三菱MVM25R型磨煤机磨辊改造分析

珠海发电厂三菱MVM25R型磨煤机自投产以来,由于磨辊辊芯与辊套配合不当及辊套表面堆焊层存在较多熔焊冶金缺陷,导致磨辊辊套频繁发生松动与断裂的现象。通过采取降低运行时磨辊液压油压力,增加辊芯与辊套的静配合过盈量,增加磨辊辊套与辊芯的结合面面积,使得辊芯与辊套的配合紧力加大了,减少了结合面产生松动的可能性,从而有效地防止磨辊辊芯与辊套的磨损、松动,避免因磨辊辊套的松动而导致辊套表面产生交变应力及承受较大冲击力而产生裂纹,延长磨辊辊套与辊芯的寿命。

Analysis of grinding roll modification of Mitsubishi coal pulverizer type MVM25R

Since being put into operation,the Mitsubishi coal pulverizers type MVM25R in Zhuhai Power Station have experienced frequent looseness and fracture of the roll ring because of the mismatch between the roll core and the roll ring as well as many fusion welding metallurgical defects in the overlay on the roll ring.By reducing the hydraulic oil pressure of the grinding roll in operation,enhancing the magnitude of interference fit between the roll core and the roll ring,and increasing the junction area between them,the tightness between the roll core and the role ring is augmented,and the possibility of junction area looseness is lowered.Thus the attrition and looseness of the roll core and the roll ring are effectively prevented,cracks caused by the alternating stress and the great impact force on the loose roll ring avoided and the service life of the roll ring and the roll core prolonged.