Air Pollution Control Equipment Selection Guide, 3rd Edition

21

Special Applications

Venturi “Scrubbers” as Evaporators

21.1 Device Type

Venturi type scrubbers have been used for decades for the direct contact evaporation of water from process liquids such as pulp mill black liquor. These devices were typically used in stages wherein the black liquor was gradually increased in concentration to avoid foaming issues and to provide adequate control over the solids. The Venturi design had advantages since the gas path is essentially open and thus reduces the chance of plugging.

The design has also been applied to waste incinerators wherein a zero or near-zero liquid discharge is required. Venturi scrubbers are used since they can recirculate at a higher solids content than most spray or tray type devices. ...