A Pulse Column Extractor with Baffle Plates of Metal Sponge

Comparison with a perforated plate column

Abstract

Performance of metal sponge plates as baffles in a pulse column was examined as compared with perforated plates. Values of HETS were measured at various conditions of pulse amplitude, flow rate, flow rate ratio, and with metal sponge plates of various dimensions. The extraction system employed was MIBK-acetic acid-water.
When nickel sponge plates of porosity 91%, foam dia. 3 mm and thickness 10 mm were set at a plate spacing of 50 mm, an efficiency of HETS = 0.17-0.55 m was obtained, while the perforated plate column operated at the same conditions provided the value of HETS = 0.17-0.58 m. For these two kinds of baffles, the dependency of HETS on flow rate and its ratio were approximately the same, but the dependency on pulse amplitude was somewhat different.
An advantage of metal sponge plates is that pressure drop and energy dissipation due to the baffles are much smaller. For example, by using metal sponge plates of appropriate foam size, thickness and spacing, the pressure drop could be reduced to as little as 1/3-1/10 of that for perforated plates, with the same value of HETS = 0.22 m.