|
Biomass briquetting technology can densify loose biomass, significantly improve the energy grade of the source, making it an effective approach to widely utilize biomass resources. However, there are still some development bottlenecks, such as the lack of microscopic mechanism research, high energy consumption, short lifetime of key equipment components, etc. Thus, further research to solve the bottlenecks on the Biomass briquetting technology is imperative.This paper presents a thorough study of briquetting microscopic mechanism and factors of energy consumption, with the primary purpose to reduce the production energy consumption. Firstly, taking the two aspects of briquetting microscopic mechanism and circular mould Static mechanical as the instruction, biological structures, physical and chemical properties and micro-mechanical properties of biomass raw are researched to present the biomass briquetting law and reduce the energy consumption at the source. Also stress on briquetting zone is analyzed to get the optimal structure parameters of circular mould. Then, basic on theory of elastic-plastic large deformation, contact mechanics and viscoelasticity, The finite element model of the biomass briquetting process, a strongly nonlinear problem, is analyzed by the finite element package ANSYS The rheologic and Stress-strain laws are revealed during the process by the simulating. The simulating results are also examined and certified by the self-designed briquetting experiment platform, which not only illustrate the validity of the microscopic mechanism but also provide the theory basis on structural optimization. The optimal briquetting conditions of the raw are also obtained by the simulating and experimental results.On the basis of biomass briquetting microscopic mechanism and Elastic-plastic large deformation theory, Factors such as Material Properties, equipment structure parameters and briquetting technological conditions are compositely researched to reduce energy consumption, by using several research methods, including statics analysis, the Finite Element Numerical Simulation and experiment.Finally, rolling forming mechanism is proposed originally based on the stress tensor theory, namely enhancing the global tensor of the materials which makes materials slip, rub and interleave easier, thus the energy consumption is decreased; based on the static analysis, the briquetting zone, the swoop angle and the height of the materials and the diameter ratio between the circular mould and press roll are obtained. And the force condition of the materials was analyzed exhaustively. Through the comparative analysis of the microstructure of the materials formed under the traditional method and rolling forming method, the rolling forming mechanism is validated; based on the FEM simulation, the rheologic law of the materials in the rolling forming processes, the stress distribution law along Y axis and the changing tendency between the frictional force and the time is revealed, which provide the important theoretical support in the optimization of the structure design; Then the universal stuff experimental equipment is used to conduct the experimental analysis about the briquetting conditions, such as rotational speed, length diameter ratio of the mould, split taper and moisture ratio and so on, and the technological parameter, and the optimal parameters for reducing the energy consumption are obtained.
|