HEAT REACTIVATED, HEAT OF COMPRESSION AIR AND GAS DRYING SYSTEMS

 Why Dry Air?

A compressor takes in atmospheric air loaded with contaminants and moisture. At 75°F/23.9°C and 75% relative humidity, a 500 SCFM/850 NM³/HR air compressor takes in about 90 gallons/340.6 liters of water in vapor form during a 24-hour period. An aftercooler is able to condense about half of it. As the air flows from the compressor into the distribution lines it cools, and the vapor condenses into a liquid causing rust, scale and ultimately leaks in pipes, valves, instruments, and air-operated tools and equipment.

Moreover, when exposed to freezing temperatures the moisture in air lines will freeze and restrict air flow. A typical PIONEER dryer pays for itself in less than a year.

Standard Features...
PHE, PHEB, PHI, PHC and PHCS Series dryers

1. Solid State Diagnostic Control Panel--PHE and PHEB Series only
2. Generous Desiccant Quantities
3. Low Air Velocities
4. Longer Contact Time
5. Low Purge Rates
6. Longer Cycle Times
7. Non-lube Valves
8. ASME Vessels--75 SCFM and larger
9. Stainless Steel Supports and Screens
10. Pressure Equalization (before switch over)--prevents desiccant bumping and powdering
11. Desiccant Fill and Drain Ports
12. Control Air Filter
13. Tower Pressure Gauges
14. Dual Pressure Relief Valves
15. Purge Mufflers
16. Purge Adjustment and Purge Flow Indicator
17. NEMA 4/12 Electrical
18. Power On/Off Switch
19. Power On Indicator
20. Failure to Shift Alarm

Options

Ç(back to top)

Dewpoint Analyzer Suppplied with the filter, two isolation valves, exhaust coil, adsorber and visual moisture indicator, sensor holder and cable.

Standard Dryers Pressure Ratings

Sizes up to 2000 SCFM: 150 PSIG/10.35 BAR G

Larger sizes: 125 PSIG/8.63 BAR G

PIONEER dryers are available for pressure up to 10,000 PSIG/690 BAR G.

                           Correction Factors

Ç(back to top)

Lubricated Compressors?

We recommend Carbon Adsorber-Alert for difficult to separate lubricants. Oil aerosols and vapors fill desiccant pores and reduce drying capacity. The Carbon Adsorber-Alert filter provides secondary protection. The elements gradually change color from white to red indicating the need for element change.

Dewpoint Analyzer Model -100°F (Optional)

 Features

1. Better Sensors--Both PDM Ultra and PDM Universal use high-capacitance aluminum oxide sensor. The PDM Universal sensor is water resistant, allowing for reliable performance in wetter environments. Both sensors are protected with a prefilter and adsorber.
2. Accessories Included--Filter, two isolation valves, exhaust coil, adsorber and visual moisture indicator, sensor holder and cable.
3. Wide Range Didgital Readout
4. Automatic Calibration
5. Dual Alarms-10A, NO?NC contacts,adjustable
6. Dual outputs-- 4-20mAand 0-100mA
7. Polycarbonate NEMA4/4X Enclosure
8. Wide pressure Range
9. Compact Size
10. Natural Gas/Corrosive Gas Sensors- Optional
11. Dewpoint Analyzer and Demand Cycle combination- Optional

Ç(back to top)

Demand Cycle - Optional

To save on purge loss and heater power usage, you may control your dryer by sensing exit air dewpoint in lieu of time cycle. The demand cycle control reduces cost of regeneration in proportion to air usage and moisture content.

• Installation--Sensor is installed at a cleaner location and protected at inlet and outlet.
• Easy Calibration--Designed for convenient and inexpensive calibration at job site.
• More Reliable--Less frequent tower switching means longer component and desiccant life.
• Better Dewpoint Control--By reading the exit air dewpoint the sensor monitors the dewpoint of the outgoing air.
• Cost Savings -

  Example

Design conditions:

• 1000 SCFM at 100 PSIG and 100°F inlet.
• Purge flow 14%=140 SCFM.
• Cost of regeneration with demand cycle, based on 4.5 SCFM/HP and $.07/KWH cost: 140/4.5 x 0.746 x 24 x 0.07 = $39.00/day. If the average flow is 500 SCFM, the regeneration cost with demand cycle is equal to 70/4.5 x 0.746 x 24 x 0.07 = $19.50/day.
   

