Requirements For The Fineness Of Raw Material Crushing in Aquatic Feed Production Lines
Aquatic feed production lines are finely ground to meet the needs of animal digestion and granulation requirements. The appropriate grinding fineness is influenced by factors such as animal growth stage, nutritional needs, feed processing technology and equipment. Reasonable selection of crushing fineness is also an inevitable requirement for reducing costs, improving production capacity, and ensuring product quality.
1. Requirements for crushing fineness of aquatic animal nutrition
The digestive tract of aquatic animals is relatively short. In order to accelerate digestion and absorption, the crushing particle size of aquatic feed should be smaller than that of animal feed. For example, in the production of eel and shrimp feed, the particle size should reach 80-120 mesh. In addition, aquatic animal formula feed has high protein content and low carbohydrate content, and the feed particle structure is compact, requiring high adhesion and water resistance.
2. Requirements for crushing fineness in production and processing
If the crushing fineness is too large, the energy consumption when passing through the ring mold or pressure roller will relatively increase, and it will affect the quality of granulation and expansion, leading to easy crushing of feed particles and poor stability in water. The appropriate grinding fineness plays an important role in the processing of aquatic feed. The smaller the fineness of material crushing, the easier it is to absorb the steam inside the conditioner, thus achieving more complete gelatinization.
In addition to the fineness of crushing, the distribution range of material particle size also has a significant impact on processing. Generally speaking, the smaller the distribution range of material particle size, the better. For the production process of first crushing and then batching, it is difficult to limit the particle size to a relatively narrow range in the subsequent mixing section because the raw materials are separately crushed before processing. Therefore, the general production process of aquatic feed adopts the process of first ingredient and then crushing or secondary crushing.
3. The requirement of feed mixing uniformity on crushing fineness
For aquatic animals, pellet feed must meet certain water stability requirements in order to meet their feeding needs. To achieve high water stability in feed, on the one hand, it is required that the material fineness is sufficiently fine, and on the other hand, it is also required that the feed raw materials can be mixed evenly. From the perspective of uniform mixing, it is generally required that 95% of the material can pass through 177-250 μ M's sieve. Special production of particles with a diameter of 0.8-1.5mm or smaller requires higher requirements for crushing fineness. A basic principle in determining the fineness of feed crushing is that the diameter of the crushed particles cannot be greater than one-third of the ring mold.
4. Requirements for the fineness of feed grinding due to feed settling and stability
A good crushing particle size makes it easy for feed to form a tight bond, thereby increasing the density of the particles and making the feed more prone to sinking. In addition, smaller crushed particles have a larger surface area, which makes the particles bind more tightly during granulation, thereby preventing water immersion and disintegration of the feed, and improving the water stability of the feed. If the particles are not tightly bound, it will make the feed easily disintegrate in water and affect the water quality.
