paradigms behind the cafÉ applications
TRANSCRIPT
PARADIGMS BEHIND THE CAFÉ APPLICATIONS
EFFOST 2012 20-23 NOVEMBER, MONTPELLIER
Food Industry
Ingredients Raw materials
Food products
•High quality and safe products •Wide product variety (Short life cycles)
Consumer’s objectives
•To maximize operation efficiency •Flexible design and operation
•To minimize Energy, Water •To minimize environmental impact
Process objectives
State of the art food process control …
STATUS OF THE FOOD INDUSTRY MONITORIZATION / DATA MANAGEMENT
AUTOMATION / CONTROL
Mathematical Models
Models …in Food Science and Technology … … What are they good for?
Mathematical Models
Models to understand mechanisms
Models to design processes
Mathematical Models
Over-processing
( important quality loss)
Optimal operation (model based optimization)
Better solutions
Unfeasible solutions
(safety condition is not satisfied)
Solution by means of a Surface Response Approach
Mathematical Models
Models for Control
…About a map with ….the size of a Empire … (J.L. Borges)
Mathematical Models
The modeling paradigm
Spatial scale
Tim
e sc
ale
Constitutive relations Physico-chemical Property models
Microscopic balances Mass, Energy, Momentum
Macroscopic balances Mass, energy, Momentum
Inventory balances
Chemical And
Biochemical networks
SPATIO-TEMPORAL SCALES IN TRANSPORT PROCESSES
The modeling paradigm
Full Simulation -8 state variables -1800 fem -solution in 1.5hrs
The modeling paradigm
The modeling paradigm
Proper Orthogonal Decomposition (POD)
Results with 31 ODE
Mathematical Models
Case studies … … and Paradigms ….
FREEZE-DRYING (preservation)
MECANISMS
FREEZING
PRIMARY DRYING
(sublimation)
SECONDARY DRYING
(desorption)
(I)
(II)
Freeze-drying
GOOD BAD
Standard cycle 36hr
Microscopic balances Mscarenhas et al (1998) Comp Methods Appl. Mech. Eng 148: 105-124
Freeze-drying
Mass balance
Energy balance
Freeze-drying
Moving boundary problem with adaptive mesh and specialized software (COMSOL)
Simplifying system
Alternative: Landau Transformations
Freeze-drying
Equations in the Landau transformed space
Boundary conditions Stephan conditions
Freeze-drying
Parameter Estimation
Model performance
ON-LINE OPTIMAL CONTROL … some results
Control
ON-LINE OPTIMAL IMPLEMENTATION … some results
Control
Batch thermal processing Thermal processing
Batch thermal processing Thermal processing
Thermal processing
Batch thermal processing
CONCLUSIONS … and more ? …
CAFE
Models are central in FOOD PROCESS CONTROL to ensure optimal quality/safety
SCALE MULTIPLICITY as the main obstacle to modeling food
OPERATIONAL MODELS are reduced order models in connection with measurements
THANK YOU!!