为了解决锤片式饲料粉碎机工作过程中噪声大的问题,运用虚拟仪器测试技术和台架试验相结合的方法,对粉碎机的噪声信号进行采集和分析,针对影响噪声的主要因素如锤片、筛网、进料口、出料口和转子转速等进行相应的声压级和频谱测试分析,...为了解决锤片式饲料粉碎机工作过程中噪声大的问题,运用虚拟仪器测试技术和台架试验相结合的方法,对粉碎机的噪声信号进行采集和分析,针对影响噪声的主要因素如锤片、筛网、进料口、出料口和转子转速等进行相应的声压级和频谱测试分析,寻找粉碎机主要噪声源及其与主要影响因素之间的规律,并通过对粉碎机各部件的结构参数进行改进设计,达到降低整机噪声的目的。研究结果表明:粉碎机噪声信号主要包含48、180、200、361、893和1 263 Hz共6种频率成分;筛网、进料口和出料口对主频成分没有影响,只影响噪声频率的幅值;筛网具有降噪作用;进料口和出料口都不同程度地增强了噪声声压级;通过对主轴转速为2 400~2 800 r/min时的空载噪声频谱图分析知,当转速升高时,噪声幅值急剧升高,可见转速对粉碎机的噪声有影响;对不同锤片数量的空载噪声频谱图分析知,锤片数量只影响噪声幅值,对主要频率变化影响较小。此外,对粉碎机进料口、出料口、筛网的结构参数进行改进设计,以出料口的改进设计为例,基于有限元法对改进前后分离装置内的流场湍动能分布情况经行了模拟,将改进前后的结果进行对比分析发现:出料口改进后分离装置内气流的湍动能较小,流动较为稳定。通过台架试验表明:当选用改进后的出料口时,粉碎机整机噪声得到明显改善,噪声总声压级降低了3 d B(A),各测点噪声声压级降低1.9~3.6 d B(A),进一步粉碎试验表明使用改进后的出料口并未影响粉碎机的生产效率以及吨料电耗,研究所采用的降噪措施可行,此法可为控制粉碎机噪声提供理论依据。展开更多
This paper aims to develop a surface modification process to improve the surface properties of the middle trough.The coatings were prepared by plasma cladding with Fe-Cr-B-Si-based alloy powders (Ig 6 and Ig7).The org...This paper aims to develop a surface modification process to improve the surface properties of the middle trough.The coatings were prepared by plasma cladding with Fe-Cr-B-Si-based alloy powders (Ig 6 and Ig7).The organizational structure and micro-hardness of the coatings were analyzed by laboratory equipments.The friction and wear tests were performed to investigate the friction-wear properties of middle trough.The coatings have higher hardness and good friction-wear properties than the substrate.The hardness and friction wear properties of the coating with Ig7 powder are better than those with Ig6 powder.The experimental results show that the surface properties of the middle trough are improved by Fe-Cr-B-Si-based alloy coating,which can improve the middle trough service life.The plasma cladding can be widely used in the surface-modification of middle trough to reduce the waste of resources.展开更多
文摘为了解决锤片式饲料粉碎机工作过程中噪声大的问题,运用虚拟仪器测试技术和台架试验相结合的方法,对粉碎机的噪声信号进行采集和分析,针对影响噪声的主要因素如锤片、筛网、进料口、出料口和转子转速等进行相应的声压级和频谱测试分析,寻找粉碎机主要噪声源及其与主要影响因素之间的规律,并通过对粉碎机各部件的结构参数进行改进设计,达到降低整机噪声的目的。研究结果表明:粉碎机噪声信号主要包含48、180、200、361、893和1 263 Hz共6种频率成分;筛网、进料口和出料口对主频成分没有影响,只影响噪声频率的幅值;筛网具有降噪作用;进料口和出料口都不同程度地增强了噪声声压级;通过对主轴转速为2 400~2 800 r/min时的空载噪声频谱图分析知,当转速升高时,噪声幅值急剧升高,可见转速对粉碎机的噪声有影响;对不同锤片数量的空载噪声频谱图分析知,锤片数量只影响噪声幅值,对主要频率变化影响较小。此外,对粉碎机进料口、出料口、筛网的结构参数进行改进设计,以出料口的改进设计为例,基于有限元法对改进前后分离装置内的流场湍动能分布情况经行了模拟,将改进前后的结果进行对比分析发现:出料口改进后分离装置内气流的湍动能较小,流动较为稳定。通过台架试验表明:当选用改进后的出料口时,粉碎机整机噪声得到明显改善,噪声总声压级降低了3 d B(A),各测点噪声声压级降低1.9~3.6 d B(A),进一步粉碎试验表明使用改进后的出料口并未影响粉碎机的生产效率以及吨料电耗,研究所采用的降噪措施可行,此法可为控制粉碎机噪声提供理论依据。
基金Funded by the NSFC-Shanxi Coal Based Low Carbon Joint Fund Focused on Supporting Project(No.U1510205)Shandong Province Key Laboratory of Mine Mechanical Engineering(No.2019KLMM210)Key Research and Development(R&D)Projects of Shanxi Province(No.201903D121065)。
文摘This paper aims to develop a surface modification process to improve the surface properties of the middle trough.The coatings were prepared by plasma cladding with Fe-Cr-B-Si-based alloy powders (Ig 6 and Ig7).The organizational structure and micro-hardness of the coatings were analyzed by laboratory equipments.The friction and wear tests were performed to investigate the friction-wear properties of middle trough.The coatings have higher hardness and good friction-wear properties than the substrate.The hardness and friction wear properties of the coating with Ig7 powder are better than those with Ig6 powder.The experimental results show that the surface properties of the middle trough are improved by Fe-Cr-B-Si-based alloy coating,which can improve the middle trough service life.The plasma cladding can be widely used in the surface-modification of middle trough to reduce the waste of resources.
