Desiccant Wheel/Rotor Dryers
This is not your father’s type of desiccant dryer. Desiccant wheel dryers are far more efficient, more compact and require less maintenance than any previous dual bed desiccant dryer.
If you are familiar with old technology dual bed/twin tower or ‘carousel’ dryers, you think of desiccant as a large volume of B-B sized round beads that are composed of about 30% clay.
Desiccant wheel dryers are entirely different in that the desiccant is pure molecular sieve desiccant that is literally grown onto a synthetic substrate, which is rolled into a round shape and encased in stainless steel.
Desiccant wheel dryers offer these advantages over dual bed and carousel dryers;
Energy Saving Improvements to desiccant Wheel Dryers
The wheel dryer design lends itself to energy saving modifications that are not practical with dual bed designs. (Read more)
How a Desiccant Wheel Dryer Works
As the desiccant wheel rotates, stationary seals divide it into 3 distinct sections: Drying, Regeneration and Cooling.
This continuous process ensures that dry desiccant is always available, therefore:
Drying Section - A process blower pulls saturated air from the hopper and through a process filter and cooling coil. Process air is forced through the drying section of the desiccant wheel where the moisture is adsorbed.The desiccated air is then heated to the required temperature for drying and circulated back through the resin hopper.
Cooling Section - The desiccant is prepared to adsorb moisture when it rotates to the drying section.
Regeneration Section - Ambient, filtered air is heated to 400° F and forced through the regeneration section removing the moisture that was adsorbed by the desiccant.
Controls – Manufacturers have different controls for their wheel dryers. Some use microprocessor controls. Some use color touch screens that are not PLC’s. These controls often use complicated “look-up” codes to identify errors or to convey other information. Others use advanced high resolution color touch screen PLC controls with clear written messages to explain errors or as reminders of maintenance operations that are due.
See the link below to discover the most advanced wheel dryer controls available.
Desiccant Wheel Dryers are available with throughput capacities from about 25 to 400 lb./hr. as portable units with casters. Larger wheel dryers with capacities from about 500 to 5,000 lb./hr. are stationery models. Sizes from about 200 to 5,000 lb./hr. are available as Central Dryers which can provide a large volume of -40 degree dry air to a number of drying hoppers, each equipped with their own heater and blower. This allows a single dryer to custom-dry different resins in different quantities at the same time.