Airtek - Heatless Air Dryers specification. - …

1 AIRTEKH eatless Air DryersTW SeriesPREMIUM PRODUCTS FOR INDUSTRYA irtek Heatless Dryers remove water vapor from compressed air through aprocess known as Pressure Swing Adsorption. Pressure dew points ranging from-40OF to -100OF are attained by directing the flow of saturated compressed airover a bed of desiccant. The most commonly used desiccant is activated alumina,a spherical shaped, hygroscopic material, selected for its consistent size, shapeand extreme surface to mass ratio. This physically tough and chemically inertmaterial is contained in two separate but identical pressure vessels commonlyreferred to as dual or twin towers.

2 As the saturated compressed air flows upthrough the on line tower, its moisture content adheres to the surface of thedesiccant. The dry compressed air is then discharged from the chamber into thedistribution solid state controller automatically cycles the flow of compressed air betweenthe towers, while the on line tower is drying, the off line tower isregenerating. Regeneration, sometimes referred to as purging, is the process bywhich moisture accumulated during the on line cycle is stripped away duringthe off line cycle.

3 As low pressure dry purge air flows gently through theregenerating bed, it attracts the moisture that had accumulated on the surface ofthe desiccant during the drying cycle and exhausts it to the protect the desiccant bed from excess liquid, all Airtek Heatless Dryers aredesigned to work with the natural pull of gravity. By directing the saturatedair into the bottom of the on line tower and flowing up throughthe bed, liquid condensate caused by system upset, is kept awayfrom the desiccant and remains at the bottom of the tower whereit can be easily exhausted during the regeneration flow purging ensures optimum performance bykeeping the driest desiccant at the discharge end of load, velocity, cycle time and contact timedetermine tower size and the amount of desiccant.

4 Toensure design dew point, each tower is carefully sized toallow a minimum of seconds of contact. Toprevent desiccant dusting and bedfluidization, air flow velocities are kept below50 feet per minute. The dryer can cycle foryears without changing the Dryers in general are the mostreliable and least expensive of all desiccanttype Dryers . Airtek Heatless Dryers are themost energy efficient thanks to standardfeatures like, Variable Cycle Control , CycleLoc , and ProPurge . Heatless Air dryer Operation2TW600 with package E (Cutaway showing air flow)Valves3 Dryers 75 to 800 SCFM are equipped with our time-proven and dependablenon-lubricated switching valves.

5 The independent, air operated valves arespecifically designed for compressed air service. They are resistant to desiccantdust and can be maintained without being removed from the ValvesWhile other Dryers use a manual valve for purge control, Airtek provides a PurgeFlow Regulator. Due to system pressure fluctuation, Dryers equipped withmanual purge valves waste air and energy by over-purging when systempressure is high and sacrifice performance by under-purging when systempressure is low. Manual purge valves do not compensate for system pressurevariance.

6 Airtek s exclusive Purge Flow Regulator saves energy and ensuresperformance by maintaining optimum purge regardless of system pressure. Toprevent the purge flow from fluctuating and to discourage unauthorizedtampering, the Purge Flow Regulator can be locked into Flow RegulatorHigh performance, Rotary Actuated Switching Valves are standard on dryers1,000 SCFM and larger. These premium, air operated butterfly valves arespecifically designed to allow higher flow with lower associated pressure provide more opening and closing force compared to other types of indicator shows the open/closed position of the valve and service can beperformed without disturbing dryer valves are so reliable, they carry a three-year factory Actuated ValvesMaster Control4 Airtek s Sequence Annunciator is a solid state visual display panel that showsexactly what is happening in the dryer .

7 The panel lights signal which tower is on line drying, and whether the off line tower is purging, repressurizing orin CycleLoc . It will also annunciate optional equipment operation and functionalarms. The panel is integral with the NEMA 4 master Control and isconveniently mounted for easy energy savings and reduced air compressor demand are achieved bycycling the dryer with the air compressor. When the air compressor unloads orshuts off, CycleLoc automatically stops the purge and holds the dryer s cycleposition until load is resumed.

8 The CycleLoc function is activated by the aircompressor s relay or pressure switch. Contacts are provided in the dryer sNEMA 4 control panel. A panel mounted light indicates CycleLoc AnnunciatorCycleLocAdditional energy savings can be achieved by adjusting the amount of purge tothe actual moisture load. When demand is expected to be less than maximum, Airtek s Variable Cycle Control provides a means to adjust the purge cycle timeto reduce the total amount of purge used for regeneration. As a result of lessfrequent cycling, the desiccant will last longer and the switching valves willrequire less maintenance.

9 The Variable Cycle Control incorporates a short cycleposition that can be employed to provide dew points as low as Cycle ControlTo accommodate the unique requirements of centrifugal compressors, all Airtekdesiccant Dryers are now programmed with a special anti-surge control. Asequenced timing circuit eliminates potential compressor surge by preventingmomentary flow restrictions from occurring at tower switch dryer operation is managed by Airtek s NEMA 4 automatic control solid state module controls all dryer functions including the ProtectionModels TW10-TW55 Models TW75-TW200 Pro-Purge Demand ControlAirtek s Pro-Purge is standard equipment on Heatless Air Dryers 250 scfmand larger.

10 It is an advanced Proportional Demand Controller that savesenergy by automatically regulating the purge cycle in response to actualloads. Moisture loads fluctuate throughout the day and rarely reach maxi-mum moisture levels, and therefore, waste energy by regenerating moreoften than is necessary. The Pro-Purge monitors actual compressed airmoisture levels and prevents cycle advancement until the designedsaturation is OperationThe Pro-Purge Panel lights indicate:Power Saver Mode/Demand Control active ON LED.