矿用直线振动筛结构故障分析

针对煤矿选煤厂直线振动筛工作过程中出现的结构故障问题,采用有限元仿真与现场测试结合的方法对振动筛出现故障的原因进行了分析研究。介绍了振动筛的主要结构及常见故障,并以某矿选煤厂发生大梁断裂的振动筛为例,对该振动筛进行三维建模和有限元模态分析,分析结果表明:随着模态阶次的增加,振型的变化逐渐由移动转为结构本身的扭曲变形。在该振动筛空载工作状态下,选用本质安全型便携式测振记录仪进行振动测试并处理测试信号,得到该振动筛的工作频率。结合模态分析结果和实际测试结果,判断出空载时频繁运行振动筛是造成其大梁断裂的主要原因。根据故障原因给出维护建议:应当尽量避免振动筛在空载或物料较少的状态下长时间运行;在振动筛投入使用前,应预先了解振动筛的工作状态及可能存在的薄弱环节,尽可能避免结构故障,保证振动筛可靠运行。

Analysis on structural faults of mine-used linear vibrating screen

In view of structural faults that occurred during operation of linear vibrating screen in coal preparation plant,the method combining finite element simulation and field test was used to analyze and study the cause of faults of vibrating screen.The main structure and common faults of vibrating screen are introduced,taking the vibrating screen with beam fracture in a coal preparation plant as an example,three-dimensional modeling and finite element modal analysis are carried out on the vibrating screen.Analysis results show that with the increase of the mode order,the change of the vibration shape gradually changes from the movement to distortion of the structure itself.Vibration test by intrinsically safe portable vibration measuring recorder is performed on the vibrating screen under no-load working state and the test signal is processed to obtain working frequency of the vibrating screen.Combined with the modal analysis results and the actual test results,it is concluded that frequent operation of the vibrating screen during no-load is the main reason for beam fracture.Maintenance suggestions are given according to the fault cause:the vibrating screen should be avoided to run for a long time under the condition of no load or less material;before the vibrating screen is put into use,the working state and possible weak links of the vibrating screen should be known in advance to avoid structural fault as much as possible and to ensure the reliable operation of the vibrating screen.