Metso Cooking Liquor Measurement - Autekautek.no/datasheets/KEMOTRON-METSO/3400_001.pdf · 3400...
Transcript of Metso Cooking Liquor Measurement - Autekautek.no/datasheets/KEMOTRON-METSO/3400_001.pdf · 3400...
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Metso Cooking Liquor Measurement3400
Digester control
Continuous monitoring of alkali
charging and all cooking phases
Updated EA/AA concentration
every second
Reducing the Kappa variations
by up to 50%
Reducing the overall chemical
consumption
Low maintenance
Automatic scaling compensation
Continuous Lo-Solids
Batch RDH
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Inline Cooking Measurement
Continuous measurement is essential for
performing e cient digester control.
The sensor of the Cooking Measurement
is constructed for direct installation into
the liquor circulation. Based on the signals
from the sensor, the Measurement provides
continuous EA/AA measurement.
Deposits on an in-line sensor can be sub-
stantial, but the sensor design of the Metso
Alkali Measurement limits the building-up
of deposits as well as the e ects hereof.
The sensor will measure conductivity from
all available ions.
When substantial changes in the composi-
tion occur, it may be necessary to perform a
1- or 2-point calibration.
However changes in the S% by 5 will result
in the EA being o by just 1%, without
corrections.
Terms of alkalinity, etc.
• Active Alkali, AA = NaOH + Na2S
as NaOH or Na2O (g/l)
• E ective Alkali, EA = NaOH + 1/2 Na2S
as NaOH or Na2O (g/l)
• Sulphidity, S% = x 100(%)
• Degree of causticizing,
C% = x 100(%)
Na2S
NaOH + Na2S
NaOH
NaOH + Na2CO
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The sensorsThe rugged 4-electrode sensor is made of stainless
steel with the electrodes mounted on the outside
of an isolator (PTFE). Within a measuring diameter
of 200 mm (8”) diameter around the sensor elec-
trode, a current is measured between one pair of
electrodes and the potential di erence between
another pair of electrodes.
This picture illustrates how heavy the scaling can
become while still having a functional sensor due to
automatic balancing of the measuring eld. In addi-
tion the Measurement provides scaling indication.
The resultsSpeci! ed accuracy: 1–2 g/l EA Na
2O compared to
laboratory ABC tests (avg. of min. 3 samples from
each test point).
Results from a Scandinavian mill with a Metso
Cooking measurement installed in the white liquor
loading show deviations of only 0.5 g/l. Moreover
the Metso sensors require less than 8 hours service
per year.
Circulation Measuring Standard range deviation
g/l NaOH (STD)
Transfer 14–29 g/l 1.4 g/l
Trim 14–37 g/l 0.9 g/l
Upper
extraction liquor 9–13 g/l 0.5 g/l
Lower
extraction liquor 6–13 g/l 0.4 g/l
Extraction 4–13 g/l 1.0 g/l
Results from installation in various cooking
circulations.
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Batch process
A mill installed a Metso Measurement in the cook-
ing circulation of each batch digester.
Metso Cooking Measurement installed in the circula-
tion pump of a SuperBatch digester.
In this way the mill was able to monitor the alkali
level and thus the consumption of alkali. When a
deviation from the standard cooking cycle oc-
curred, the mill was able to adjust the after-feed of
white liquor to the digester and thus compensate
for the variations before the cook was ! nished. This
improved the mill’s ability to reduce variations in
the Kappa number.
Continuous process
A mill installed a Metso Cooking Measurement in
the C6 trim circulation to be able to detect varia-
tions in the alkali concentration caused by plugging
in the boiler or by variations in the alkali of the
white liquor or in the pulp quality.
Metso Cooking Measurement installed in the C6 trim
circulation in a continuous digester.
With the continuous measurements and the
counteraction against variations in the alkali
concentration, the mill reported a decrease in the
Kappa-variations from ±6 to ±3.
