Effect of Magnetic Field on a Loosely Packed, Tightly Packed and an Over-Tightly Packed Metal Powder Bed

The effect of alternating magnetic field on the pressure drop inside a fixed bed with different types of packing is experimentally investigated. The bed was packed with three different masses of iron(III)oxide powder as a loosely packed, tightly packed and an over tightly packed bed system. A Helmholtz coil was used to apply an AC magnetic field (60 Hz) and the pressure drop measurements were made for a range of flowrates between 29 SCFM to 25 SCFM at a small deceleration of 0.03 in/s(2) (0.001 m/s(2)). The magnetic field was applied continuously throughout the time of pressure-drop measurements, and also was turned off before the measurements began to analyze the behavior of the bed. It was found that in a loosely packed bed system, the pressure drop decreased for all magnetic field orientations compared to the no magnetic field configuration, whereas in the tightly packed bed samples, the pressure drop values can be increased or decreased by altering the magnetic field orientation. In the tightly packed bed samples, the pressure drop values did not alter when the magnetic field was turned off during the flow and is only needed until the flow enters the bed.