Experimental Study On Cold Compression Molding Characteristics Of Straw And Coal Mixture

In order to make further efficient use of crop straw resources and provide theoretical basis for the development,optimization and process selection of relevant production equipment,the systematic cold compression molding experimental research was conducted on a specially designed compression device in this thesis.The molding characteristics of biomass briquette with mixture of corn straw and lignite under different biomass contents,mold cross section diameters and compression speeds were studied.The influence law of each test factor level on relative parameters such as specific energy consumption and drop strength of biomass briquette was analyzed and the corresponding mathematical model was obtained.The paper research found The cold compression molding rules of the mixture of straw and coal under certain conditions were found from this research,and the main conclusions were showed as follows.(1)Through the single-factor experimental study,the compression model was established by analyzing the test data,and the influence of each factor on the specific energy consumption in the briquette molding process was analyzed.When the biomass content of biomass briquettes is higher,the diameter of the mold cross section is smaller,and the compression speed is faster,the larger the energy consumption required for molding.(2)By the experiments and analysis on the drop strength of biomass briquettes under different forming conditions,the influence of different forming conditions on the drop strength of briquette is as follows:when the biomass content is 25%,the briquette has the best molding effect and the highest drop strength.The drop strength of briquettes gradually increases as the diameter of the mold cross section increases.Briquette drop strength increases with the increasing of compression speed,and when the compression speed is between 10mm/min to 40mm/min,the drop strength changes gently,but when the compression speed is between 55mm/min to 70mm/min,the drop strength changes greatly.(3)From the research of quadratic response surface experiments and analysis,the regression equation of the specific energy consumption of each factor level in the process of biomass briquette molding and the regression equation of each factor level of drop strength were obtained.The influence order of each factor level on specific energy consumption was gained as follows:B(diameter of mold cross>A(biomass content)>C(compression speed)section).And the influence order of each factor level on drop strength was found as B(diameter of mold cross section)>C(compression speed)>A(biomass content)(4)By optimizing the parameters of the regression equation,the best process parameters for biomass briquette molding were got:the optimal factors for the mixed molding of corn straw and lignite were obtained:biomass content was 18.66%,the diameter of the molding section was 19.88mm,the compression speed was 40mm/min,the specific energy consumption was 23185.1kJ/kg,and the falling strength was 98.6%.At the same time,the results of parameter optimization are proved to be reliable and the regression equation obtained from the quadratic response surface test can be used to select the factor level in production practice.