Desiccants for Absorption air dryer
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1. Activated alumina
Activated alumina/Desiccant beads have a white, spherical, non-toxic, odorless, insoluble in water and alcohol. They are able to stand out thermal shock and abrasion with highly mechanical stability and strong absorption (impervious). The particle shape does not expand or crack after absorbing.
Activated aluminum is used in heatless dryer systems to create a continuous supply of dry air with moisture better than -70 ° C dew point. Remove acid and other types of transformer oils, lubricants and refrigerants to form degraded acids when used. Activated aluminum will remove the corrosive acid thus protecting valuable equipment: Particle size: 3-5mm, 4-6mm, 5-7mm
| Property | Unit | Bead | ||
| Diameter | Mm (Ins) | 3-5 (1/8”) | 4-6 (3/16”) | 5-7 (1/4”) |
| Static Water Adsorption | %wt | 16-18 (@60% RH 25 | ||
| Bulk Density | g/cc | 0.68-0.75 | 0.65-0.72 | 0.62-0.68 |
| Surface Area | m2/g | 300-360 | ||
| Pore Volume | cm2/g | 0.38-0.42 | ||
| Loss On Attrition | %wt | ≤ 0.4 | ||
| Crush Strength | N | ≥ 120 | ≥ 130 | ≥ 150 |
2. Molecular Sieve
is the synthetic crystallization of zeolites, in which atoms are arranged in a certain pattern. Inside, the structure has many holes linked by smaller-sized niches to form molecules. The molecule can absorb about 20% of the weight of water before the relative humidity of the surrounding air increases. These characteristics allow the molecule to maintain very low dew points (-50 ° C 10% by weight of absorbed water). The material is also capable of rapidly absorbing water vapor and maintaining high adsorption efficiency at high temperatures up to 90 ° C.
| Property | Unit | Bead | Pellet | ||
| Diameter | Mm (Ins) | 1.6-2.5 (8x12 mesh) | 3-5 (8x12 mesh) | 1/16” | 1/8” |
| Static Water Adsorption | %wt | ≥ 26 | ≥ 26 | ≥ 26 | ≥ 26 |
| Static CO2Â Adsorption | %wt | ≥ 17.5 | ≥ 17.5 | ≥ 17.5 | ≥ 17.5 |
| Bulk Density | g/cc | ≥ 0.62 | ≥ 0.62 | ≥ 0.62 | ≥ 0.62 |
| Loss On Ignition | %wt | ≤ 1.50 | ≤ 1.50 | ≤ 1.50 | ≤ 1.50 |
| Loss On Attrition | %wt | ≤ 0.10 | ≤ 0.10 | ≤ 0.20 | ≤ 0.20 |
| Crush Strength | N | ≥ 30 | ≥ 80 | ≥ 30 | ≥ 7 |
3. Some application of Desiccant beads(Activated alumina)
Activated alumina is widely used, it is an effective absorber in gases such as acetylene, methane, oxygen along with liquids such as Benzene, Freon, hydraulic oil, Kerosene, transformẻ and vegetable oils.
3.1 Catalyst application
Activated aluminum is used for a wide range of adsorbent and catalytic applications including absorption of catalysts in the production of polyethylene, in the production of hydrogen peroxide, as a selective adsorbent for Many chemicals include arsenic, fluoride, in removing sulfur from the gas stream (Claus Catalyst process)3.2 Absorbing
Used as a desiccant, it works by a process called adsorption. The water in the air actually sticks to the main alumina in the middle of the small segments, when the air passes through them. Water molecules are stuck so that air is dried out as it passes through the filt This process is reversible. If the alumina desiccant is heated to ~ 200 ° C, it will release clogged water. This process is called regeneration of desiccants.
3.3 Fluoride adsorbent
Activated alumina is also widely used to remove fluoride from drinking water. In the United States, there are extensive fluoride programs for drinking water. However, in certain areas, such as India's Jaipur area, there is enough fluoride in the water to cause fluorosis. The new aluminum filter can easily reduce fluorine concentration from 0.5 ppm to below 0.1 ppm
3.4 Vacuum system
In the vacuum system, activated aluminum is used as a charge material in the fore-line trap to prevent the oil from being generated by the vane pump from the rear spill into the system.3.5 Biological materials
Its mechanical features and non-reactivity in the biological environment allow it to be a suitable material used to cover friction surfaces in body prostheses.