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Enhanced Process Control Through Advanced Instrumentation
1. Introduction2. Working principle3. Installation points4. Practical cases
“If you cannot measure it,you cannot improve it.”
Lord Kelvin, Engineer/Philosopher(1824‐1907)
On‐line contactless sensor• Accurate measurement of the water mass in paper & pulp sheet
• Universal calibration for all grades• Advanced, microwave technology• No required microwave reflectors• Non‐radioactive• Non‐sensitive to colour, fogging or surface appearance
• Output in gr/m2, oz/ft2 or %• Fixed point or cross beam available
1. Introduction2. Working principle3. Installation points4. Practical cases
Method of Measurement Sensor Operation• Planar Microwave Sensor
Microwaves vs. NIR (near infrared)Water molecules are stimulated
throughout the entire sheet thickness
Short microwave technology Near infrared sensor
Limited to a penetration of 3 microns
Contactless moisture meter ‐ Data specs• Working distance from the pulp & paper sheet: 3‐10 mm
• Accuracy: 0,02/0,2%• Calibration: universal for all grades• Sampling rate: 1024 sps• Sensor network connection: Ethernet• Connection to control unit: Up to 16 sensors connected• Connection to DCS: via control hub 4‐20mA or Ethernet• FFT capabilities: trough PC software supplied with the unit• Normalization: through a special normalization glass• Normalization intervals: suggested once per month
1. Introduction2. Working principle3. Installation points4. Practical cases
Installation points
Best position
Possibleposition
Free draw
Contactless microwave
sheet moisture meter(Fixed point)
Contactless microwavesheet moisture meter
(CMD profile)
Microwave consistency meter
(Fixed point)
To DCS
Fixed point
1. Introduction2. Working principle3. Installation points4. Practical cases
“Does higher vacuums alwaysequate to more drainage?”
Theory of dewatering in formingThe dewatering paradox.
• Vacuum @ suction boxes:‐ 50%
• Dryness @ couch roll:+ 0,8%
• Steam pressure‐0,5 bar
Results:• Vacuum reduction• Steam saving• Kw/h drive load reduction• Higher dryness @ couch• Higher fabric & foils life
6 hours
Dry content when changing the vacuum settings in %
1.3
1.4
1.5
1.6
1.7
1.8
1.9
14
15
16
17
18
19
20
%%
Dryness before CR Dryness before Top former
‐2
‐1
0
3
5
7
Kpa
bar
S5 pressure After dr Vac B11
Contactless moisture meter – DCS trends
0
5
10
15
20
25
30
0
50
100
150
200
250
300
350
400
450
500
9:47 AM
Solids gr/m2 SmartScan gr/m2Reel Speed m/min t/hSteam Flow Specific steam consumption t/tMoisture at reel
Contactless moisture meter – DCS trends
2
2.2
2.4
2.6
2.8
3
3.2
3.4
0
50
100
150
200
250
300
350
400
450
500
t/t
gr/m
2
Solids gr/m2 SmartScan gr/m2 Specific steam consumption t/t
Contactless moisture meter – DCS trends
• Sensor was installed between the third press and the first dryer.
Contactless moisture meter – DCS trends