Jiangsu Liangyou International Mechanical Engineering Co., Ltd

Ring die pellet mill working principle The basic structure of the pelletizing chamber is mainly composed of these parts: the die, the rollers, feeding scraper and cutting knives.When the machine is started, the electric motor will drive the ring die to rotate. And the rollers will also revolve on its own axis due to the friction between itself and the die. By means of gravity and the centrifugal force generated by rotating of the ring die, material will be firmly attached to inner surface of the ring die. The feeding scraper will ensure the material to be continuously and evenly pushed forward along the die to be prepared for pelletizing. Then the material is squeezed by the roller and the die, and with the gradually increasing pressure, the density of the material also becomes higher. Thus the material temperature will rise, which softens the lignin in it and makes it easier to be shaped. At this time, the material is compressed into the die holes and shaped into small cylindrical strips with diameters of 2 - 12 mm (depending on the size of the holes). Dies-steel mould FDSP dies are manufactured in the following steels: · X46Cr13 (i.e."stainless" steel or "chrome-steel") · 20MnCr5 (i.e."alloy" steel) · 18NiCrMo5 (i.e. similar to 20MnCr·5 but with a higher alloy content). The X46Cr13 steel dies are vacuum / through hardened. The heat treatment achieves 53-55HRc hardness on the surface and in the core. The high chrome content makes it corrosion resistant. Although it costs more than a normal alloy, X46Cr13 is by far the most common material used through out the feed milling industry. Pellet Diesmade in 20MnCr5 and18 NiCrMo5 steel, on the other hand, are case hardened to obtain 60-62HRc hardness for approximately 0.8-1.2mm. Under the case hardened layer the steel remains malleable and therefore less brinle. The pellet mill dies made of this steel are more resistant for pelleting extremely difficult fibre-rich products such as beet pulp, alfalfa, straw and hay. Dies-perfect drilling FDSP ring dies have an extremely precise and regular perforation: the "honey comb" layout of the holes is faultless. Deep hole via gun drill drilling: ring die holes array evenly, uniform wall thickness between holes, to ensure ring die works successfully in pellet mill with smooth surface of pellet. It is important to upgrade smooth and polish level of ring die holes in order to decrease temperature difference, lower energy consumption, raise capacity, and reduce loss of nutrition FDSP reach international advanced level relate to hardness of ring die, evenness and smoothness of holes. Vacuum heat treatment 1.Suitable hardening temperature of vacuum furnace ensures higher hardness and impact toughness. 2.Suitable drawing temperature ensures no cracks of ring dies and little wear of hole and surface, which improves the workinglife. 3.In same loading, adding backfill air pressure will boost die's cooling and hardness. 4.CNC control technology ensures the stability of ring dies.