Process and apparatus for drying and calcining sodium bicarbonate

Apparatus for drying and calcining sodium bicarbonate and cooling sodium carbonate comprising:

• a plurality of adjacent fluid bed sections interconnected by means permitting continuous fluid flow of particulate material from a first to a last one of said adjacent fluid bed sections, at least a first one of said fluid bed sections comprising a wet cake fluid bed dryer section, a last one of said fluid bed sections comprising a particulate material fluid bed cooling section and a sequence of adjacent fluid bed sections between said first and said last ones of said fluid bed sections comprising a plurality of adjacent fluid bed calciner sections;
• means for providing an essentially carbon dioxide gas to said fluid bed dryer section to fluidize a particulate feed material delivered to said dryer section;
• means for heating said fluidized particulate feed material in said fluid bed dryer section to vaporize water from said particulate feed material in said fluid bed dryer section;
• means for providing a mixture of carbon dioxide and water vapor to each of said plurality of adjacent fluid bed calciner sections to fluidize particulate material in each of said fluid bed calciner sections and means to heat the particulate material in each successive fluid bed calciner section to increase the total amount of sodium bicarbonate converted to sodium carbonate in each successive fluid bed calciner section;
• means for providing atmospheric air to said fluid bed cooling section to fluidize the particulate material in said fluid bed cooling section;
• and
• means for cooling said fluidized material;
• whereby a sodium bicarbonate wet cake material delivered to said first fluid bed dryer section is dried in said dryer section and moved as a particulate material successively through each of said fluid bed calciner sections to said fluid bed cooling section wherein it is withdrawn as a substantially anhydrous sodium carbonate particulate product.