Savings = $39.00-19.50 = $19.50/day or approximately $7,000.00/year.

Ç(back to top)

External Heater Type Regenerative Dryers

PHE Series--External Heater Type

The PIONEER PHE Series has an electric heater to raise the temperature of purge air. The higher the temperature, the greater the capacity of air to absorb moisture, thus heating of the purge air reduces the volume of dry air required for regeneration. Purge air is heated by an industrial quality, low-watt density long-life electric heater. The heater is in a tube through which purge air flows in an unrestricted manner and insures uniform heat distribution. The heater element does not come in contact with the desiccant which prevents physical deterioration of the desiccant material. PHE dryers are simple in design, easy to maintain and reduce the purge air requirement in the 4-6% range. This feature makes them particularly suitable for installations where a limited compressor capacity is available. A typical -40°F PDP dryer system uses an eight-hour cycle: four hours drying, three hours/tower heating, fifty-five minutes/tower cooling and five minutes repressurization. NEMA 4 Electrical is standard. The heater, hot air lines, dryer vessel, etc. are covered with insulation for maximum efficiency. Moreover, the insulation enhances the safety of the equipment. For durability the insulation is covered with a protective aluminum jacket. PHE dryers are available in sizes up to 800 SCFM (PHE800).

 Additional Features ...

(in addition to the Standard Features )

1. Adjustable Heater Temperature Control--Internally located for safety
2. Adjustable Internal Heater Temperature Shut Down Control--Requires manual resetting for safety and internally located for safety
3. Step/Check Control--Bypasses the timing sequence and moves the setting to the next stage; provides quicker and easier cycle check
4. Heater 'On' Indicator
5. High Heater Temperature Shut Down Indicator
6. Drying time elapsed indicator- Helps troubleshooting
7. Protected Insulation

Ç(back to top)

For Lower Dewpoints...Pioneer PHEB Series--Blower Purge

Because purge air is needed at near atmospheric pressure, use of a blower for purging is ideal, especially in larger drying systems. Since compressed air is not needed for drying, the blower option allows plants with limited compressor capacity to have nominal -40°F/-40°C PDP protection. A properly sized and installed system can deliver dewpoints down to -80°F/-62°C. Use of a blower is highly recommended in drying gases like natural gas, or whenever it is not desirable to purge gas into the atmosphere for reasons of safety or cost. By using dry air for cooling the desiccant, the PIONEER design virtually eliminates dewpoint spikes.

Additional Features...

In addition to the 27 features of the PHE series Dryers

1. Highly Reliable Positive Displacement Blower
2. Belt Guard
3. Two-Step Depressurization--To minimize desiccant bumping
4. Blower Protection--Blower is protected from high pressure by a blower check valve
   and a pressure relief valve.
5. Expansion Joint--Helps eliminate vibration from blower and provides quieter operation

Built for Magic Chef, this PHEB 1200 incorporates standard aluminum jacketed insulation, standard blower arrangement and optional Best Aire Gold Filtration and by-pass Package.

PHE and PHEB Series Specifications

 NOTES:

1. *At 100°F (37.8°C), 100 PSIG (6.9 BAR G).
2. Desiccant is factory filled through phe/PHEB 800; shipped separate in larger sizes.
3. Standard voltage is 460 VAC/3 Phase/60 Hertz; nonstandard available.
4. Cycle time is 8 hours: 4 hours drying, 3 hours heating, 55 minutes cooling and 5 minutes repressurization.

PHE Series Flow Diagram

PHEB Series Flow Diagram

Ç(back to top)

PHI Series--Internal Heater Type

PHI Series dryers are similar to the PHE Series except that the heaters are installed in the heater tubes located in the drying and regenerating towers. The heaters heat both the desiccant and the purge air to make these dryers even more efficient than the PHE Series dryers. The nominal -40°F/-40°C PDP is typical although if properly sized and installed, systems can provide dewpoints down to -80°F/-62°C. 

This is a Model PHI 800 Dryer with optional 16-hour time cycle built for Elliott Company- shown without aluminium jacketed insulation which is now standard.

PHI Series Flow Diagram

  PHI Specifications

NOTES:

1. At 100°F (37.8°C), 100 PSIG (6.9 Bar G).
2. Desiccant is factory filled through PHI-800; shipped separate in larger sizes.
3. Standard voltage is 460 VAC/3 phase/60 Hertz; nonstandard available.
4. Cycle time is 8 hours: 4 hours drying, 3 hours heating, 55 minutes cooling and 5 minutes repressurization.

