Packing behaviour of a Li2TiO3 pebble bed under cyclic loads

In the temperature range from room temperature to 973 K and the mechanical loading range from 0.1 to 3 MPa, a Li2TiO3 pebble bed was successively loaded and the packing behaviour of the bed was observed. Deformation caused by the mechanical loading is partly relaxed when the bed is heated without the load. After a large numbers of thermal and mechanical loading cycles, the packing factor of the bed increased from the initial packing factor of 66.9% to finally about 68.5%. This progressive increase in packing leads to production of a cavity region at the top of the pebble bed, therefore it is important to obtain a high initial packing factor.