PURPOSE: To provide adjustability for the amount of exhaust at any desired time from the outside by regulating the gap between the exhaust hole and a conical cover installed thereabove using a sleeve, and by sweeping out the stored object by the use of a spiral scraper which passes through said gap and rotates.

CONSTITUTION: An adjusting sleeve 15 is installed inside a cylinder 4a fixed to the bottom of an exhaust cover 4, where the sleeve 15 is in slide contact with the cylinder 4a. The position of the sleeve 15 is adjusted by moving the shaft 8 with a motor 14 with a shaft 10 and a gearing 9 interposed. The stored object flows out to an opening 2a from the gap between the sleeve bottom and a bottom plate 2 to stop with the rest angle specific to the substance. When another motor 19 rotates the exhaust pipe 17 and thereby a scraper 16, that portion of the stored object lying stably around said opening 2a is swept out of the exhaust holes 17b, 17a. As the motor 14 shifts the sleeve 15 vertically, the amount of exhaust is adjustable from outside.