Wheel Dryer simultaneously dries and regenerates desiccant.
Press Release Summary:
Capable of throughputs from 100-400 lb/hr, NovaWheel(TM) rotating wheel dryer continuously puts dry desiccant into service while regenerating saturated desiccant in same rotational cycle. Use of steel link drive chain to drive desiccant wheel minimizes dew point variation. Cylindrical wheel contains desiccant-impregnated honeycomb divided into 3 sections for moisture removal, purge, and regeneration. Rotor turns counter-clockwise, moving each segment of honeycomb through 3 stages.
Original Press Release:
New Wheel Dryer Dries and Regenerates Desiccant in One Operation while Eliminating Dew-Point Variation
NovaWheel (TM) Dryer Is Simpler, Smaller, Less Expensive than Twin-Tower Units
BALTIMORE, MD, U.S.A., September 28, 2006: A new rotating wheel dryer that continuously puts dry desiccant into service while regenerating saturated desiccant in the same rotational cycle provides resin processors with a simpler, more compact, lower-cost alternative to conventional twin-tower dryers, it was announced today by NOVATEC.
The NovaWheel (TM) dryer also exhibits less variation in dew point than other wheel dryers because models of all sizes use a steel link drive chain instead of a belt to drive the desiccant wheel, according to dryer product sales manager Mark Haynie. "Because belt drives invariably undergo distortion, slippage occurs, causing rotation speed and thus dew-point performance to vary from target settings," he said.
In conventional twin-bed dryers, the desiccant adsorbs the moisture from a stream of hot air that has passed through a hopper full of resin. The desiccant must be regenerated after each resin batch has dried, first by heating to around 400 deg. F (204 deg. C) to drive off moisture, then cooling to recover full adsorption capacity. Conventional twin-tower dryers employ two desiccant beds to limit the batch drying process to the roughly four hours required to extract moisture, one bed being regenerated while the other is used for dehumidification.
Although NOVATEC's NovaWheel dryer also carries out adsorption and regeneration simultaneously, it does so in single, continuous operation. The cylindrical wheel in the dryer contains desiccant-impregnated honeycomb that is divided into three sections (visible in the cross section of the wheel shown in the accompanying schematic). Air from the resin hopper that has been cooled and filtered goes through a blower and then is split into two streams, one passing through the moisture-removal section of the desiccant wheel, the other through the purge section, where desiccant that has already been regenerated is now cooled down. At the same time, a stream of hot air passing through the third section regenerates the desiccant in that section. The rotor turns slowly in a counter-clockwise direction, moving each segment of the honeycomb through the three stages.
"The NovaWheel dryer provides more consistent dew point performance by eliminating the spikes and deviations that typically occur with twin-tower dryers during the changeover from one bed to another," Haynie said. "The new dryer is particularly effective with heat-sensitive resins like PET and PETG because of its more efficient cooling after regeneration. And with 'difficult' materials like nylon, rotor speed is easily adjusted to prevent over-drying."
NOVATEC is introducing the smaller units during the next two business quarters, with throughputs ranging from 100 to 400 lb./hr (45 to 180 kg/hr.). Larger units will appear in 2007, with the largest size expected to have a throughput of 4,500 lb./hr. (2,045 kg/hr.). "Investment costs for the smaller NovaWheel units will be 10 to 15% less than for twin-tower dryers of similar throughput ratings," Haynie said. "Larger units will cost up to 50% less and take up only a quarter to a third of plant floor space."
NOVATEC, INC. is a leading supplier of resin drying, blending, and pneumatic conveying systems to plastics processors. The ISO 9001-certified company specializes in custom-engineered material handling systems that meet specific process and production requirements. Its range of dryers is the broadest in the industry, including desiccant, hot air, compressed air, and infrared systems, as well as the patented NovaDrier (TM) compressed air / membrane dryer and the NovaVac II (TM) vacuum dryer. NOVATEC, Inc. is headquartered at 222 East Thomas Avenue, Baltimore, MD 21225 U.S.A. Tel: 410-789-4811. Fax: 410-789-4638. Email: sales@novatec.com.
Robert J. Martino
Martino Communications Inc.
8 Main Street / P.O. Box 379
Hastings-on-Hudson, NY 10706 USA
Tel: 1-914-478-0754
Fax: 1-914-478-0959
bob@martinocommunications.com
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