A problem to be solved by the present invention is to suppress the occurrence of a problem caused by switching of the shutter to the closed state in a state in which the curled glass remains in the curled discharge opening. A gravity discharging device configured to be capable of switching between a grained discharging state for discharging the grains stored in the graining tank to the outside of the gas and a discharging stop state for stopping the discharge of the grains； In the curled discharge structure, it is preferable to provide a control means for controlling the opening and closing of the shutter, and when the control means detects switching of the curled discharge device to the discharge stopping state, whether or not the preset shutter closing operation condition is established The shutter is switched to the closed state when the condition of the shutter closing operation is established and the shutter is kept in the open state when the condition of the shutter closing operation is not established. The control unit controls the opening and closing of the shutter of the curled discharge port and the curled sensor that detects the stay of the curled discharge at the curled discharge outlet. When the control unit detects the switching of the curled discharge unit to the discharge stopped state, It is determined whether or not the curled-up sensor detects the curled-up state. If the curled-up sensor detects the curled-up state, the shutter is kept in the open state. The control means determines whether or not the curled-up sensor detects the curled-up stay again when the curled-up outlet is detected, and when the curled-up sensor detects the curled stay The shutter is held in the open state, and when the stay is not detected, the shutter is switched to the closed state.본 발명의 과제는, 곡립 배출구에서 곡립이 체류하고 있는 상태에서 셔터가 폐쇄 상태로 전환되는 것에 기인한 문제의 발생을 억제하는 것이다.곡립 탱크에 저류한 곡립을 기체 외부로 배출하는 곡립 배출 상태와 곡립의 배출을 정지하는 배출 정지 상태로 전환 가능하게 구성한 곡립 배출 장치에, 곡립 배출 장치의 곡립 배출구를 개폐하는 셔터를 구비한
