Transcript www.ffinetwork.org

Section 4
Milling Operations for Fortification
Operation Guidelines
Examples of Record Keeping
Premix Receiving and Safety
Maintaining Premix Supply
Feeder Calibration and Premix Feed Rate
Check-weighing Procedure
Equipment Maintenance and Troubleshooting
Fortification Operation Guidelines
1. Know actual production rate of mill
2. Calibrate feeders to production rate of mill
3. Ensure feeder hopper contains enough premix (see
video)
4. Start mill and run for at least 15 minutes to reach normal
production rate
5. Start feeder at required setting as determined by the
feeder calibration process
6. Conduct check weighing at start of mill production run
and every 2 hours to verify correct addition rate. Adjust if
addition rate is greater than 10% above or below target,
and recheck addition rate
Fortification Operation Guidelines
7. Check weights at the start of every shift or every 2
hours of operation
8. Maintain check weight within 5% of target
9. Ensure that the feeder does not run out of premix. This
is the most important check on the production line. To
do this:
• Check the low-level signal
• Check each premix feeder routinely and fill hopper
• Record weight of material left in premix supply
container
• Compare actual premix use with the expected premix
use based on flour production
Fortification Operation Guidelines
10. At the end of a production run, turn off the premix
feeder before shutting down the mill
11. Production records need to record the following:
• The lot number of the premix used
• Check weights
• Feeder adjustments if made
• Times of check weighing
Flour Ingredient Usage Report
First Shift
Production
Report
Example
Date:
Mill:
Beginning Lot #
701 CCN
Flour Production
Time
052 AGU
Enrichment
Grade
MT Flour
%
700 CCN
Malt
KG
%
Bleach
KG
%
KG
7:00
8:00
9:00
10:00
11:00
12:00
13:00
14:00
Shift Total
0.00
0.00
0
0
Shift Total
MT Flour
0
KG
KG
0.00
KG
0
0
Begin Inventory
Transfer to Mill Floor
0
Total to account for
0
0
0
0
0
0
Closing Inventory
Disappearance
INGREDIENT
Enrichment
Malt
Bleach
NEW LOT #
SUPERVISOR (name):
OPERATOR (name):
START TIME
STOP TIME
Feeder Check Report Example
Flour Fortification Feeder Check
First Shift
Date:
5/31/2012
Mill:
B Mill
Fortification - Feeder Test
Enrichment
Lot #
701 CCN
Time
Flour Grade
Flour Rate
(Mt/hr)
Target
(g/min)
Test #1
(g/min)
7:00
8:00
9:00
10:00
11:00
12:00
13:00
14:00
MXE
MXE
MXE
MXE
MXE
MXE
MXE
MXE
9.4
9.4
9.4
9.4
9.4
9.4
9.4
9.4
24.6
24.6
24.6
24.6
24.6
24.6
24.6
24.6
24.2
24.5
24.8
24.1
24.6
24.8
24.9
24.7
* Required only if Test #1 is out of specification
SUPERVISOR (name):
OPERATOR (name):
Test #2*
Adjusted
(g/min)
Test #3*
Re-check
(g/min)
Premix Receiving Procedures
1) Assess package
condition
2) Ensure that you
received what you
ordered
3) Record Lot #
and type of premix
4) Remove and file
certificate of
analysis
Premix Safety
Premixes are concentrated sources of vitamins and minerals
and are too concentrated for direct consumption.
Mill workers must follow these safety instructions:
1. Label premix boxes with
warning labels and handling
precautions
2. Inform all workers handling
the premix of the material
safety data sheet (MSDS) or
product information sheet
with safety instructions
WARNING. COMBUSTIBLE DUST.
Avoid generation of dust to prevent
dust explosions. Keep away form
sources of heat and ignition.
Prolonged and/or repeated contact
may cause skin irritation. Gloves, dust
mask, and protective clothing should
be worn when handling. Wash
thoroughly after using.
Premix Safety
3.
Wear long sleeves, gloves and dusk mask when filling the feeder
hopper, even if it just takes a minute. The operator may also wear
safety goggles, a hair net, safety helmet or other protective
devices depending on mill policy.
4.
Wash hands and any skin exposed to the premix after filling
hoppers.
5.
Clean any premix spill immediately by putting meal on the spill
prior to sweeping.
Some people have allergic skin reactions
to flour fortificants, in particular niacin.
This can be avoided by following the precautions outlined.
Maintaining Premix Supply
1. Keep Small Quantities on Mill Floor
• Estimate amount of premix needed and have sufficient quantities
in the mill for production
2. Stock Rotation
• Record the production lot number(s) upon receipt
• Develop a rotating first-in, first-out (FIFO) system
Maintaining Premix Supply
3. Use of Active Containers
•
•
•
•
•
Place a scoop inside the container for convenient use
Keep paper, plastic, and other contaminates out of the
container as they may get in the feeder cause its malfunction
After the hopper is filled, put the scoop back in the container or
another designated location
Seal container and close outer container if applicable
Keep operating container away from damaging conditions
including heat, light, and moisture
Maintaining Premix Supply
4. Assign specific mill staff these responsibilities:
•
Stock control
- Order new premix at intervals that take into account
usage rates, time for processing the order and receiving
a shipment.
•
Premix handling in the mill
- Including storage, movement to the production line and
addition to the feeder(s)
•
Premix quality control
- Inspect the premix when a shipment arrives, periodically
check the storage conditions of unopened premix, and
check the production line process
Feeder Calibration Instructions
Confirm the flour flow rate (kilograms per hour) for the production line.
