BOKELA
HiBar Filtration
2 / 2015 e
Continuous Pressure & Steam Pressure Filtration
with Large Filter Units
BOKELA HiBar Filtration
Continuous Filtration with Rotary Drum or Disc Filters
HiBar Pressure Filtration
compressed air/gas is used for filtration
HiBar Steam Pressure Filtration
superheated steam is used for cake washing and cake dewatering
Features of both versions
continuous filtration process with rotary drum or disc filters
hermetically sealed process
high filtration pressure difference up to ∆p = 6 bar and temperature up to T = 160°C
(in special cases vessel pressure up to 15 bar, T < 200°C)
efficient cake washing with minimal wash liquor demand
cake discharge generally by compressed air blowback
reliable sluice technologies for cake discharge out of the vessel
BOKELA HiBar Filtration
Continuous Filtration with Rotary Drum or Disc Filters
HiBar Filtration with large filter units is made for:
fine and difficult to filter particles
high specific throughput rates e.g. for bulk materials
extremely low cake moistures
toxic products like emitting suspensions
low-boiling suspensions
hot suspensions and high process temperatures
effective cake washing in up to 3 counter-current steps
high energy efficiency by recirculating of hot filtrates
gentle product handling
BOKELA HiBar Filtration Plant Design
Plant Design for Large and Small Filter Units
With horizontal pressure vessel for large units
with rotary disc or drum filters
for filtering, washing and dewatering of bulk
materials with high throughput rates
Oyster design (vertical vessel) for small units
with rotary drum or disc filters
for sophisticated separation tasks like washing and
drying of valuable products in the chemical industry,
pharmaceutical industry, food industry, etc.
BOKELA HiBar Filtration Plant Design for Large Filter Units
Rotary Drum and Disc Filters in Horizontal Pressure Vessels
HiBar Drum Filter
HiBar Disc Filter
Principle of Plant Design
Continuous Pressure Filtration & Steam Pressure Filtration
Superheated
steam
Compressor
Steam Pressure Filtration
clean solids by excellent
cake wash
lowest moisture content
extraction of soluable
components
steam cabins
disc filter
pressure vessel
filtrate receiver
hermetically sealed process
no product contamination
no emissions
closed gas circuit
Slurry pump
cake blow off tank
discharge sluice
Filtrate
high throughput rates
continuous operation
low moisture content
Filter cake
small specific footprint
simple peripheral equipment
(tanks, pumps)
energy saving in downstream thermal drying
good bulk material handling
low transport cost
Why Pressure Filtration?
Higher pressure difference increases throughput & reduces moisture content
mechanical demoisturing limit
Capillary Pressure pC [bar]
6
5
4
3
2
1
t2: demoisturing
time
t2 = ∞
higher throughput rates
mS ~ ∆p, n
t2 = 120 s
separating of fine particles
t2 = 60 s
pressure filtration
reduced moisture contents
t2 = 0 s
(overcoming of the capillary
forces)
S = f [ (∆
∆p – pke), t2, ...]
vacuum filtration
pce
improved filter cake washing
pce: capillary entry pressure
0
0
0,5
Saturation S [-]
Sremanent Sequilibrium (3 bar)
1
Svacuum
Theory of Filter Cake Formation
.
& s ⋅ A F = ρ s (1 − ε ) ⋅
Ms = m
2
n
α1
⋅ κ ⋅ ∆p ⋅
⋅ A F ⋅ 3,600
⋅
η Lrc
60
360 0
product
parameters
machine
process
parameters parameters
product
parameters
ms
ηL
κ
rC
ε
[kg/m²s]
[kg/ms]
[-]
[1/m]
[-]
specific solids throughput
filtrate viscosity
solids concentration coefficient
cake resistance
porositiy
process
parameters
n
∆p
[1/min]
[N/m²]
filter speed
pressure difference in form zone
machine
parameters
α1
Α
[°]
[m²]
cake forming angle
filter area
BOKELA HiBar Steam Pressure Filtration
Innovative Hybrid Process
HiBar Steam Pressure Filtration is an innovative hybrid process which achieves extremely dry and pure
filter cakes. Pure steam is used for dewatering, washing and cake drying. A filter cake formed at the low
temperature of the feed slurry enters a specially designed steam cabin immediately after emerging from
the slurry in the filter trough. Here, a superheated steam atmosphere exists and the following
phenomenon takes place which can be described by the model of the condensate front.
