Importance of in-line colour measurement of sugar for product quality and factory performance By Tim Diringer and Bjarne Christian Nielsen Copyright Neltec 2012

20 Years ago the first colour measurement has been installed in the Danish Assens factory

Today more than 100 instruments are installed all over the world

Definition of process control

Process control is the method to keep the process and the quality of the final product inside the targets, by controlling and regulating various process parameters Definition of process control

Process product input Influencing parameters

Online data collection in a sugar factory Diffuser: Temperature, flow rate Purification: pH, level, temperature, turbidity, colour Evaporators: Temperature, pressure, level Crystallisation: Temperature, pressure, level, density Centrifugals: ???

Control, alternator,699, boiler, 643, 644, 647, cane throughput,76, chemical, 577 – clarification, 227, 228, condenser, conveyor, crystallizer, diffuser, 160, 165 – evaporator, 300, flocculant addition, juice flow, mill, pan boiling, rotary drum filter, 248, 257, 258, sugar dryer, turbine, 700 Peter Rein, Cane Sugar Engineering page 755

centrifugation Sugar massecuite Spray water Layer thickness

Leaving syrup on the crystals reduces pol, increases ash and leads to caking A combination of the two above (very common) How centrifugals influence sugar quality The centrifugals influence the sugar quality and the mill profit in 3 ways: Overwashing dissolves good sugar, generates more molasses and decreases capacity

Nowhere in processing can so much sugar be lost so quickly and with so little notice as in centrifugation

To avoid sugar losses the operator must see the result of the centrufigation process and act accordingly

Step by step to operational measurements

Lab measurements

time delay

Lab measurements time delay No information about origin of error

A factory with an output of 1200 t/d raw sugar produces 50 t raw sugar per hour 50g of sugar are used for the analysis This is 0, % of the total amount of sugar If a sample for determing the colour in soloution Is taken every 2 hours

On-line measurement fast results no information about origin of error

On-line measurement of each batch centrifugal tells something about origin of errors.

Measurement of a colour profile for each batch centrifugal pinpoints the origin of the error very operational

The instrument The Neltec ColourQ is the ideal tool to control product quality and to pinpoint process problems

Installation on a belt conveyor

installation on a screw conveyor

optimizing the centrifugals

1 st step: Get an overview of the centrifugal performance

2 nd step: learn to interprete the colour profiles

Colour of sugar in centrifugals 1 and 4 is 40 % higher than the colour of sugar in centrifugal 3

Spray nozzles of centrifugal number 1 hve been replaced

Backing screen of centrifugal 4 has been washed

Improvements at Manildra-Harwood Mill Amount of sugar within the specs increased

Improvements at Manildra-Harwood Mill Molasses purity was reduced from 44 to 41

Improvements at Manildra-Harwood Mill The amount of massecuite required to produce 100 tons of sugar was reduced from 200 tons to 195 tons

To rely on the data collected inline, the following aspects must be fullfiled: Accuracy of the instrument Reliability of the calibration

Lab control in a refinery

To ensure product quality, in line measurement is necessary In line colour measurement helps the operators to understand the process Time span from occuring to solving of a problem is reduced dramatically Capacity increases and sugar losses decrease Conclusions

"To measure is to know" (Lord Kelvin, 1883)

Thank you for your attention!

Questions?