Method and apparatus for transferring heat to or from material

Apparatus for transferring heat to or from a substance to be treated, comprising:

• a hollow vessel which is at least partially floatable and is supported for at least vertical movement;
• an outer housing extending below and at least partially encompassing said vessel;
• transfer means for feeding the substance into said vessel and for withdrawing the substance from the vessel;
• means for forming a fluidised bed of particulate material within said housing between said vessel and said housing, said fluidised bed effecting heat transfer therethrough to or from said vessel;
• means to provide a fluidising fluid to the housing so as to fluidise the bed and to substantially wholly floatingly support the vessel during operation;
• means to support the vessel when the bed is not fluidised while allowing vertical movement of the vessel when the bed is fluidised;
• and
• movement means for moving said vessel whilst the vessel is substantially wholly floatingly supported by said fluidised bed.