Major Processes in Feed Manufacturing Flashcards
Major processes in feed manufacturing:
-ingredients receiving
-grinding
-batching and mixing
-conditioning and pelleting
Receiving center ingredients terms:
-unprocessed grains
-processed bulk ingredients
-soft feed ingredients
-heavy feed ingredients
-liquids
-micro-ingredients
Receiving center equipment:
-scales
-unloading mechanisms (truck dumper, hopper bottom trailers or RR cars, mechanical scoops, front end loader for barges)
-receiving hopper and conveyors
-cleaning/screening devices (magnets, grain scalpers, grain cleaners)
-elevator legs
Grinding operation
-increases surface area
-enhances energy and nutrient digestibility
Functions of grinding:
-to achieve proper and uniform particle size
-to improve the efficiency of pelleting operations as well as pelleted feed quality
-to maintain desired physical characteristics of the feed such as flowability and limiting dust
Warehouse
-ingredients and totes are stored on racks
-First in first out ingredient rotation
Factors to consider with grinding equiptment:
-target particle size
-grinding capacity requirement (depends on particle size)
-energy consumption (roller mill more efficient at larger particle size)
-maintenance cost
-environmental safety
Target particle sizes
-fine (less than 400 microns)
-medium (400-700 microns)
-coarse (greater than 700 microns)
Maintenance cost for roller mills
-re-corrugation
-freight cost (location of corrugation shop vs. feed mill)
-routine gap adjustment higher maintenance time (daily particle size samples)
Maintenance cost for hammermill
-screen replacement
-hammer replacement
-minimal maintenance time
Roller mill environmental safety
-less dust
-lower noise levels
Hammermill environmental safety
-require dust control (bag house air permit)
-high noise levels
-risk of fire or explosion
Particle size is controlled by what in hammermill operations?
-screen size
-hammer tip speed
-air assist system
-hammer setting
-hammer pattern
Grind size is controlled by what in roller mills?
-number of roll pairs
-roll gap
-roll speed
-corrugations
-corrugation numbers
When might roller mill technology not be feasible?
-when the product is not friable, fragile, or breakable (high fiber and moisture ingredients)
-no value from maintaining a uniform particle size with minimal fines
Hammermill advantages:
-can produce a wide range of particle sizes
-can handle friable materials and fibers
-cost of purchase is low compared to roller mills
-low maintenance cost
-easy to operate
Hammermill disadvantages:
-particle size could vary greatly (less uniform)
-high energy usage compared to the roller mill
-generates lots of heat (high energy wastage)
-is noisy with high potential for dust pollution
Roller mill advantages:
-relatively low energy consumption
-relatively less noisy
-relatively less heat production and thus less moisture loss
-uniformity of particle size of milled product
Roller mill disadvantages:
-investment costs are high
-complicated operation
-high maintenance cost
-problems with fibrous material (grinding issue)
-strict cleaning requirement before grindind
Batching and mixing objective
-accurate weighing of ingredient
-minimum batching time
-production of feed with uniform distribution
What is the last thing to add during batching and mixing?
oil
What should be added close to the end during batching and mixing?
feed additives
What size particles are mixed first?
largest
Batching equipment
-micro bin systems
-tote bag systems
-scales (major and minor)
-weigh buggy
Mixer uniformity analysis
calculation of mixer CV (mean of samples, standard deviation of samples)
CV calculation
CV% = (standard deviation/mean) x 100
What rating is a CV <10%
excellent
What remedy/corrective action is taken with CV <10%
non
What rating is a CV of 10-15%
good
What remedy/corrective action is taken with CV 10-15%
increase mixing time by 25-30%
What rating is a CV of 15-20%
fair
What remedy/correction action is taken CV 15-20%
increase mixing time by 50%, look for worn equipment, overfilling, or sequence of ingredient addition
What rating is CV of 20% +
poor
What remedy/corrective action is taken for CV 20%+
possible combination of all the other corrective actions and to consult the extension personnel or feed equipment manufacturer
Recommended mixing time for a paddle
Dry mix: 3 min
Wet mix: 3 min
Recommended mixing time for a twin shift paddle
Dry mix: 0.5 min
Wet mix: 1 min
Recommended mixing time for a double ribbon mixer
Dry mix: 1-2 min
Wet mix: 2-3 min
Recommended mixing time for a twin shaft ribbon mixer
Dry mix: 0.75-1 min
Wet mix: 2 min
Recommended mixing time for a vertical mixer?
Dry mix: 5-10 min
Wet mix: 5-10 min
Causes of weighing variation
-hand-weighing ingredients
-micro-ingredients and premix dose errors
-discrepancies between call size and scale resolution
What scale should always discharge first?
the major scale
What must be serviced and checked regularly for accuracy?
weighing scales
