In order to effectively increase the output of the ring mold, in addition to the quality of the ring mold itself, correct operation and maintenance can effectively increase the life of the ring mold.
1. Regular maintenance of the pellet machine
1. Because the pellet machine belongs to the main equipment of the feed factory, the manufacturer should first carry out daily maintenance, weekly warranty and monthly maintenance work to ensure that the pellet machine maintains a good and stable, non-jumping working state. If there is a malfunction or some wearing parts in the equipment Wear, especially the wear of the transmission wheel and the spindle, should be repaired and replaced in time to ensure the normal use of the concentric circle of the ring mold.
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.
Second, ring mold work maintenance
1. Due to the different types of feed produced, which involve the difference in ring die material, opening ratio, inner cone hole, effective length of die hole and decompression hole design, 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 a new ring die for 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.
3. Maintenance of ring mold
1. When the ring die is not used for a period of time, the original feed should be squeezed out with non-corrosive oil, otherwise, the heat of the ring die will dry and harden the feed left in the die hole, resulting in the following situations:
(1) When starting to run, the die hole is blocked and the material cannot be squeezed;
(2) At the beginning of production, the ring die bears high stress and weakens its strength, which may cause ring die cracking;
(3) 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.
3. If the die hole is blocked and the material cannot be discharged, oil soaking or oil boiling can be used to re-granulate. If it is still unable to granulate, the block material can be drilled with an electric drill, and then grinded and polished with oily materials and fine sand before use.
4. When loading and unloading the ring die, do not hit the surface of the ring die with a hard steel tool such as a hammer.
5. The use record 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, which reduces the service life of the ring die or does not discharge.
4. Analysis of the causes of abnormal particles and improvement methods
Feed production units often produce abnormal pellets during the production of feed, which affects the appearance and inherent quality of pellets, which affects the sales and reputation of the feed factory.
V. Summary of granulation technology for 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.
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 type of feed must ensure that the starch is fully gelatinized to achieve high temperature and processing conditions. The ring die thickness is generally thicker and the pore size The range is wide, and the length-to-diameter 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.
Aquatic feed mainly includes fish feed, shrimp feed, turtle feed, etc. The crude fiber content in fish feed is higher, and 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.
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 hole and inner cone hole, and the squeezing force Larger. 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.
Hops have a high content of brazing dimension and contain 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 θ6.
Chrysanthemums, peanut shells, cottonseed meal, wood chips contain a large amount of brazing dimension, the content of brazing dimension is above 20%, the oil content is small, the friction resistance of the material through the die hole is large, the granulation performance is poor, and the hardness of the granule The requirements are low, and it is generally difficult to meet the requirements for forming. The diameter of the particles is large, generally between θ6 and θ8, and the aspect 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.
For the granulation of various materials, the dogma must not be moved. The correct ring mold parameters and operating conditions must be selected according to the material characteristics of the materials and the specific characteristics of each feed manufacturer. The high-quality feed can be produced only according to local conditions.