Rotating guide means for discharging particulate materials

An apparatus for permitting controlled release of flowable particulate material comprises a chamber 20 for temporarily housing the particulate material, an outlet channel for exit of the material from the chamber at least partly under the action of gravity A. Guiding means are positioned in outlet channel 22 for assisting passage of the particulate material. The guiding means comprise elongate fingers 26a-e arranged on shaft 24a to rotate about a first axis extending transversely across channel 22, and second elongate fingers 28a-e arranged on a shaft 24b to rotate about a second axis extending transversely across channel 22. The axes are in the same direction but are laterally displaced from each other. The fingers on the respective shafts may rotate in opposite directions and may interdigitate. The apparatus may be a pyrolysis plant.