01. Perform regular maintenance on the pellet machine
1. First, the manufacturer should carry out daily maintenance, weekly warranty and monthly maintenance work on the host machine to ensure that the pellet machine maintains a good, stable and non-jumping working state. If there is a fault in the equipment or some wearing parts are worn, especially the transmission wheel and the main shaft If the beating is worn, the spare parts should be repaired and replaced in time to ensure the normal use of the concentric circle of the ring die.
2. Install an iron suction device at the feed inlet to prevent metal foreign objects from falling into the granulation chamber, causing severe damage to the ring mold and cracking.
3. When installing the ring mold, you should check the transmission keys, hoop, wear-resistant bushing ring of the drive wheel, wear-resistant bushing at both ends of the pressure roller shaft, gap adjustment wheel, feeding scraper, cutter, etc. The wear condition of the parts should be replaced in time to ensure the normal operation of the pellet machine. If the hoop is worn and the ring die cannot be held tightly, the vibration of the pellet machine will be increased, which will seriously affect the service life of the ring die and even crack the ring die. It should be replaced in time. In addition, the wear of the feeding scraper will reduce the output of the pellet machine.
02. Pay attention to the daily use of ring molds
1. Due to the different types of feed produced, which involve different ring mold materials, aperture ratio, inner cone holes, effective length of mold holes and design of relief holes, companies with advanced professional technology should be found to combine feed materials and actual use Design and customize ring molds of different processes to ensure the maximum use value of ring molds.
2. To use the new ring mold of prawn feed, the new pressure roller processed by concentric grinding must be replaced to match it.
3. The gap between the pressure roller and the ring mold must be controlled between 0.1-0.3mm. Do not allow the eccentric pressure roller to contact the surface of the ring mold or the gap on one side is too large. This is a size that is not easily noticeable by the naked eye and installation. It causes the abrasion of the ring die and the pressure roller to increase or no discharge.
4. When the pellet machine is started, the feeding amount must be from low speed to high speed. Do not run at high speed from the beginning, causing the ring die and pellet machine to be damaged due to sudden overload or the ring die is blocked.
03, pay attention to the maintenance of ring mold
1. When the ring die is not used for a period of time, the original feed should be extruded with non-corrosive oil, otherwise the heat of the ring die will dry and harden the feed that was originally left in the die hole, resulting in the following situations:
*When starting to run, the die hole is blocked, and the material cannot be squeezed;
*At the beginning of production, the ring die bears high stress and weakens its strength, which may cause ring die cracking;
*Some die holes are blocked, the output is reduced, and the benefit is reduced.
2. After using the ring mold for a period of time, you should check whether there is any local protruding part on the inner surface of the ring mold. If this phenomenon occurs, polish the protruding part with a grinder to ensure the output of the ring mold and the service life of the pressing roller.
3. If the die hole is clogged and no material can be discharged, oil soaking or oil boiling can be used to re-granulate. If the granule still cannot be granulated, the plug can be drilled out with an electric drill, and then grinded and polished with oily materials and fine sand before use.
4. When loading and unloading the ring mold, the surface of the ring mold cannot be beaten with a hard steel tool such as a hammer.
5. The use records of each ring mold should be made in order to accurately calculate the actual service life of the ring mold.
6. The ring die must be stored in a dry and clean place. If it is stored in a humid place, it will cause corrosion of the die hole, and reduce the service life of the ring die or not discharge.
04、Summary of granulation technology of different materials
With the popularization and application of pellet feed in livestock and poultry, aquatic products and other emerging industries, as well as emerging industries such as compound fertilizers, hops, chrysanthemums, wood chips, peanut shells, and cottonseed meal, more and more units use ring mold pelletizers. Different formulations and regional differences, users have different requirements for pellet feed. Each feed manufacturer requires good pellet quality and the highest pelleting efficiency for the pellet feed it produces. Due to different feed formulations, the selection of ring die parameters when pressing these pellet feeds is also different. The parameters are mainly reflected in the choice of material, aperture, hole shape, aspect ratio and aperture ratio. The selection of ring die parameters must be determined according to the chemical ingredients and physical properties of the various raw materials that make up the feed formula. The chemical ingredients of the raw materials mainly include protein, starch, fat, cellulose and so on. The physical properties of raw materials mainly include particle size, moisture, capacity and so on.
