MAGNETIC CATCHER Russian patent published in 1996 - IPC

FIELD: well drilling equipment; applicable in removal of foreign ferromagnetic objects in cleaning wells. SUBSTANCE: to increase the force of magnetic attraction and efficiency in removal of objects of irregular shape, the permanent magnet and magnetic circuit are made in form of semicylinders, direction of radial magnetization are opposite and distance between ends of semicylinders of magnetic system, outer diameter D inner diameter d of the magnet, its total cross-section Sm and areas of working end surfaces of external magnetic circuit Se and internal magnetic circuit Si are connected by relation: h=(0.3-0.5)x(D-d); Sm=(0.7-1.0)xSe; Se=(0.6-1.0)xSe. EFFECT: higher efficiency. 2 dwg