Vacuum-Pressure Transfer System

For certain applications, UCC recommends a “combination” vacuum / pressure transfer system. These systems combine the simplicity and lower headroom requirements of a vacuum system under the hoppers with the high capacity and long distance conveying capability of a positive pressure system.

In a combination system, a short vacuum system conveys ash from the hoppers to a transfer bin. A longer pressure system conveys ash from the transfer bin to a remote storage bin for disposal.

Possible Combination NUVEYOR Vacuum System and NUVA FEEDER Pressure System:

NUVEYOR Vacuum System:

  • Ability to stop and restart due to low ash-to-air ratios
  • Low headroom requirements below the fly ash collection hoppers
  • Capable of handling a wide range of ash types
  • Full load/no load control allow system to achieve rated capacity more efficiently
  • Wear sections follow each change in pipeline direction
  • Low maintenance at precipitator and economizer areas
  • Single pneumatic valve under each hopper
  • Single air intake per row
  • One I/O per hopper valve
  • No plugging
  • Proven temperature tolerant design for large particle economizer ash

Performance Specs:

Max Distance: 1,500 ft (4,500 m)
Maximum Capacity: 80 TPH
Mass Ratio ash : air: 5-22
Air Velocity: 3,000 – 5,200 ft/min (16-27 m/sec)
Maximum Conveyor Line Pressure: 20 in Hg (530 mm Hg)
Maximum Prime Over Pressure: 22 in Hg (560 mm Hg)


NUVA FEEDER Dilute Phase Pressure System:

  • Dilute to medium phase conveying
  • Long distance conveying without the need for a transfer vessel
  • Capable of high capacity conveying
  • Control system keeps the conveying line filled for longer periods, resulting in high conveying efficiency and lower operating costs
  • Low sensitivity to ash characteristics; capable of conveying larger and more dense particles
  • Proven ability to handle economizer ash
  • Ability to stop and restart system operation without plugging due to moderate ash-to-air ratios
  • Full load control prevents line plugging
  • The use of a bin vent filter reduces maintenance on silo roof
  • Highly stable condition with no pressure surges
  • Ideal for high altitude applications where vacuum systems are not effective

Performance Specs:

Max Distance: 8,000 ft (2,400 m)
Maximum Capacity: 175 TPH
Mass Ratio ash : air: 5-22
Air Velocity: 2,400 – 4,800 ft/min (12-25 m/sec)
Maximum Conveyor Line Pressure: 40 psi (275 kPa)
Maximum Prime Over Pressure: 45 psi (300 kPa)
  1. Why would a vacuum/pressure transfer system be used over either a vacuum or pressure system?[+]
    A vacuum/pressure transfer system would be recommended where there is a need for long conveying distance and high capacity is needed along with keeping headroom low.
Pipe Landing2Pipes and Fittings
- Nuvaloy, Dur-rok, Ceramic, Expansion Joints, Connections
Gates and Valves Landing2Gates/Valves
– Fly Ash Diffusers, Fly Ash Intakes, Swing Disc, 40D, Butterfly, TERS, Hopper & Bin Isolation Gates, Sheardisk, Vent and pressurizing valves
Tanks and Vessels Landing2Tanks/Vessels
– Silo level probes, storage bins
Separating Equipment LandingSeparating Equipment
– Bags, Cages