TROPACK Desiccants

Desiccant Capsules
18. November 2018
Automotive Desiccant Bags
17. November 2018

TROPACK Desiccants

Desiccants Silica Gel, White Gel, Rubingel, Orange Gel, Molecular Sieves and Clay

TROPACK adsorbent agents have an extremely porous surface area. Like a sponge, they possess the capacity of soaking up moisture and to store it inside their internal cavities. Those are set up as layers, pores and channels. The adsorption agents themselves are water-insoluble. The stored moisture will be released to the ambient air again, once the adsorption agent is heated. There are different types of adsorption agents:


SILICA GEL

is one of the widest used desiccants against moisture with a wide range of applications. It consists of irregularly shaped and porous particles and is a form of silicic acid. The raw materials are mostly sodium silicate and sulphuric acid. Silica gel is inert, odourless, non-toxic and non-corrosive. The large inner pore surface of silica gel allows adsorption up to approx. 36 % of its own weight. It is available as white silica gel or indicator gel, such as orange gel, Envriogel or Rubingel.


MICROPOROUS WHITE SILICA GEL

is a maximum drying silica gel. The water vapour adsorption capacity of this desiccant is approx.: 15 % by weight at 20 % r h, or 25 % by weight at 40 % rh.

Grain 0.2–1 mm
– predominantly used in the insulation glass sector for dehydrating air between the glass panels. This silica gel can also be found inside desiccant cartridges and capsules. Other highly pure microscopic silica gels are used with fragrance carriers and the maintenance of pour ability of chemicals and pharmaceuticals. Further applications are in the cosmetic industry.

Grain sizes 1–2 or 2–3 mm
– used inside filters of gas masks, the insulation glass sector and for the dehydration of liquids and cooling agents.

Grain 1–3 mm
– represent a universal grain size for drying air and gas in smaller sized equipment and for the drying of cooling agents.

Grain 2–5 mm
– have an elevated adsorption capacity with excellent low pressure characteristics for the drying of gases (ethane, ethylene, butane, chlorine, natural gas, methane, methylene chloride, sulphur dioxide, nitrogen and hydrogen).


LARGE-PORE WHITE GEL

used where water may occur in an air or gas flow. Here it serves as buffer gel and is used upstream of narrow-pore gel.


RUBINGEL

is a silica gel in beaded form containing a ruby color humidity indicator. The color “ruby” indicates activity of the desiccant and the color “yellow” indicates the activity threshold point has been reached. Up to a water load of approx. 5 % by weight, it is absolutely ruby; at increasing water adsorption, the indicator turns yellow. The overall adsorption capacity of rubingel is at approx. 20 % by weight at 40 % rh. The advantage of Rubingel is the very exact visual control of the saturation of the desiccant.


ORANGE GEL

is a white silica gel with moisture indicator that is free of heavy metals and particularly environmentally compatible. Active; up to a water load of approx. 6 % by weight, it is orange; at increasing water adsorption, it turns white. The overall adsorption capacity of this silica gel is at approx. 23 % by weight at 40 % rh. Its benefit compared to the white gel is visual saturation control.


MOLECULAR SIEVES

synthetic zeolites characterized by a precisely defined and regular pore diameter possessing a crystalline structure. Regardless of the relative humidity, molecular sieves adsorb about 20-22 weight-% of water vapour. The volume of a molecular sieve is very low at the same time providing excellent adsorption capacities and regenerates at temperatures of 300 to 400 °C. Molecular sieves are available in different pore sizes. The diameter of these pore sizes is measured in ångström. Standard pore sizes of molecular sieves used by Tropack are 3Å, 4Å and 10Å


CLAY

a mineral (60–80 % montmorillonit) with strong water adsorption and swelling capability. Clay comes in colors from grey/dark grey to reddish. When active, clay can also take up to approx. 19 % by weight at 40 % rh. depending on quality. The loaded clay material can be regenerated at 150 ° C.