Packed Towers
Packed tower scrubbers are a highly efficient way to remove soluble contaminants from air and other gas streams. Packed towers are also used for stripping contaminants from liquid streams and for direct-contact cooling of gas streams.
Key Advantages of Packed Towers are:
- Used for high efficiency mass transfer (scrubbing and stripping) or heat transfer (gas cooling)
- All ERG designs are bespoke and matched to the detailed requirements of the application specification
- ERG uses industry-standard random packing to optimise operating efficiency with system pressure drop and equipment size
- All packages carry a performance guarantee and are designed to provide robust operation at the lowest capital and operating costs
Our extensive design and operating experience enables us to optimise the system performance.
Design Parameters
- Flowrate ranges from 100 to 100,000 m³/hr per tower, multiple towers in parallel can be used for higher flowrates
- Contaminant loadings depend on type, with typical inlet loadings ranging from 100mg/m³ up to 100,000 mg/m³
- Typical removal efficiency 99.5%, up to 99.95% as required
- Vessel diameters from 200 to 4,000mm, heights typically up to 10m, or higher if the process requires it
- Removal of any soluble gaseous contaminant
- Cooling saturated gas streams from typically 60°C to <30°C or as required
Diagram of a typical chemical scrubber
Key features
- Complete systems supplied including recirculation pump, pipework, fan, access platform, instrumentation and control system – and may be integrated further with other ERG mass/heat transfer equipment (e.g. quench, venturi, carbon filter, etc.) into a single Air Pollution Control solution
- Commonly used packing types include Snowflake/AstraPAC and 1”, 1.5” and 2” Pall rings
- Recirculated liquor flowrate selected to minimise pump flow and energy consumption at optimal scrubbing performance
- Liquor distribution across packing using sprays, trough or ladder distributors depending on application
- Droplet elimination using chevron, impaction blade or woven mesh design to suit the application – clean in place sprays available to assist with on-line maintenance
- Scrubber sump tank integrated into the packed column vessel
- Chemical dosing, water make-up and blowdown control to match specific performance requirements
- Instrumentation selection to give robust operation, high reliability and tight performance control
- System control by stand-alone MCC/C&I panel or integrated DCS, with HART or Profibus protocols available as standard
- Vessels designed as standard to PD5500 (metal) and BS EN 13121 (GRP) with UKCA or CE marking to PE(S)R or PED as appropriate. Other design codes are available as required
- Material selection to suit contaminants and reaction chemistry: common materials include uPVC, PP, cPVC, Derakane® GRP, Crystic® GRP, 304SS, 316SS
- Heat transfer using in-line heat exchangers
Examples of typical scrubbing solutions
- HCl scrubbing water/dilute HCl solution to recover HCl for reuse
- HCl scrubbing using NaOH solution to achieve extremely low discharge concentrations
- SO2 scrubbing using NaOH solution – for scrubbing solutions with lime see here
- H2S scrubbing using NaOH and NaOCl solution
- NH3 scrubbing using dilute sulphuric acid solution
- VOC scrubbing using water or mineral oils
Further information is available in the product brochure
UK office: +44 1403 290 000 Middle East office: +962 6515 9021 Email: info@ergapc.co.uk