High energy wash of ljungstrom air preheater

An apparatus for cleaning the basket section of an air preheater, the basket section being enclosed within a chamber and rotatable around a hub positioned in the chamber, the apparatus comprising;

• an elongate beam spaced from and parallel to the basket section, the beam having an inner end secured to the hub and an outer end secured to the inside wall surface of the chamber;
• an elongate threaded rod spaced from and parallel to the beam, the rod having an inner end mounted in a rotatable bearing member secured to the hub, the rod having an outer end which extends beyond the chamber wall, and the rod being carried near the outer end in a rotatable bearing member secured to the inside wall surface of the chamber;
• a drive unit mounted outside of the chamber, and the drive unit engaging the outer end of the threaded rod, such that the rod can be rotated by the drive unit;
• a carriage assembly which straddles the threaded rod and the beam, the carriage assembly including at least one carriage drive block, the drive block being secured to the carriage assembly and having a central threaded opening therein which engages the threaded rod, to thereby enable the carriage assembly to move along the threaded rod as the rod rotates;
• the carriage assembly further including top roller means mounted on the carriage assembly and engaging the top face of the beam, and bottom roller means mounted on the carriage assembly and engaging the bottom face of the beam, said roller means enabling the carriage assembly to be moved along the beam;
• a nozzle assembly which includes a head block fastened onto the carriage assembly between the bottom roller means and the basket section, a fluid passage inside the head block, a jet nozzle installed in the head block and in communication with the fluid passage and at least one inlet line which connects the fluid passage with a source of washing fluid;
• an automatic programmer unit which includes a means for actuating the drive unit, a first counter means associated with the basket section, and a second counter means associated with the drive unit actuating means and with the threaded rod;
• wherein
• the washing fluid is directed through the inlet line and jet nozzle and onto the basket section, to thereby remove solid deposits from the basket section;
• the first counter means is adapted to register one complete revolution of the rotating basket secton and to actuate the second counter means after registering each complete revolution of the basket section;
• and
• the second counter means is adapted to actuate the drive unit actuating means, to cause the threaded rod to rotate a set number of revolutions, as registered by the second counter means, and to thereby advance the carriage assembly a predetermined distance along the threaded rod.