Biomass Molding Detecting Technology And The Optimal Mold Design

Biomass fuel plays an pivotal role in the development of our country; therefore, the government pays great attention. Molding equipment in China shows crucial problems which mainly lie in the severe wear, short lifespan, high power consumption. At present, systematic research on molding equipment that have been carried out is not sufficient and no effective detection methods are come up. Meanwhile, there is not enough research on the value and distribution of the related friction, stress, stain and the pressure as well as their influence on the molding effects. These problems have handicapped mass production and industrialized application of biomass molding seriously. So, to address these problems, basing on the modern testing technology, this paper designed special detection sensors to perform relating experiments. At the same time, a favorable mechanical model has been established and optimized according to the experimental results.To accomplish the goals, four orthogonal tests were conducted.First, orthogonal strain test was carried out and the results showed that:ring strains are positive while axial strains are negative; All groups have maximums and the locations of that are basic the same-the end of the cone. And each curve basically can be substituted with two intersecting lines.Then, orthogonal density experiment was performed and the results showed that:the length-diameter ratio is the most important factor, taper comes next and diameter takes the third place. The best molding condition for density is25°for taper,35mm for the diameter of mold and6for the length-diameter ratio.Third, orthogonal drop strength test was finished and the results showed that:the taper is the most important factor, length-diameter ratio comes next and diameter takes the third place. The best molding condition for drop strength is25°for taper,35mm for the diameter of mold,5for the length-diameter ratio.At last, orthogonal radial compressive strength was done and the results showed that:the diameter is the most important factor, taper comes next and length-diameter ratio takes the third place. The best molding condition for radial compressive strength is25°for taper,40mm for the diameter of mold,5for the length-diameter ratio.Through the ANSYS simulation analysis, there are some findings:when the wall of the mold is thin, the mold bent, being away from the actual test results. Mold showed the "instability" phenomenon under external force. When the wall is thick, the analysis results were consistent with the experimental results:radial dimensions of the mold increased significantly, the length decreased obviously and the cone were convexed. All inlets and outlets of the mold concaved clearly. Considering each factor, the best molding condition is25°for taper,35mm for the diameter of mold,5for the length-diameter ratio.Through the analysis of the forming process, pressure vessel model can be built. It can be seen that the distributions of pressure and friction are in line with the strain. In the plastic deformation area, pressure and the radius present a linear relationship; In the shape area, the pressure show a hyperbolic relationship with the radius. At the same time, the molding pressure goes up with the mold length-diameter ratio linearly.