Method for discharging granular powder brought into fixed state inside hollow structure

A method for, when a granular powder stored inside a hollow structure is brought into a fixed state and cannot be discharged from a discharge port of a bottom portion of the hollow structure, breaking down the granular powder in the fixed state, and then discharging the granular powder from the discharge port, the method comprising

• the steps of:
• suspending a rack rail of a predetermined length into an upper space in the hollow structure from an opening formed in a ceiling portion of the hollow structure;
• lowering a lifting body moving along the rack rail from the opening to the upper space in the hollow structure along the rack rail;
• building a work scaffold so as to project in a horizontal direction on the lifting body in the upper space in the hollow structure using a part carried into the hollow structure from the opening;
• poking and breaking down the granular powder in the fixed state under the work scaffold by a worker connected to the work scaffold with a safety belt in a state where the discharge port of the bottom portion of the hollow structure is closed:
• dropping the poked and broken down granular powder to a passage formed in the granular powder in the fixed state under the work scaffold from a top surface of the granular powder to the discharge port in the closed state of the bottom portion of the hollow structure;
• adding a next rack rail to a lower end of the rack rail under the work scaffold by the worker connected to the work scaffold with the safety belt in a state where the passage is blocked with the poked and broken down granular powder;
• opening the discharge port of the bottom portion of the hollow structure to discharge the granular powder stored in the passage;
• and
• lowering the lifting body to the added rack rail to lower the work scaffold.