The DPB Series process design offers the end user the opportunities to significantly reduce the energy costs associated with achieving a reliable -40°F (-40°C) pressure dew point. This is achieved by eliminating or reducing purge air requirements (compressed air utilized to regenerate desiccant beds) typical of other desiccant dryer designs.

Inlet Flow capacities have been established at an inlet pressure of 100 psig (7 kgf/cm2), and a saturated inlet temperature at 100°F (38°C). To determinemore
Unit of Measure

Specifications

Flow

 3600 scfm

Heater Rated Output

 58 kW

Blower Power

 5.4 hp

Height

 128 in

Width

 97 in

Length

 117 in

Inlet/Outlet Connection

 6" ANSI Flg

Repl. Desiccant

 2610 lb

Weight

 9833 lb

Operating Parameters

Maximum Working Pressure

 150 psig

Minimum Working Pressure

 60 psig

Inlet Air at 100°F ±2°F

 100 ±2 psig

Ambient Temperature

 80°F ±5°F

Ambient Dew Point Temperature

 70 °F

Inlet Pressure Dew Point

 100 °F

Outlet Pressure Dew Point

 -40 °F

Maximum delta P

 5 psid

Drying Time

 4 hours

Inlet Air Pressure

 60–150 psig

Inlet Air Temperature

 40–120 °F

Features 

N/A 1. Reliable and Durable Air Flow Control Components

  • High quality inlet and purge valves feature air operated butterfly valves which offer high cycle life, resilient elastomeric seats for leak free service, low profile nickel plated disks offer low pressure drop, stem bushings ensure smooth operation, and no field lubrication required.
  • Durable pneumatic actuators are isolated from the air stream and can’t be contaminated by incoming moisture. The inlet valves are double acting rack and pinion and use air power to both open and close. A spring return holds the purge valves closed prior to start-up and upon loss of pressure protects the desiccant bed from outside contamination. Dual pistons offer a large control area, high torque, and a rapid response. Position indicator shows if valve is open or closed. Valves may also be operated manually.
  • Pilot air is filtered by a 1 micron particulate filter to ensure dependable actuation. An isolation valve allows for easy filter element service. Non-lubricated pilot valves with hermetically sealed coils and ISO 5211/Namur interface are standard.
  • Check valves are soft seated for sure closures and minimal wear. Check valves are spring loaded to prevent back flow leakage when the downstream (closing) pressure is low.
  • Separate depressurization valves allow slow depressurization of the off-stream tower. Mufflers keep noise below OSHA requirements.
  • Repressurization valve allows tower to be fully repressurized before switchover which eliminates bed movement and loss of pressure downstream.

    2. Durable and Eficient Blower
  • High quality blowers
  • Intake filter protects blower and desiccant beds from contamination
  • Mounting pads and flexible air connections are used to eliminate vibration

    3. Heater Design for Long Life
  • Low watt density (23 W/in2) elements with Incoloy sheaths
  • Temperature is controlled by an adjustable, digital indicating controller with thermocouple input which minimizes temperature swings
  • Protection against overheating and element burnout provided by hi-limit provisions on controller plus an overtemperature thermocouple
  • Over current protector with manual reset is provided

    4. Insulation Reduces Heater Size
  • Fully insulated heater vessel and upper purge piping standard
  • Minimizes heat losses which reduces heater size
  • Protects plant personnel from hot surfaces
  • Durable melamine foam and fiberglass protected by jacket of polyester fabric impregnated with PVC

    5. Large Desiccant Beds Ensure Consistent Dew Points
  • 30% extra desiccant provided to compensate for natural bed aging over the expected 3 to 5 years bed life
  • 7.2 seconds of contact time for saturated air with the desiccant.
  • High grade of activated alumina has high crush strength and is resistant to abrasion

    6. Quality Tower Design
  • Cleanable, stainless steel air flow diffusers on inlet and outlet ensure even flow distribution and eliminate channeling through the bed
  • Separate fill and drain ports
  • ASME code constructed and stamped pressure vessels standard.
  • Pressure relief valves on all models
  • Finished with heat resistant enamel

    • Process Designs

    N/A
    Standard Air Drying and Filtering Process

  • Compressed air is prefiltered prior to the desiccant dryer by a 1 micron solid particle particulate filter and then by a oil removal filter [to 0.008 ppm (0.01 mg/m3)].
  • The wet, compressed air now enters the bottom of Tower 2 of the two dual towers filled with a bed of activated alumina desiccant through the inlet switching valve A. Inlet switching valve B is closed. Inlet valves A and B are butterfly valves with double acting actuators.
  • The activated alumina adsorbs the moisture in the compressed air as the air flows upward through Tower 2. Upflow drying protects the bed from water and heavy contaminants by separating them from the air stream as they enter the tower. Cleanable, stainless steel, flow diffusers on the inlet and outlet of the tower ensure even flow distribution through the bed-which avoids channeling.
  • The dry air exits the dryer through outlet check valve F. A FHT Series High Temperature afterfilter filters desiccant dust particles to 1 micron in size at the dryer outlet.

    FEATURES, BENFITS, OPTIONS

    Standard Controller
  • Tower Status
  • Service Reminder
  • Heater on
  • Heater temperature
  • Desiccant bed temperature
  • Failure to switch
  • RS 232 port
  • NEMA 4 enclosure

    Option E = Energy saving demand controller
  • Energy saving demand controller provides an integrated humidity/temperature sensor from the on-line drying tower. Sensor “over-range” and “under-range” alarms. High humidity alarm.
  • Vacuum fluorescent text, 2 line 16 characters. Highly visible in darkness or sunlight
  • English, Spanish, French languages
  • Automatic restart after power loss
  • Remote indication of alarm
  • Power on light
  • Heater on light
  • Tower status (drying, switchover, heat, cool, etc.)
  • Tower switch switchover, failure (low heater temp/high heater temp)
  • Dry Contacts (power, heater-on)
  • LED sensor over-range or under-range temp/humidity dew point
  • Service reminder
  • RS 232 port
  • NEMA4 enclosure

    Option D = dewpoint monitor with energy saving demand controller
  • Digital dew point monitoring (text display)
  • All of the features of the Energy Saving Demand Controller
  • High dew point alarm

    Option V
  • Insulate vessel shell and hot piping from heater to vessels

    Option F1
  • Mounted Grade E prefilter and FHT afterfilter with drain valve on separate skid package.

    Option F2
  • Mounted Grade E prefilter and FHT afterfilter with drain valve with block and by-pass valves on separate skid package.