new paper machine energy considerations -...
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New Paper Machine Energy Considerations
Dick ReeseDick Reese and Associates IncDick Reese and Associates, Inc.
Peachtree Corners, GA770-448-8002
New Paper Machine Energy Considerations
Mi i i hi k k i i h d i i Minimize thick stock system size with good agitation Install compact wet end system Install vertical agitators in stock chests Install vertical agitators in stock chests Install modern energy-efficient refiners and deflakers Install additive injection system Install additive injection system Install adequate water system surge capacity Install forgiving press section with excellent
dewatering Install a modern press section steam box
I t ll d t d d t t ith Install modern steam and condensate system with dryer management system
New Paper Machine Energy Considerations (cont)
Install good monitoring of steam electricity and Install good monitoring of steam, electricity and water and display for operators
Install energy-efficient vacuum pumps (blowers if gy p p (electricity cost is high)
Properly size pumps Install variable-frequency drives Install energy-efficient agitators in chests and pulpers
If a size press is required install metering type and If a size press is required, install metering type and run starch solids as high as possible
Recover heat from dryersy
POM Compact Wet EndPOM
Header
Wet
Fibre recovery
Pulper
Headbox
R fi i
Wet broke
Suction boxes
Additives
Pressure Screen
Cleaner Plant
POMixTRefinerRefining Chest
POMp Degasser POMlock
seal pitLast cleaner stages
2nd stage Screen
Compact Wet End SystemHead tank
POMix
POMpPOMp
POMit
POMlocksPOMp
Flexible Cascade TM
POM Compact Wet End Principles
Gas removal right after wire section air/gasless short circulation, no flotation of dirt and
pitch on air bubbles, less microbiological activity, less flocs, less pulsations
Closed process No tanks with open surfaces to collect pitch and dirto a s ope su aces o co ec p c a d d
Compact dimensioning Minimal space requirement and fast flow speeds,
which cleans up the pipeswhich cleans up the pipes As a result stable, fast and clean process
POM Wet End System ResultsSTABLE
Improved process stability due to fast response to adjustments, such as beating or chemical addition.
Less consistency variations from system (POMlock, POMix) and less pulsations due to airless short circulationairless short circulation.
FAST Reduced start-up, stabilisation and grade change times due to smaller system volume,
up to 1/6 of conventionalp At least 2 x faster basis weight changes and machine start-ups Less waste from change over losses and start-ups
CLEAN Improved cleanliness due to airless compact system (less tanks, no open surfaces, fast
flow speeds) Less fresh water, 50% less cleaning efforts and 50% reduction in biocide usage
Conventional Wet EndEquipment to be removed
Wet broke Additives
Fibre recovery
Mi i
POMix
Pulper
Headbox Suction boxes
Mixing Chest
Machine Chest
Pressure Screen Wire Pit
Cleaner Plant
TRefinerRefining Chest
Seal Pit
WW2
Reject tank
Last cleaner stages POMp and
POMlock
Reject tank for screens
Reject tank for
cleaners
2nd stage Screen
POM H dPOM Header
POMix PrincipleO c p e
Intense mixing unit, which Intense mixing unit, which substitutes conventionalsubstitutes conventionalsubstitutes conventional substitutes conventional machine chest, mixing chest machine chest, mixing chest and pump between themand pump between them
Saves EnergySaves Energy
Specially designed forSpecially designed forSpecially designed for Specially designed for optimum flow patterns and optimum flow patterns and blending for stable thick stock blending for stable thick stock dosagedosagegg
Holding time 1Holding time 1--2 min, which 2 min, which is enough to filter fast and is enough to filter fast and ggmedium variations from the medium variations from the stock preparationstock preparation
Saved energy can be calculated by comparing electricity used in POMix mixer vs. machine chestmixer + mixing chest mixer + pump between machine and mixing chest. For example on a 4 m3
POMix the yearly saving in energy is about 19 200 EUR/a:
Energy Consumption kW(used energy)
MWh/a(8000 h/a)
Cost in EUR(50 EUR/MWh)
POM System: 7 56 2 800POM System:POMix mixer
7 56 2 800
Conventional:Machine chest mixer
18 144 7 200
C ti l 9 72 3 600Conventional:Mixing chest mixer
9 72 3 600
Conventional:Pumps between chests
28 224 11 200
POMix vs conventional 48 384 MWh/a 19 200 EUR/a
Pay back time for a POMix from energy alone is about three years.
Energy Savings from POM Wet End
POMp Degasser saves about 20% electricity in degassing vs. vacuum tank (deculator). POMp is a pump and a large part of the
d l t i it b d f i lik ith d l tused electricity can be used for pumping unlike with a deculator. POMix Stock Processor saves over 50% electricity vs.
conventional machine and mixing chest. POM system volume is less than 1/3 of conventional and
therefore the required steam to heat the water is over 3 times less.less.
