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A new type of contactless stirrer and/or pump has been developed for Aluminium industry.Large scale synchronously rotating permanent magnet cylinders,which are magnetized orthogonal to the axes,are used to create travelling magnetic field in Aluminium furnace through a thick bottom or wall,which induces stirring in a liquid metal pool similarly to traditional AC three-phase inductors.Flowrate of up to 600 tons per hour can be achieved with negligible energy dissipation even if the total wall thickness of the furnace is 30 cm.The advantage of the permanent magnet inductor is much lower energy consumption-maximum energy consumption of the stirrer to produce sufficiently high mechanical torque does not exceed 20 kW even for 600 ton per hour stirrer.Produced metal flow is quite similar to that,which is achieved by the AC three-phase induction stirrers offered by ABB and other companies.AC three-phase inductors exhibit very high Joule losses in the coils of the machine,but the permanent magnet system working at frequency in the range from0.5 Hz to 2 Hz produces negligible Joule losses both in liquid Aluminium as well as in stainless steel plate of the furnace bottom enclosure and in the permanent magnet material itself,so relatively weak air cooling is sufficient.The linear permanent magnet stirrer has been experimentally tested on a small scale lab model in a shallow pool of InGaSn eutectic.The tests confirm the predicted flow intensities and flow pattern,and give sufficient results for validation of the large scale flow simulations.Principal schematics of investigated system and the free surface deformation of the liquid metal due to action of the stirrer are shown below.The linear permanent magnet system may be used also as a contactless pump for liquid Aluminium in two-chamber furnaces,for tapping the liquid metal or for transportation and precision dozing.If high flow rate is required simultaneously with considerable elevation of the liquid metal level,the wall thickness of the channel should be lower and frequency of the travelling magnetic field higher comparing to the case of stirring application.Two sided pump has also been considered for a fiat channel,promising two times higher magnetic field induction and four times higher delivered pressure head.Seeing in perspective wide range applications of the proposed system a patent has been obtained.
A new type of contactless stirrer and / or pump has been developed for Aluminum industry. Larger scale synchronously rotating permanent magnet cylinders, which are magnetized orthogonal to the axes, are used to create traveling magnetic field in Aluminum furnace through a thick bottom or wall, which induces stirring in a liquid metal pool similarly to traditional AC three-phase inductors. Flowrate up to 600 tons per hour can be achieved with negligible energy dissipation even if the total wall thickness of the furnace is 30 cm. advantage of the permanent magnet inductor is much lower energy consumption-maximum energy consumption of the stirrer to producerized high mechanical torque does not exceed 20 kW even for 600 ton per hour stirrer.Produced metal flow is quite similar to that, which is achieved by the AC three- phase induction stirrers offered by ABB and other companies. AC three-phase inductors exhibit very high Joule losses in the coils of the machine, but the permanent mag net system working at frequency in the range from 0.5 Hz to 2 Hz produces negligible joule losses both in liquid aluminum as well as in stainless steel plate of the furnace bottom enclosure and in the permanent magnet material itself, so relatively weak air cooling is sufficient .The linear permanent magnet stirrer has been experimentally tested on a small scale lab model in a shallow pool of InGaSn eutectic.The tests confirm the predicted flow flow intensities and flow pattern, and give sufficient results for validation of the large scale flow simulations .Principal schematics of investigated system and the free surface deformation of the liquid metal due to action of the stirrer are shown below. The linear permanent magnet system may be used also as a contactless pump for liquid Aluminum in two-chamber furnaces, for tapping the liquid metal or or for transportation and precision dozing .If high flow rate is required simultaneously with appropriate elevation of the liquid metal level, the wall thickness of the channel should be lower and frequency of the traveling magnetic field higher comparing to the case of stirring application. Two sided pump has also been considered for a fiat channel, promising two times higher magnetic field induction and four times higher delivered pressure head. Seeing in perspective wide range applications of the proposed system a patent has been obtained.