Study On The Rheological Rule Of Biomass Briquetting And The Modal Characteristics Of The Feed Screw Based On ANSYS

Biomass resources are abundant, its efficient development and utilization can not only improve the ecological environment,but also contribute to alleviate energy shortage status all over the world. Biomass briquetting technology can densify loose biomass,and can supply raw materials for other biomass energy utilization technologies.But there are still some development bottlenecks,such as the rheological for densification process studies incomplete,low productive capacity,short lifetime of key equipment components,vibration and so on.So Biomass briquetting technology study has a profound significance to establish new field of energy.The hydraulic briquetting technology of biomass is the research object in this paper.Through the in-depth theoretical study and discussion of the raw material characteristics and the mechanism of briquetting process,the whole hydraulic rheological briquetting process is analyzed,and the raw materials rheological evolution model is obtained.Comparison biomass raw materials to metal powder and soil in densification process,find them exist similarities,so,the theoretical knowledge of rheology is studied in biomass briquetting process,and the different constitutive equations are established in the briquetting process.Biomass briquetting process is numerical simulated by using the theoretical knowledge of elasto-plastic,rheology and viscoelasticity theory.The deformation principles and rheologic laws are revealed during briquetting process,the stress and strain distribution is also obtained.The analysis results show that the rheology displacement of the outer layer is shorter than the middle layer.The lowest flow velocity appears on edges of die cone angle,the SEQV and friction stress reached the highest value and had stress concentration correspondingly.The study also found that there is still residual stress in briquette after briquetting process,which is the reason of stress relaxation and creep phenomenon.This is the first time to study the rehology phenomenon through simulate by ANSYS.As improved the mold's lifetime and compared with the customary model,the die cone angle are fillet processing.The study comes to a conclusion that the improved scheme can reduce the stress value on die cone angle,the stress evenly distributed and the fuel quality improvement.The research and analysis of compression and mold optimization provided good application and reference value with biomass briquetting process optimization.The screw is the core components of screw feed device.There the raw materials is occurred the initial rheological.In the equipment operation,the screw is at the spin state.Darnell-Moll theory is used to analy the screw conveyor pricciple in this paper.The screw is modeled with APDL language of ANSYS,and built the screw-specific parametric finite element analysis program.First of all,study the static analysis of screw is carried out.The analysis results show that the stress in the spiral blade is distributed by layer.The stress value is gradually increased from the spiral groove edge to the top,reached the maximum stress in the screw front. Secondly,the screw is analyzed,the modal equations of motion and the mass matrix are gotten,obtained the first-order natural frequency of screw is 19.536HZ.The excitation frequency is much smaller than the first-order natural frequency.Analysis showed that the work frequency is far away from the critical speed,the structure can avoid the resonance region effectively.The study laid a foundation for optimizing structure design and analyzing reliability of briquetting equipment.