水稻秸秆拆解工艺参数优化及纤维自交织结构

    Optimization of rice straw disassembly process parameters and fiber self-interweaving structure

    • 摘要: 大尺寸高长径比纤维是影响非织造秸秆纤维生态毯质量的关键。机械揉搓是获得高长径比纤维的最佳处理技术工艺。该研究探究了揉丝机主轴转速和锤齿间隙对不同含水率秸秆纤维拆解揉丝的影响,其工艺参数为主轴转速、锤齿间隙及物料含水率,指标输出为秸秆丝化率与标定单位生产率,并对纤维自交织结构特性进行评价。结果表明,采用Box-Behnken响应面法(response surface method, RSM)开发了一个可确定输入和输出参数间的函数,2种评价指标模型均具有较高的可信度,决定系数分别为R2>0.95,R2>0.84。优化数学模型工艺参数:含水率41.2%,主轴转速2 498 r/min,锤齿间隙12.84 mm组合下秸秆丝化率达 96.93%,标定单位功率生产率为29.33 kg/(kW·h)。大尺寸高长径比秸秆纤维长度>70 mm和长宽比>80比例增幅分别达120.55%和16.01%,有效改善纤维自交织能力,所开发的RSM模型秸秆的实际揉搓拆解丝化率达96.27%,加工成本降低27.50元/t,可广泛应用于生产大尺寸纤维秸秆基高值农用制品。该研究为生物质秸秆的有效循环利用和高值化材料产业的绿色可持续发展提供重要依据和技术支撑。

       

      Abstract: Rice straw is an important renewable resource. Under the circumstance of global resource shortage and energy shortage, it is of great significance to vigorously develop comprehensive utilization of straw. It is not only an important way to realize agricultural circular economy and low-carbon economy, but also involves sustainable development issues such as soil fertility, environmental security and efficient utilization of renewable resources in the entire agricultural ecosystem. Straw fiber ecological blanket has a good function of air permeability and water permeability, and has a significant positive effect on the ecological protection of soil surface microenvironment. Mechanical kneading is the key technology for the dismantling and optimization of agricultural waste straw fiber. In this study, the optimal process input is the spindle speed, hammer tooth clearance and material water content, and the output is the straw silk rate and calibrated unit productivity. An intelligent model was developed using Box-Behnken response surface method (RSM) to determine the functional relationship between input and output parameters. The three evaluation index models all have high reliability, and the determination coefficients are R2 > 0.95 and R2 > 0.84, respectively. The variance analysis of RSM regression model clarified that the influence of various factors on straw silk ratio was in the order of spindle speed > water content > hammer tooth clearance, and the linear relationship between spindle speed and straw silk ratio was increasing. The significant influence on the calibrated unit power productivity of the kneading machine is in the order of hammer tooth clearance > spindle speed > moisture content. When the hammer tooth clearance is constant, it decreases first and then increases with the spindle speed and straw moisture content. The results of factor interaction analysis showed that when the water content of straw was 40%, the spindle speed was 2 500 r/min, and the hammer tooth clearance was 13 mm, the silk ratio of rice straw was 96.75%. When the straw moisture content is 60%, the spindle speed is 2 300 r/min, and the hammer tooth clearance is 11.08 mm, the maximum calibrated unit power productivity is 29.96 kg/(kW·h). Mathematical model process parameters optimization: straw moisture content is 41.2%, spindle speed is 2498 r/min, hammer tooth clearance is 12.84 mm. Under the combination of these parameters, the rice straw silk ratio is 96.93%, and the calibrated unit power productivity is 29.33 kg/(kW·h). Under optimized conditions, the proportion of fibers with length of 40-70 mm and > 70 mm showed an increasing trend, especially the fiber with length of > 70 mm increased by 120.55%. The proportion of fiber length-to-width ratio > 50-80 and > 80 increased from 17.39% and 6.52% to 38.64% and 16.01%, respectively. Ultra depth of field microscopy showed that the self-interweaving formability of kneaded straw fiber was significantly improved. The optimized mechanical kneading cost of straw fiber can be reduced by 27.50 yuan/t. The mechanical kneading technology strategy of the RSM model developed in this paper is effective for improving the decomposition rate of biomass straw and reducing the consumption of biomass straw, and can be widely used in the production of high-value agricultural products based on large fiber bundles of straw. The mechanical kneading technique strategy of the RSM model developed in this paper is effective for improving the decomposing silk rate and reducing the consumption of biomass straw, and can be widely used in the production of large-size fiber bundle straw based high-value agricultural products.

       

    /

    返回文章
    返回