BOKELA HiBar Filtration Continuous Pressure & Steam Pressure Filtration with Large Filter Units 2 / 2018 en
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 Compressor steam cabins disc filter filtrate receiver Slurry pump Filtrate Superheated steam Steam Pressure Filtration clean solids by excellent cake wash lowest moisture content extraction of soluable components pressure vessel hermetically sealed process no product contamination no emissions closed gas circuit cake blow off tank discharge sluice high throughput rates continuous operation small specific footprint simple peripheral equipment (tanks, pumps) Filter cake low moisture content energy saving in downstream thermal drying good bulk material handling low transport cost Why Pressure Filtration? Higher pressure difference increases throughput & reduces moisture content Capillary Pressure p C [bar] 6 5 4 3 2 1 p ce 0 mechanical demoisturing limit t 2 = t 2 = 120 s t 2 : demoisturing time t 2 = 60 s t 2 = 0 s pressure filtration vacuum filtration p ce : capillary entry pressure 0 0,5 1 Saturation S [-] higher throughput rates m S ~ p, n separating of fine particles reduced moisture contents (overcoming of the capillary forces) S = f [ ( p p ke ), t 2,...] improved filter cake washing S remanent S equilibrium (3 bar) S vacuum
Theory of Filter Cake Formation. M s = m& s A F = ρ s 2 η r n 60 1 ( 1 ε) κ p A 3, 600 L c α 360 0 F product parameters process parameters machine parameters product parameters process parameters machine parameters m s [kg/m²s] specific solids throughput η L [kg/ms] filtrate viscosity κ [-] solids concentration coefficient r C [1/m] cake resistance ε [-] porositiy n [1/min] filter speed p [N/m²] pressure difference in form zone α 1 [ ] cake forming angle Α [m²] 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 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 cold and saturated hot and dry filter cloth filtrate / condensate wet & sticky cake mc = 35 % dry cake mc = 23 %
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 segments cake discharge Control head BOKELA HiBar Steam Pressure Filtration Process and Plant Principle compressed air (P 2 ) steam (P steam ) wash water P 1 = pressure inside vessel P steam = P 1 P 2 = blowback pressure for cake discharge P 2 > P 1 cake (P atm ) sluice filtrate, condensate and air suspension feed p Filtration = P 1 P atm 6 bar
Application of Steam Pressure Filtration Conventional Filter Addition of liquid or dry material Refinement with liquid or dry additives Conventional Filter Drier Thermal drying Conventional Filter Drier Chem. Reactor Chemical Material Conversion Conventional Filter Product recirculation Drier Thermal drying with dry product re-circulation or with additives Washing on Convent. Filter Alternative: Hybrid Separation Process HiBar Washing on Convent. Filter Multiple washing with re-slurring 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 Product Data ph value of suspension [ - ] 1-2 Suspension temperature [ C] 45 Process and Operation Data Solids throughput (dry) [t/h] 2.7 Cake moisture [wt%] < 26 Steam per t solids [kg/t] 50
HiBar Steam Pressure Filtration of FGD-Gypsum Filtration, Washing and Dewatering Vacuum Drum Filter HiBar Steam Pressure Filtration filter area [m²] 18 10 number of filters [-] 2 2 cake thickness [mm] 17-20 16 filter speed [rpm] 0.75 1 pressure difference [bar] 0.7 1.5 cake discharge scraper Air blow back Target reducing of reducing of reducing of reducing of solids throughput [t/h] 12 12 cake moisture [%] 11 3.3 wash liquor [m³/h] 3 1.2 Cl- content in the cake [mg/kg] 50-100 40-50 solids in the filtrate [wt-%] 1.5 0.3 1.0 steam consumption [t/h] 0 0.8 gas throughput [m³/h] 600 700 energy [kw] 50 30 flocculants no no 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 Typical Moisture Contents of Met Coal Concentrates Steam Consumption for Coal Ultrafines Dewatering vs Moisture Content Vacuum Continuous Pressure Filtration Hi-Bar Steam Pressure Filtration Ultrafines (x < 250 µm) 23 28 wt% 16 19 wt% 8 12 wt% specific steam consumption [kg steam /t DS ] 140 120 100 80 60 40 20 0 0 2 4 6 8 10 12 14 16 18 20 22 moisture content [wt.-%] 18.06.2014 day 1 23.06.2014 day 2 24.06.2014 day 3 pressure difference p = 3 bar 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 -17- -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 Iron Ore Concentrates: Technologies and Results Dewatering of Fine Concentrates: Technologies and Results Vacuum Filtration Continuous Pressure Filtration ( p = 4 bar) Hi-Bar Steam Pressure Filtration Moisture Content 10 14 wt% 6 9 wt% < 3 wt% target moisture for rail transport in winter moisture content mc [wt.-%] 10.0 9.0 8.0 7.0 6.0 5.0 4.0 3.0 2.0 1.0 magnetite slurry, xmagnetite 50 = 35 µm slurry 0.0 0 1 2 3 4 5 dewatering ratio t 2 t/t 21 /t[-] 1 [-] p = 0.7 p = 5.5 bar p = 5.5 bar 14 kg steam/t solids m s = 8.2 t/m²h n = 1.5 3 rpm -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 Filter building (foot print L x W x H = 13.7 m x 8.5 m x 13 m) 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 x 50 = 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% -21- HiBar Steam Pressure Filtration of Bauxite Residue Converting Red Mud to Dry Bauxite Residue (DBR) The blown-off DBR filter cake...... falls into the sluice... onto the conveyor...... and forms a heap of dry and flowable DBR
Exemplary Application Products Exemplary application of HiBar Filtration with large filter units bauxite coal concentrates iron ore concentrates copper concentrates lead concentrates zinc concentrates mineral bulk products like gypsum, fertiliser or similar phosphate products pigments (organic and inorganic) precipitation & crystallisation products starches wheat, potato, tapioca tailings like 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 disc 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) 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 Services Disc Filter HiBar Filter DYNO Filter (sieve) Filter Revamping Trouble Shooting Consulting Development Backflush Filtration Drum Filter HiBar Oyster Filter FILTRATEST Pan Filter Pressure Filtration HiBar Pressure & Steam Pressure Filtration Backflush Filter Laboratory Equipment FILTRATEST DYNOTEST www.bokela.com BOKELA GmbH Tullastr. 64 76131 Karlsruhe Germany phone: +49 721 96456-0 bokela@bokela.com BOKELA Australia Pty Ltd Brisbane, QLD 4000 Australia phone : +61 7 3121 3312 bokela@bokela.com.au