Experimental Studies of Drilling Tools Magnetic Catchers with the Parallel Connection of Permanent Magnets

¹ T. F. Gorbachev Kuzbass State Technical University, Kemerovo, the Russian Federation
² JSC NC VostNII industrial and environmental safety, Kemerovo, the Russian Federation

Abstract

The article presents the results of bench and industrial tests of drilling tools magnetic catchers with the parallel connection of permanent magnets. The catchers are developed on the basis of optimization studies of the mathematical model of the U-shaped magnetic system. The catchers on ferrite-barium magnets with U-shaped magnetic systems showed very low characteristics. The catcher with unshielded magnetic system also showed low power and magnetic parameters. Production tests of such a catcher in a real iron ore well demonstrated its unsuitability for the extraction of the drilling tool elements. Laboratory studies of a magnetic catcher with the shielded U-shaped magnetic system on powerful rare earth magnets have shown that it has high power and magnetic parameters. Its industrial tests in the mine showed high efficiency of the extraction of the drilling tool broken off elements, in particular, crowns and pneumatic hammers. A catcher with the parallel connection of rare-earth magnets with step-shaped magnetic cores was also studied. It has even higher characteristics. The use of step magnetic cores allows to reduce the consumption of magnetic materials by a third. The best results were shown by a catcher with a quadruply connected magnetic system made according to the cruciform configuration on rare earth magnets. The results of the experimental studies well agree with the calculated data, the difference is 10-20%.