热镀锌沉没辊系轴端压力与锌渣的关系

Relationship between axial end pressure and zinc slag of submerged roll system for hot galvanizing

某钢厂热镀锌机组沉没辊系存在轴端锌渣聚集的问题,为了改善因锌渣聚集导致机组降速而影响产量的状况,需要找出锌渣聚集的的原因及解决方案,开展了轴端压力对锌渣聚集的影响机理及治理技术研究。首先通过现场生产跟踪,发现沉没辊系轴套与轴瓦的间隙与锌渣聚集量有一定关系。考虑到零部件的磨损,因此分析了轴端压力对锌渣聚集的影响机理,然后表示出轴套与轴瓦间隙量的数学模型,通过条元法分别对稳态运行过程中沉没辊、稳定辊和矫正辊进行受力分析,得到带钢对辊面的支持力、辊子承载量和辊子可正常工作的临界接触角,最终得到轴套与轴瓦间的挤压接触应力模型。在此基础上分析了轴端压力对锌渣聚集效应的影响。结合生产实际,以带钢与辊子包角为优化目标,提出使得轴端不发生锌渣聚集效应的工艺参数优化模型。选取3种典型规格带钢进行辊端压力模拟,计算值与实测值误差小于5%,证明了稳态运行过程中辊端压力计算模型的正确性。通过优化计算得到使轴端不发生锌渣聚集效应的辊端压力所对应的带钢与辊子包角设定值,将其应用到现场生产后,沉没辊系轴套与轴瓦的磨损量降低了60%以上,减小了锌渣流入轴套与轴瓦间隙的程度,从而解决了沉没辊系轴端锌渣聚集的问题,提高了生产效率。同时为其他热镀锌机组沉没辊系因锌渣聚集而导致机组产量降低的问题提供了解决思路。

The problem of zinc slag accumulation at the shaft end exists in the sinking roll system of the hot galvanizing unit in a steel plant.In order to improve the situation that the unit speed is reduced due to the accumulation of zinc slag,it is necessary to find out the cause of zinc slag accumulation and the solution.Therefore,the research on the mechanism of the influence of the shaft end pressure on the zinc slag accumulation and the treatment technology has been carried out.First of all,through on-site production tracking,it was found that the clearance between the shaft sleeve and the bearing bush of the sinking roll system had a certain relationship with the amount of zinc slag accumulation.Considering the wear of parts,the mechanism of the influence of the shaft end pressure on the zinc slag accumulation is analyzed,and then the mathematical model of the clearance between the bearing sleeve and the bearing bush is expressed.The stress of the sinking roll,the stabilizing roll and the straightening roll in the steady state operation process is analyzed by the strip element method,and the support force of the strip steel to the roll surface,the bearing capacity of the roll and the critical contact angle of the roll for normal operation are obtained,Finally,the extrusion contact stress model between the bearing sleeve and the bearing pad is obtained.On this basis,the influence of shaft end pressure on zinc slag aggregation was analyzed.Combined with production practice,taking the wrap angle of strip steel and roller as the optimization objective,an optimization model of process parameters is proposed to avoid zinc slag accumulation effect at the shaft end.Three typical specifications of strip steel are selected for roll end pressure simulation,and the error between the calculated value and the measured value is less than 5%,which proves the correctness of the calculation model of roll end pressure during steady operation.The set value of the wrap angle of the strip steel and the roller corresponding to the pressure at the end of the roller that makes the shaft end free of zinc slag accumulation effect is obtained through optimization calculation.After it is applied to the field production,the wear amount of the shaft sleeve and the bearing bush of the submerged roll system is reduced by more than 60%,reducing the extent of the zinc slag flowing into the gap between the shaft sleeve and the bearing bush,thus solving the problem of zinc slag accumulation at the shaft end of the submerged roll system,and improving the production efficiency.At the same time,it provides a solution to the problem that the sink roll system of other hot-dip galvanizing units reduces the unit output due to the accumulation of zinc slag.