Power station boiler building – system 3
Three Macawber dense-phase pneumatic conveying systems were supplied to convey bed ash between 5t/h for the two smaller conveying systems and 56t/h for the larger system 3. Material transfer distances are between 158ft and 230ft. The ash systems use 2 x 4 cu.ft. vessels with 4” pipe lines and system 3 uses an 30 cu.ft. vessel on a 10” pipe line. All dense-phase systems are located under feed hoppers with start and stop controlled in automatic by the feed hopper and silo reception level probes to maintain empty feed hoppers and full reception silos. System 1 is used on the Economizer line with a water cooled top plate and dome filling component to withstand the high temperatures. System 2 and 3 are standard in that no additional equipment is required to handle high temperature up to 390°F material temperature. Other Ashveyor equipment supplied were switch type diverter valves, isolation high temperature knife gate valves, wear resistant bends and end diverters placed on top of the reception silos. System 3 conveyed the ash material directly in to the fluid bed of the boiler.
MATERIAL CHARACTERISTICS
Bed Ash 0.004” to 0.08”
Bulk Density 69 lb/ft³
Temperature 390°F to 660°F
Moisture Content Dry
Condition Free Flowing
SYSTEM OBJECTIVES
1. Dense phase low velocity conveying.
2. Reliable operation.
SYSTEM PERFORMANCE
Transfer Capacity 5 – 56t/h
Conveying Distance 158ft to 230ft
Reception Points 1 feed and 1 reception point per system.
IMPROVEMENTS ACHIEVED
1. Increased transfer rate.
2. Reduced compressed air requirements.
3. Spillage free conveying.
System 3