Page 307 - Chemical Process Equipment - Selection and Design

9.10. SPRAY DRYERS 271
LE 9.15. Performance Data of Continuous Fluidized Bed Dryers
(a) Data of Fluosatatic Ltd.

Coal Sand Silica Sand Limestone Oron Ore
_________ ~~
Material size, mesh $0 -25-0 - 18-0 ”-0 -3-0
16
Method of feed twin bucket conv. conv. conv.
screw elev.
Product rate (Ib product/hr) 448,000 22,400 11 2,000 67,000 896,000
initial moisture (% w/w basis) 11 6 6 15 3
Final moisture (% w/w basis) 5.5 0.1 0.1 0.1 0.75
Residence time (rnin) 1 1.25 1.5 1.25 0.5
Dryer diameter (ft) 10 3.0 7.25 5.5 8.5
Fluid bed height (in.) 18 12 12 12 18
Air inlet temperature (“F) 1000 1200 1200 1200 1200
Air outlet 1:emperature (“F) 170 212 21 2 21 2 21 2
Air quantil:y (ft3/min std.) 40,000 2000 9000 13,000 45,000
Material exit temperature (“F) 140 220 220 220 220
Evaporatican (Ib/hr) 24,640 1430 6720 1 1,880 20.430
Method of heating coal gas oil oil oil
Heat consumption (Btu/lb water evaporated) 1830 1620 1730 1220 2300
Fan installed HP 240 20 80 115 350
(Williaims-Gardner, 1971 ).
(b) Data of Head Wrightston Stockton Ltd.
Silicious Glass
Coal Grit Sand Sand Asphalt
Method of feed screw chute chute chute chute
feeder
3.
1.
1.
Material size in. -&in. -36 mesh --in. --
16 In.
Product rate (Ib product/hr) 190,000 17,920 15,680 33,600 22,400
initial mciisture (% w/w basis) 14 5 7 5 5
Final moisture (% w/w basis) 7 0 0 0 0.5
Residence time (min) 2 If 3 3 10
Dryer diameter 7ft3in. 3ftOin. 4ft6in. 6ft6in. 8ftOin.
Fluid bedl height (in.) 21 12 12 12 24
1000 1400 1400 1400 470
Air inlet temperature (OF)
135 230 230 230 220
Air outlel: temperature (OF)
Air quantity (ft3/min std) 20,000 2000 2000 3500 7000
Material ‘exit temp (“F) 140 230 230 230 220
Evaporated rate (lb/hr) 11,200 896 1097 1680 1120
Method of heating coke- gas oil town gas oil gas oil
oven gas
gas
Heat consumption IBtu/lb water evaporated) 2000 2250 2000 2200 1800
Fan installed HP 21 0 32; 18 30 90
(Wiiliams-Gardner, 1971).
(c) Datal of Pennsalt Ltd.
Abrasive Clay Granular Household
Grit Granules Sand Desiccant Salt
Product rate (Ib/hr) 2200 1000 14,000 150 13,500
initial moisture (% w/w basis) 9 22 6 25 4
Final moisture (% w/w basis) dry 3 dry 7 0.03
Air inlet lemperature (“F) 580 160 325 300 390
Air outlet temperature (OF) 21 0 120 140 205 230
Method of heating gas steam gas gas steam
Heat consumption (Btu/lb water evaporated) 2700 3800 2700 3600 51 00
Bulk density (Ib/ft”) 120 60 90 30 60
Average drying time (rnin) 2.5 30 3 24 4
Fan capacity (ft3/min std.) 2.5 1.35 1.05 0.84 1.05
Installed fan HP 10 45 25 5 50
(Williams-Gardner, 1971).