1 Tissue Shoe Presses

Transcription

1 1 Tissue Shoe Presses

2 Tissue Shoe Presses Technology and safety in pressing

3 TECHNOLOGY BACKGROUND Tissue VS P&B grades shoe press Paper & Board Tissue Mating roll can be hydraulically supported roll or solid press roll No deflection in case of hydraulic supported roll Homogeneous deflection in case of press roll Deflection of press rolls only dependent on line load Mating roll is the Yankee cylinder Deflection is not homogeneous over width Deflection is depending on line load, temperature profile, gravity forces and stiffness of deckles Shoe module is against a Yankee Dryer! 3 Tissue Shoe Presses

4 TECHNOLOGY BACKGROUND Tissue Machine Typical Configurations Single press Shoe press Large diameter press On Yankee Double press With counter roll before Yankee 4 Tissue Shoe Presses

5 PROCESS NOTES 5 Tissue Shoe Presses

6 Tissue Shoe Press on Yankee design Shoe design concepts Shoe width: mm Adjustable tilt during PM operations by means of 2 or 3 applied forces The tilt value (K) ranges between 1 to 6 as function of the different shoe press running conditions and related to the results the operators would like to obtain: higher bulk on the paper or drier at press outlet (MPa) Some designs allow different pressure zones: i.e. edge zones can be loaded at different NIP value NIP width (mm) 6 Tissue Shoe Presses

7 SHOE PRESS BENEFITS Post press dryness +6/8% Dryness is a function of press diameter/type and number of presses REF. +2/3% +4/5% Single press Large diameter press Double press Shoe press Dryness increase Drying energy reduction Cost Savings Post Press Dryness increase of 1% = Reduction of 4% Drying Energy 7 Tissue Shoe Presses

8 Dryness - % SHOE PRESS BENEFITS DRYNESS vs TILT - SHOE PRESS LOAD 120 kn/m & 80 kn/m ,8 44, , F2 TILT K F 1 Toipa 17 g/m² 120 kn/m 80 kn/m Tissue Shoe Presses

9 Nm³/ton SHOE PRESS BENEFITS GAS CONSUMPTION EFFECTS SHOE PRESS LOAD 120 kn/m & 80 kn/m kn/m 80 kn/m F2 TILT K F 1 Toipa 17 g/m² Tissue Shoe Presses

10 TT SHOE PRESS Operational costs Shoe Press vs Conventional Press AHEAD-2.0S 16FT STEEL YANKEE 350 days/year production 90% efficiency 16,5 gsm grade -22,7% reduction -25,2% reduction 15% crepe ratio 8600 kcal/nm 3 Net heat value of gas ASSUMED ENERGY COST (EUROPE) Gas: 0,45 Euro/Nm 3 Steam: 29 Euro/t Electricity: 0,065 Euro/kWh 10 Tissue Shoe Presses

11 Caliper - mm (x10 plies) Softness - HF SHOE PRESS BENEFITS SOFTNESS & CALIPER VS TM CONFIGURATION DOUBLE PRESS 0.94 SINGLE PRESS Toipa 17 g/m² SHOE PRESS Tissue Shoe Presses

12 Bulk - [cm³/g] Softness - HF SHOE PRESS BENEFITS SOFTNESS & BULK VS TM CONFIGURATION Toipa 17 g/m² 50 5 DOUBLE PRESS SINGLE PRESS SHOE PRESS Tissue Shoe Presses

13 Softness - HF SHOE PRESS BENEFITS SOFTNESS vs TILT - SHOE PRESS LOAD 120 kn/m & 80 kn/m Toipa 17 g/m² F2 TILT K F kn/m 80 kn/m Tissue Shoe Presses

14 TISSUE SHOE PRESS Technical Features 14 Tissue Shoe Presses

15 TOSCOTEC RECENT HITS ON SHOE PRESS IN TISSUE SHOE PRESS LOADING TYPES Shoe press with High oil Pressure (HP) loading devices: Oil pressure range: bar Loading surface: limited (i.e. cylinders, ) 2 shoe press loading concepts Shoe press with Low oil Pressure (HP) loading devices: Oil pressure range: 1 7 bar Loading surface: extended (i.e. blocks, cushions, ) 15 Tissue Shoe Presses

