Method for classifying articles and method for fabricating a magnetocalorically active working component for magnetic heat exchange

摘要

A method for classifying particles comprising magnetocalori­cally active material according to magnetic transition tem­perature comprises providing a source 14 of particles 15, wherein the particles comprise magnetocalorically active materials having differing magnetic tran­sition temperatures. A magnetic field is sequentially applied at differing temperatures to the source, the magnetic field being sufficient to exert a magnetic force on the source that is greater than the inertia of a fraction of the particles causing the fraction of the particles to move and produce a particle fraction. The particle fraction is collected at each temperature to provide a plurality of separate particle frac­tions of differing magnetic transition temperature. A method for fabricating a magnetocalorically active working component for magnetic heat exchange involves the arrangement of the particle fractions in order of increasing or decreasing average magnetic transition temperature. Preferably, the source is subjected to a temperature gradient and may be placed in a thermally conductive container 11. The source may be moved along the temperature gradient to alter the temperature of the source by thermal conduction.