| 摘要 |
An apparatus for repairing curved grinding surfaces in bowl mill coal pulverizers by welding hardfacing material onto the grinding ring surface. The inventive apparatus includes novel guide structure imparting an arcuate motion to the welding torch as it traverses the grinding surface. In a preferred form a welding torch is pivotally mounted about an axis at or near the center of curvature of the grinding surface, pivoted along the circumference of the curved grinding surface to effect welding repairs. The pivotal positioning and motion of the welding torch assures a constant distance and angle relative to the grinding surface, and thus a strong, primary, non-overlapping weld bond across the entire width of the ring. In a preferred form the apparatus employs dual, independently adjustable, simultaneously indexed torch heads. In a further aspect the invention includes a novel positioning device for initial placement of the welding torch, adjustable to accommodate wear to certain portions of the grinding ring on which it rests.
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