Through on-site analysis, the main reasons for the blockage are as follows:
1. Actively increase drainage
In the early stage of production, the fluidity of the material is guaranteed to prevent clumping, and about 500ml of drainage water is properly added before the material enters the extruder to maintain the fluidity of the material.
2. The influence of steam
The most ideal production conditions in the pellet feed production process are: proper moisture content of raw materials, good steam quality, and sufficient conditioning time. The correct use of dry saturated steam granulation can effectively improve the output of the extruder and the quality of the pellets. To ensure good pellet quality and high output, in addition to the normal operation of the transmission parts of the extruder, the quality of the dry saturated steam entering the conditioner of the extruder should also be ensured. Applicable saturated steam has the function of softening and lubricating during the granulation process, which can increase productivity, reduce frictional heat energy, and prolong the service life of the machine; it can reduce power consumption, promote the gelatinization of starch and the bonding of fibrous fibers; it can increase the viscosity of granules. The forming rate is improved, the powder is reduced, and the surface of the particles is smooth and beautiful, which is conducive to sales.
The steam quality is poor, so that the moisture is too small when the material leaves the conditioner, and it is easy to block the die hole when it enters the extruder, and the fluidity of the material becomes poor, resulting in machine blockage. Specifically in:
①Insufficient steam pressure and high moisture content will easily make the material absorb too much water. At the same time, when the pressure is low, the temperature of the material when it is tempered is also low, the starch cannot be gelatinized well, and the granulation effect is poor;
②The steam pressure is unstable, fluctuating from high to low. The granulation personnel should adjust the feeding amount at any time to make the steam volume reach the optimal level. A little carelessness during granulation will cause the moisture content of the material to be too high when it exits the conditioner.
In order to reduce the number of blockages caused by steam quality, the boiler room should provide high-quality and stable dry saturated steam, and the granulation personnel during production should randomly check the moisture content of the material after conditioning. It is advisable to hold it into a ball, let go and just disperse.
3. Influence of tempering effect
In order to make pellet feed meet the competitive demands of the market, it must be of good quality. The conditioning effect of the material before granulation is very important, because it directly affects the output of the extruder and the quality of the granules, especially the water stability of the special aquatic bait is an important indicator. If the material is not fully tempered and matured before granulation, it is difficult to guarantee its stability in water. The so-called tempering is to pretreat the powdery material before granulation, which is the process of fully stirring and absorbing the powder to be granulated and an appropriate amount of steam in the conditioner. Select the conditioning equipment that meets the technical requirements, so that the material can be fully stirred and mixed with the steam in the conditioner, so as to soften the material and gelatinize the starch, which is conducive to the compaction of the powder material and produces qualified products. The conditioner needs to have a long time of heat preservation, heating and humidification, and the number of layers can be combined and installed as needed to ensure that the material can fully meet the conditioning requirements, improve the surface and internal quality of the granular material, and improve its water resistance in water.
Through on-site debugging, the number of blockages of the pellet machine can be reduced by adjusting the steam. However, since the general boiler equipment has been finalized and the steam provided has been determined, it is necessary to pay attention to the treatment method of water and gas in the steam pipeline, and try to eliminate the steam pipeline. Condensed water in the conditioner, and the steam pressure at the front end of the conditioner must be very stable. At the same time, attention should also be paid to the selection of the conditioner. The conditioner is determined according to the output of the granulator and the type of material. It cannot be lengthened and enlarged at will, otherwise, the granulation effect will be counterproductive and the machine will be easily blocked.