1. Livestock and poultry feed mainly contains wheat and corn. The starch content is high and the fiber content is low. It is a high starch feed. Compressing this kind of feed must ensure that the starch is fully gelatinized to achieve high temperature and processing conditions. The thickness of the ring die is generally thick. The aperture range is wide, and the aspect ratio is generally between 1:8 and 1:10. Broilers and ducks are high-energy feeds with high fat content and easy granulation. Generally, the long diameter is relatively large, ranging from 1:10 to 1:13.
2. Aquatic feed mainly includes fish feed, shrimp feed, turtle feed, etc. The crude fiber content in fish feed is higher, while the crude fiber content in shrimp feed and turtle feed is less and the protein content is higher, which belongs to high protein feed. Aquatic materials require particles to be stable in water for a long time, with a consistent diameter and neat length. This requires that the materials be fine-grained and have a high degree of maturity during granulation, using pre- and post-maturation processes. The diameter of the ring die used for fish feed is generally between θ1.5-θ3.5, and the length-diameter ratio range is generally between 1:10 and 1:12. The aperture of the ring die used for shrimp feed is in the range of θ1.5-θ2.5, and the aspect ratio is in the range of 1:11-1:20. The diameter of the ring die used for turtle feed is large, ranging from θ3 to θ8. Due to the high protein content, the aspect ratio ranges from 1:12 to 1:20. The selection of the specific parameters of the aspect ratio must be based on the formula. Nutrition indicators and user requirements are determined. At the same time, the design of the hole shape of the die hole does not require stepped holes as much as possible under the conditions of strength, to ensure that the cut particles are uniform in length and diameter.
3. The compound fertilizer formula is mainly composed of inorganic fertilizer, organic fertilizer, minerals, etc. The inorganic fertilizer in the compound fertilizer, such as urea, is more corrosive to the ring die, while the minerals are very abrasive to the ring die die hole and inner cone hole. The pressure is greater. The diameter of the compound fertilizer ring die is generally large, ranging from θ3 to θ6. Due to the large friction coefficient, the die hole is difficult to discharge, so the long diameter is relatively small, generally between 1:4 and 1:6. At the same time, due to the compound fertilizer Containing bacterial species, the temperature can not exceed 50 degrees -60 degrees, otherwise it is easy to kill the vaccine. Therefore, the compound fertilizer requires lower granulation temperature and generally thinner ring mold wall thickness. Because compound fertilizer wears on the ring die holes severely, the requirements on the hole diameter are not strict. Generally, the ring die is scrapped when the gap between the pressure rollers cannot be adjusted. Therefore, the length of the stepped hole is used to ensure the aspect ratio and improve the final service life of the ring die.
4. The hop bran content in hops is high and contains bacteria, and the temperature generally cannot exceed 50 degrees. Therefore, the ring mold for pressing hops has a thinner wall thickness and a shorter long diameter, generally about 1:5, and the particle diameter is larger. Between θ5 and θ6.
5. Chrysanthemums, peanut shells, cottonseed meal, wood chips contain a large amount of coarse brazing dimension. The coarse brazing dimension content is more than 20%, the oil content is small, the friction resistance of the material through the die hole is large, and the granulation performance is poor. The hardness requirement is low, and it is generally difficult to meet the requirements. The particle diameter is large, generally between θ6 and θ8, and the length to diameter ratio is generally about 1:4 to 1:6. Due to the small bulk density of this type of feed and the large hole diameter of the die hole, the outer circle of the die hole area must be sealed with tape before granulation, so that the material is fully filled into the die hole to form, and then the tape is torn.