Patent ID: 7753086

Claim:
A method for filling particulate material in a vertical tubes, in which the material is conveyed down via at least one damper device, comprising the steps of: gradually pulling the damper device up from inside of the tube, wherein at least one of the at least one damper device is formed as a spiral shaped duct, as the tube is filled with the material so that a lowermost portion of the spiral shaped duct is spaced from the top layer of the filled material; conveying the particulate material down the spiral shaped duct while the spiral shaped duct is rotating inside the tube, the spiral shaped duct having its outer perimeter adjacent an inner wall of the tube and its axis coaxial with a longitudinal axis of the tube; and flinging the material with a horizontal velocity component towards the inner wall of the tube before the material comes to rest on a top layer of filled material inside the tube.