Steam generator sludge lancing method
AssigneeWestinghouse Electric Corp.
InventorsThomas H. Dent, Diane E. Jordan, William E. King, Frank W. Rieger
Life of this patent
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Abstract
A method for removing sludge that may be deposited on a tubesheet of a steam generator comprises placement of fluid headers at the elevation of the sludge to be removed establishing a circumferential fluid stream at that elevation. A fluid lance is moved along the line between the headers emitting a pulsating fluid jet perpendicular to a line of movement of the fluid lance at an elevation substantially corresponding to the level of sludge deposits. The fluid jet forces the sludge to the periphery of the tubesheet where the sludge is entrained in and carried away by the circumferential fluid stream.
Claims9
A method for removing sludge deposits from a steam generator comprising the steps of:
- inserting fluid injection apparatus into said steam generator near the base thereof;
- placing fluid suction apparatus in said steam generator in a position substantially opposite said fluid injection apparatus;
- positioning a movable fluid lance in said steam generator near said base;
- supplying a first fluid to said fluid injection apparatus at between approximately 35 to 45 gpm and establishing a peripheral fluid stream from said fluid injection apparatus to said fluid suction apparatus;
- supplying a second fluid to said fluid lance and causing said fluid lance to emit pulses of fluid with each pulse being approximately 14-16 gpm and having a pulse length of approximately 3-7 seconds and simultaneously discharging the same along said base dislodging said sludge deposit while forming a sludge-fluid mixture that becomes entrained in said peripheral fluid stream;
- moving said fluid lance in a linear direction along said base;
- and
- discharging said mixture into said fluid suction apparatus.
Dependencies are inferred from the claim text.