Process control in spray drying FrieslandCampina, young company ...

Process control in spray drying FrieslandCampina, young company ...

Process control in spray drying FrieslandCampina, young company ...


Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

<strong>Process</strong> <strong>control</strong> <strong>in</strong> <strong>spray</strong> dry<strong>in</strong>gJohn Niederer, Frank JeurissenDecember 3 rd 2009FrieslandCamp<strong>in</strong>a, <strong>young</strong> <strong>company</strong> long history

Our membersBus<strong>in</strong>ess GroupsDefend andexpand coreactivitiesExpand <strong>in</strong>growth marketsDefend andexpand coreactivitiesCreate newopportunities

FrieslandCamp<strong>in</strong>a DomoIngredients Bus<strong>in</strong>ess Group Royal FrieslandCamp<strong>in</strong>aMarkets:Infant nutritionInfant formula:0 – 6 monthsFollow on formula:6 – 12 monthsGrow<strong>in</strong>g Up Milk :1 – 6 yearsProducts• Ingredients• Base powders• Total formulation

Markets:Medical nutritionProducts• MPC’s• Specialty prote<strong>in</strong>blends powder• Case<strong>in</strong>ates• Hydrolysates• Base powders• Total formulationMarkets:Cell cultureCell culture media forproduction ofbiopharmaceutical drugsMicrobialdiagnosticsMicrobial test<strong>in</strong>g formedical diagnosesProducts• Hydrolysates

Markets:PharmaceuticalexipientsB<strong>in</strong>ders and fillers forpharma applicationsProducts• Direct CompressionLactose• Wet GranulationLactose• Inhalation LactoseWhey process<strong>in</strong>gWhey storageEvaporatorCrystalliserCentrifugeFluid beddry<strong>in</strong>gPackag<strong>in</strong>gLactoseFeedSpray towerPackag<strong>in</strong>gUltra filtrationEvaporatorWhey Prote<strong>in</strong>ConcentratesMa<strong>in</strong>ly water removal…Spray towerPackag<strong>in</strong>g

Spray Dry<strong>in</strong>g: some typical problems• Different products, different recipes, same tower;• Clean<strong>in</strong>g In Place (microbiology, crosscontam<strong>in</strong>ation);• Energy expensive/relatively <strong>in</strong>efficient (ca. 10 timeshigher than evaporation);• Powder moisture content, its standard deviation andspecification;• Dry matter content variation <strong>in</strong> substrate;• Throughput;• (Manual) <strong>control</strong>;• …Concentrateflow rateFICOperator ManipulatedVariablesOperator MonitoredVariablesDryer <strong>in</strong>let airtemperatureDITICTICDryer outlettemperatureFB <strong>in</strong>let airtemperatureTICAIPowdermoisture

Some disadvantages current tower <strong>control</strong>:• Moisture measurements by hand, every few hours;• Control changes slow and by hand;• t delay moisture content from residence time bed;• Operation strongly dependent on operatorexperience;• Operator runs safe (i.e. not too close to spec);• Operator has to react on variations ambient (e.g.approach<strong>in</strong>g hail storm);• …Hence: operation usually not optimal!Actual powder moisture of a WPC: vochtigheid (%) jan-07 apr-07 aug-07 nov-07 feb-08 jun-08 sep-08 dec-08

Advanced <strong>Process</strong> ControlUse of a statistical multivariable model to predictprocess behaviour to reduce process variation.Subsequently, move closer to process limits:SPECIFICATION OR LIMITBEFORE APCWITH APCWITHOPTIMIZATIONModel development APCDevelop multivariate dynamic model from statisticalanalysis step changes.Model predicts direction, shape and size of response.

Expected results Advanced <strong>Process</strong> Control• Decrease <strong>in</strong> standard deviation moisture;• More constant product quality;• Higher average moisture content powder (sellexpensive water);• Decrease <strong>in</strong> specific energy consumption;• Increase <strong>in</strong> throughput (shorter batch time);• Possible <strong>in</strong>crease <strong>in</strong> production capacity (if extracapacity can be sold).APC trial with Connoisseur (Invensys)Three stages with go/no go decision:• Benefit study; based on analysis production data(few weeks);• Implementation trial; develop <strong>control</strong> and proveresults Benefit study (5-6 weeks);• F<strong>in</strong>al implementation (4-5 weeks).

APC: Benefit studyBased on high frequency production data:• Typical average moisture content ca. 1-1.5% belowspecification (product dependent);• Typical standard deviation moisture content ca.0.3%.Prediction results APC:• 5% reduction <strong>in</strong> specific energy consumption;• 5-10% <strong>in</strong>crease <strong>in</strong> throughput (product dependent).APC: Implementation trialDevelopment of two models:• Steady state model of optimisation function;• Dynamic model for the predictive <strong>control</strong> function.Reason 2 models: moisture content too <strong>in</strong>frequent(e.g. 2 h).Moisture can therefore not be part of a dynamic<strong>control</strong>ler.

Feed pump speedT outletT <strong>in</strong>letSteady state OptimiserPowder moistureAir HumidityOutlet air humidityCalculated setpo<strong>in</strong>ts for:- outlet air temperature;- humidity.Feed pump speedT outletT <strong>in</strong>letDynamic MPV <strong>control</strong>lerAir HumidityOutlet air humidityExample step change:

Some key relationships:Feedrate vs. T outlet :T <strong>in</strong>let vs. T outlet :Feedrate vs. RH outlet :Implementation trial: without APC

Implementation trial: turn APC onResults implementation trialRun 1Run 2∆ moisture (%)+ 0.9%+ 0.5%∆ feedrate (l/h)∆ T outlet(°C)+ 10.2%- 13°C+ 14.0%- 10°CHowever: runs <strong>in</strong> December, ambient below 0°C!

Conclusions• APC trial performed on dairy <strong>spray</strong> dryer;• Increase <strong>in</strong> powder moisture of ca. 0.7%;• Increase <strong>in</strong> throughput exceed<strong>in</strong>g 10% (with idealdry<strong>in</strong>g conditions, i.e. cold outside);• Increase <strong>in</strong> throughput comparable to expectationsBenefit study;• No significant <strong>in</strong>crease <strong>in</strong> steam consumption;• Operators happy with the system!Control Challenges• Start up / shut down optimisation / CIP• Inl<strong>in</strong>e QC (Soft sensors)• Incorporation first pr<strong>in</strong>ciple models• Proces <strong>control</strong> for batch systems- L<strong>in</strong>e <strong>control</strong>, e.g. evaporator/dryer orevaporator/crystalliser/dryer- L<strong>in</strong>e optimisation• Plann<strong>in</strong>g & scenario development- site wide- <strong>in</strong>ter site

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!