METHOD OF GUNITING STEEL-TAPPING HOLE OF METALLURGICAL UNIT Russian patent published in 2003 - IPC

FIELD: metallurgy; repair of lining of metallurgical units; repair of steel-tapping holes. SUBSTANCE: device made in form of two metal tubes of various diameter are secured in steel-tapping hole; said tubes are located on one axis and are interconnected by means of at least three welded metal plates. Ratio of diameters of smaller and larger tubes is equal to 1: (1.4-2.2). Length of tube of larger diameter is no less than height of two tap-hole units. Device is placed in steel-tapping hole by tube of lesser diameter and tube of larger diameter is used as template for welding concrete gunite which is applied of defective area layer by layer at 2-5-min delay. Thickness of layer is no more than 150 mm and number of layers does not exceed three. EFFECT: increased service life of repaired steel-tapping hole. 3 cl