Plant design & functionality
Wherever difficult to filter products or large amounts of suspension are to be filtered – such as concentrates from ore, coal and mineral processing or their tailings – BoHiBar Disc filters offer outstanding solutions.
BoHiBar Disc filters represent the most advanced technology for continuous pressure filtration. High filtration pressure differences up to 6 bar (g) and most modern filter and plant design are the reasons why even with very fine-grained, difficult-to-filter products, large specific throughputs and very low residual moisture are achieved. The space requirement is minimal.
For particularly low residual moisture, steam pressure filtration can be performed on these filters, too. This innovative hybrid process produces dry solids which open up new possibilities for product marketing through the re-usage of residues or significant improvements in product handling and transport.
BoHiBar Disc filters are available in various sizes with filter areas up to 168 m2 per filter unit.
Applications of the BoHiBar Disc filter:
- Alumina (Bauxite Residue)
- Coal
- Iron Ore
- Base Metals
- Tailings
Features and benefits:
- filtration of fine-grained products
- filtration of large quantities of suspension
- minimal footprint
- less need for filter cloths as filter area is much smaller compared to discontinuous filter equipment
- fully automatic and continuous operation
- lowest residual moisture, especially with steam pressure filtration
- saving of costs for thermal drying up to the avoidance of thermal drying
- possibility for re-usage of residues
- significant improvements in product handling and transport
Plant design & functionality
BoHiBar Disc filters from BOKELA represent the most advanced technology for continuous pressure filtration.
The basic principle is also known as hyperbaric filtration and very simple: a continuous rotary filter is installed completely in a pressure vessel filled with compressed air of up to 7 bar (a). A pump feeds the slurry into the filter trough in the pressure vessel. The filtrate flows through the filtrate pipes to the control head of the filter and from there to the filtrate separator. The filter cake is removed from the filter cloth by a reverse blast of compressed air and discharged through a solids sluice from the pressure vessel.
- filtration with high differential pressures Δp up to 6 bar (g)
- most modern disc filters with innovations known and proven by BoVac Disc filter technology
- option of installing steam hoods for steam pressure filtration
- closed process area (hermetic) inside the pressure vessel
- manholes allow quick and easy access to the pressure vessel from both sides and allow easy replacement of spare parts via a drawbridge
- reliable double gate valve for solids discharge
- low maintenance requirement due to innovative wear protection components
High solids throughput & low residual moisture
By using high pressures of up to 7 bar (a), BoHiBar Disc filters offer considerably higher pressure differences for filtration and demoisturing of the filter cake than vacuum filters.
Benefits:
- high solids throughputs even with fine particulate suspensions
- low residual moisture due to intensive demoisturing
- smaller filter area
Dry solids by steam pressure filtration
BoHiBar steam pressure filtration is an innovative hybrid process which releases synergies through the combination of mechanical and thermal principles of action. In order to accelerate and intensify the demoisturing process, the filter cake is treated with steam. Each filter disc is equipped with a specially developed steam cabin, which covers only a limited part of the filter surface up to the steam break-through point. The cake is then dried by a compressed air stream to its final moisture content. Due to the accelerated dewatering, the residual moisture of the filter cake can be halved compared to a pressure filtration.
Benefits:
- extremely low residual cake moistures
- highly effective cake washing by condensing steam
- saving of drying air
Easy maintenance & high availability
BoHiBar Disc filters stand out with their most modern filter and plant design, characterized by reliable operation and ease of maintenance:
- high availability (> 92 %) thanks to innovative design and preventive maintenance concept
- fully automated operation with automated startup, shutdown and cleaning procedures (cleaning in place)
- high flexibility in operation in case of product fluctuations
- low maintenance requirement due to innovative wear protection components
- fast and effective maintenance of the entire system due to good accessibility and sophisticated maintenance aids
- reliable sluice technology with easy maintenance from the outside
Technical data
| Filter Type [–] |
S42 | S84 | S168 |
| Disc Diameter [m] | 3.2 | 3.2 | 3.2 |
| No. of Discs [–] | 3 | 6 | 12 |
| Filter Area [m²] | 42 | 84 | 168 |
| No. of Segments per Disc [–] | 20 | 20 | 20 |
| No. of control heads [–] | 1 | 1 | 2 |
|
Pressure Vessel Design [–] Pressure Vessel Diameter [m] |
vertical 4.5 |
horizontal 4.8/5* |
horizontal 4.8/5* |
*) for steam pressure filtration
