Transcript Sensor Selection: Still an Issue in Sugar Crystallization

SeedMaster and SeedMaster 2
in advanced sugar crystallization control
Striving for perfection of forms
in nature
and
in the crystallizer.
K-PATENTS OY
Finland
PROFICON KFT.
Hungary
PROCESS CONTROL KFT.
Hungary
JOINING FORCES TO HELP YOU TO DO IT BETTER
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The main issue: product quality and cost of production
Large amount of fines
(Scale : 1 by 1 mm)
Conglomerates
2
Poor product quality results in high cost of production
Pan farm
Product screen
Product crystals
Mixer
Fines and conglomerates
Melter
Centrifugal station
Tank
Green liquor and fines
Re-circulated fines and conglomerates
RE-CIRCULATION OF CRYSTALS MEANS:
• Waste of energy and time.
• Decreased production capacity (tons of product per hour).
• Increased use of water.
• Throwing out money and facing a bleak future.
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Supersaturation: the most important parameter in
crystallization

Supersaturation = sugar in solution / sugar at saturation
Supersaturation = f (C, Q, T, m, b, c)
C : syrup / mother liquor concentration (%)
Q : syrup / mother liquor purity (%)
T : temperature ©
m, b, c : syrup quality parameters ()
Largest sensitivity to liquid concentration.

1.
2.
Important notes:
Supersaturation is a multivariable function (no single measurement is
able to provide data on it).
To calculate it, syrup / mother liquor concentration has to be
measured even when crystals are already present.
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Supersaturation limits
Critical supersaturation limits to avoid unwanted nucleation
(M.Saska: International Sugar Journal, 2002, 500…507)
CRITICAL SUPERSATURATION LIMITS
M.Saska: ISJ. 2002, Vol. 104., No.1247, 5001,2
SUPERSATURATION
1,19
T = 60 C
1,18
1,17
1,16
1,15
T = 70 C
1,14
1,13
T = 75 C
1,12
T = 80 C
1,11
1,1
74
76
78
80
82
84
86
88
90
92
94
96
98
100
102
MOTHER LIQUOR PURITY (%)
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The lessons to learn
1.
Supersaturation is the most important parameter of crystallization.
2.
Monitoring and control of supersaturation is extremely important not only for reliable
automatic seeding, but during the full course of crystallization.
3.
4.
5.
6.
7.
In monitoring supersaturation during a complete strike the first task is to measure liquid
concentration selectively, that is undisturbed by crystal content. Only the process
refractometer is able to do that.
Besides supersaturation a second massecuite parameter correlated to crystal content is
also required.
There is no direct way to measure supersaturation and crystal content.
The myth of a single-parameter sensor imitating playing a double role perfectly is perfectly
ungrounded and misleading.
Instead of data of questionable value, like conductivity, capacitance, density etc.,
advanced sugar crystallization requires relevant and meaningful data, most of all:
supersaturation to improve crystallization practice.
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SeedMaster software option for on-line calculation of
supersaturation and automatic seeding
SeedMaster supersaturation data
and trend display (refinery in Finland)
K-PATENTS process
refractometer PR-01-S
SeedMaster supersaturation data
(United Sugar Refinery, Jeddah, Saudi Arabia)
More in the USA (6), Colombia,
Peru, Iran etc.
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SeedMaster 2: a unique device for sugar
crystallization control
Inputs : syrup / mother liquor concentration (refractometer),
temperature (refractometer or transmitter),
density OR brix OR stirrer motor consumption transmitter.
Outputs: supersaturation
crystal content
mother liquor purity
density
massecuite solids content
mean crystal size
consistency
SeedMaster 2
()
Type of outputs:
(%)
4 – 20 mA
(%)
digital data transm.
(kg/m3) (serial and Ethernet
(brix)
Modbus)
(mm)
(%)
Main features:
• transmission of up to 7 massecuite parameters
• automatic seeding based on supersaturation or density set-point
• advanced local operators’ station features
• can serve 2 crystallizers simultaneously
• operating temperature range: 5 – 50 deg. Celsius
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An example of SeedMaster 2 application
Components
K-PATENTS OY :
PR-01-S / PR-23-GP
refractometer(s)
PROCESS CONTROL KFT.: SeedMaster 2
PROFICON KFT. : Consultation, training
THIRD PARTY :
Standard transmitter
LOCAL LABORATORY :
Data input
MOTOR CONS.
DENSITY
THIRD PARTY TRANSMITTER :
DENSITY
THIRD PARTY TRANSMITTER:
MOTOR CONSUMPTION
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The many faces of a unique device
Data and trends of important parameters
for the last 4 strikes (per pan)
Main display
Trending supersat. and cryst. cont.
Supersaturation and brix
Supersaturation and cryst. cont.
Trending s.sat. and m.liq. purity
Strike history on supersaturation
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COMPARING performance of any known single sensor
and the K-PATENTS refractometer + SeedMaster 2
combination
Is or can supersaturation be measured or calculated?
Single sensor SeedMaster 2
NO
YES
Is it good practice to use it for reproducible seeding?
NO
YES
Is it able to accomplish reliable automatic seeding?
NO
YES
Is it sufficient for syrup feed control?
YES
YES
Approx.
YES
Does it provide information on crystal content?
Is advanced crystallization control possible with its use?
NO
YES
Does it provide all the required information on a strike?
Far from it Even more
Can it be used in manual and automatic control, too?
With
compromise
YES
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Comparing SeedMaster and SeedMaster 2
SeedMaster
Refractometer
:
Extra hardware :
Software
:
Calculated parameter :
Data output
:
Data trend displ. :
Automatic seeding:
Strike history
:
SeedMaster 2
PR-01-S
not needed
yes, option
supersaturation
1x 4 – 20 mA
supersaturation
yes
supersaturation
trend for 1 strike
Number of crystallizers served:
1
Some of the references
:
USA (6), Iran (8), Colombia (3),
Peru (2), Saudi Arabia (1), Thailand (1)
Refractometer :
PR-01-S, PR-23-…
Extra hardware :
yes, needed
Software
:
yes, included
Calculated parameters :
supersaturation
+ 6 additional ones
Data output
:
2x 4 – 20 mA, digital
(per pan)
transm. (all of the param.)
Data trend displ. :
11 param. for 4 strikes
Automatic seeding:
yes
Strike history
:
yes (4 strikes)
Number of crystallizers served:
2
References
: Thailand (1), new device
Paper in the Intern. Sugar Journal
in December, 2006.
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SeedMaster and SeedMaster 2
Common features :
1. Both devices are unique without competition.
2. Both rely on the use of K-PATENTS process refractometers.
3. Both are based on experience gained by PROFICON in sugar crystallization control
during more than two decades.
SeedMaster :
1. The software option is sold by K-PATENTS representatives worldwide.
2. Product support: PROFICON Kft., Hungary.
SeedMaster 2 :
1. SeedMaster 2 and refractometers can be ordered from K-PATENTS OY, Finland or
from its representatives.
2. SeedMaster 2 can be ordered from the manufacturer and support companies
(see below).
3. Manufacturer: Process Control Kft., Hungary.
e-mail: [email protected]
Web: www.processcontrol.hu
4. Product support: PROFICON Kft., Hungary.
e-mail: [email protected]
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