Vacuum-Pressure Transfer System
For certain applications, UCC recommends a “combination” pressure / vacuum transfer systems. 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 transfer 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.
Transfer System Performance Specs
Possible Combination NUVEYOR Vacuum transfer 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
- 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 transfer systems are not effective
- 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)
