SAND DISCHARGING METHOD AND SAND DISCHARGING APPARATUS

摘要

PROBLEM TO BE SOLVED: To avoid piping closing beforehand, and to enable sand to be discharged stably and efficiently without relying on the skill of an operator.;SOLUTION: A siphon type sand discharge method includes the steps of: determining whether flow rate values of slurry feed flow show decrease tendency over time and pressure values in a piping 13 show decrease tendency backward from a piping tip 14, on the basis of measured values of a flow meter 20 and a pressure gauge 21 installed at a predetermined position of the piping 13, and performing operation for decreasing the revolution speed of a cutter 11 until the tendencies are resolved when the tendencies are shown in the piping 13; and determining whether the density of the slurry feed flow is equal to or more than a predetermined value on the basis of the measured value of a density meter 22 installed at a predetermined position of the piping 13, and pulling up the piping tip 14 to separate it from a water bottom when the density of the slurry feed flow is equal to or more than the predetermined value.;COPYRIGHT: (C)2014,JPO&INPIT