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Magnetic Levitation Technology for Materials Transport
Tech News 442 DRC Magnetic Levitation (Mag-Lev) Technology for Materials Transport November 1994 Mine Safety Systems Objective To develop a magnetic levitation transport system that can reduce the cost and improve safety in transporting coal from the face of underground coal mines to the surface. Background Many conventional mining operations use conveyor belts to transport coal from an underground face to the surface of the mine. The Mag-Lev Transport System design replaces conveyor belts with magnetically levitated coal haulage containers moving through a dedicated pipeline. Cost estimates, based on current design data, show the Mag-Lev Transport System would have operating and capital costs that are less than or equal to those of an equivalent-capacity conveyor belt system. The safety hazards associated with conveyor belt systems include exposure to moving parts and pinch points, potential fire hazards due to mechanical friction, and the exposure of miners to respirable dust. These hazards would be eliminated or significantly reduced by this novel technology. Approach The Mag-Lev Transport System uses magnetic levitation technology that allows noncontact, frictionless conveyance of a levitated body within a dedicated transit corridor. The mag-lev technology utilizes two types of permanent magnets coupled with an electronic position control system to achieve noncontact levitation. Levitation is provided by neodymium-iron boron (NdFeB) magnets mounted in the base of the haulage containers and inexpensive ceramic-5 magnets located in the bed of the transit corridor. An electronic position control system is used to overcome the inherent instability of the repelling permanent magnets. Proximity sensors, a signal processing circuit, electromagnetic actuators, and fixed ferrous side rails are the major components of the positioning system. Results U.S. Bureau of Mines researchers have developed a one-half commercial-scale bench model to demonstrate transport that is frictionless and 100% contact free. Payloads of 153 kilograms (338 pounds) have been magnetically levitated with the model while traveling frictionless and contact free along its corridor. The USBM has incorporated the mag-lev technology into a freight pipeline system design for moving bulk materials at low speeds. Other potential commercial applications include conveyance of materials in clean rooms, warehouses, and manufacturing and processing facilities. Flywheel energy storage systems may also benefit from the application of this technology. Patent Status The U.S. Department of the Interior has applied for a patent on the Permanent Magnet Mag-Lev Pipeline Transport System and the Electronic Positioning System. Additional patent information may be obtained by contacting the U.S. Bureau of Mines, Office of Technology Transfer, 801 Seventh St. NW, Washington, DC 20241 (telephone: 202-501-9323). For More Information Contact John J. Geraghty, electronics engineer (telephone: 303- 236-0777, ext. 735), or William E. Wright, mechanical engineer (telephone: 303-236-0777, ext. 707), U.S. Bureau of Mines, Denver Research Center, Building 20, Denver Federal Center, Denver, CO 80225. .
