Absorption columns, also called “flasks” or “chemical scrubbers”, are an industry-standard treatment for acidic gases, inorganic gases, particles and in some cases organic gases.
Absorption columns is a treatment system which works according to the principles of the transfer of material (pollutant) from a gaseous state to an absorbent liquid phase. The transition is made by contact between air and liquid in various forms.
There are several types of surveyors, which differ in several characteristics:
• Fill medium
o One type of scrubber contains a filler substrate, which increases the surface space contact between liquid and air in order to increase the rate of material passage and the efficiency of the treatment. These columns are usually large due to low flow velocities required in the cross section of the column.
o A “spray scrubber” is a type of scrubber which does not contain a filler substrate. These systems transport the material in the air by spraying the liquid. Accordingly, the flow velocities are higher and the system is smaller.
• Flow type
o Counter-flow – the most efficient flow system. The liquid is sprayed from the nozzle and flows downward from the top. The gas flows from the bottom of the column upwards, while coming into contact with the liquid and transferring the pollutant to the liquid phase.
o Cross-flow – a less efficient but common form of horizontal absorption columns. In this configuration, the air is pumped through the column while the absorption fluid is sprayed vertically.
• Absorption type
o Chemical scrubber – The efficiency of absorbing some types of pollutants can be improved by the use of different chemicals (acids, bases, etc.) which react with the pollutant or precipitate its absorption in the absorption fluid.
o If not possible, the pollutants must be highly soluble in the absorption fluid.
• Venturi scrubber – A unique absorption column, which operates according to the Venturi principle. The scrubber contains a narrow cone-shaped component which allows for extremely high flow velocities (and a high pressure drop). These high speeds, in a low cross section, coupled with sputtering, allow for high handling efficiency in very small particles.
The absorption fluid is collected at the bottom of the column and is spun in the system. Depending on the type of control required, according to the pollutants and the type of column, continuous / periodical drainage, absorption and completion water are carried out accordingly.
A.B.P. Chemical Engineering and Ventilation Ltd. designs, manufactures and maintains all types of scrubbers.
Main uses of a chemical scrubber:
• Treatment of various acids: HCl, HF, HBr etc.
• Treatment of organic substances that are soluble in water
• Treatment of odors (H2S)
• Micro particles and particles
• Relevant industries: All industries, depending on the type of pollutants.
Main characteristics of a chemical scrubber
• The units are constructed from painted steel plates, galvanized, stainless steel or plastic according to requirement and process conditions
• There are many types of scrubbers adapted to a wide variety of pollutants and industries
• This method of treatment produces sewage that must be treated or disposed of