Patent attributes
The invention concerns a process and a device (2) for the pneumatic conveyance of powdered material (4), in which a cylindrical chamber (10, 12), which can be connected with a reservoir (6) by a sealable inlet (14, 16) and with a delivery line (28) by a sealable outlet (18, 20), is alternately filled with material from the reservoir (6) and emptied of this material by applying a negative pressure to the chamber with its outlet (18, 20) closed and its inlet (14, 16) open through a bordering wall formed by a gas-permeable filter element (50) to draw material into the chamber (10, 12) from the reservoir (6), and by then admitting a gas under pressure into the chamber (10, 12) with its inlet (14, 16) closed and its outlet (18, 20) open to force the material previously drawn into the chamber (10, 12) out of the chamber and into the delivery line (28). To prolong the service life of the filter element (50) and to avoid contamination of the filter element more easily, it is proposed, in accordance with the invention, that the filter element (50) be designed as a hollow cylinder and that it surround at least a portion of the chamber (10, 12).