APV Dryer Handbook - Umbc

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56 COST BENEFITS In comparison to a spray dryer, the Spin Flash dryer has a much shorter residence time and consequently is considerably smaller and requires less building space. Its ability to dry to even higher solids than a spray dryer results in operating cost savings. Table 8 (see page 57) shows a detailed size and cost comparison based on actual test drying of yellow iron oxide. It can be seen that the investment in a Spin Flash dryer plant is some 31% lower than a spray dryer for the same powder capacity and that Spin Flash operating costs are approximately 28% lower. These figures, however, do not include the capital investment in filtration equipment. CONCLUSION Despite its obvious size and cost advantages, there are many instances when a Spin Flash dryer cannot replace a spray dryer. Typically, such cases occur when UNIT SLUDGE OF VARIOUS METAL HYDROXIDES DOLOMITE YELLOW IRON OXIDE ALUMINA ALUMINUM SILICATE INLET AIR TEMPERATURE °F 482 590 617 482 842 536 968 932 410 437 212 914 662 1112 1292 °C 250 310 325 250 450 280 520 500 210 225 100 OUTLET AIR TEMPERATURE °F 185 293 212 194 212 194 338 257 203 203 126 320 311 275 257 °C 85 145 100 90 100 90 170 125 95 95 52 TEMPERATURE OF THE FEED °F 60 60 55 65 60 55 32 55 50 70 70 55 70 60 60 °C 15 15 13 13 15 13 0 13 10 21 21 TOTAL SOLIDS IN FEED % 70 34 35 29 20 58 67 62 50 28 43 35 33 78 65 RESIDUAL MOISTURE % 4.5 0.4 0.6 12.5 5.5 0.3 0 1.0 5.0 9 0.32 2.7 3 0.1 0.5 MEAN PARTICLE SIZE µm 40 15 5 70 20 50 5 15 10 10 16 20 15 5 3 BULK DENSITY gr/cm 3 0.8 0.45 0.3 0.4 0.2 0.45 0.8 0.9 0.7 0.3 0.14 0.76 0.32 1.6 0.6 CALCIUM CARBONATE WITH BINDER CALCIUM CARBONATE (PURE) FERRITE TARTRAZINE (AZO DYE) FOOD YELLOW (C.I. 15985) CALCIUM STEARATE POLYVANADATE NICKEL CATALYST ON DIATOMACEOUS EARTH BARIUMSULPHATE Table 7. Selection of typical Spin Flash dried products and their main operating parameters TITANIUM DIOXIDE
a free flowing spherical particle of a particular size range is required or when agglomeration is needed. There are, however, many situations both in the food and chemical industries where the particular capabilities of the Spin Flash dryer to produce powders from paste warrant careful consideration of its use. SIZE AND COST COMPARISON: spray dryer vs. Spin Flash dryer SPACE REQUIREMENTS SPRAY DRYER SPIN FLASH CSD 70/71 SFD 59 Heater type (gas) direct fired direct fire Chamber diameter 14 ft 4.25 m 2.625 ft 0.8 m Building floor area 650 ft 2 60 m 2 325 ft 2 30 m 2 Building height 46 ft 14 m 16.5 ft 5 m Building volume 24,700 ft 3 700 m 3 5,300 ft 3 50 m 3 CAPACITY Powder 880 lb/h 400 kg/h 880 lb/h 400 kg/h PERFORMANCE DATA Feed solids (%) 30 45 Feed rate 2,995 lb/h 1362 kg/h 1,951 lb/h 887 kg/h Water evaporation 2,115 lb/h 961 kg/h 1,071 lb /h 486 kg/h Powder moisture (%) 0.4 0.4 Gas consumption 4,416 SCF/h 125 sm 3 /h 2,192 SCF/h 62 sm 3 /h 1000 BTU/SCF 8,900 Kcals/m 3 Power consumption (kWh) 40 30 INVESTMENT COSTS – Approx U.S. $ Building 175,000 50,000 <strong>Dryer</strong> equipment 600,000 510,000 Baghouse 55,000 40,000 Installation 150,000 80,000 ASSUMPTIONS $980,000 $680,000 Gas cost ($/M BTU) $ 4.50 Electricity cost ($/kWh) $ 0.07 Salaries per hour Manpower required = 1/2 operator $30.00 VARIABLE OPERATING COSTS/HOUR Wages $15.00 $15.00 Gas 19.87 9.86 Electricity 2.80 2.10 TOTAL $37.67 $26.96 Cost per lb of powder $0.043 $0.031 Table 8. Size and cost comparison 57
Page 1:
Improving Process Profitability...C
Page 5: I N T R O D U C T I O N The drying
Page 8 and 9: 8 POWDER TYPE D R Y E R S Fine Free
Page 10 and 11: 10 Direct heating is used extensive
Page 12 and 13: 12 corresponding number of conventi
Page 14 and 15: 14 Two particular types are the dou
Page 16 and 17: 16 particular application and the m
Page 18 and 19: 18 whether there is any need to re-
Page 20 and 21: 20 material comes into contact with
Page 22 and 23: 22 together since both share simila
Page 24 and 25: 24 circulation. Alternatively, and
Page 26 and 27: 26 Each of the types available are
Page 28 and 29: 28 At this time Pulse Drying techno
Page 30 and 31: 30 E F F I C I E N T E N E R G Y U
Page 32 and 33: 32 DRYER FEED MOISTURE CONTENT (% W
Page 34 and 35: 34 DRYING COLUMN SCREW FEEDER PARAM
Page 36 and 37: 36 way a dryer can be turned down i
Page 38 and 39: 38 3. The wetted particles sink int
Page 40 and 41: 40 TEMPERATURE (°C) 150 100 50 0 4
Page 42 and 43: 42 flow patterns, residence time di
Page 44 and 45: 44 As indicated by this partial lis
Page 46 and 47: 46 FEED HP PUMP COMPRESSED AIR AGGL
Page 48 and 49: 48 S P I N F L A S H D R Y E R S fo
Page 50 and 51: 50 PROCESS DESCRIPTION The Spin Fla
Page 52 and 53: 52 Figure 24 illustrates the very r
Page 54 and 55: 54 The drying chamber would be main
Page 58 and 59: 58 S P R A Y D R Y E R S SPRAY DRYE
Page 60 and 61: 60 inwards towards the centerline o
Page 62 and 63: 62 a high speed by a spinning disc.
Page 64 and 65: 64 internal bowl diameter, radial d
Page 66 and 67: 66 variations, some plants utilize
Page 68 and 69: 68 Condensation deposits can freque
Page 70 and 71: 70 HIGH FAT PRODUCTS If the powder
Page 72 and 73: 72 INLET TEMPERATURE The powder coo
Page 74 and 75: 74 POWDER DENSITY The density of sp
Page 76 and 77: 76 chamber wall, tending to scour a
Page 80: Local Office APV Separations Produc
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APV Dryer Handbook - Umbc

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