speed 1136 rpm = 17.5 m/s vcircumferential foil è ~ 29 speed 682 rpm = 1.5 m/s vcircumferential foil è ~ 24 for example 7 closed) closed) in direct comparison modifying the rotor design from LC to HC Rotor construction (open 5 Trial rotors Rotor construction (open We accept the challenge! presented by Rainer Cornelius With optimized rotor- and foil design for pressure screens Energy saving 4 6 Trial tip speed 588 rpm = 15.3 m/s vcircumferential foil Trial installation HF 5 Rotor construction 8 6 2 5 1 15 2 Trial screen HF 5 Rotor construction (open 4 closed foil number / foil area foil arrangement foil form foil fixing rotor speed rotor design open rotor body + foil arms + foils 1 74 rotor body + foil arms 34 4. Energy requirement 12 39 1 rotor body idle running 8 closed) When designing a rotor according to the request for lowest energy consumption it is necessary to survey the construction design as well as the details of single components: Rotor construction
Rotor construction 4 3 2 bearing unit idle running rotor body with foil arms with foil arms and foils 1 25 3 35 4 45 5 55 6 65 7 75 8 9 Foil fixing / foil form Trial screen HF 5 Ø 4 mm round bolt 94 x 21.5 mm foil form 1 Foil fixing / foil form 25 2 15 1 5 1 15 2 25 3 35 4 45 5 55 6 65 7 75 8 11 Trial screen HF 5 Rotor rotation direction 5 Ø4 with foil 94 x 21.5 Ø4 with foil 94 x 25.5 Ø4 with foil 115 x 27 4 foil 94 x 21.5 with foil 94 x 21.5 3 2 1 1 2 3 4 5 6 7 8 12 Trial screen HF 5 rotating direction clockwise (standard) rotating direction counterclockwise 13 Foil arrangement Trial screen HF 5 8 7 6 5 4 3 2 foils vertical straight foils vertically staggered (CCW) 55 575 6 625 65 675 7 725 75 14 Reasons to choose an open rotor Used mainly with lower circumferential speed Better stock mixing Lower reject thickening Lower tendency to pulsations
OCC fractionation 72 BDT/D OCC fractionation 72 BDT/D OF8 / 1 OF8 / 2 Andritz Fiedler Competitors Open rotor QIC PDIA PI PI FIC FFIC Rotor circumferential speed m/s 21 24 Intermediate chest Current consumption kw 75 86 OF8 /1 Feed LF SF Feed LF SF Flow l/min 8134 3739 4395 7981 3593 4388 FI PDIA Consistency 3.1 3.7 2.6 3.1 3.9 2.7 PI PI FIC CSF ml 252 35 152 252 325 222 FFIC Long fiber chest Short fiber chest Shive (#.15 Haindl McNett) 1.46 3..17 1.46 3.41.42 OF8 /2 R16+R3 (Haindl McNett) 32.8 4. 25.2 32.8 35.3 3.8 FI Shive reduction 88. 71.2 Long fiber yield 76.7 93.9 15 16 OCC fractionation 72 BDT/D OCC screening 52 BDT/D OF8 / 1 long fiber OF8 / 1 short fiber accept coarse screening OF8 / 2 long fiber OF8 / 2 short fiber 17 18 19 OCC screening 52 BDT/D Installed Andritz Andritz Rotor circumferential speed reduced from 22 m/s to 18 m/s Capacity unchanged ~ 25 Increased service life of the screen basket 25 2 15 1 5 Energy consumption 2 Unbleached short fiber screening 9 BDT/D IR 21.15 # IR 21.15 # IR 28.15 # IR 21.15 # IR 21.15 # kw
Drillscreen baskets 376 959 583 Total power consumption [kw/h] Sample point Unit [mm2/kg] [mm2/kg] [] [] Inlet coarse screening 429 4934 84 92 Accept MC-slot screening 683 387 Target No spinning problems in waste paper screening system Reduction in power consumption resulting in cost savings Improved cleanliness for short fiber 1 UV5 Bird M 4 NEW tertiary NEW quarterny 21 2-21 -2 Bird M 4 quarterny 5 23 27 total 423 313 11 total 536 27 266 Guaranteed capacities for OCC screening system of 35 BDMT/d for long fiber and 3 BMDT/d for short fiber fractions Targets OCC fractionation screening system, 2, 4, 6, 8, 1, 12, secondary 141 115 27 Improvement of sticky removal rate: From 84 to 92 tertiary 62 45 17 MC slot screening system secondary 115 8 35 Beloit S 32 A Beloit S 32 A Beloit S 48 A Position primary no. 1 primary no. 2 load 141 141 load new 79 79 62 62 