(634e) KΤ-3: a Novel Tickler for Solids Removal from Slurry Vessels

Ticklers (kickers) are relatively small impellers that are often part of the mechanical agitation system in stirred tank reactors (STRs) and storage vessels that contain slurries. Mounted on the agitator shaft at close proximity to the tank bottom, a tickler minimizes settling of solids on the tank bottom. After the level of a draining slurry recedes below the main impeller(s), tickler efficiency for solids suspension is critical to avoid flow obstruction and pump plugging. Typical pitched blade (PBT) or flat blade (FBT) ticklers provide the necessary suspension, but often produce the equally undesirable effects of pump starvation and protracted drainage times by throwing the slurry outward (i.e. toward the wall) instead of inward (i.e. toward the centerline discharge nozzle). Subsequent removal of the solids deposited on the vessel bottom, and possibly even the wall, may require the added complexity of extraneous liquid sprays. The KT-3 tickler was designed by engineers in The Dow Chemical Co. to minimize solids deposits (i.e. heels), while also overcoming these other slurry difficulties, in vessels that drain through a centerline exit. It does so by generating a swirling motion in the unbaffled vessel bottom, which washes the vessel surface and sweeps solids towards the centerline. After successful implementation in multiple vessels within Dow manufacturing and pilot plants, the KT-3 tickler is now commercially available from Lightnin/SPX Process Equipment.