Experimental performance evaluation of sintered Gd spheres packed beds.

Research in magnetic refrigeration heavily relies on the use of packed spheres in regenerators, however little investigation to verify that such non-monolithic arrangements guarantee a sufficiently constrained structure has yet been performed. This work presents a preliminary comparison of the performance of AMRs consisting of Gd spheres with diameters ranging from 450-550 microns partially sintered by Spark Plasma Sintering (SPS) to similar spheres, sorted in the same size range and from the same batch, but merely packed. Pressure drop is compared at uniform temperature and at a range of heat rejection temperatures and temperature spans. Performance is compared in terms of temperature span at a range of heat rejection temperatures (295 – 308 K) and 0 and 10 W cooling loads. Results show a moderate increase of pressure drop with the sintered spheres, while temperature spans were consistently 2.5 - 5 K smaller. These results are coherent with previously presented results [1].