Abstract: Spacers are roller welded or laser welded to a disk, welding the interstices between the spacers and the disk liquid tight. Nothing can accordingly accumulate in the interstices to contaminate the centrifugate.

Abstract: A device for removing air from hermetically sealed, automatically emptying centrifuge drums and consisting of an air-removal valve atop a reservoir with a manometric switch and a level-sensitive switch and connected to controls. The controls open the valve when the pressure in the reservoir exceeds a predetermined level and close it when the pressure drops below that level. The valve closes however, as soon as the level of the liquid in the reservoir reaches the level-sensitive switch. The device, which is preferably mounted in the product intake of a hermetically sealed, automatically emptying centrifuge, allows air to be removed automatically without allowing product to escape, foam to form, or oxygen to enter. The reservoir can be thoroughly cleaned automatically.