Packed Tower Gas Scrubbers

Specialist Gas Scrubbers

PACKED TOWER GAS SCRUBBERS

Environmental pollution by airborne vapours, gases, fumes, odours and particles is becoming increasingly unacceptable and new government legislation and guidelines are forcing companies to review how and what contaminants they release to atmosphere.

Thor UK offer many different solutions to the problems associated with gas and vapour discharge. The most conventional and still hugely popular method is packed tower scrubbing…

DESCRIPTION

A packed tower scrubber removes soluble and noxious gases, and mists with droplet sizes greater than 5 µm, from gas streams. Contaminant gases, such as hydrochloric acid, sulphur dioxide and ammonia vapour, are made to flow through a bed packed with media. The media can be plastic, ceramic or stainless steel rings or saddles, designed to provide a high surface area yet allow a high throughput. A scrubbing liquor is pumped through the bed, intimately mixes with the gas stream and dissolves the contaminant gases. Mist droplets impinge on the wetted surfaces of the packing or are captured on in-built mist elimination mesh or plates.

Packed tower scrubbers are not designed to remove particulate material - they tend to become blocked. However, some particulate materials are soluble in scrubbing liquor, and these can be separated effectively.

The scrubbing liquor is usually passed counter current to the gas stream, but it can flow co-current or crosscurrent. Counter current flows can achieve the highest efficiency of mass transfer but co-current can be more effective if blockages are likely to be a problem. After passing through the packed tower, it may be possible to regenerate the liquor for recycling and reuse. Otherwise, the liquid discharge may have to be treated before disposal.

There are many variations on the packed tower design. For example, in bio scrubbers, micro organisms are cultivated on the surface of the packing to treat gaseous pollutants of organic origin. Although most packed tower scrubbers are tall vertical structures, they can be horizontal for low-profile requirements.

APPLICATIONS

Packed tower scrubbers are used in sewage treatment facilities, metal finishing operations and the paper and chemical industries for the efficient removal of acid gases, odours and mists. Different scrubbing liquors are employed to dissolve, neutralise or oxidise contaminant gases. Water, hydrogen peroxide, caustic soda and ozone gas can all be used to treat particular pollutants. Sulphur dioxide, for example, can be removed with more than 99 % efficiency.

Please enquire with the sales office for more information...