| 摘要 |
PURPOSE:To prevent the scattering of the powder body into atmosphere by a method wherein the retrieving work of the powder heat insulator filled within the roof and the side board of a heat insulating tank is effected under a condition of shutting it out of the atmosphere. CONSTITUTION:Mixed body of the powder body and a gas for mixing filled into the space 4 of the heat insulating tank 1 is transported into a powder body separating tank 7 from the powder body sucking port 6a of a powder body retrieving nozzle 6. A part of the gas for mixing, which is separated in the powder body separating tank 7, is returned into the space 4 of the heat insulating tank 1 from the return gas passageway 6g of the powder body retrieving nozzle 6 through a filter 15 and a return gas pipeline 14 while the other part thereof is returned from the roof 2b to the same tank through the same filter and pipeline respectively. The powder body, from which the gas for mixing is withdrawn already, is sunk and deposited at the lower part of the separating tank 7 and, thereafter, is transported therefrom, therefore, the powder body will never be scattered into the atmosphere. |
