Activated Carbon Discarb Filter Applications

An Activated Carbon Discarb Filter with its activated carbon filtration is ideal for removing unpleasant or even dangerous odours and gases from a wide variety of sources. Also with the ever increasing awareness of this problem from public health authorities and environmentalists has resulted in an increase in the use of the unique properties of activated carbon filtration.

Carbon will adsorb chemical molecules in the air stream in varying degrees according to the type of contaminant and the period of time the air remains resident in the carbon. Activated Carbon in it’s loose granular form can present problems as there is a tendency for granules to abrade one another, this causes both settlement of the carbon – creating potential bypass voids and produces carbon dust that can be re-entrained into the air-stream. Furthermore the unique bonding method eradicates these problems by producing a solid and stable biscuit of consistent quality and dimensional stability that produces an even resistance. Once formed the biscuits are bonded in a rigid mitred ‘U’ channel Frame or discarb matrix.

Due to the complex nature of adsorption carbon filters are generally designed to suit the application, however, the following information is given as an indication of the physical requirements for it’s use.

Activated Carbon Discarb Filter Construction

Operational Criteria for Activated Carbon

As far as possible water vapour should be eradicated from the air-stream to eliminate condensation within the filter that could cause porous blockage causing a dramatic increase in resistance – this also applies to loose carbon, however humidity levels as high as 80% RH are normally acceptable providing no interstitial condensation takes place.

To ensure proper operation of the filter, avoid air-stream temperatures exceeding 40°C. If you anticipate temperatures above the recommended level, take steps to reduce the temperature using a fresh air bleed, cooling coil, or heat exchanger. For catering and food preparation applications, remove smoke and grease from the air-stream before it enters the carbon filter.

Dwell Times for Optimal Use

To ensure satisfactory operation of a carbon filter, you need to meet certain criteria that do not apply to particulate filters. The most important aspect is the “dwell time” (the period of time the air is in contact with the carbon). Also the minimum dwell time used is 0.1 seconds and this is shown below as maximum permissible airflow. Then the dwell time may increase considerably according to the contaminant to be removed.

Technical Information and Performance

Because adsorption is a complex process, designers generally tailor carbon filters to the application. However, the following information provides an indication of the physical requirements for using them.