Why is the quality of the desiccant in my adsorption dryer important?
July 8, 2022
Adsorption dryers can only be energy efficient if they contain premium desiccant material. The desiccant used in Pneumatech adsorption dryers is carefully selected from a wide range of European and North-American suppliers, based on following key selection criteria:
Crushing strength
Desiccant is subject to continuous cyclic load. Due to this load, low-quality desiccant will easily break up resulting in small dust particles, hereby quickly losing its water attraction capabilities, blocking valves or clogging the downstream dust filter and silencer.
Water resistance
Standard desiccant will degrade when it comes in contact with liquid water. Although a water separator should be installed upstream of an adsorption dryer, some water carry-over to the lower part of the adsorption dryer can never be excluded. All Pneumatech adsorption dryers are therefore equipped with water-resistant desiccant material in the bottom part of the vessel.
Lowest total cost of ownership
We carefully balance initial capital investment with ongoing running cost. Silica gel has the highest adsorption capacity and is therefore used in heat regenerated adsorption dryers (PE & PB). In the dynamic operation conditions of heatless adsorption dryers (PH) only a small percentage of the total static adsorption capacity is used because of the relatively short cycle times. The use of silica gel in the case of -40°C/-40°F PDP applications would increase the initial investment significantly, but would not bring any purge loss reduction or other benefits. Heatless adsorption dryers are therefore filled with activated alumina3 which provide equal dew point requirements (-40°C/-40°F PDP) and energy efficiency at lower investment costs.
³Exception is the PH2-45 which makes use of molecular sieves. 4NWR: non water resistant 5WR: water resistant
