Continuous Pressure&

Steam Pressure Filtration

Hi-Bar Filtration

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009

e

0

1

2

3

4

5

0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1

Sättigung S

Dru

ck p

[bar

]

mec

han.

Ent

feuc

htun

gsgr

enze

kapillarer Eintrittsdruck

Sr S3 bar SVakuum

Druckfiltration

t2: demoisturing time

30 s

pke

t2 = ∞ t2=0

Vakuumfiltration

120 s 60 s

25.06.2007

1

-1-

What are the advantages ?

Pressure Filtration

higher throughput rates

mS ~ ∆p, n

separating of fine particles

reduced moisture contents

(overcoming of the capillary forces)

S = f [ (∆p – pke), t2, ...]

improved filter cake washing

0

1

2

3

4

5

6

0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1

Saturation S

Cap

illary

Pre

ssur

e p C

[bar

]

t2: demoisturing time

t2=120s

t2=60st2=30s

pce

t2=∞

t2=0pressure filtration

capillary entry pressurevacuum filtration

mec

hani

cal d

emoi

stur

ing

limit

-2-

Theory of Filter Cake Formation

machineparameters

processparameters

productparameters

( ) 600,3A36060

npr

21AmM F01

cLsFss

.⋅⋅

α⋅⋅∆⋅κ⋅

η⋅ε−ρ=⋅= &

ms [kg/m²s] specific solids throughputηL [kg/ms] filtrate viscosityκ [-] solids concentration coefficientrC [1/m] cake resistanceε [-] porositiy

productparameters

n [1/min] filter speed∆p [N/m²] pressure difference in form zone

processparameters

α1 [°] cake forming angleΑ [m²] filter area

machineparameters

-3-

continuous filtration process with drum or disc filters

high filtration pressure difference of up to ∆p = 6 bar

cake discharge by air-blow-back

reliable sluice technology for sluicing the cake out of the vessel

Standard version of Hi-Bar Filtration:compressed air is used for filtration

Hi-Bar Steam Pressure Filtration:superheated steam is used for cake dewatering and cake washing

Hi-Bar Filtration Processes

Features of Both Versions

-4-

Hi-Bar Filtration Plant Design

With horizontal pressure vessel(large units) for:

filtering, washing and dewateringof bulk materials withhigh throughput rates

With vertical pressure vessel(small units) for :

sophisticated separation tasks likewashing and drying of valuable productsin the chemical industry, pharmaceuticalindustry, food industry, etc.

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Benefits of Hi-Bar® Filtration

Benefits of Hi-Bar Filtration

-6-

Hi-Bar Drum and Disc Filterin Horizontal Pressure Vessel

Hi-Bar Drum Filter Hi-Bar Disc Filter

-7-

Hi-Bar Filter in Horizontal Pressure Vessel Technical Data

Sizing of Drum Filters

56 - 1686 - 84[m²]Filtration Area

3.22.2[m]Disc Diameter

SXS[-]Filter Type

Sizing of Disc Filters

6.8 - 20

1.8

M

40 - 8116 - 40[m²]Filtration Area

3.22.4[m]Drum Diameter

XLL[-]Filter Type

-8-

Hi-Bar Steam Pressure Filtration Model of the "Condensate Front"

continuous moving of an even condensate fronthomogeneous heating of the whole filter cakeemptying of nearly all poresviscosity reduction of the residual liquidexcellent washing out (extraction)

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Hi-Bar Steam Pressure FiltrationProcess and Plant Principle

cake

filtrate, condensate

and air

compressedair

sluice

suspensionfeed

wash water

steam(Psteam)

∆pFiltration

=P1 – PATM ≤ 6 bar

Psteam = P1

P1 = pressure inside vesselP2 = pressure at cake discharge

P2 > P1

-10-

Hi-Bar Steam Pressure Disc Filter in a Horizontal Pressure Vessel

steam cabin

-11-

Filter area 6–24 m²

Oyster Disc Filter

Filter area 0.4–8.8 m²

Oyster Drum Filter

BOKELA Hi-Bar Oyster FilterDisc and Drum Filter

Filter

Pressure Vessel

Sluice

Main Parts steam

cabin

-12-

Hi-Bar Oyster Filter Plant

Oyster Drum Filter with steam cabin& exchangeable filter cells

filter area: 3.6 m²

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Oyster FilterExcellent Accessibility - Easy Maintenance

excellent accessibility for maintenance work by completely hinged pressure vessel

• no release of vessel inspection required

smooth design of all components

avoiding of unnecessary clearance volume

no unnecessary seals

CIP-equipment

-14-

Oyster Drum Filter with Exchangeable Filter Cells

• leading and tailing filtrate pipes• excellent cell emptying by filtrate

discharge at the leading and tailing edge of the cell

filtrate pipes

exchangeable cells

• optimal filtrate separation • no filtrate entrainment

Oyster Filter with steam cabin

-15-

Oyster FilterSluice System

Sluice with proven and well established swing valvesSingle or tandem sluice (depending on filter size)Avoiding of product sticking by heatingCIP

swing valve (solids sealing)

