Gas scrubbers

VSS-Umwelttechnik offers suitable gas scrubber for almost all tasks of waste gas cleaning. The range extends from the individual gas scrubber to combinations which are individually adapted to local conditions and existing gas compositions.

Our standard gas scrubber also wet scrubber function in accordance with the absorption principle. The program boasts reliable models of proven quality which may be combined in the form of a modular system, depending on the requirements.

Gas scrubber standard program

• Vertically designed spray scrubber (type NKV)
• Horizontally designed spray scrubber (type NKH)
• Vertically designed packed-bed columns (type KFVG)
• Horizontally designed packed-bed columns (type KFHG)
• Venturi scrubber (type RSV-BR)
• Small-scale gas scrubber (type KGV)
• Process small-scale gas scrubber (type PURGAVI)

Materials employed

• Polypropylene (PP)
• Polyethylene (PE)
• Polyvinyl chloride (PVC)
• Polyvinylidene chloride (PVDF)
• GRP
• PFA
• V2A or V4A stainless steel, Hastelloy and others
• PEMS (porcelain enamel metal substrate)
• Steel with plastic lining

Physical or chemical absorption

For an effective cleansing, the solubility in water of the substance to be absorbed is decisive. A distinction should be drawn between physical and chemical absorption. In the case of physical absorption, pure water is used for scrubbing. As regards chemical absorption, purging the exhaust air of contaminants is chemically effected. Depending on the type of waste gas, either acidic or alkaline scrubbing liquids are applied and, where required, oxidising or reducing agents added. The chemicals which are added to the scrubbing liquid react with the contaminants in the air. Neutral salts are formed and the transport of the contaminants back to the gaseous phase is prevented.

When washing out hydrogen sulphide with caustic soda solution, for example, sodium sulphide and sodium hydrogen sulphide are formed, amongst other chemicals, which may again release hydrogen sulphide into the gaseous phase. In order to prevent the latter, an oxidising agent (e.g. hydrogen peroxide) is added to the scrubbing liquid.

Scrubber types

Amongst other matters, the efficiency of a gas scrubber depends on the extent of the interfacial area between exhaust air and scrubbing liquid. In order to obtain the largest surface area possible, there are different methods by means of which small scrubbing liquid drops are formed. The latter enlarge the surface area significantly.

Packed-bed scrubber KFVG and KFHG types

In a packed-bed scrubber of the KFVG type, the scrubbing liquid trickles down the column from the top. Simultaneously, air is led through from the bottom up (counter-current scrubber). As regards the KFHG model, the exhaust air is conducted horizontally through a packed-bed column (cross-current scrubber). A packed bed ensures optimum exchange of materials. The packings tear the trickling liquid into evenly formed droplets, so that the surface of the liquid is significantly extended. Optimum mass transport from the gaseous into the liquid phase is thus guaranteed.

Spray scrubber NKV and NKH types

In our spray scrubbers of the NKV and NKH types, the air is conducted vertically or horizontally through the absorption zone. The scrubbing liquid is injected in a co-current and counter-current flow to the direction of the gas and produces a very large absorption surface or interfacial area. The large surface area is obtained through the spray pattern of the nozzles, several spray manifolds, positioned one behind the other, enhance the contact time between the gas – liquid phase.

KFVG 1000 standard gas scrubber

Gas scrubber type KFVG

Gas scrubber type NKH