Abstract: The invention relates to apparatus for extracting a substance stored in the divided state in a silo. The apparatus includes: a de-bridging system inside a converging bottom portion of the silo; a decompression enclosure at the bottom of the silo and having a diameter greater than the diameter of the end section of the converging portion of the silo; and a drive assembly for driving the substance along a horizontal duct in a direction substantially perpendicular to the vertical axis of the silo which duct is in communication with the bottom end of the decompression enclosure and includes a vertical outlet chute. A rotary loading arm is provided for keeping the drive assembly loaded with the divided substance so long as the divided substance flowing.

Abstract: A rotating helical coiled spring for conveying, extracting, quantity-controlling or mixing particulate products. A supple material such as a brush is attached to the periphery of the spring and brushes against a rigid wall or tube as the spring is rotated thereby propelling the particulate product in a direction generally parallel to the axis of the spring.

Abstract: To continuously mix two flowable products such as a solid product in the divided state and a liquid product, two concentric ducts are provided each with associated entraining means. The entraining means of the outer duct serves to move a first one of the flowable products along the duct from an entry port towards an exit port for the mixed products and includes a helical element urging the first product into rotation in passage along the outer duct. The second duct opens into the outer duct between the entry and exit ports of that duct and the entraining means of the inner duct serves to move the second flowable product through the inner duct and into the outer duct in the center of the first product stream.