| 摘要 |
PURPOSE:To restrain variation of duct pressure in the case of variation of ratio of solid material and the like in transported fluid such as drainage of muddy water in a muddy water type shield construction method, so as to prevent breakage of a transport pipe and pumps. CONSTITUTION:Variable speed type pumps are used for the uppermost stream and the lowermost stream pumps P2, Pn or all pumps P2, P3, ...Pn of a mud drain pipe 25. A pressure detector 29 is provided on a duct between a first variable speed type mud drain pump P2 and a second variable speed type mud drain pump Pn of the lowermost stream. The pressure detector 29 is connected to a central monitoring board 39, and rotating speed of the second variable speed type mud drain pump Pn is controlled by means of the central monitoring board 39. The second variable speed type mud drain pump Pn is controlled by means of the central monitoring board 39 based on the detected value of the pressure detector 29, and duct pressure is conformed to a set value in spite of flow, viscosity, and specific gravity of fluid, ratio of solid material, and the like. |
