Apparatus for heat treatment of particulate materials

An apparatus for drying product, for use in an industrial plant having a waste heat source, comprising:

• (a) a fluidized-bed dryer unit having an interior for receiving the product, wherein product disposed in the dryer unit travels from one end of the dryer to the other end while being dried;
• (b) an air or inert gas fluidizing stream for fluidizing the product particles contained within the dryer unit;
• (c) a first heat exchanger for transferring heat from the waste heat source to the fluidizing stream to increase its temperature before it flows to and through the dryer unit;
• (d) a second heat exchanger for transferring heat from the waste heat source to a third heat exchanger embedded within the dryer unit;
• (e) wherein the interior of the vessel is heated to about 300° F. or less;
• and
• (f) wherein “waste heat source” means a gaseous or liquid stream having an elevated heat content resulting from an operation of a process or piece of equipment separate from the heat treatment apparatus, such gaseous or liquid stream being used for the secondary purpose of providing heat content to the heat exchanger instead of being discarded.

A particulate material drying apparatus incorporated into an industrial plant operation having at least two different types of waste heat, such apparatus comprising:

• (a) a fluidized-bed dryer unit having an interior for receiving the particulate material, wherein particulate material disposed in the dryer unit travels from one end of the dryer to the other end while being dried;
• (b) an air pre-heater operatively disposed between the dryer unit and the two different waste heat sources to transfer heat from each of the waste heat sources to an air stream passing through the air pre-heater before it flows to and through the dryer unit, wherein the air stream fluidizes the particulate material particles contained within dryer unit;
• (c) a heat exchanger operatively connected to the dryer unit for transferring heat from at least one of the waste heat sources to the dryer unit for increasing the interior temperature of the dryer unit;
• and
• (d) wherein “waste heat source” means a gaseous or liquid stream having an elevated heat content resulting from an operation of a process or piece of equipment separate from the heat treatment apparatus, such gaseous or liquid stream being used for the secondary purpose of providing heat content to the heat exchanger instead of being discarded.