Development Of Roller Briquetting Machine With Plungers And Optimization Of Parameters

Fossil fuels such as coal, oil, and natural gas are increasingly depleted, and the burning of fossil fuels has brought many problems to the environment. Biomass energy has the advantages of renewability, low pollution and so on, and it has become a hot spot of research and development in recent years. It has important practical significance to carry out the research of biomass solidification molding technology.The study of this paper is supported by "12th Five Year" National Science and Technology Support Program(2012BAD30B0205),and its main content is ’the development of the Portable Low Energy Consumption and Movable Biomass Fuel Forming System’, some researches are carried out taking roller briquetting machine with plungers as the research object, the specific works are as follows:(1)Forming mechanism and influencing factors of biomass cold curing densification formation were detailedly analyzed and stated, which provided a solid theoretical basis for the development of roller briquetting machine with plungers.(2) The characteristics of both the piston stamping forming machine and the die roller briquetting machine(The piston stamping forming machine has lower energy consumption and lower productivity while the die roller briquetting machine has higher productivity and higher energy consumption) were combined, a new kind of roller briquetting method was put forward in the biomass curing molding field. Compared with other same type briquetting machine, a series of plungers distributed on the roller mesh into the holes of forming roller in the briquetting process, which could avoid the loss of energy consumption and the serious wear problem in the process of biomass materials squeezed outside the holes of forming roller. The prototype was designed and manufactured, and the feasibility of this method was verified by the experiment. The experimental results showed that all the indexes meet the design requirements, and realize continuous and stable production. The biomass ambient temperature densification method put forward in this study has certain enlightenment on reducing the energy consumption of traditional briquetting machine and reducing the wear of the key parts.(3)In view of geometric nonlinearity, material nonlinearity and nonlinear boundary conditions in the biomass material forming process of roller briquetting machine with plungers, the briquetting process was simulated by nonlinear FEA software ABAQUS. At the same time, aiming at finding out the reasons of high energy consumption for the traditional roller briquetting method, the numerical simulation of two kinds of roller briquetting methods had carried on the comparative study based on the ABAQUS nonlinear finite element analysis software, the numerical results showed that the maximum stress value of the traditional roller briquetting method occurred at the contact point between the roller and the forming roller, while the maximum stress value of the roller briquetting method with plungers occurred at the bottom of roller plungers. Compared with the traditional roller briquetting method, materials were more easily entered into the holes of forming roller to occur plastic deformation for the roller briquetting method with plungers, and its energy loss problem was reduced.(4)To seek for the optimal forming parameters of roller briquetting machine with plungers and explore the influence law of forming parameters on the forming results, the experimental data was processed and analyzed by the experiment design method of Design-Expert BBD (Box-Behnken Design), and the regression equations of the experimental factors on the experimental indexes were established. The results showed that the optimal results of moisture content of sawdust, length to diameter ratio of forming mold and speed of forming roller are 15.5%,5.3,47.25r/min, respectively. On this condition, density of forming particle and productivity of briquetting machine can reach 1.17g/cm3, 75 kg/h, respectively. The maximum relative error is 0.426% between the experimental value and the predicted value of the density of forming particle, while it’s 2.733% on the productivity of briquetting machine, so there’s high consistency.