Patent ID: 7931860
Filing Date: 2011-04-26
Classification: A61L

Abstract:
1. A process for treating material, comprising the steps of feeding material to be treated into a gravity drop steam heating tower, bringing pressurized steam into direct contact with the material in the gravity drop steam heating tower via steam nozzles positioned in the gravity drop steam heating tower, the gravity drop steam heating tower having an upper end portion, a lower end portion, a distance between the upper end portion and the lower end portion, a central axis extending between the upper end portion and the lower end portion, an interior, and an interior wall, the steam nozzles including a first set of spaced apart steam nozzles positioned along the interior wall at about a distance of one-third of the distance between the upper end portion of the gravity drop steam heating tower and the lower end portion of the gravity drop steam heating tower down from the upper end portion of the gravity drop steam heating tower, the steam nozzles of the first set of steam nozzles being angled upwardly and toward the center axis of the gravity drop steam heating tower at an angle of 22 degrees±4 degrees, and the steam nozzles including a second set of spaced apart steam nozzles positioned along the interior wall at about a distance of two-thirds of the distance between the upper end portion of the gravity drop steam heating tower and the lower end portion of the gravity drop steam heating tower down from the upper end portion of the gravity drop steam heating tower, the steam nozzles of the second set of steam nozzles being angled upwardly and toward the center axis of the gravity drop steam heating tower at an angle of 45 degrees±10 degrees, heating the material to the biological kill temperature using the pressurized steam as the material falls through the gravity drop steam heating tower, after the material has been treated in the gravity drop steam heating tower, heating the material using conduction to facilitate vaporization of liquids entrained in the material, and releasing vapor entrained in the material after the material has been heated by conduction.