Magnets pulley

Magnetic pulleys are available ia diameters from 152 to 1524 mm and ia widths that match the conveyor belt width. The material burden on the belt, belt speed, and type of tramp iron expected to be encountered are all considerations ia magnetic pulley selections. 

Selection. The magnetic pulley width should match that of the belt. The face width is normally 51 mm wider than the belt width up to 1067 mm wide, and 76 mm on widths ia excess of 1219 mm. The speed of operation of the conveyor belt should be determined by calculating the maximum capacity to be handled. Using this iaformation, the diameter of the pulley required to handle the capacity can be determined (Table 2). The operating belt speed must be acceptable for the diameter selected. If the recommended belt speed is exceeded, the pulley diameter that can handle the belt speed must be used. 

Inclined belts provide additional areas of contact with the pulley magnetic field and can tolerate higher capacities than normal for a magnetic pulley apphcation. Table 3, which iadicates the correction factor to be appHed to the capacity, can be used with Table 2 to make the magnetic pulley diameter selection for an inclined belt. The initial cost of units can be related to the capacity or volume throughput. Costs mn about 35 for each m /h on the smaller units about 50 for each m /h on larger units. 

Table 2. Capacities of Magnetic Pulleys for Tramp Iron Removal, m /h...

Magnetic Pulleys. Magnetic puUeys of special design are used in the concentration of magnetite and other ferromagnetic minerals. For best results, the feed should be screened into various-sized fractions and each fraction treated on a separate puUey separator unit. Typical feed size is 100 X 50 mm, 50 x 25 mm, and 25 x 6 mm. When treating material of —10 mm, an axial pole magnetic puUey should be utilized, as this provides uniformity of field across its width. 

Drum and Pulley Magnets Since Thomas Edison invented and developed the magnetic pulley for the concentration of nickel ore, drums and pulleys have become the most common types of magnetic separators. These devices can be built with either a permanent magnet or an electromagnet, and the drum separator can operate with... 

Dry magnetic drums can be designed to perform as lifting magnets or pulleys. Magnetic drum devices have stationary magnets pulley drums rotate. Other schematics of possible arrangements are presented in Fig. 19-44. 

Magnetic pulleys. These vary in size from 0.203 to 1.219 m in diameter and from 2.03 to 1.526 m in width. The acceptable depth of the material on the conveyor belt depends on the diameter of the pulley and the linear velocity of the belt (see Table 19-18). Table 19-19 indicates the maximum capacity for such units. Depending on the apphcation, the correction factors given in Table 19-20 should be apphed. For sizing and maximum efficiency, multiply the actual volume of material to be handled by the correction factor shown and select the magnetic pulley having a capacity equal to or greater than the resultant volume. 

TABLE 19-18 Maximum Depth of Material for Separator by Magnetic Pulley Based on Pulley Diameter and Linear-Velocity Belt... 

TABLE 19-19 Maximum Capacity for Magnetic Pulley Separator ... 

TABLE 19-20 Correction Factors for Magnetic-Pulley Capacities ... 

Magnetic pulley, conveyors, and elevators, rotary cooler, screening, crusher-mixer Particulates (dust) Exhaust system, cyclone, and baghouse... 

Coarse Ore Treatment. Coarse ore concentrating drum selection is based on capacity to be handled and the size of the particle to be treated. As in the case of magnetic pulleys, a sized feed is desirable for optimum operation. Recommended capacity and diameters for coarse ore drums are as follows ... 

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