Upper swing valve (pressure sealing)

Lower swing valve

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BOKELA Hi-Bar Oyster FilterSizing

* No single cell design

4

3

2

1

discs

3.5 x 3.5 m8.8 m²1.9 mM9*

2.8 x 2.8 m5.0 m²1.4 mS5

2.2 x 2.4 m2.0 m²0.9 mXS2

3.5 x 3.5 m6.0 m²2.2 mXS1

floor spacefiltration areadiametertype

24.0 m²

18.0 m²

12.0 m²

6.8 m²

3.6 m²

1.0 m²

filtration area

3.5 x 3.5 m2.2 mXS4

3.5 x 3.5 m2.2 mXS3

3.5 x 3.5 m2.2 mXS2

type

M7

S4

XS1

3.5 x 3.5 m1.9 m

2.8 x 2.8 m1.4 m

2.2 x 2.4 m0.9 m

floor spacediameter

Dru

m F

ilter

sD

isc

Filte

rs

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-17-

Application of Steam Pressure Filtration

Filter Drier+ Thermal drying

Filter Drierchem.

Reactor(+) + Chemical Material Conversion

or

Filter + +Thermal drying withdry product re-circulationor with additives

DrierProductRe-Circulation

Filter ....Filter+ + (+)

Multiple washingwith re-slurring, high wash water consumption, evaporation, ...

Re-slurrying

Alternative:Hi-Bar Steam Pressure Filtration

SteamPressure Filtration

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Steam Pressure Filtration with the Oyster Filter Anorganic Compound

thermal efficiency: 1,010 MJ/t : 330 MJ/t = 305%

nextprocess

step

nextprocess

step

Hi-BarOysterFilter

filterstoragetank

storagetank

mc = (25-) 35 %pore liquid: 538 kg/t

energy consumption:1,010 MJ/t

- high energy costs- long cleaning periods incase of product change

- product loss product damage- investment and maintenance

mc = 15 – 20 %pore liquid: 250 kg/t

steam consumption: 110 kg/tenergy for steam production: 330 MJ/t

- no dryer required due toExtremely low moist. content

- quick product change- reduced energy costs- continuous operation

required: moisture content mc < 20 %(for product handling without sticking)

thermaldryer

mc < 20 %

-19-

Steam Pressure Filtration with the Oyster Filter Anorganic Compound

Oyster Drum Filter with steam cabin

filter area: 3.75 m²-20-

Steam Pressure Filtration with the Oyster Filter Precipitated Calcium Carbonate (PCC)

thermal efficiency: 1,140 MJ/t : 469 MJ/t = 243 %

Vacuum Drum Filter

low moisture contents* improve the product handling and * simplify the process design: - no product recirculation - no product mixing - careful product treatment without product damage - reduced energy costs

mc required < 25 %drying energy: 1140 MJ/tfor ∆mc (37% to < 25%)

Thermal Dryer

recirculated solids: 50 % StorageTank

cake moisture: 37 %pore liquid: 587 kg/t

driedCaCO3

StorageTank

cake moisture: 24 %pore liquid: 316 kg/t

steam consumption: 250kg/tenergy for steam: 469 MJ/t

Thermal Dryer

Hi-Bar Steam Pressure Filtration

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Hi-Bar Steam Pressure FiltrationWashing and Dewatering of FGD-Gypsum

0.80(t/h)steam consumption700600(m³/h)gas throughput

1212(t/h)solids throughput

3.311(%)cake moisture

1.23(m³/h)wash liquor

40 - 5050 - 100(mg/kg)Cl- content in the cake

0.3 – 1.01.5(wt-%)solids in the filtrate

3050(kW)energynonoflocculants

Results

Air blow backscrapermethod of cake discharge1.50.7(bar)pressure difference10.75(rpm)filter speed1617 - 20(mm)cake thickness22number of filters1018(m²)filter area

Hi-Bar Steam Pressure Filtration

Vacuum Drum Filter

Target:

reducing of

reducing ofreducing of

reducing of

-22-

Hi-Bar Steam Pressure FiltrationDewatering of Fine Coal

Comparison of Filter Performances

coal concentrate 1 coal concentrate 2technical data pressure Hi-Bar pressure Hi-Bar

disc filter SPF disc filter SPF

No. of Filters 1 1 1 1

filter area (m²) 120 146 120 85

solids throughput (t/h) 100 100 70 70

cake thickness (mm) 17.5 15 12.5 10

filter speed (1/min) 1.25 1 1 1.7

pressure difference (bar) 2.5 2.5 2 2.5moisture content (wt-%) 19.5 8.5 18 9.5water per 1t solids (kg/t) 242 93 196 105

gas throughput (m³/h) 4,500 1,600 3,500 2,100

power consumption (kW) 248 97 165 120

steam consumption (t/h) 0 9.2 0 7steam/kg water removal (kg/kg) - 0.62 - 0.67

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Comparison of Filter Technologies

