What is a wet scrubber?
The basic purpose of a wet scrubber is to remove contaminates from an air or gas stream. This makes a wet scrubber an air pollution device that removes particulate matter (PM) and acid gases from waste gas streams collected at stationary point sources. The pollutants are removed through impaction (inertial), diffusion, interception and absorption of the pollutant onto droplets of liquid. This creates the basis for a four stage cleaning action. The liquid containing the pollutant is then collected for disposal, and can also be cleaned to make a fifth stage of cleaning action. In some cases, the sludge removed from the liquid can be reclaimed or recycled.
The degree of removal of P.M. required quantity and characteristics of the contaminants to be removed and the conditions of the air or gas stream will all have a bearing on scrubber type selected and materials used for any given application.
Wet scrubbers are available in numerous designs using different principles and vary widely in effectiveness, first cost, operating cost maintenance cost, space required and materials of construction.

What does it clean?
Wet Scrubbers are primarily used to clean both acid gas and PM. Particulate sizes in both coarse (10 µm aerodynamic diameter and smaller) and fine (2.5 µm aerodynamic diameter and smaller) can be processed through these single venturi machines. They work best on particulate sizes that range from 0.5 µm to 5 µm. Further cleaning can be achieved by using a wet scrubber as a pre-cleaner for a packed bed scrubber. Wet scrubbers have been used to control some incidental VOC (volatile organic compounds) but generally they are limited to control PM and high solubility gases. Efficiency ratings for wet scrubbers rely on increasing static pressure across the venturi. Therefore it takes more energy to increase the cleaning efficiency. In generalities, wet scrubbing using venturi action can reach over 99% efficiency.
When looking for a wet scrubber, decide before hand whether you are looking for a chemical (or gas) scrubber or a particulate scrubber, as there are differences in performance between the two basic types of scrubber. Wet scrubbers have the ability to handle moisture laden gas streams, corrosive gases and particulate, as well as high temperatures (within limitations) depending on the materials of construction used in the scrubber manufacturing process.

Advantages of Wet Scrubbers
Wet scrubber systems are smaller and more compact than ESP’s or Bag Houses. They have a lower capital cost with similar operation and maintenance costs. Particulate matter with the following characteristics are best handled using wet scrubbers.
• Sticky materials
• Hydroscopic materials
• Combustible, corrosive and explosive materials
• Particles that are difficult to remove in their dry form
• PM in the presence of soluble gases
• PM in waste gas streams with high moisture content

Air Flow:
• gas flow rates 0.2 to 478 standard cubic metres per second (500 to 100,000 scfm)
• Inlet gas temperatures 4 to 400 deg C (40 to 750 deg. F) ( lower temperatures can be achieved if freeze protection is used.)
• Waste gas pollutant loadings from 1 to 115 grams per standard cubic meter (0.1 to 50 grains per standard cubic foot)

Particulate Capture:
DeVansco units are designed to capture particle sizes from as small as 1/4 micron, depending on the static pressures used. This means that we can eliminate a major portion of the particulates found in smoke.
The cleaning action of these units meets or exceeds OSHA Standards and the National Fire Code.
There are no filter elements to change and the units are flooded with water providing fire suppression for most applications.
• Hazardous materials are safely collected and turned into a caked condition for easy disposal and a better condition for recycling.
• Take the green approach and let us clean your air captured directly at the source.

Minimum Water Consumption;
Wet scrubbing uses high volumes of water in proportion with the amount of particles in the air. We re-circulate the scrubbing water to reduce the fresh (make up) water demand.
• Typically, these scrubbers require 0.11% of pump flow rate as make-up water.
• Example:
40 USGPM flow rate
Air @ 50% R.H.
Makeup water requirement 21 US Gallons in 8 hours.

Lower Horsepower Demands:
• Using selected radial and backwardly inclined fans designed specifically for air handling systems with high moisture content makes these units operate efficiently in the correct power band.
• Our pump system is designed to with energy consumption in mind and uses the latest in pump and electric motor technology to keep the energy demand at the lowest possible levels.
• Our scraper conveyors are designed to run at very slow operating speeds, to make the most use of energy and still maintain the highest torque capabilities in the industry.

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