The Research And Design Of Biomass Pellet Maker With Plunger-ram Die At Normal Temperature

Although there is a full range of densification equipment for biomass fuel molding in our country, the defects of high energy consumption, fast mold wear and other technical problems still are big bottlenecks, which result in higher conversion costs, and severely restrict utilization of the biomass resource in a large-scale.A complete new kind of biomass pellet forming principle with plunger-ram die at normal temperature was put forward, that innovatively combing the piston extrusion principle with the ring die pellet forming principle. The vice extrusion meshing pairs which form in co-rotating of plunger-ram and ring die, compress biomass material within the molding holes, so in this way, they keep biomass material out of molding holes in ring die from compression and friction in contact with the faces of forming molds, in which the power consumption of non-compression densification will be drastically reduced, and the wear of the forming molds will be effectively mitigated.In the paper, the mechanism of biomass open molding at normal temperature has been firstly studied, in which a kind of suitable structure of through straight hole for ring die were researched and determined. Then the transmission mechanism between plunger-ram and ring die was analysed and designed, the main structural parameters and dimensions of plunger-ram die forming mechanism were figured out. Finally, according to the project planning specifications, a biomass pellet maker with plunger-ram die working at normal temperature has been designed by employing the CAD/CAE system Solidworks.In the performance test, this pellet forming machine behaved absolutely well at different rotating speed in non-load running, when the biomass materials of sawdust and confetti were put to the test of practical densification, the compression quality of pellet fuel stabilized in a relatively good level, the unit density of solid pellets was almost above0.8g/cm3that met the requirements of storage, transportation and employing, which verified the feasibility and practicality of pellet maker with plunger-ram die mechanism.