Hi-Bar Steam Pressure FiltrationDewatering of Hematite Iron Ore Concentrate

noyesthermal drying of cake

3880 - 100(kg/t solids)steam consumption

97248(kW)power

912.5(wt-%)moisture content

60.8(bar)pressure difference

2,500585(kg/m²h)specific solids throughput

15035(t/h)solids throughput

6060(m²)filter area

Hi-BarSteam Pressure

Filtration

Steamingon

Vacuum Filter

-24-

12.5585vacuum

9.02,0006.0C

limonite

11.0550 - 690vacuum

9.02,5003.0B

hematite/limonite

12.5480vacuum

6.98203.3A

hematite

MoistureContent

[mass %]

SpecificSolids Throughput

[kg/m²h]

PressureDifference

[bar]

Iron Ore

Pressure Filtration versus Vacuum Filtration

Hi-Bar Steam Pressure FiltrationDewatering of Hematite Iron Ore Concentrate

25.06.2007

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Moisture Content Versus Time- Second Filtration / Continuous Operation -

15

17

19

21

23

25

27

29

31

33

35

250 300 350 400 450 500 550

No. of Test Trial

Moi

stur

e C

onte

nt [%

]

67 % A / 33 % C, No. 254 - 268, 13.11 - 15.11

75 % A / 75 % C, No. 269 - 292, 13.11 - 15.11

100 % A, No. 293 - 354, 15.11 - 1.12

75 % A / 25 % B, No. 355 - 453, 3.12 - 8.12

75 % C / 25 % D, No. 454 - 518, 10.12 - 15.12

100 % A, No. 519 - 536, 17./18.12

Target: mc = 23 %

extremely low moisture content

Hi-Bar Steam Pressure Filtration Dewatering of Red Mud

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Soda Content Versus Wash Ratio- Second Filtration, Continuous Operation -

0

0,3

0,6

0,9

1,2

1,5

0 1 2 3 4 5 6Wash Ratio [kg wash water / kg solids]

Soda

Con

tent

[%

]

all measurements

upper trend line

lower trend line

tendency from first filtration

Hi-Bar Steam Pressure Filtration Dewatering of Red Mud

extremely low soluble soda content

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mc = 35 % mc = 23 %

Vacuum Filtration Hi-Bar Filtration

Hi-Bar Steam Pressure Filtration Dewatering of Red Mud

Comparison of Filter Technologies

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Results and Economy of Hi-Bar Steam Pressure Filtration

PRODUCT: Anorganic Product CaCO3 Fine Coal Gypsum

steam consumption per ton dry solids mSteam 110 kg 250 kg 70 kg 80 kg

CALCULATION OF PORE LIQUID (mSolid = 1t) moisture content pressure filtration mc 35 % 37 % 20 % 11 %

calculated mass of pore liquid in filter cake mL 538 kg/h 587 kg/h 250 kg/h 124 kg/h

moisture content steam pressure filtration mc 20 % 24 % 10 % 3 %

calculated mass of pore liquid in filter cake mL 250 kg/h 316 kg/h 111 kg/h 31 kg/h

reduction of pore liquid using steam ∆mFI 288 kg/t 272 kg/t 139 kg/t 93 kg/t

CALCULATION OF ENERGETIC EFFICIENCY steam consumption mSteam 110 kg/t 250 kg/t 70 kg/t 80 kg/tenergy comsumption of thermal dryer(boiler efficiency = 75 %) qSteam 330 MJ/t 469 MJ/t 131 MJ/t 150 MJ/t

energy consumption thermal dryer(0.1l oil per kg steam) q(∆mFI) 1010 MJ/t 1140 MJ/t 583 MJ/t 389 MJ/t

thermal efficiency = ∆mL / mSteam η 306,1 % 243,1 % 445 % 259,3 %

SPF

PF

25.06.2007

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Hi-Bar Filtration Pilot Plant

mobile plant for on site operation

Hi-Bar Pressure and Steam Pressure Filtration

pressure up to ∆p < 6 bar

disc or drum filter

automatic filter control

all necessary peripheral equipment ensuring a quick start up of pilot operation

View of the Pilot Plant

-30-

Hi-Bar Filtration Pilot Plant

Pilot Drum Filterwith steam cabin and

exchangeable filter cellsfilter area: 0.6 m²

Pilot Disc Filterfilter area: 3.75 m²

-31- -32-

www.bokela.com

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Hi-Bar Oyster Filter

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Brazilphone: +55 11 3052 0444

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