Page 370 - Chemical Process Equipment - Selection and Design

. Typical Performance Data of Rotary Vacuum Filters

Vacuum Pump (9)
Approximate Feed solids Filtration rate (9)
Material particle size conc. wt % kg/(mz)(hr) rn3/(m2)(min) rnm Hg
~1.c finer
FOotation coal 3343%-200 mesh 22-26 300-600 1.5 500
Copper concentrates 90%-200 mesh 60-70 250450 0.5 500
Magnetic concentrates 80-95%-325 mesh 55-65 1000-2000 2.5-3 0 6o0450
Coal refuse 35-50°4-250 mesh 3540 100-125 0.6 500
Magnesium hydroxide 15 microns av. size 10-15 40-60 06 500
Drum fhr
(1) Sugar cane mud Limed for flocculation 7-1 8 by VOI. 25-75 0.2 500
CaC03 mud irecausticising - 3540 500-600 1 .a2 250380
(2) Corn starch 15-18 microns, av. size 3242 110-150 0.9-1 560
Sewage sludge
Primary Flocculated 5-8 15-30 0.5 500
Primary digested Flocculated 4-7 10-20 05 509
(3) Leached uranium ore 50-60%-200 mesh 50-60 150-220 05- 500
Flocculated
Kraft pulp Long fibre 1-14 220-300 Barometric ieg
(4) Kaolin clay 9&75%-2 micron 25-35 30-75 05 600
Belt drum filter
(5) Sugar cane rnud Seperan flocculated 7-18 by VOI. 90-250 02 500
Sewage slud!ge
Primary Flocculated 5-8 30-50 05 500
Primary digested Flocculated 4-7 1535 05 500
Corn gluten Self flocculating 1620 0ZiU.S. gal 15-30 06 500
Corn starch 15-18 microns, av. size 32-42 150-250 0 9-1 500
(3) Gold cyanide ieached off 65%-200 mesh 50-60 300-600 05 500
(3) Spent vegetable carbon 98%-325 mesh 100-130 gdlitres 30-50 1.5 500
Dextrose processing
Steel mill dust 2040%-2 microns 40-50 17cMOo 061 2
(3) Sodium hypcxhlorite Fine 12 150 09 500
Top feed drum
iron ore concentrates 24%-200 mesh 35 6300-7300 15 150
8 mesh top size
(6) Sodium Chloride 5-10%-100 mesh 2535 1000-1 500 30 150
Bone char 1 %-7’0 mesh a20 1200-1 700 40 90
(6) Ammonium sulphate 5-15%-35 mesh 3540% by vol 1000-1 700 4SO 75
____ --
?lltlng pan filter
(7) Gypsum frorr digested 4C50 micron av. 3540 600-900 1.2-1.5 500
phosphate rock
(5) Leached cobalt residue -200 mesh - 45-50 250 3 380
(8) Alumina-silica gel catalyst - 12 270 0.9 500
(7) Pentaerythritol 30-40 75-1 00 3.6 500
Notes: (1 ) Filtrate very dirty-must be recirculated back to clarifier-cake washed. (6) top feed filter drier.
(2) String discharge filter. (7) Two or three stages of counter-current washing.
(3) Cake washed. (8) Three stages of counter-current washing.
(4) Roller discharge drum filter. (9) Based on total filter area.
(5) Filtrate? very clean-goes directly Po evaporation-cake washed.
(Data of Envirotech Corp.).

ata of Centrifugal Filters and Sedimentation Centrifuges (Purchas, 1977)
(a) Operating Ranges of Main Types off Centrifugal Filters
Minimum Solid Minimum
Automatically Automatically Concentration Minimum Filtrability Maximum
Type of Discharged at Discharged at g-Factor in Feed [% by Possibility Particle Coefficient Retention
Centrifuge Continuous Full Speed Reduced Speed Range (5) Volume (s) Washing Size, mm (k)(m/sec) Time (Sec)
of
Oscillating X 30-1 20 40 no 0.3 5 x w4 6
Tumbler X 50-300 40 no 0.2 2 x 6
Worm Scresn X 500-3000 20 poor 0.06 I x 15
Pusher X 300-2000 30 good 0.08 5 x 10-~ 60
Peeler X X 300-1 600 5 very good 0.01 2 x IO-^ as wanted
Pendulum X 200-1 200 5 very good 0.005 7 x 10-~ as wanted
(Hultsch ancl Wilkesmann; Purchas, 1977). (continued)
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