Less waste from grade changes and start-ups, which will reduce the energy consumption (pulping, refining, pumping etc.)
CounterFlow™ Stock MixingCounterFlow Stock Mixing
Counter Flow™ provides a much higher pumping rate than conventional impellers because it can efficiently p yoperate at much higher impeller-to-tank diameter ratios. This is a greater advantage where stagnancy can be a problem Alternative impeller technologiescan be a problem. Alternative impeller technologies require significantly greater power and produce less flow.
CounterFlow vs. Side Entry AgitationEntry Agitation
50 seconds into process: CF mixes traces
50 Seconds into Process
50 seconds into process: CF mixes traces with vessel content; tracer is pushed by axial flow in vessel with SE
200 Seconds into P
200 seconds into process: CF has zonal mixing; SE show channeling and tracer
Process
mixing; SE show channeling and tracer flows directly in the vessel outlet
CounterFlow vs. Side Entry AgitationSide Entry Agitation
300 seconds into process: CF provides
300 Seconds into Process
300 seconds into process: CF provides relatively uniform mixing; with SE unmixed tracer continuously flows into vessel outlet with very little mixing.
500 S d i t500 Seconds into Process
500 seconds into process: (past end of process) CF has comparatively uniform mixing; SE has non-uniform mixing.
High Density Tower
OptiFiner Prop Metso OptiFiner Pro is a new compact refining concept. Fibers travel the full length of the refining zone in conventional Fibers travel the full length of the refining zone in conventional
refiners, suffering excessive impacts that lead to increased fines and weakening of the refined fibers. As much as 70% of the total fibers may not be treated at all.total fibers may not be treated at all.
OptiFiner Pro feeds stock evenly across the bars in the refining zone where fiber treatment occurs. All of the stock is treated equally, providing higher refiner loadability and better energyequally, providing higher refiner loadability and better energy efficiency.
Tremendous flexibility in operation is gained and easier installation due to smaller physical size.installation due to smaller physical size.
Estimated equipment cost is 15% higher than new disk refiners.
OptiFiner Pro vs. DD RefinerNo Load SavingsParameter Units Pro 1 DD-34 Pro 3 DD-42
Maximum Production
BD MTPD
140 140 350 350Production MTPD
Maximum Motor hp 845 800 2010 1750
Speed rpm 1500 600 750 514
No-Load hp 63 287 120 442
No-Load Reduction hp 224 322
No-Load Savings @$0.05/kWh
$ per year
70,140 100,800
OptiFiner DF Deflaker
Stock outletGap adjustmentp j
Stock inlet
Coupling
Shaft assembly
FillingsShaft seal
18
Shaft seal
DeflakingDeflakingPower Consumption Function of flow
600
400
500
W DF 1/250
DF-1/315
200
300
Pow
er, k
W
DF-0/132
DF-1/200
DF-1/250
DF-1/160
100
200P
DF-00/55
DF-00/75DF-0/110
00 20 40 60 80 100
Flow, l/s
Deflaking of Broke Screening g gReject
Additive Dilution Systems
Use whitewater or headbox consistency stock for additive dilutionstock for additive dilution
High velocity injection improves mixing and permits reducing chemical usageand permits reducing chemical usage
Relative Steam Application Efficiency
Pounds Steam Per ExtraPound Water Removed
Heating White Water 5 to 10
Fourdrinier Steam Box 2 to 5
Press Steam Box 0.75 to 2
Dryers 1.2-1.3
Steam and Condensate System Opportunities Install stationary syphons with low operating differential
pressures, modern steam joint design, and dryer bars. Minimize number of dryers draining to condensers. Use blow through control or managed differential pressure Use b o t oug co t o o a aged d e e t a p essu e
control to minimize steam venting on sheet breaks. Minimize steam venting and system leaks. Optimize thermocompressor sizing and operation More efficient Optimize thermocompressor sizing and operation. More efficient
designs now available. Properly balance cascade systems.
Shut off steam to bottom unorun or felt dryers Shut off steam to bottom unorun or felt dryers. Use pilot-operated safety relief valves. Make sure there is tight shut off of dryer vent valves. Improve steam and condensate piping insulation. Consider dryer management systems.
Effective Energy Monitoring Programs-TIP 0404-63 Monitor energy flows to each paper machine. Monitor energy flows to each paper machine. Establish key energy parameters Highlight variables that affect energy consumption.
Include energy parameters in operator rounds and centerlining Include energy parameters in operator rounds and centerlining efforts.