Screen type Beloit S 48 A Beloit S 48 A Beloit S 32 A Beloit S 24 A Beloit S 18 A Position primary no. 1 primary no. 2 load 159 15 load new 122 shut down 37 15 Screen type 26 coarse screening system Total annual (33 days) energy savings: 2,977,92 kw / year 24 22 fine screening system Rorotors Scope of supply (design examples) 25 Barscreen baskets 65 7 Dirt spot reduction Accept capacity: 75 BDT/D Improvement of sticky removal efficiency Guaranteed energy savings: more than 36 kwh Installation of two separate reject screening system for coarse screening and MC slot screening MC slot screening: reduction from slot width #.35 mm to #.2 mm Coarse screening: reduction from hole dia. Ø 1.4 mm to Ø 1.2 mm Targets 75 8 85 Ingersoll Rand 21 Milled.15 # Sting Ray rotor 29 9 285 accept reject 3.4 2 1.13.2 18. 525. 82. 7.8 Shive reduction Ingersoll Rand 21 BarRo22 65 36 accept reject 3.8 22 1.13.8 18. 3. 93. 83.3 9 BDT/D 23 75 8 85 9 95 Energy consumption Pcs./m2 m/s kw BDT/D 4 2 8 6 1 Consistency RR (mass) Shive Dirt spots Shive reduction Schmutzpunktreduzierung Screen Screen basket Rotor Rotor circumferential speed Current consumption Capacity / screen kw 21 Unbleached short fiber screening
OCC fractionation screening system UV5 OCC Fractionation screening system UV5 Scope of supply (design examples) Barscreen baskets Rorotors Competitor Screen basket #.2 mm #.2 mm Rotor OEM Rotor speed [rpm] 494 388 Power consumption 156 72 Capacity [BDT/D] 25 325 Spinning problems yes no Capacity increase [] 3 Energy saving [] 54 27 28 OCC Fractionation screening system UV5 Softwood pulp 95 BDT/D Delta 8 Targets Cost savings per year: ~ 1,844,262. Baht (Assumptions: 312.4 operating days/year x 24 hours x 3 Baht/kWh x 82 kw) Elimination of spinning- / stringing problems Improved rotor and screen basket lifetime Quality improvement of screening line 1 Capacity improvement of screening line 1 Improved screening capacity Unchanged cleanliness 29 3 31 Softwood pulp 95 BDT/D Delta 8 Kappa 3 4 x primary Inlet pres. 1.9 bar 32 Softwood pulp 95 BDT/D Delta 8 2 energy saving Higher throughput Shive removal: from 9 to 94 Dirt removal > 3 mm: from 94 to 1 Screen basket Competitor Ø 1.2 mm Rotor Delta rotor #.25 mm Rotor speed [m/s] 24 2 Power consumption [Amp] 2 16 Capacity [BDT/D] 32 36 Shives (Sommerville.15 mm) [].5 accept.5 Dirt count > 3 mm accept [pcs/ 5 g] ~ 1.4 8.5.3 ~ 1.4
Mixed tropical hardwood 1.3 ADMT/D HI-Q 312 Mixed tropical hardwood 1.3 ADMT/D HI-Q 312 Target Capacity increase from 83 ADMT/D (2 primary screens in operation / 1 screen in standby) to 1.3 ADMT/D (3 primary screens in operation) Improvement of cleanliness in pulp 33 34 Mixed tropical hardwood 1.3 ADMT/D HI-Q 312 Mixed tropical hardwood 1.3 ADMT/D HI-Q 312 Barscreen baskets Scope of supply (design examples) Rorotors Pulp grade MTHW : Acacia 7 : 3 MTHW : Acacia 7 : 3 Screen basket type milled Slot width [mm].2.17 Rotor Type OEM Sting ray Rotor speed [rpm] 111 75 Rotor tip speed [m/s] 32.5 22.7 Motor rate [kw] 25 25 Power consumption / screen 22 115 Reject rate mass [] 12 15 18 2 Feed consistency [] 3.1 Capacity / 1 pc. primary screen [ADMT/D] 415 54 35 36 37 Mixed tropical hardwood 1.3 ADMT/D HI-Q 312 Capacity increase of 23 per primary HI-Q 312 screen from 415 ADMT/D to 54 ADMT/D Capacity increase of total screening plant (by usage of 3 primary screens) to 1.63 ADMT/D Increase in consistency from 3.1 to 48 energy savings meaning cost savings of 172,8 USD per year total energy savings of screening system is 45 kw/h (Assumptions: 32 operating days/year,.5 USD/kWh) ROI: the return of investment by usage of Rothan 8 month Improved dirt & shive removal efficiency: secondary stage can handle increased reject rate from primaries We accept the challenge!