masutti tissue machine improvements

INTERNAL

Tissue Machine Improvements

Carlos Masutti

INTERNAL

Tissue Machine ImprovementsValmet Portfolio

31 May, 2016 © Valmet | C. Masutti / Tissue Machine Improvements2

Air System

Headbox

Yankee Section

Suction and

Press Section

Felt Section

Wire Section

Reel Section

Creping Section

Roll Wrapping

and Handling

Dust ControlRefining Screening

Audits

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Tissue Machine ImprovementsEnergy Saving Platform

About 70% of the mill energy is used in the drying process

Yankee hood/yankee dryer are the highest energy consumers

Valmet can help saving energy in different ways

Reduced costs, higher profitability, protection of environment


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Tissue Machine ImprovementsEnergy Studies and Service Optimization

Step 1

Concentrate on

most potential areas

in process

Process

measurements and

testing at mil site

– Data collection

– Analysis of measured

data

– Comparison with

similar TM´s

Step 2

Direct On-Field

optimization based

on Step 1 results

– Immediate savings by

system optimization

Step 3

Report results and

identify realistic

potential

improvement areas

and propose:

– Short term

improvements

– Medium term

improvements

– Long term

improvements


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Tissue Machine ImprovementsStarting points

Yankee Hood and Air System

Yankee Dryer

Paper measurements

Hood & air system mechanical

– Inspection (optional)

Other possible areas

– Building Heating and Ventilation

– Etc…


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Tissue Machine ImprovementsStep 1 – Measurements and Benchmarking


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Tissue Machine ImprovementsStep 2 – On Field optimization based on Step 1 results


Typical recommendation

– Increase air humidity

– Restore hood balance

– Reduce excessive combustion air

5,0

4,0

3,0

2.0

1,0

0,1 0,2 0,3 0,4 0.5

Constant impingement velocity

Exhaust air humidity (kg H2O/ kg d.a.

Sp

ecif

ic E

ner

gy C

on

sum

pti

on

(MJ/k

g H

2O

)

450°C

350°C

250°C

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Tissue Machine ImprovementsStep 3 – Report Results


Typical recommendation

– Increase air humidity

– Restore hood balance

– Reduce excessive combustion air

WEDE

m=2,805 kg/s

Yankee speed: 1260 mpmBW at reel: 17,2 g/m2

m = mass flow [kgDA/s]V = volumetric flow [m3/s]t = temperature [°C]x = humidity [kgW/kgDA]

m=0,874 kg/sV=0,753 m3/st=23°Cx=0,010 kg/kg

m=0,921 kg/sV=0,663 m3/st=13°Cx=0,005 kg/kg

m=11,434 kg/sV=33,70 m3/st=391°Cx=0,379 kg/kg

m=0,895 kg/s

1185 rpm

838 rpm

85%

HE

by-passed

m=2,690 kg/sV=7,55 m3/st=297°Cx=0,439 kg/kg

1185 rpm3470 rpm 3470 rpm

m=4,607 kg/sV=10,22 m3/st=302°Cx=0,210 kg/kg

m=0,799 kg/sV=0,688 m3/st=23°Cx=0,010 kg/kg

m=1,003 kg/sV=0,722 m3/st=13°Cx=0,005 kg/kg

m=14,682 kg/sV=35,80 m3/st=402°Cx=0,195 kg/kg

50%45%

100%

287 sm3/h 264 sm3/h

p=-1050 Pa

p=-500 Pa

p=+4400 Pa

p=-290 Pa

p=+4560 Pa

p=-680 Pa

p=+14440 Pa

p=-430 Pa

p=+14100 Pa

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Tissue Machine ImprovementsStep 3 – Realistic potential improvement


Short term

Survey / Machine

• Fine tuning

• Energy usage

• Personnel

training

Indicative energy

saving per year

1

5%

Medium term

Survey / Machine

• Equipment or

system

replacement /

modification

Indicative energy

saving per year

2

10%

Long term

Study and use of

alternative energy

(cogeneration,

etc.)

• Adjustment of

existing equipm.

Indicative energy

saving per year

30%

P

M

2Eco

Diverter

Postburner

Boiler Boiler Atm.

Atm.

Atmosfera

3

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Tissue Machine ImprovementsAir System Balance


INTERNAL



Over Pressure

Under Pressure

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each Kg/s of blown/sucked air, fuel cost 35€/MWh

Wasted hot air

If the hood is in overpressure... If the hood is in underpressure...

Reheated cold air

INTERNAL

Tissue Machine ImprovementsAir System Balance – Overpressure


Fires DamagesBad

ProfileLosses

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Tissue Machine ImprovementsAir System Balance – Underpressure


Wet Edges

DustPlugging

& Fires

Production losses

INTERNAL

Tissue Machine ImprovementsAir Humidity


5,0

4,0

3,0

2.0

1,00,1 0,2 0,3 0,4 0.5

Constant impingement velocity

Exhaust air humidity (kg H2O/ kg d.a.)

Speci

fic

Energ

y C

onsu

mption (

MJ/

kg H

2O

)450°C

350°C

250°C

Higherhumidity

Lower exhaust

air mass flow

Lower

Make-up

Less air to be heated to the hood blowing temperature

Lower burner consumption

INTERNAL

Tissue Machine ImprovementsDrying cost


15600

15700

15800

15900

16000

16100

16200

16300

16400

16500

16600

350 370 390 410 430 450 470 490 510 530 550

KWe_cost/KWt_cost=3.6




Total drying consumption calibrated to gas/elect cost ratio Gas+Steam+Elect*(Kw/h.e_cost/KW/h.t_cost)

Hood temperature [°C]

Tota

l D

ryin

gcosnsum

ption

[KW

h]

Total drying cost depends on the

cost ratio between gas and electricity.

