Wet Scrubbers - Venturi VW Series

Because of its open design, high concentrations of scrubbing liquid can be used, eliminating wet/dry zoning and allowing the effective handling of high solid inlet loadings.

The unit operates as follows. Contaminated gas is accelerated in the converging section before entering the throat. Scrubbing liquid is fed into the inlet section tangentially through a number of pipes and ensures that the whole surface area of the section is flooded. The dust laden gas immediately hits the film of scrubbing liquid, where some separation takes place. As the gas and scrubbing liquid enter the venturi throat, they are intimately mixed. This ensures that the highest possible volume of water is taken up by the gas, which becomes saturated in this area.

Due to the sudden increase of gas speed at the narrowest cross section of the throat, the scrubbing water is atomised into tiny droplets. The high relative speed between the gas/dust mixture and the droplets cause the dust particles to strike the droplets at high speed and become entrained by them. Te droplets carry on through the throat, where they coalesce into bigger droplets, which are removed from the gas stream in the flooded elbow of
the venturi, where the cleaned gas makes a sharp turn into the entrainment separator.

The purpose of the entrainment separator is to remove any water droplets retained in the cleaned gas. Entrainment separation can include cyclonic, chevron, varied demistors or packed sections when more cooling or absorption is required. A deflector plate at the bottom of the separator ensures that droplets are not reentrained.

The collected dust along with the water is discharged from the bottom of the cone on the separator vessel while the cleaned gas leaves from the top either horizontally or vertically, depending on site requirements.

For applications with variable exhaust volumes the VVW model is used. This unit incorporates a device capable of altering the size of the venturi throat. This device can be operated either manually or automatically, enabling the scrubber to operate at constant pressure loss and, therefore, at constant efficiency, regardless of the gas volume being handled.

The venturi scrubber is recognised by industry as the most efficient gas scrubber for the collection of dust and submicron fumes. Venturis can be designed to meet the most stringent codes-present or future- and never become obsolete. Efficiencies exceeding 99.9% can be achieved, giving emission levels lower than 50mg/nm3.

Because of their simple construction and small number of moving parts, normal maintenance can easily and speedily be carried out.

Typical Applications of Wet Scrubbers - Venturi VW Series

• KILNS
• ROTARY DRYERS
• FLUIDISED BEDS
• FLASH & MULTIPLE HEARTH ROASTERS
• RECOVERY BOILERS
• SPRAY DRYERS