Balslton Sample Filter Cartridge and Housing Selection
Disposable Adsorption Units (DAUs) contain a bed of adsorbent granules. Utilizing a wide choice of adsorbents, the DAUs selectively remove vapors from air and other gases.Because the adsorbed vapor remains trapped in the solid bed, the DAU has a fixed upper limit of total weight of vapor which can be captured. It is usually not feasible to regenerate the filter when it has reached its adsorption limit. DAUs should be used only when small quantities of vapor are to be removed.
Considerations in Using Adsorbent Cartridges The following factors should be considered when selecting a DAU:
1. Solid adsorbents are effective only for vapors. Since liquids will damage or inactivate most solid adsorbents, the DAU must be preceded by an efficient coalescing filter.
2. In contrast with Microfibre Filters, which operate at their initial efficiency throughout their life, adsorbent cartridges have a limited holding capacity. When the adsorption capacity is reached, no further adsorption occurs. The limiting capacity, or “breakthrough” point, is not sharply defined, and the exit vapor concentration will increase rapidly as saturation is approached. To avoid unwanted vapor contaminants downstream,it is necessary to change the adsorbent cartridge well before it has reached its ultimate adsorption capacity.
3. Adsorption is reversible, if operating conditions change, a vapor may desorb rather than adsorb. For example, if a temporary surge in vapor impurity concentration causes a relatively high concentration to be adsorbed on the solid, a subsequent decrease in inlet vapor composition will result in desorption of vapor from the solid to the gas stream.
4. The efficiency of a given adsorbent for a given vapor depends upon the specific operating conditions. Therefore, again in contrast to filtration, it is not possible to assign a single efficiency rating to an adsorbent. While it is not possible to predict or guarantee an adsorption efficiency for any specific set of conditions, it is possible to enhance the conditions beneficial to adsorption and avoid conditions which interfere with adsorption. Conditions which aid adsorption are: low temperature, high pressure, low flow rate, and absence of competing vapors (particularly water vapor).
|000||Compressor oil vapors, C5and heavier hydrocarbons,aromatics, oxygenatedhydrocarbons, chlorinatedorganics, freons, carbondisulfide.|
| Silica Gel
||101||Recommended only forwater vapor.|
|Molecular SieveType 13X
||103||Most C4 and lighterhydrocarbons, ethylene,propylene, acetylene,ethylene oxide, ammonia,mercaptans, sulfur hexafluoride,triethylamine, andsmaller amines.|
|Mixed Sodium &CalciumHydroxides
||107||All acidic gases, includingsulfur trioxide, sulfurdioxide, nitrogen dioxide,carbon dioxide, hydrogensulfide, hydrogen chloride,phosphorus trichloride,boron trifluoride.|
1. Please refer to Ordering Information for complete explanation of nomenclature.
2. In DAU 9933-05-107 and DAU 9933-11-107, color indicator turns violet when adsorbent is spent.
3. In DAU 9933-05-101 and 9933-11-101, adsorbent turns pink when vapor capacity is reached.
4. Maximum operating temperature is 180°F (82°C).