Conveyors pulleys

Drive the ball bearings on the shaft with the driving-on sleeve. - Secure the round nut with the lock washer. - Clean the friction surface of the conveyor pulley. 

Screw out screws 10 lor the protecting cover, inserting the wrench through one of the holes in the conveyor pulley. 

If the ball bearing should be exchanged, screw jack screws into the threaded holes of the conveyor pulley and tighten against the protecting cover until the bearing is pressed loose. 

Worm wheel shaft with conveyor 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. 

Fig. 3. Suspended magnets, where A = conveyor belt width B = suspension height C = overall height D = distance to magnet centerline and E = location of lift point, (a) Manually cleaned over conveyor mn system, (b) manually cleaned over head pulley, and (c) self-cleaning separator over head...

Belt Conveyors. A belt conveyor is made up of an endless fabric or elastomer covered belt that traverses between two or more pulleys, and is supported at intermediate points by idler roUs. These conveyors can handle a wide range of materials, from fine powders to large, lumpy stone and coal. Material can be transported at rates of over 5000 t/h and the conveyors operated at belt speeds ranging from 20 to 300 m /min over very long distances. VersatiHty, reHabiHty, and range of capacities have made belt conveyors the most commonly used bulk handling conveyors in industry. 

Take-Ups. A take-up is requited on a belt conveyor to ensure the proper belt tension at the drive pulley and along the conveyor, as weU as to ensure the proper troughing contour between idlers. A take-up is also needed to compensate for changes in belt length caused by elastic stretch during start-up, and any elongation characteristics of the belt that occur over a period of time. 

Manually adjusted screw or ratchet take-ups that adjust the position of the tail pulley to control belt tension can be used on relatively short, light duty conveyors. Automatic take-ups are used on conveyors over about 25 to 30 m long. The most common is the weighted automatic gravity take-up (see Fig. la). Other types of automatic take-ups have hydrauHc or pneumatic powered devices to adjust a snub pulley position and maintain a constant belt tension. The requited take-up movement varies according to the characteristics of the belt constmction and the belt length. Typically, take-up movements for pHed belts are 2% to 3% of the center distance between head and tail pulley, and about 0.5% for steel cable belts. The take-up movements requited for soHd woven belts are usually shorter because of the lower elastic stretch. Take-up requirements for a particular situation should be confirmed by the belt manufacturer. 

Conveyor-belt speeds above approximately 300 ft per minute (1.5 meters per second) impart sufficient momentum to material discharging at its head pulley to cause lifting of material streams in a trajectory from the head pulley. A trajectory is illustrated in Fig. 19-7. Blades of the sample cutter are positioned to intersect the trajectoiy. See Fig. 19-7 for an example of a linear-traversing bottom-dump cutter installation. Calculation of trajectory profiles are described in the Conveyor Equipment Manufacturers Association publications and similar references. 

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. 

Unless a material discharges freely, cleaners are required on belt conveyors and may be helpful on others. Common types use a rotating brush, powered from the convevor head-pulley shaft or independently, or a spring-mounted blade. The latter is applicable only at some point where the belt conveyor lies reasonably flat. Whenever cleaners are used, provision should be made for catching and chuting the material back into the main discharge stream or to a collecting container which can be periodically emptied. 

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

Materials Handling Rubber lining for grabs, hooks and clamps. Wear resistant linings for chutes, hoppers storage bins etc. pulley rubber lagging for conveyor rollers. Soft natural rubber for wear resistance. Various rubber materials for roller coverings. 

Power Generation Corrosion resistant linings for water treatment plant and cooling pipelines. Wear- resistant linings for coal handling plant, pulley rubber lagging for conveyor rollers etc. Soft natural rubbers and other synthetic rubbers... 

Figure 5.10. Closed belt (zipper) for conveying in any direction (Stephens-Adamson Co.), (a) Arrangement of pulley, feed hopper and open and closed belt regions, (b) The tubular belt conveyor for horizontal and vertical transport a section of the zippered closed belt is shown, (c) Showing how the zipper closes (on downward movement of the belt in this sketch) or opens (on upward movement of the belt).

Related Calculations. This procedure is valid for conveyors using rubber belts reinforced with cotton duck, open-mesh fabric, cords, or steel wires. It is also valid for stitched-canvas belts, balata belts, and flat-steel belts. The required horsepower input includes any power absorbed by idler pulleys. 

---