The optimal working point can be different for

every machine/production/energy cost

INTERNAL

Tissue Machine ImprovementsHow to keep it on the best setting?


AIR SYSTEM BALANCE

IMPINGEMENT SPEED

IMPINGEMENT

TEMPERATURE

EXHAUST HUMIDITY

Automatically defines and

maintains optimal air system

conditions

Ensure constant lower

point consumption

INTERNAL

Tissue Machine ImprovementsABC – Advantage Balance Control


F F

F

F

MT

TT

T

• personalized algorithm

• set of sensor installed on the hood

and air system

• detecting and adjustment of the

drying parameters

• detecting and adjustment of the air

system flow characteristics

Flow measurements Moisture measurementsTemperature measurements

INTERNAL



T

TT

T

F F

F

F

M

ABCControl panel

DCSExisting

control

systemDedicated

ADLS/3G/4G

And SAFE

industrial router

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• accessible from local net or through a VPN connection

• ABC pages accessible through internet connection and web

browser

• sampling and calculating time 15 s

• hundreds of variables stored and used for recurring reports

INTERNAL

Tissue Machine ImprovementsHood Internal


Distribution box

Crescent header

Insuflation boxes

INTERNAL

Tissue Machine ImprovementsHood Profile – The Challenge


Do we have uniform CD temperature and CD blowing

speed profiles in existing Yankee Hoods?

Do we have same temperature

in these two points?

Do we have same blowing speed

in these two points?

INTERNAL

Tissue Machine ImprovementsHood Profile – Partial Solution


We can control the uniformity of CD temperature and CD blowing

speed by designing so called staggered crescent headers?

Staggered crescent headers

give uniform CD evaporation

But we need to operate wet and dry end

hoods with about same evaporation rate

Wet end hood

Dry end hood

Wet and dry end hood sections

cannot be operated independently

Wet end has normally more

evaporation than dry end

INTERNAL

Tissue Machine ImprovementsHeli Hood


Uniform CD

temperature and CD

blowing speed in wet

end hood

Uniform CD

temperature and CD

blowing speed in dry

end hood

Both hood sections can

work independently

with their own blowing

temperature and

blowing speed

Uniform paper moisture

profile with all blowing

temperature and

blowing speed

combinations

CD profiles after each

hood section are

uniformPatent pending

INTERNAL

Tissue Machine ImprovementsHeli Hood - Design


Patent pending

A B

Blowing temperature and

blowing speed difference

in points A and B have

«no meaning» anymore

Location of points A and B

is different in all cross

nozzle boxes

CD profiles after each

hood section are uniform

INTERNAL

Tissue Machine ImprovementsDrying profiling capability - conventional hood


The impingement speed has the typical ”sawtooth”

profile, so the dryness control under each chamber is

limited

damper postion [%] 100 60 100 100

impingement speed [m/s] 120 90 120 120

sheet strip time under chamber [%) 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

avg impingement speed on sheet strip avg 120 120 120 120 120 120 120 120 120 120 120 90 90 90 90 90 90 90 90 90 90 120 120 120 120 120 120 120 120 120 120 120 120 120 120 120 120 120 120 120 120

0

20

40

60

80

100

120

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41

360 mm 360 mm 360 mm 360 mm

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Tissue Machine ImprovementsExample – What happens with a conventional hood?


damper postion [%] 100 100 100 100

impingement speed [m/s] 120 120 120 120



0

20

40

60

80

100

120

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41

360 mm 360 mm 360 mm 360 mm

0

5

10

Mo

istu

re a

t re

el [

%]

NO WAY TO CONTROL!

INTERNAL

Tissue Machine ImprovementsDrying profiling capability – Advantage AirCap Heli


The impingement speed profile can be ”tuned and

combined”, in order to build a profiling drying curve.

That in turn allows a better profiling capabilty.

damper postion [%] 100 100

impingement speed [m/s] 120 120


damper postion [%] 100 60 100

impingement speed [m/s] 120 80 120



0

20

40

60

80

100

120

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41

360 mm 360 mm 360 mm 360 mm

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Tissue Machine ImprovementsDrying profiling capability – Advantage AirCap Heli


damper postion [%] 100 80

impingement speed [m/s] 120 100


damper postion [%] 80 60 80

impingement speed [m/s] 100 80 100



0

20

40

60

80

100

120

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41

360 mm 360 mm 360 mm 360 mm

0

5

10

Mo

istu

re a

t re

el [

%]

FLEXIBLE AND EASY SYSTEM

TO CONTROL!

INTERNAL

Tissue Machine ImprovementsAirCap Heli - Conclusions

AirCap Heli allows a much

better peaks of moisture

control, specially in very small

distances between peaks

To get the best of AirCap Heli

profile control Valmet is

developing a fully automatic

control system


P

1P2

P3

P4

P5

P...

INTERNAL

Tissue Machine ImprovementsAdvantage ReDry Concept


INTERNAL

Tissue Machine ImprovementsAdvantage ReDry Benefits

PPRC increases up to 2%

Reduces energy consumption

Air is “free”

Possible to clean without

shutting down the machine


INTERNAL

Tissue Machine ImprovementsAdvantage ReTurne

Jet going to saveall still carries

a huge amount of energy!

ReTurne is an Energy Recover

system

Recovers up to 50% of Jet

Energy

Energy fed into Fan Pump

system


INTERNAL

Tissue Machine ImprovementsNIP Measurement & Calibration

Press load compromises:

Safety

Paper profile

Felt and roll cover wear

Coating

Runnability

Measures and calibrate NIP

load

Ensure NIP profile


INTERNAL

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