ASG


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The remediation plant - installed and operated by Prague based ADI Altlastensanierungesellshaft (ASG) in the Ostrava suburbs - will treat soil from a large tract of land within the city centre, contaminated over many years by coke ovens and coal based chemical plants. Following remediation, treated soil will be returned to the inner city site to stabilise the area for future redevelopment.

To meet stringent Czech emission standards, particularly when operating in such a highly populated area, contaminated acid gases discharged from remediation at high temperature, will be passed through a two stage primary treatment process before entering the scrubbing system. Primary treatment comprises a ceramic filter for the removal of particulate, and an oxidisation plant for the abatement of harmful VOCs. Following pre-treatment, acid gases will be ducted to the ACWa AIR scrubbing system for cooling and final treatment before discharge to atmosphere.

In accordance with the operator's requirement to relocate the plant at other sites, on completion of the Ostrava project, the scrubbing system will be skid mounted and capable of being easily and speedily dismantled and reassembled by company operatives.

124,000 m³/hour of hot gases at temperatures up to 750°C enter a hastalloy saturating quench elbow, where they are cooled rapidly by water to 85°C before entering the base of the scrubbing tower. The gases pass upwards through a 3.2 m dia by 12.1 m high GRP Scrubbing tower where they are scrubbed by alkaline liquor flowing downwards from a distributor. The tower is filled with packing media designed to provide a large surface area per unit volume, which facilitates efficient transfer of acid gases to the scrubbing liquor. When absorbed within the liquor, gases react with the sodium hydroxide to allow further process gases to be more easily absorbed.

Cleaned gas, discharged from the top of the scrubber, passes through a chevron mist eliminator to reduce the carry over of water. The system is designed to remove 96% of sulphur dioxide.

After completing the process, alkaline scrubbing liquor collects in a sump at the base of the scrubber, from which it is pumped to the distributor at the top of the packings and to the sprays in the quench elbow.

The complete skid mounted plant is pre-wired to the control panel, which monitors the system and ensures safe operation and optimum efficiency of the process by preventing damage from high temperatures and controlling the composition of the liquor.

Project Details

Client: ASG, Ostrava, Czech Republic

Industry: Environmental

Application: A skid-mounted scrubbing system which will cool and clean flue gases discharged from a soil remediation process.

Technologies

Wet Scrubbing Systems
Packed Towers