变工况下钢厂转炉支承螺栓断裂机理分析

在变工况条件下,炼钢厂转炉在运行过程中支承螺栓容易发生断裂,针对这一问题,以某钢厂130 t转炉为例,对不同工况下炼钢转炉支承螺栓的断裂机理进行了研究。首先,推导了转炉的倾动力矩方程,采用MATLAB计算不同倾动角度下转炉倾动力矩,得到了倾动力矩曲线,从而准确计算出了不同工况下支承螺栓的载荷;然后,采用有限元方法对支承螺栓进行了建模,对最大受力情况下的支承螺栓及其销轴进行了力学分析;最后,对支承螺栓结构进行了优化改进,并对优化后的支承螺栓进行了性能验算。研究结果表明:转炉在旋转至65°时,支承螺栓的受载最大,出钢口对侧螺栓过度圆弧处最大等效应力接近材料屈服强度极限;所采用分析方法可为后续定量增大支承螺栓安全系数提供依据,以确保转炉在不做较大结构修改前提下的安全运转。

解析滑轮的转动

在滑轮问题中,绳的张力并没有直接作用在滑轮上。分析定滑轮和动滑轮的转动,发现绳的张力是通过转化为摩擦力矩或支承力矩间接起作用的。并且在滑轮的转动中,摩擦力矩总是在发挥着作用。

一种钛锭翻转装置能力扩展改造技术应用实践

电子束冷床熔炼炉熔铸的钛锭基本是在竖直拉锭舱中形成,取锭后需要通过翻转装置将锭坯由竖直状态翻转为水平状,便于转移到机加工作业区进行表面去除加工。攀枝花云钛实业有限公司现有翻锭机设计能力为钛锭毛坯最大尺寸220×1400×8400 mm,最大有效载荷12 t。新建电子束冷床熔炼炉生产的钛锭最大尺寸、重量增加到220×1570×10150 mm、15t。为充分利用现有资源降低成本,在不增加液压动力和设备的前提下,通过对现有翻锭机结构改造,实现了攀枝花云钛实业有限公司翻锭机能力扩展。

Analytical solutions of hard roof's bending moment,deflection and energy under the front abutment pressure before periodic weighting

The distribution of front abutment pressure is closely related to the force,deformation and energy distribution of hard roof before periodic weighting. So it is necessary to carry out research on the relationship between them. According to front abutment pressure distribution feature,using the location of peak front abutment pressure as the dividing point,coal seam is divided into two parts along the direction of mining: the yield zone that is the area between the faceline and the point where the maximum front abutment pressure occurs,and the elastic zone that is the part before the point of peak front abutment pressure. The proposed mechanical model of unit width hard roof at the panel center before periodic weighting consists of five parts including the yield zone. All parameters of the deflection equations for each of the five parts that satisfy the continuity conditions and natural boundary conditions are obtained by using the Matlab software. The continuous curves of front abutment pressure,deflection,bending moment and bending strain energy density distribution of hard roof are obtained by iterative approximation method,and the relationship between the yield zone width and the above curves are analyzed in detailed.