A method for cleaning a plurality of drainpipes installed in a movable equipment by causing a flow of a cleaning solution through the drainpipes includes the steps of connecting provisional pipes to the plurality of drainpipes, feeding a cleaning solution into the provisional pipes and the drainpipes, and applying negative pressure suction force to the provisional pipes and the drainpipes to cause a flow of the cleaning solution in the opposite direction to a drain direction in normal use, to thereby clean the drainpipes.
A system is provided which is capable of cleaning a drainage pipe in a short time for removal of scale without detaching the drainage pipe from movable equipment. The system comprises: a reservoir tank containing a cleaning liquid; a feed pipe connecting the reservoir tank and a downstream side of the drainage pipe of the movable equipment and including feed pump means for feeding the cleaning liquid to the downstream side of the drainage pipe from the reservoir tank; a suction pipe connecting an upstream side of the drainage pipe and the reservoir tank; and vacuum pump means for sucking gas from the reservoir tank; wherein the suction pipe is provided with gas separation means for separating gas from gas, liquid and solid sucked from the drainage pipe; wherein a gas suction pipe for feeding the separated gas back into the reservoir tank is connected parallel to the suction pipe between the gas separation means and the reservoir tank.
A descaling composition for use in removing scale deposited on a member made of titanium or a titanium alloy, the descaling composition containing a hydroxycarboxylic acid, a sulfamic acid and ammonium sulfate as effective components and effectively inhibiting titanium ions from dissolving out.
A descaling composition for use in removing scale deposited on a member made of titanium or a titanium alloy, the descaling composition containing a hydroxycarboxylic acid, a sulfamic acid and ammonium sulfate as effective components and effectively inhibiting titanium ions from dissolving out.