Lo-Solids process
The Lo-Solids digester contains a number of
recirculation loops in order to remove the dissolved
wood solids from the system as well as to control
the alkali concentration by addition of white liquor.
To compensate for variations in the cooking liquor a
mill installed a number of Metso Cooking Measure-
ment to be able to adjust the white liquor feed on
an on-line basis.
Kraft pulp mill applications
Continuous Clari! ed white liquor
process Transfer circulation
Trim circulation
MCC circulation
ITC circulation
Lower counter current loop
Recirculation
Extraction
Lo-Solids Clari! ed white liquor
Recirculation
Upper extraction liquor
Lower extraction liquor
Modi! ed cooking circulation
Wash circulation
Extraction
Batch process Clari! ed white liquor
Hot black liquor
Warm black liquor 2
Hot white liquor
Cooking liquor
RDH process Clari! ed white liquor
Warm ! ll liquor
Hot ! ll liquor 1, 2, and 3
Circulation liquor
Cooking liquor
M&D sawdust Clari! ed white liquor
Pulp to the second
postdigester
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For more information, contact your local automation expert at Metso.
www.metso.com/conductivity
The information provided in this brochure contains descriptions or characteristics of performance
which in case of actual use do not always apply as described or which may change as a result of
further development of the products.
An obligation to provide the respective characteristics shall only exist if expressly agreed in the
terms of contract. Availability and technical speci cations are subject to change without notice.© M
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Installation of the Metso Cooking Measurement
Metso Cooking Measurement sensor installed in a measuring pipe. It is placed in a bypass loop, thus providing
safe withdrawal of the sensor during the digester operation in case of the need for removal of any substantial
deposits.
A rack of Cooking Measurement monitors and sensors. Sensor mounted in-line.
Cooking liquor
Cooler
Sample
Measurement
Measuringpipe
Mounting across a pump
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For more information, contact your local automation expert at Metso.
www.metso.com/conductivity
The information provided in this brochure contains descriptions or characteristics of performance
which in case of actual use do not always apply as described or which may change as a result of
further development of the products.
An obligation to provide the respective characteristics shall only exist if expressly agreed in the
terms of contract. Availability and technical speci cations are subject to change without notice.© M
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Metso CookingLiquor Measurements3400Speci! cations Concentration ranges: 27 preprogrammed recipes for circulating loops of batch and continuous digesters
Output: Two current outputs 4 - 20 mA for concentration, conductivity or temperature
Temperature measurement: –40 to +250°C
Display: LCD Sensor connection: Series 4000 sensors with 11-pole strip connector and MF20 cable adaptor
Local or remote measuring range selection: Four cooking set-up modes.
Control voltage: 12 – 30 V DC
HART® communication is available EnclosureMaterial: Cast aluminium, PE coated
Protection: IP67
Dimensions: 144 x 144 x 107 mm
Mounting: Panel, wall or pipe Ambient temp.: -10 to + 60°C
Storage temp.: -20 to + 70 °C
Weight: 2.3 kg
Wall Panel
Pipe
Mounting options
Pipe mounting kits
Type For pipeNo. dimension
4902 a 25-38 mm b 35-52 mm c 50-73 mm d 72-94 mm e 82-114 mm
Dimensions
Wall mounting Type 3407 Type 3417
Panel mounting Type 3408 Type 3418
Power supply Loop powered Line powered
16 – 30 V DC 85 – 265 V AC,
on mA1 6 VA
Alarm No alarm Two relays
250 V AC, 8 A
Display Non-Illuminated illuminated
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For more information, contact your local automation expert at Metso.
www.metso.com/conductivity
The information provided in this brochure contains descriptions or characteristics of performance
which in case of actual use do not always apply as described or which may change as a result of
further development of the products.
An obligation to provide the respective characteristics shall only exist if expressly agreed in the
terms of contract. Availability and technical speci cations are subject to change without notice.© M
ets
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World wide support for Metso Concentration Measurements
Go to www.metso.com/conductivity to nd your local expert