Abstract: A machine for heat and/or cold treatment of lumpy material, more particularly a drum dryer for pasta, has a number of chambers (6) distributed around the drum periphery. Each chamber (6) is bounded in known manner at the inner and outer drum periphery by a perforated wall (8, 10) to enable air or another treatment gas to flow through. At least one perforated wall (8, 10) is associated with a retaining device, more particularly a tensioning device, at least one of the perforated walls (8, 10) and preferably at least the outer wall (10) being divided in the axial and/or peripheral direction around the drum periphery. Advantageously each chamber (6) is associated with a separate perforated wall (10) which can be tensioned by a tensioning device.