The device has an adjustable disk (12) for closing an outlet opening (11) arranged in a base region of a storage container, and a hydraulic cylinder (13) e.g. single-acting hydraulic cylinder and double-acting hydraulic cylinder, for moving the disk to a closed position and an opened position. Width of the opening is adjustable, and a quantity adjusting device (16) i.e. pivoting lever (15), is adjusted to different positions for presetting the opened position of the disk. The cylinder is directly arranged between the disk and the quantity adjusting device.
