The reason and solution for the blocking of ring die in sawdust pellet machine - 1

As market competition in feed industry grows increasingly fierce, many feed mills, especially aquatic bait factory, need to produce more pellet feed of∮1.5 ~ 2. 5mm in order to meet the market demand. But in the process of production of small aperture pellet feed, problems like low yield and blocking of ring die in sawdust pellet machine would appear frequently. It is quite difficult to dredge the ring die of small aperture, which makes a lot of trouble to feed manufacturers. In the following content, we would talk about the problem on the basis of the practical experience for many years.


 
1. The raw material
Raw materials of different formulations would directly affect the quality of pellet after pelletizing with sawdust pellet machine. Materials of high starch content are easy to be gelatinized by steam, these materials have certain viscosity after conditioning, which is advantageous to the forming of pellet in sawdust pellet machine. For raw materials of high crude fiber content, a certain amount of grease should be added in the process of granulating to reduce the friction between the material and the ring die, which is helpful for the material to flow through the ring die, and the appearance of pellet formed is smooth. Besides, the grinding fineness of raw material should be uniform and moderate, because the grinding fineness of raw material determines the surface area of feed composition. The particle size of pellet is finer, the surface area is larger, the faster the material absorbs moisture vapor would be, which is conducive to adjusting quality and pellet forming.
 
2. The influence of steam
The three elements for the most ideal production conditions of pellet feed production process are the proper moisture of raw material, steam of good quality and sufficient conditioning time. The correct use of dry saturated steam can effectively improve the yield of pellet machine and the quality of pellet. To guarantee the good quality and high yield of pellet, in addition to the normal operation of the transmission part of sawdust pellet machine, the quality of the dry saturated steam into the pellet machine should also be guaranteed. Applicable saturated steam has soften and lubrication function in the process of pelletizing, which can increase the productivity, reduce the friction heat energy and prolong the service life of ring die. Besides, it can reduce the power consumption, promote the bonding gel and fiber of the starch, improve the rate of pellet forming of biomass pellet mill, reduce the powder and make the pellet surface smooth and beautiful.
 
3. Steam quality control
Rational design and installation of steam piping system should not only ensure the steam pressure and flow rate, but effectively prevent the condensed water in the pipe into the conditioning in the using process. Applicable steam pressure should be 0.2 ~ 0. 4mpa. In general, the pressure fluctuation should not be greater than 0. 5mpa to ensure that the steam pressure always in a stable state. So the pressure reducing valve to be used should have good quality and stable using effect. After steam conditioning of material, generally the moisture content should be kept at about 15% with the temperature of about 85℃. Under high steam pressure, the steam quantity material absorbs is less and the gelatinization is poor, which is suitable for materials with high moisture. Steam absorption of materials is more under low steam pressure, more moisture would be absorbed with good gelatinization effect, which is suitable for materials of low moisture content. In short, steam quality control has great influence on the conditioning effect of materials before pelletizing. Only steam meeting the requirements of pelletizing can play the twice the result with half the effort.
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