2-7 What is Desiccant?
Desiccant is a material which attracts and holds (absorbs) water from the air. Our dehumidifying dryers use a synthetic crystalline metal aluminosilicate desiccant blended with a clay binder and formed beads.
Absorbed water is driven from saturated desiccant by heating it to a high temperature (reducing desiccant capacity to hold water) and forcing air through it. This moisture removal process is called regeneration.
2-8 The Process/Regeneration Cycle
Our dehumidifying dryers have two desiccant beds. While one bed is
When a desiccant bed is
During regeneration, the dryer heats air to over 500°F (260ºC) and forces it through the desiccant bed. Moisture driven off the bed bleeds to the atmosphere.
If you measure the temperature of the air bled to the atmosphere (bleed temperature), you should observe a rise after a period of time. This condition, bed breakthrough, indicates that the bed is dry. At bed breakthrough, the bleed air temperature peaks between 350°F (176ºC) and 400°F (204ºC).
The Dew Point meter measures the dew point of the process air. A properly regenerated bed produces process air dew point of
2-9 Specifying a Drying/Conveying System
Many variables were considered in the selection of your drying system, including type of materials, residence time, throughput of the extruder or injection molding machine, ambient air moisture and temperature, and the altitude at the processing site. If your operating environment changes, the manufacturer can advise you on necessary equipment and process time and temperature modifications required for your system.
Cabinet Series Dehumidifying Dryer | 13 |
