Abstract: An improved countercurrent solid-liquid contacting apparatus, and more particularly an improved counter-current crystallizer column is disclosed. The present invention embraces the discover that column efficiency and product purity can be substantially enhanced by reducing axial liquid back-mixing by using stationary solid beds and transport means at spaced intervals along the column length.

Abstract: An incrustation resistive crystallizer apparatus is disclosed. The crystallizer housing has conduit means for ingress of solution to be crystallized, separate conduit means for ingress and egress of cooling fluid, means for recovery of mother liquor and product crystals either together or separately. A plurality of essentially horizontal perforated plates substantially conforming to the interior shape of the housing are vertically spaced along the housing length. A support member capable of translational movement along the housing length holds the plates in the above-described position. A plurality of mobile bodies are disposed on the upper surface of the plates. A heat transfer conduit disposed substantially parallel to the coaxial support member penetrates through apertures in the horizontal plates. A compound excitation device adapted to produce two waveforms is attached to the support member. The first waveform causes translational plate movement for scraping the surface of the heat transfer conduit.