Model of the Condensate Front
filter cake: before ...
during ...
after steaming
superheated
steam
cold and
saturated
continuous moving of a condensate front
homogeneous heating of the filter cake
emptying of nearly all pores
viscosity reduction of the residual liquid
excellent washing out (extraction)
extremely low moisture content
vacuum filtration
Steam Pressure
Filtration
wet & sticky cake
mc = 35 %
dry cake
mc = 23 %
hot
and dry
filter cloth
filtrate / condensate
HiBar Steam Pressure Filtration
Process and Plant Principle
In a specially designed and patented steam cabin covering only part of the filtration area, the filter cake
is only partially exposed to steam, which accelerates and intensifies the dewatering process.
steam cabins
cake discharge
segments
Control head
BOKELA HiBar Steam Pressure Filtration
Process and Plant Principle
compressed
air (P2)
steam (Psteam)
wash water
P1
= pressure inside vessel
Psteam = P1
P2
P2
∆pFiltration
sluice
cake (Patm)
= blowback pressure for
cake discharge
> P1
filtrate,
condensate
and air
suspension
feed
= P1 – Patm ≤ 6 bar
Application of Steam Pressure Filtration
Conventional
Filter
Addition of liquid
or dry material
Conventional
Filter
Drier
Conventional
Filter
Drier
Chem.
Reactor
Conventional
Filter
Product
recirculation
Drier
Washing on
Convent. Filter
Washing on
Convent. Filter
Refinement
with liquid or dry additives
Thermal drying
Chemical Material Conversion
Thermal drying with
dry product re-circulation or with
additives
Multiple washing
with re-slurring
Alternative:
Hybrid Separation
Process
HiBar
BOKELA HiBar
Steam Pressure Filtration
HiBar Steam Pressure Filtration of an Organic Acid
Filtration, Washing & Dewatering
Greatest Pressure Drum Filter Worldwide
HiBar Drum Filter L-Type 40
Filter area
[m²]
40
Drum Diameter
[m]
2.4
pH value of suspension
[-]
1-2
Suspension temperature
[°C]
45
Product Data
Process and Operation Data
[t/h]
2.7
Cake moisture
[wt%]
< 26
Steam per t solids
[kg/t]
50
Solids throughput (dry)
HiBar Steam Pressure Filtration of FGD-Gypsum
Filtration, Washing and Dewatering
filter area
number of filters
Vacuum
Drum Filter
HiBar Steam
Pressure Filtration
[m²]
18
10
[-]
2
2
16
cake thickness
[mm]
17 - 20
filter speed
[rpm]
0.75
1
pressure difference
[bar]
0.7
1.5
scraper
Air blow back
[t/h]
12
12
[%]
11
3.3
[m³/h]
3
1.2
cake discharge
Target
solids throughput
reducing of
cake moisture
reducing of
wash liquor
reducing of
Cl- content in the cake
reducing of
solids in the filtrate
steam consumption
gas throughput
energy
[mg/kg]
50 - 100
40 - 50
[wt-%]
1.5
0.3 – 1.0
0
0.8
[m³/h]
[t/h]
600
700
[kW]
50
30
no
no
flocculants
HiBar Steam Pressure Filtration of Coal Ultrafines
Waste-to-Money
Hi-Bar Steam Pressure Filtration is capable to produce extremely dry ultrafines below
10wt-% moisture which now offers new options in coal ultrafines treatment.
steam cabins
HiBar Disc Filter in horizontal pressure vessel for Steam Pressure Filtration
HiBar Steam Pressure Filtration of Coal Ultrafines
Waste-to-Money
Ultrafines
(x < 250 µm)
Vacuum
23 – 28 wt%
Continuous
Pressure Filtration
Hi-Bar Steam
Pressure Filtration
16 – 19 wt%
8 – 12 wt%
Steam Consumption for Coal Ultrafines
Dewatering vs Moisture Content
specific steam consumption [kgsteam/tDS]
Typical Moisture Contents of Met Coal
Concentrates
140
120
18.06.2014
day 1
100
23.06.2014
day 2
24.06.2014
day 3
80
60
pressure difference
∆p = 3 bar
40
20
0
0
2
4
6
8
10
12
14
16
18
20
22
moisture content [wt.-%]
-17-
HiBar Steam Pressure Filtration of Coal Ultrafines
Waste-to-Money
HiBar Pilot Plant Operation for Steam Pressure Filtration of Coal Ultrafines
HiBar pilot plant
Dry coal with moisture content
mc = 8 wt%
mc = 8 wt%
Clear filtrate
Benefits of HiBar Steam Pressure Filtration
bulk material characteristics even under frost conditions
lower transport weight
no post-dewatering due to compacting during transport („flow moisture point“)
lower or even no energy cost for thermal drying
marketing as stand-alone product
-18-
HiBar Steam Pressure Filtration of Iron Ore Concentrates
Hi-Bar Steam Pressure Filtration achieves lowest moisture contents of mc = 3 wt% with fine
iron ore concentrates. This improves transport in cold regions with long frost periods or makes
transport possible at all.
