What is Packed bed scrubbers and the scrubbing of SO2?
A packed bed scrubber is a wet scrubber that eliminates fumes, chemicals, soluble gases, acids, and smells. A specially created packing medium that is moistened with re-circulated liquid, allows contaminated gas to pass through it.
Through physical or chemical processes, the liquid solvent absorbs the gaseous pollution. Before the contaminated products precipitate, they are removed by blowdown, from the tank with make-up water input.
Let us understand some concepts of packed bed scrubbers and the scrubbing of sulphur dioxide.
1: The design capacities for Packed Bed Wet Scrubbers range from, 10 to 75,000 CFM per unit.
2: It has 99.99% efficiency.
3: The configurations are vertical and horizontal.
4: Cross-flow and counter-flow models.
5: Designs for construction are circular and rectangular.
Features of Wet Scrubbers
· FRP-RTP (Reinforced Thermoset Plastic) and dual laminate PVC and CPVC are among the materials used in building.
· Mild steel, stainless steel, and mild steel with FRP lining may be used as well.
· Numerous packaging materials, including rings and saddles made of different materials are used. There is also structured packaging available.
· A facility's centralized control or monitoring systems can be connected to, or used in stand-alone mode with complete instrumentation, and electrical controls.
· There are chemical treatments available to improve gaseous pollutant absorption, such as oxidation and neutralization. When necessary, pH control is offered.
· It is resistant to corrosion.
Scrubber-liquid recirculation, using corrosion-resistant circulating pumps
Spray nozzles that do not require a plug to wet packing made of a variety of corrosion-resistant materials, are used.
Caustic Sulfur Dioxide Scrubbing Flue vapours from several combustion processes frequently, contain sulphur dioxide. A high-temperature gas stream that comes out of an incinerator or thermal oxidizer may be used for same.
In a high temperature application like this, Netsol Water Solutions will typically offer a Tower before a vertical counter-flow Packed Tower Scrubber. Prior to gas adsorption in the Packed Tower Scrubber, a Venturi Scrubber may be used to catch and remove PM, if solid particle is present.
Bringing down the temperature to improve absorption
A tower may reduce the incoming stream's temperature from (800°F - 1,800°F) to (140°F - 180°F). The hot incoming gas stream is saturated with atomized water added by spray nozzles in the quench tower, which causes the temperature to drop through evaporative cooling.
This lower temperature enables the Packed Tower Scrubber to be built, with more affordable materials and improves the gaseous SO2 absorption, by the recirculating NaOH and water scrubbing liquid.
The absorbed SO2 is neutralized by NaOH, resulting in a mixture of soluble sodium salts. An extensive surface area for reaction is provided by the well-chosen packaging material. Salts, SO2 in solution, and scrubbing fluid fall into the tank, and are evacuated.
Later, the residual water droplets are then removed from the gas stream before it exits the scrubber, by passing through the moisture eliminator pad at the top of the packed tower. The removal efficiency can be increased to over 99%.
For affordable, high-quality solutions, Netsol Water offers full in-house fabrication and engineering services. Installation, start-up help, training, and field service, are all ways that we serve our clients with. Each Packed Bed Scrubber is sized and created to meet particular customer needs. To identify the ideal design parameters for each installation, we will assess fume removal applications.