Abstract: A heat exchanger is formed of inner and outer fluid tubes. The inner fluid tube has a profile that undulates in a smooth manner toward and away from the centroid of the inner fluid tube as the profile extends circumferentially about the centroid. The inner tube has axially opposite end margins that each form cylindrical tube portions. The cylindrical tube portions have a diameter greater than the diameter of the remainder of the inner fluid tube. The inner fluid tube defines an inner fluid passageway. The outer fluid tube encircles the inner fluid tube and extends from one of the cylindrical tube portions of the inner fluid tube to the other in a manner defining an outer fluid passageway between the inner fluid tube and the outer fluid tube. The outer fluid tube has an inlet and an outlet that extend radially through the outer fluid tube.

Abstract: A recirculating batch peanut drying apparatus including a drying station for heating the peanuts, a tempering station for cooling the peanuts after heating, and a recirculating device which transports the peanuts in a continuous flow between the drying station and the tempering station.