Structure Design Of Straw Ring Die Molding Machine And Force Analysis Of Ring Die

Straw briquetting technology is an important branch of biomass energy conversion technology, which has great significance for domestic biomass resources exploitation and utilization. Nevertheless, there are some problems, such as lack of briquetting microscopic theory, high energy consumption and short life of ring die, which seriously restrict the promotion of straw briquetting technical.In this paper, based on briquetting microscopic theory, the influence of material structure, physicochemical property and microscopic mechanical properties on molding process was analyzed and straw briquetting mechanism was presented. The mechanical model of ring die was built to analyze the strength situation of material and ring die. A new-style of straw ring die molding machine was designed and developed, which the technical index was set, the major parameter was optimized, the key component was designed and the three-dimensional model of the ring die was built.The ring die model and ring die briquetting model was built in order to carry out the numerical simulation of structural statics, structural dynamics and structural thermodynamics, which can reveal the stress field, strain field, temperature field and displacement distribution. The influence of length-diameter ratio and die hole chamfer on the stress field of ring die was mainly discussed. Study results indicated that the appropriate angle and radian of die hole chamfer can reduce the depreciation rate of die hole effectively. When the length-diameter ratio is4.5:1, the maximum stress is the maximal and when the length-diameter ratio is5:1, it is the minimal, which indicates that the ring die abrasion is the maximal when the length-diameter ratio is4.5:1and it is the minimal when the length-diameter ratio is5:1. The ring die temperature is the highest when the length-diameter ratio is5.5:1and the temperature is the most favorable for straw material molding when the length-diameter ratio is5:1. The stress of the die hole is the maximum when the die hole angle is30°and the stress is the minimal when the die hole angle is60°. Study results in this paper provided the scientific basic for ring die material selecting, ensuring ring die strength and extending ring die life.