Abstract: A device for the delivery of bulk materials into the suction pipe of a pneumatic transport installation comprises a vertical pipe designed for charging the bulk material, and a closing element installed on its lower end and placing the charging pipe into communication with the suction pipe of the installation. The closing element comprises a cylindrical shell with a coaxially built in sleeve, the inside diameters of both the shell and the sleeve being approximately equal to the inside diameter of the charging pipe, and a helical band located in said shell. The pitch of the helical band is close to the diameter of the shell and its width at the end facing an under-band portion of the shell is equal to the radius of said shell. The band is connected to said sleeve which is kinematically linked with a reversible drive for joint rotation with it so that, when rotating in one direction, the helical band compacts the bulk material in the under-band portion of the shell until said portion is completely filled.