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2. Food Traceability. ISO definition Traceability is the
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1. 1 Dynamic Simulation Model for tracking grain lots in an elevator AE 503 Term Project
Maitri Thakur
Agricultural and Biosystems Engineering
May 2, 2007
2. 2 Food Traceability ISO definition
Traceability is the ability to trace the history, application, or location of that which is under consideration.
A grain of wheat or a truckload
A standard location size (field, farm, or county)
A list of processes that must be identified (pesticide applications or animal welfare)
3. 3 Food Traceability Respond to security threats
Respond to food safety problems
Document chain-of-custody
Document production practices (e.g. organic)
Meet consumer desires or social preferences
Provide due diligence for safety/quality assurance
Protect integrity of brand name
Authenticate claims (e.g. Bordeaux wine)
4. 4 Traceability ?
5. 5 Movement of grains for export in the U.S.
6. 6 Traceability in Bulk Grain Handling
7. 7 Problem Statement Grain lots commingled:
To meet buyer specifications as close as possible and to maximize the profit.
Lot identity is not maintained.
Recent experiences with regulatory issues have introduced a growing need to track product identity
Grain elevators facing the problem of having to segregate their incoming products in batches of different end use quality (e.g. GMO and non-GMO)
8. 8 Storage Bin- Grain Flow Methods FIFO First In, First Out
Mass Flow
LIFO Last In, First Out
Funnel Flow
NIFO Next In, First Out
Simultaneous Bin emptying
and filling with Funnel Flow
9. 9 Objective The objective of this project is to build a dynamic simulation model that tracks individual grain lots in the outbound load from a grain bin following funnel flow
10. 10 Grain and Bin Specifications Shape : Cylindrical, Flat-bottom, Bottom-draw
Diameter (D): 15 feet (4.6 m)
Opening diameter (d) : 30 cm (0.3 m)
Grain : Soybeans
Angle of Repose (T) : 35
Coefficient of friction (c) : 0.3
Bulk Density (?) : 770 Kg/m3
11. 11
12. 12 Differential Equations Forces acting on m1:
m1g + ?gAh Fc - Fc=m1d2x/dt2 . (1)
where,
m1 = Mass of load 1
g = Acceleration due to Gravity
? = Bulk Density of Grain
A = Surface area of mass m2
h = Height of mass m2
Fc = Frictional Force = cdx/dt
c = Coefficient of friction of grain
x = Displacement of mass m1
13. 13 Differential Equations
14. 14 Differential Equations
15. 15 Model Inputs and Outputs Inputs
Mass of load 1 (m1)
Mass of load 2 (m2)
Outputs
Proportion of load 1 in outbound load (c1)
Proportion of load 2 in outbound load (c2)
16. 16 Simulink Model
17. 17 Inputs
18. 18 Results
19. 19 Results
20. 20 Results
21. 21 Conclusions Proportions of loads m1 and m2 in the outbound load can be determined at any given time
At t = 0:
Proportion of m1 = 1 and Proportion of m2 = 0
Proportion of m1 decreases and m2 increases with increasing time (FUNNEL FLOW).
As m2 empties out, proportion of m1 starts increasing exponentially till it reaches an equilibrium value
Profiles of c1 and c2 vary depending on m1 and m2
22. 22 Further Development More grain loads
Experimental determination of flow dynamics Relation with Angle of Repose
Model applicable for different grains
LIFO (Real world application)
Simultaneous filling and emptying
23. 23