The ring die and roller of Pellet mill are very important working and wearable parts. The rationality of the configuration of their parameters and the quality of their performance will directly affect the production efficiency and quality of the pellet produced.
The relationship between Diameter of the ring die and the pressing roller and the production efficiency and quality of the Pellet mill:
The large-diameter ring die and press roller pellet mill can increase the effective working area of the ring die and the squeezing effect of the press roller, which can improve production efficiency, reduce wear costs and operating costs, so that the material can pass through the granulation process evenly, avoid excessive extrusion, and improve the output of the Pellet mill. Under the same quenching and tempering temperature and durability index, using small-diameter ring dies and pressing rollers and large-diameter ring dies and pressing rollers, the power consumption has obvious power consumption difference. Therefore, the use of large-diameter ring die and pressure roller is an effective measure to reduce energy consumption in granulation (but it depends on the specific material conditions and granulation request).
Ring die Rotation Speed:
The rotation speed of the ring die is selected according to the characteristics of the raw material and the size of the particle diameter. According to experience, a ring die with a small die hole diameter should use a higher line speed, while a ring die with a large die hole diameter should use a lower line speed. The line speed of the ring die will affect the granulation efficiency, energy consumption and firmness of the particles. Within a certain range, the line speed of the ring die increases, the output increases, the energy consumption increases, and the hardness of the particles and the pulverization rate index increase. It is generally believed that when the diameter of the die hole is 3.2-6.4mm, the maximum linear speed of the ring die can reach 10.5m/s; the diameter of the die hole is 16-19mm, the maximum line speed of the ring die should be limited to 6.0-6.5m/s. In the case of a multi-purpose machine, it is not suitable to use only one ring die line speed for different types of feed processing requirements. At present, it is a common phenomenon that the quality of large-scale granulator is not as good as that of small-scale granules when producing small-diameter granules, especially in the production of livestock and poultry feed and aquatic feed with a diameter of less than 3mm. The reason is that the line speed of the ring die is too slow and roller diameter is too large, these factors will cause the perforation speed of the pressed material to be too fast, thus affecting the hardness and pulverization of the material rate index.
Technical parameters such as hole shape, thickness and opening rate of ring die:
The hole shape and thickness of the ring die are closely related to the quality and efficiency of granulation. If the aperture diameter of the ring die is too small and the thickness is too thick, the production efficiency is low and the cost is high, otherwise the particles are loose, which affects the quality and granulation effect. Therefore, the hole shape and thickness of the ring die are scientifically selected parameters as the premise of efficient production.
Hole shape of ring die: The commonly used die hole shapes are straight hole, reverse stepped hole, outer tapered reaming hole and forward tapered transition stepped hole.
Thickness of the ring die: The thickness of the ring die directly affects the strength, rigidity and granulation efficiency and quality of the ring die. Internationally, the thickness of the die is 32-127mm.
The effective length of the die hole: the effective length of the die hole refers to the length of the die hole for extrusion of the material. The longer the effective length of the die hole, the longer the extrusion time in the die hole, the harder and stronger the pellet will be.
The diameter of the conical inlet of the die hole: the diameter of the feed inlet should be larger than the diameter of the die hole, which can reduce the entry resistance of the material and facilitate the entry of the material into Die hole.
The opening rate of the ring die: The opening rate of the working surface of the ring die has a great influence on the production efficiency of the granulator. Under the condition of sufficient strength, the opening rate should be increased as much as possible.