Section 4 Milling Operations for Fortification

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Section 4Milling 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
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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

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Fortification Operation Guidelines

• Check weights at the start of every shift or
  every 2 hours of operation
• Maintain check weight within 5 of target
• 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

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Fortification Operation Guidelines

• At the end of a production run, turn off the
  premix feeder before shutting down the mill
• Production records need to record the following
• The lot number of the premix used
• Check weights
• Feeder adjustments if made
• Times of check weighing

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ProductionReportExample
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Feeder Check Report Example
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Premix Receiving Procedures
3) Record Lot and type of premix
2) Ensure that you received what you ordered
4) Remove and file certificate of analysis
1) Assess package condition
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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.
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Premix Safety

• 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.
• Wash hands and any skin exposed to the premix
  after filling hoppers.
• 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.

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Maintaining Premix Supply

• Keep Small Quantities on Mill Floor
• Estimate amount of premix needed and have
  sufficient quantities in the mill for production
• Stock Rotation
• Record the production lot number(s) upon receipt
• Develop a rotating first-in, first-out (FIFO)
  system

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Maintaining Premix Supply

• 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

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Maintaining Premix Supply

• 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

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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
• If fortifying in the mill, check the flour
  production scales and confirm with a weigh-off if
  possible
• 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.

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Feeder Calibration Instructions

• Next, determine the premix feed (discharge) rate
  at different speed settings on your feeder.
• Fill hopper half full with premix
• Set feeder to maximum discharge
• Run feeder for 2 minutes
• Weigh the premix that has been discharged
• Calculate maximum discharge per minute by
  dividing total weight by 2
• Repeat multiple times at different speeds or
  percent settings
• Make a chart that shows the premix discharge rate
  per minute at different speed settings from 0 to
  100 of maximum discharge
• Display the chart near the feeder. See example on
  next slide.

Operator at a feeder control panel.
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Feeder Calibration Chart Example
Actual results from commercial premix feeder
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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)

1. Adjust feeder control to calculate delivery rate
   (consult your mills calibration chart)
2. Check the weigh-off and adjust accordingly

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Check-Weighing Procedure
2. Position the container at feeder discharge
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
3. Collect premix for 2 minutes
1. Zero the scale or weigh the sample container
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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
  food-grade lubricants)
• Inspect for wear adjust and/or replace parts as
  needed
• Maintain inventory of spare parts that may need
  replacement

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Troubleshooting Premix Flow

• Compact and sticky premix may ball, bridge or
  tunnel in the feeder. This results in feed rate
  variability.

• ACTIONS
• Frequently inspect the premix feeder, especially
  after it is newly installed
• Specify and use premix feeders with mechanical
  agitation (see next two slides)
• Empty feeders that will be unused for any length
  of time
• Have premix supplier change the levels of
  excipients and free-flow agents

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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
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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

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Troubleshooting Flour Flow

• If the flour or premix flow is intermittent,
  fortification level will not be correct.

• ACTIONS
• Frequently inspect the feeder and flour flow
• Install low-level alarm or indicator light on
  hopper
• Install electrical interlock system between the
  mill and feeder controls (described in section
  three on the mill set-up)

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Troubleshooting Magnets

• If using elemental iron, the surface of rare
  earth magnets in the production process may
  collect iron powder.
• ACTIONS
• No change required. This will not affect the iron
  fortification level or the magnets performance
  regarding tramp metal.
• Install magnets in a location so that the flour
  stream acts as a continuous cleaning mechanism as
  it passes over the magnet.
• If the iron powder bridges between the magnet
  tubes, use a magnet system with a larger distance
  separating the tubes.
• Use a non-magnetic iron source, such as iron
  salts.
• Continue to inspect and clean magnets following
• good manufacturing practices (see photo).

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Troubleshooting Power Supply

• Variations in voltage can alter flour production
  and premix feed rates, which will cause the flour
  to be fortified incorrectly.
• ACTIONS
• Install voltage regulators when working with
  single-phase voltage feeder motors
• Use three-phase motors
• Work with electric supplier to provide uniform,
  high-quality power into the plant
• Negotiate with energy company to provide alerts
  before power outages

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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
• Confirm that premix is appropriate for type of
  flour
• Confirm that the correct addition rate is used
• Put sample bags in opaque containers
• Analyze flour sample as soon as possible
• Make sure both the premix and fortified flour is
  not exposed to high heat (gt40C) or light during
  storage
• 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

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More Information on Operations
Contact the Flour Fortification Initiative at
info_at_ffinetwork.org