This is typically done at one of two points in a continuous system:
1. If fortifying in the mill, check the flour production scales and
confirm with a weigh-off if possible
2. If fortifying in packaging and load-out, check the scales of the
flour transfer system in which the flour will be fortified and
confirm with a weigh-off if possible
In a batch system, check the weight of material delivered to the batch
mixer by confirming scale reading accuracy.
Feeder Calibration Instructions
Next, determine the premix feed (discharge) rate at different speed
settings on your feeder.
1. Fill hopper half full with premix
2. Set feeder to maximum discharge
3. Run feeder for 2 minutes
4. Weigh the premix that has been discharged
Operator at a feeder control panel.
5. Calculate maximum discharge per minute by dividing total weight by 2
6. Repeat multiple times at different speeds or percent settings
7. Make a chart that shows the premix discharge rate per minute at
different speed settings from 0 to 100% of maximum discharge
8. Display the chart near the feeder. See example on next slide.
Feeder Calibration Chart Example
20.0
17.5
Premix (g/min)
15.0
y = 0.2024x - 1
R² = 0.996
12.5
10.0
7.5
5.0
2.5
0.0
0
10
20
30
40
50
60
70
80
90
100
110
Feeder Setting (%)
Actual results from commercial premix feeder
Determining Premix Feed Rate
1. Identify the premix addition rate recommended by the premix
supplier
2. Multiply by the flour production line flow rate to calculate the
premix delivery required in grams per minute
Premix Addition
(grams / MT flour)
X Flour Flow Rate
(MT/minute)
= Premix Required
(grams/minute)
3. Adjust feeder control to calculate delivery rate (consult your mill’s
calibration chart)
4. Check the weigh-off and adjust accordingly
Check-Weighing Procedure
1. Zero the scale
or weigh the
sample container
2. Position the
container at
feeder discharge
3. Collect premix
for 2 minutes
4. If you zeroed the
scale in step one,
the weight shown is
that of the premix.
Otherwise, subtract
the container weight
from the total to
determine premix
weight
Equipment Maintenance
• Follow the recommended maintenance schedule from
the equipment supplier (request supplier to provide this
information in local language)
• Lubricate moving parts as required (use approved foodgrade lubricants)
• Inspect for wear; adjust and/or replace parts as needed
• Maintain inventory of spare parts that may need
replacement
Troubleshooting: Premix Flow
Compact and sticky premix may ball, bridge or tunnel in the feeder.
This results in feed rate variability.
ACTIONS:
1. Frequently inspect the premix feeder, especially after it is
newly installed
2. Specify and use premix feeders with mechanical agitation
(see next two slides)
3. Empty feeders that will be unused for any length of time
4. Have premix supplier change the levels of excipients and
free-flow agents
Hopper Agitators Improve Flow
A mechanical agitator in the hopper prevents the premix from bridging,
clumping and compacting. Some models come with an agitator device.
See video.
Photo by Jeff Gwirtz
Hopper Design Improves Flow
The hopper of the premix feeder at left is made of flexible
material. A mechanical device such as the motor and paddle
pictured at right causes the flexible wall to pulsate and prevents
the premix from bridging. Click here for video of the pulsating
feeder and here for video of the paddle at work. Photos by Jeff Gwirtz
Troubleshooting: Flour Flow
If the flour or premix flow is intermittent, fortification level will
not be correct.
ACTIONS:
1. Frequently inspect the feeder and flour flow
2. Install low-level alarm or indicator light on hopper
3. Install electrical interlock system between the mill and feeder
controls (described in section three on the mill set-up)
Troubleshooting: Magnets
If using elemental iron, the surface of rare earth magnets in the
production process may collect iron powder.
ACTIONS:
1.No change required. This will not affect the iron fortification level or
the magnet’s performance regarding tramp metal.
2.Install magnets in a location so that the flour stream acts as a
continuous cleaning mechanism as it passes over the magnet.
3.If the iron powder bridges between the magnet tubes, use a magnet
system with a larger distance separating the tubes.
4.Use a non-magnetic iron source, such as iron salts.
5.Continue to inspect and clean magnets following
good manufacturing practices (see photo).
Troubleshooting: Power Supply
Variations in voltage can alter flour production and premix feed
rates, which will cause the flour to be fortified incorrectly.
ACTIONS:
1. Install voltage regulators when working with single-phase
voltage feeder motors
2. Use three-phase motors
3. Work with electric supplier to provide uniform, high-quality
power into the plant
4. Negotiate with energy company to provide alerts before
power outages
Troubleshooting: Nutrient Loss
Quantitative testing may show that vitamins and mineral content is
consistently lower than the expected value. Vitamin A and riboflavin
are particularly vulnerable due to exposure to light.
ACTIONS:
1.Confirm that premix is appropriate for type of flour
2.Confirm that the correct addition rate is used
3.Put sample bags in opaque containers
4.Analyze flour sample as soon as possible
5.Make sure both the premix and fortified flour is not exposed to high
heat (>40°C) or light during storage
6.If the dust collection stock is yellow, the collection system may be
removing riboflavin near the premix addition point. In this case:
• Confirm and set suction to proper pick-up velocity
• Position suction system away from premix addition point
More Information on Operations
Contact the Flour Fortification Initiative at
[email protected]