Parameter optimization design of negative pressure straw picking，crushing and impurity removal integrated recovery device based on DOE-response surface

To address issues such as incomplete picking, high impurity content, and unstable crushing quality during straw recycling, an integrated straw picking, crushing, and impurity removal device based on negative pressure delivery（referred to as the negative pressure straw recycling device）was designed．4 factors and 5 levels experimental optimization approach was conducted using central composite design（CCD）method．Response indicators included maximum equivalent stress, maximum deformation, and natural frequency．A regression model was established to determine optimal parameter combination（rotor speed 1500 r/min, blade length 148.2 mm, blade holder height 128.7 mm, rotor diameter 300 mm）．After optimization, maximum equivalent stress decreased by 41.2%, total deformation reduced by 37.8%, and structural safety factor increased to 2.1．Static and modal analyses were conducted using ANSYS finite element analysis platform to verify structural safety and dynamic stability．Results showed that first-order natural frequency of 95.382 Hz significantly exceeded operating frequency range of 25.0 to 41.7 Hz, effectively avoiding resonance．Field trials showed that device achieved 95.7% picking rate, over 92% crushing qualification rate, controlled impurity content at 7.8%, and delivered an operational efficiency of 1.9 t/h, with significantly outperforming conventional equipment in overall performance．A theoretical support and methodological reference were provided for optimized design and engineering application of negative pressure straw recycling devices．