Agglomerating finely divided agglomerative materials in a rotating drum

Abstract

The agglomerating drum has a generally cylindrical configuration with an inner cylindrical wall. A scraper is rotatably positioned within the agglomerating drum in spaced relation to the inner cylindrical wall with its axis spaced from the axis of the drum. The scraper has a tubular body portion with a plurality of parallel rows of blades extending radially therefrom. Each of the rows extends lengthwise along substantially the entire length of the scraper body portion and follow a helical path having a single turn about the axis of the tubular body portion. Agglomerative material is introduced into the rotating agglomerating drum and forms a layer of agglomerative material on the drum inner cylindrical wall. The scraper is rotated in the same direction as the direction of rotation of the agglomerating drum and at a preselected synchronous speed with the agglomerating drum. The rows of parallel blades on the scraper form a plurality of spaced elongated generally longitudinal ridges and valleys in the layer of agglomerative material on the drum cylindrical wall. The ridges have a slight arcuate configuration and form less than a single convolution throughout the entire length of the agglomerating drum. The spaced elongated ridges in the layer of agglomerative material extend lengthwise in the drum substantially parallel to the axis of the drum and serve as longitudinally extending lifters to mix and agitate other particulate agglomerative materials introduced into the drum by lifting portions of the other particulate agglomerative material from the underside of the bed and depositing the material on the upper surface of the bed.