. The temperature of pellets should be consistent with the room temperature.
3.Selection of ring die and roller
1). Ring die is made of carbon steel, alloy structure steel or stainless steel. We can choose the ring die according to the corrosion of material and work intensity. Generally, we choose stainless steel for corrosive materials and ring die with small hole. Roller is usually made of carbon steel or alloy structural steel.
2). Compression ratio of ring die. Compression ratio of ring die is the ratio of effective working length and die hole diameter. Compression ratio of ring die can be selected according to the raw material formula and the product requirement. Low compression ratio can increase production, reduce energy consumption, and decrease abrasion of ring die and press roller. But it will produce loose pellets with different length, and high rate of powder; On the contrary, high compression ratio produces strong pellets with smooth appearance and low rate of powder, but the production cost is high. Users can choose the compression ratio of ring die according to their own needs. Generally, compression ratio of the ring die for livestock and poultry feed is below10, and for aquatic pellet feed is more than 10.
4. Proper operation and maintenance of pellet mill
1)Adjustment of the gap between ring die and roller
For the adjustment of the gap between new ring die and roller, the highest points of ring die and roller should be slightly contacted. If the adjustment is in the working state, pressure of ring die and roller should be increased properly. If the gap between ring die and roller is too large, the roller will not rotate, resulting in blocking. If the gap is too small, it will increase the abrasion and the load, causing serious damage. We should check the gap in time, at least once every four hours. When adjusting each roller, attention should be paid to the adjusting direction.
2)Maintenance of pellet mill
Check the transmission parts, meters, valves, add lubricating oil (lithium based lubricant), and remove iron filings on the iron.
3)Correct installation or replacement of ring die and roller
Generally, the new ring die matches the new roller and the old ring die matches the old roller, so that the gap between ring die and roller is equal approximately. In this way, the force and discharging of the whole ring die are uniform, and the production efficiency can be improved.
Before assembling, the cleaning work should be done to ensure the surface clean. Attention should be especially paid to the screw hole cleaning of ring die.
Pay attention to the bearing inspection when assembling roller, replace it in time once bearing is damaged. There should be a certain gap when assembling roller, so that the roller can rotate freely. Add oil to roller in time. Once roller is short of oil, it will cause the damage of the bearing and the roller shaft, even seriously cause the whole roller to be scrapped.
After pelleting, materials with oil must be pressed into the die hole to ensure that it will be not corrupted. More attention should be paid to the carbon steel ring die.