Ç(back to top) 

 Heat of Compression Dryers--Full Stream and Split Stream

A PHCS Split stream of Compression Dryer built for Dow Chemical -- shown without aluminium jacketed insulation which is now standard.

Full Stream (PHC Series)

The system utilizes the normally wasted heat of compression to regenerate the desiccant bed, saving valuable energy. This system operates on a one-hour time cycle: one-half hour drying and one-half hour regenerating. The important design feature is the repositioned after cooler. The hot air first goes to the regenerating tower, and then to the after cooler. The hot air coming out of a compressor (before the after cooler) is not saturated and therefore can hold much more moisture. The relative humidity of such air at 350°F/176.7°C is seldom higher than 10%. The system uses this hot and thirsty air to regenerate the desiccant bed. With an inlet temperature of 250-350°F/121.1°C-176.7°C these systems deliver approximately 0°F/-17.8°C PDP; The higher the inlet temperature, the better the regeneration and lower the dewpoint. Its major advantages are virtually no operating cost, simplicity of design and no air loss. Its major disadvantage is that the decrease in inlet temperature and flow reduces regeneration capability, which in turn raises the dewpoint. If air flow through a desiccant tower during regeneration is considerably less than the air flow through the same desiccant tower during drying, insufficient regeneration will occur; and, when the same tower dries air, the dewpoints will be higher. The problem arises because the regeneration is dependent upon the inlet air flow and temperature. The fluctuations in flow and inlet temperature cause dewpoint variation. A thermostatically controlled heater is often added to raise the inlet temperature thus reduce dewpoint fluctuation.

Split Stream (PHCS Series)

The split stream design overcomes many disadvantages of the full stream heat of compression design by incorporating a cooling cycle. The cooling cycle uses dry air to prevent dewpoint spikes at tower switch over. The split stream heat of compression dryer operates on an eight-hour time cycle: four hours drying, three hours regenerating, one hour cooling. The hot air from the compressor with low relative humidity flows into the left tower and regenerates the desiccant. The moisture loaded hot air then flows into the after cooler and the separator. The after cooler removes about 70% of the moisture. The air then flows to the right tower, where the air is dried down to approximately -40°F/-40°C PDP. At the end of the three-hour regeneration cycle, the cooling cycle begins. The three-way inlet valve switches the cooling cycle valves open, the two-way valve closes and the cooling air modulating valve controls the amount of dry cooling air. During the one-hour cooling cycle, the inlet air flows from the three-way inlet to the after cooler, the coalescing separator, and the right drying tower. At the air outlet about one-third of the cool dry air is diverted to the regenerating tower where it cools the desiccant. The cooling air re-enters the air stream after passing through the cooling air modulating valve. The split stream heat of compression design is the preferred choice when zero purge air loss, minimum energy consumption, lower and consistent pressure dewpoint are required. The cooling cycle prevents dewpoint spikes at switchover and provides more consistent and lower dewpoint.

PHC Series Full Stream Flow Diagram

PHCS Series Split Stream Flow Diagram

PHC Series Specifications

NOTES:

1. At 100°F/37.8°C, 100 PSIG/6.9 BAR G.
2. Desiccant is factory filled through PHC-800; shipped separate in larger sizes.
3. Standard voltage is 115 VAC/1 phase/60 hertz; nonstandard available.
4. Cycle time is one hour: 30 minutes drying and 30 minutes regeneration.
5. PHCS Series dimensions, desiccant weights and shipping weights are similar to that of PHEB Series dryers.

 Ç(back to top) 

Warranty

Pioneer standard products are warranted to be free from defects in material and workmanship for a period of one year from the date of shipment, provided the equipment is installed and used according to Pioneer recommended usage. Pioneer liability is limited to the repair of, refund of, purchase price paid for, or replacement in kind of, at Pioneer sole option. In no event shall Pioneer be liable or responsible for transportation, incidental, consequential damages, even if the possibility of such damages has been made known to Pioneer Air Systems, Inc. The usual maintenance and replacement-type products are not covered by this warranty. One year mechanical parts only warranty applies to equipment outside the U.S.A., Canada and Mexico.

Extended Warranties Available

Disclaimer

Information provided here is deemed current at the time of publication. PIONEER disclaims all liability for any errors resulting in loss or damage.

Ç(back to top)