Dewatering of Fine Concentrates:
Technologies and Results
Dewatering of Fine Iron Ore Concentrates:
Technologies and Results
magnetite slurry, xmagnetite
slurry
50 = 35 µm
Moisture Content
Vacuum Filtration
Continuous Pressure
Filtration (∆p = 4 bar)
Hi-Bar Steam
Pressure Filtration
10 – 14 wt%
6 – 9 wt%
< 3 wt%
moisture content mc [wt.-%]
10.0
9.0
8.0
7.0
∆p = 0.7
6.0
∆p = 5.5 bar
5.0
∆p = 5.5 bar
14 kg steam/t solids
4.0
3.0
2.0
ms = 8.2 t/m²h
n = 1.5 – 3 rpm
1.0
0.0
target moisture for rail
transport in winter
0
1
2
3
4
5
dewatering ratio
ratio t2t/t21/t[-]
dewatering
1 [-]
-19-
HiBar Steam Pressure Filtration of Bauxite Residue
Converting Red Mud to Dry Bauxite Residue (DBR)
HiBar Steam Pressure Filtration Offers New Possibilities for Bauxite Residues
HiBar disc filter (70m²) with steam cabins
minimum moisture content remarkably below
the thixotropic point (mc < 28wt%)
improved handling and improved disposal
sand-like bulk characteristics i.e.
good transport and handling characteristics
minimized content of soluble soda
industrial re-usage of bauxite residue possible
for re-cultivation, street or dam building or other
applications
HiBar Steam Pressure Filtration of Bauxite Residue
Converting Red Mud to Dry Bauxite Residue (DBR)
HiBar Steam Pressure Filtration Plant with 2 HiBar Disc Filters for Bauxite Residue Dewatering
2 x HiBar disc filter 70 m² per
filter with 5 discs per filter
1 filter in operation, 1 filter as
stand-by unit
red mud with very small particle
size of x50 = 1.9 µm
filtration pressure difference
∆p = 4 - 6 bar
solids throughput: 32 t/h
moisture content mc in wt%
pressure filtration
mc < 28 wt%
steam pressure filtratation:
mc < 25 wt%
Filter building (foot print L x W x H = 13.7 m x 8.5 m x 13 m)
-21-
HiBar Steam Pressure Filtration of Bauxite Residue
Converting Red Mud to Dry Bauxite Residue (DBR)
The blown-off DBR filter cake ...
...
and forms a heap of dry and
flowable DBR
... falls into the sluice
... onto the conveyor ...
Exemplary Application Products
Exemplary application of HiBar Filtration with
large filter units
bauxite
pigments (organic and inorganic)
coal concentrates
precipitation & crystallisation products
iron ore concentrates
starches
copper concentrates
•
lead concentrates
tailings like
zinc concentrates
•
•
mineral bulk products like
•
•
gypsum, fertiliser or similar
phosphate products
•
wheat, potato, tapioca
bauxite residue
iron ore tailings
zinc leaching tailings
etc.
HiBar Filtration Discharge Sluices
Chamber Discharge Sluice - Different Solutions Available
Proven double valve
arrangement
Conical intermediate
chamber to avoid
solids bridging
Heating / CIP as
required
Gate Valves
Swing Valves
COPERION Rotary Valve
reliable and proven
equipment for PTA and
other non-abrasive
products
-24-
HiBar Filtration in Horizontal Pressure Vessel
Filter Sizes
Sizing of Disc Filters
Filter Type
[-]
XS
S
Disc Diameter
[m]
2.2
3.2
Filtration Area
[m²]
6 - 84
56 - 168
Sizing of Drum Filters
Filter Type
[-]
M
L
XL
Drum Diameter
[m]
1.8
2.4
3.2
Filtration Area
[m²]
6.8 - 20
16 - 40
40 - 81
HiBar Filtration Pilot Plant
Mobile Plant for Pilot Operation Tests at the Site
drum filter
HiBar Pressure & Steam Pressure Filtration
maximum operation pressure: < 6 bar,g
drum filter 0.3 m² (0.2 m²) / disc filter 1 m²
maximum operation temperature:
180°C (drum) / 170°C (disc)
disc filter
overall installation dimensions:
approx. 3,600 x 5,000 x 4,000 mm
total weight: approx. 6,000 kg
material of construction: SS AISI 316L
power supply: 360 - 440 V AC, 50/60 Hz
Vacuum
Filtration
Dynamic
Crossflow
Filtration
Membrane Filtration
Sieve Filtration
DYNO Filter (MF)
Filter Revamping
DYNO Filter (sieve)
Filter Revamping
Trouble Shooting
Consulting
Development
Services
Disc Filter
Hi-Bar Filter
Backflush
Filtration
Drum Filter
Hi-Bar Oyster Filter
FILTRATEST
Pressure
Filtration
Pan Filter
Hi-Bar Pressure &
Steam Pressure
Filtration
Laboratory
Equipment
Backflush Filter
FILTRATEST
DYNOTEST
www.bokela.com
BOKELA GmbH
BOKELA Australia Pty
BOKELA do Brasil Ltda
BOKELA India Pvt Ltd
Tullastr. 64
76131 Karlsruhe
Deutschland
Springfield, QLD 4300
Australia
Baner Pune 411 045
Maharashtra
India
phone: +49 721 96456-0
[email protected]
phone : +61 7 3288 1400
[email protected]
R. Santiago Ballesteros 610
Sala 6, Cinco
32010-050 Contagem – MG
Brazil
phone: +55 31 2565 0976
[email protected]
phone: +91 955 26 69 200
[email protected]