16 TOSCOTEC RECENT HITS ON SHOE PRESS IN TISSUE STABILITY High oil pressure higher stiffness of the system (ζ) HP Systems LP Systems Sensitive to vibrations Load bouncing tilt changes - + Sensitivity to pressure control Tissue Shoe Presses

17 TOSCOTEC RECENT HITS ON SHOE PRESS IN TISSUE SAFETY - Protection from shoe contact on Yankee In case of catastrophic event where both felt and shoe belt fail, the shoe may touch the Yankee surface 1.5 Shoes that have a mechanical movement can be limited in stroke and 5.5 safe the shoe from contact to the Yankee dryer surface 17 Tissue Shoe Presses

18 TOSCOTEC RECENT HITS ON SHOE PRESS IN TISSUE SAFETY - Hydraulic oil pressure control The oil pressure control for the shoe loading is crucial to avoid extra forces on the Yankee shell which may damage it With LP loading devices Δ 1bar Δ kn in the NIP force With HP loading devices Δ 1bar Δ 1-4 kn in the NIP force Safety load cells or/and safety pressure transmitters may be necessary to control the NIP force Hydraulic pressure limiter on hydraulic unit 18 Tissue Shoe Presses

19 TOSCOTEC RECENT HITS ON SHOE PRESS IN TISSUE SAFETY - Shoe pressure module loading Lifting arms and tie rod solution Loading arms solution Tie Rod Load arms Safer for felt - ++ Reduced forces exchanged in the frame + - Stiffness of the system Tissue Shoe Presses

20 TOSCOTEC RECENT HITS ON SHOE PRESS IN TISSUE SHOE BELT - Shoe pressure module loading Belt life parameters - Belt material and manufacturing - Felt type, felt roughness on belt side and presence of bat - NIP load and tilt values - Design of the shoe module geometry Belt geometry: - With tie rod locking device the deformation of the belt is higher - With loading arms the deformation can be reduced 20 Tissue Shoe Presses Belt tensioning: - Hydraulic tensioning with variable load (belt life, belt type, working conditions), automatic oscillation with controller - Springs tensioning (fixed value)

21 TISSUE SHOE PRESS TOSCOTEC SOLUTION TT NextPress 21 Tissue Shoe Presses

22 SHOE PRESS CONFIGURATION IN TISSUE Option to standard pressing in CWP processes DOUBLE PRESS SINGLE PRESS SHOE PRESS DIFFERENT SOLUTIONS FOR DIFFERENT RESULTS 22 Tissue Shoe Presses

23 SHOE PRESS CONFIGURATION IN TISSUE Shoe Module Technical Features MAIN FEATURES Special designed hydraulic cylinders Ø 25 mm Polyurethane layer between pistons block and shoe Shoe made of aluminum (< Young module); mm width 6 NIP controlled zones for edges optimization Hydraulic pressure range bar with max pressure control Tilt range from 1 to 6 Maximum NIP load: 150 kn/m Maximum speed 2000 m/min 23 Tissue Shoe Presses

24 SHOE PRESS CONFIGURATION IN TISSUE Shoe module loading type NO NIP loading force on TM and building structure NO NIP loading force on TM and building structure 24 Tissue Shoe Presses

25 SHOE PRESS CONFIGURATION IN TISSUE Shoe module pressure zones Pressure zones 6 differentiated zones of pressure Different edge pressure zones with edge relieve of 5% Effective response to stealing edges and improve in belt lifetime Central, inlet Drive side, inlet Edge relieve:+- 5% Edge relieve:+- 5% Tender side, inlet Drive side, outlet Tender side, outlet Paper direction Central, outlet 25 Tissue Shoe Presses

26 Toscotec TT NextPress TOSCOTEC Shoe Press Technology THANK YOU! VISIT Any US AT Questions BOOTH NO. G01 It s Tissue?!