Pressure pulse cleaning apparatus

An apparatus for loosening and removing sludge and other impurities from the interior of a heat exchanger vessel of the type having a plurality of parallel heat exchanger tubes mounted in a tubesheet in orthogonal relationship thereto, wherein said interior is at least partially filled with water, comprising:

• a. a pulse generator connectable onto a wall of the heat exchanger vessel having an opening for generating a succession of pulses of expanding gas to create shock waves in the water that impinge upon and loosen said sludge and impurities;
• and
• b. a pulse distributing conduit having a first end connected to the opening of the pulse generator, and a second end that extends into the interior of the heat exchanger vessel when said pulse generator is connected onto said vessel wall for directing said pulses at about a 30 degree angle with respect to said tubesheet to both minimize the peak stress that said pulses apply to the tubes nearest said second end, and to reflect the resulting shock waves over a broad area within said vessel in order to uniformly displace said water throughout said vessel, wherein the internal volume of the pulse distributing conduit is substantially less than the volume of expanding gas creating shock waves so that said conduit effectively conducts said expanding gas to said water within the heat exchanger.

An apparatus for loosening and removing sludge and other impurities from the interior of the secondary side of a steam generator of the type having a plurality of parallel heat exchanger tubes mounted in a tubesheet that are surrounded by a tube wrapper and define a main tube lane, wherein said secondary side contains sufficient water to at least completely submerge said tubesheet, comprising:

• a. an air gun type pulse generator connectable onto a wall of the steam generator and having an opening for generating a succession of pulses of expanding gas to create shock waves in the water that impinge upon and loosen said sludge and other impurities, and
• b. a nozzle which is alignable along the main tube lane and which has a first end connected to the opening of the pulse generator and a second end that includes a tip portion which extends beyond said tube wrapper when said pulse generator is connected onto said wall and is oriented about 30 degrees with respect to the tubesheet when said conduit is connected to said opening and which is generally aimed toward a center portion of the tubesheet for both minimizing the peak stress that the pulses emitted therefrom apply to the heat exchanger tubes nearest the tip portion, and for causing the resulting shock wave to reflect off of the tubesheet in order to cause a uniform displacement of the water submerging the tubesheet.