Provide information to operators, engineers, and managers to encourage continuous improvementencourage continuous improvement.
Appoint an energy champion to monitor and improve paper machine energy consumption.
d ff d Discuss energy cost and conservation efforts in production meetings.
Conduct periodic checks of key systems. Benchmark machine operation with best achievable for
equipment installed.
Key Performance Indices A & B Paper Machine Energy Tracking
B PM Current Values / 24 Hour Trends
Machine BreakMachine Information
A PM Current Values / 24 Hour Trends
Machine BreakMachine Information
N N
50
32683.45.4
Machine BreakPaper Grade #Basis WeightReel Moisture
Reel SpeedSize Press Moisture
lb/3300sq ft%%fpm
89161
30572.95.1
978Machine BreakPaper Grade #Basis WeightReel Moisture
Reel SpeedSize Press Moisture
lb/3300sq ft%%fpm
N N
44.1p
Production Ratep
tph
600
Total Steam Consumption
T t l El t i it C ti
Steam
kWh/tonElectricity
lb/ton5119
34.5p
Production Ratep
tph
3597
306
Total Steam Consumption
T t l El t i it C ti
Steam lb/ton
kWh/tonElectricity
600Total Electricity Consumption kWh/ton
1413Water Consumption gal/tonWater
Energy Cost
306
1256Warm Water Consumption
Total Electricity Consumption
gal/ton
kWh/ton
2500Water Consumption gal/tonWater
Energy Cost
986Warm Water Consumption gal/ton
50.28Total Energy Cost *Energy Cost
8.2Total Energy Consumption MMBtu/tonEnergy Consumption
$/ton30.16Total Energy Cost *Energy Cost
5.7Total Energy Consumption MMBtu/tonEnergy Consumption
$/ton
Track Specific Energy Indices-Track Specific Energy IndicesTAPPI TIP 0404-63 Steam consumption (kg or lb steam/ton of paper) Electricity consumption (kWh/ton) Natural gas consumption (m3 or kscf/ton) Total energy consumption (kJ or MMBtu/ton)
W t ti ( 3 l/t ) Water consumption (m3 or gal/ton) Compressed air consumption (m3 or kscf/ton) Condensate return to power house (%) Condensate return to power house (%) Total energy cost ($/ton)
Vac m P mp Compa isonVacuum Pump Comparison
Model H4408 CL4002 904M2 Turbo Blower
Vintage 1930-1960 1960-1984 1984- 2005-Vintage 1930 1960 1960 1984 1984 2005
CFM@in Hg 4,000@20” 4,000@20” 4,000@20” 4,000@20”
RPM 257 400 327 10,000
Seal Water 100 gpm 60 gpm 65 gpm 0 gpm
Horsepower 205 180 160 80
Hp/cfm 0.051 0.045 0.040 0.020
Modern Vacuum BlowersModern Vacuum Blowers
Saves electricity and water in vacuum system
Facts• 30 to 60% power savings in vacuum system• Water free solution• Water free solution• Easy to install• Economical to own and operate• Excellent option for vacuum system rebuild• Excellent option for vacuum system rebuild
and optimization• Pumping energy recoverable• Corrosion free materials• Corrosion free materials• Fast and easy maintenance• Payback depends on electricity cost and
i f d d tenergy savings from reduced water use
True Cost of Operating Outside Best Efficiency Range
Estimated Cost of VFD Estimated installed cost of low voltage VFD:
<100 hp=$30,000150 h $40 000 150 hp=$40,000
200 hp=$50,000 250 hp=$60,000 300 hp=$70,000 350 hp=$80,000
In addition substation or infrastructure upgrades may In addition substation or infrastructure upgrades may be required.
Replacement of medium voltage motors will be more Replacement of medium voltage motors will be more expensive.
Energy Efficient Repulper gy p pRotor Blade
Energy is aEnergy is a controllable operatingoperating expense
Batch Repulper Power ResponseBatch Repulper Power ResponseThree Day Comparison
Penetration of Injection Jet into StockPenetration of Injection Jet into Stock Flow-High Velocity vs. Low Velocity
Typical Heat Recovery (4 stages)(Wi C di i )(Winter Conditions)
138 ºF sat138 F satGlycol(Building Heating)1350 usgpm
Energy recovered
25.7 MBTUH (70%)
Stage 2Stage 3
Pocket Ventilation
110 ºF94 ºF
S 1
Stage 2
111ºF 85 ºF Process Water205 usgpm
77 ºF70 ºFStage 1
Stage 4
Hood Exhaust62,430 cfm180ºF/140ºF
70 F
102 ºF sat
97 ºF sat
(3152 lbs. D.A./min)94 ºF105 ºF
final temp.