1. Peter Ferket Charles Stark North Carolina State University
Batching and Mixing
Peter Ferket
Charles Stark
North Carolina State University

2. Batching & Mixing Objective
Accurately weigh each ingredient
Minimize batching time
Produce a feed that has a uniform distribution of nutrients and medications

3. Equipment

4. Batching Equipment Micro Bin Systems Tote Bag Systems Scales
Major
Minor
Weigh Buggy

5. Scales

6. Batching – Scale Fill Test
Major & Minor Scales
Fill test evaluates full range of load cells
Add test weights
Record weight
Remove weights
Fill scale to 1/3 capacity
Fill scale to 2/3 capacity
Document results
2/3
1/3
200 lb

7. Batching – Manual Weighing
Weigh Buggy
Platform Scale

8. Feed Mill Designs Pre-batch grind Post-mix grind Post-pellet blend
Post-batch grind

9. Batching – Micro System
Multiple Hopper Scale
Single Hopper Scale

10. Batching - Totes
Totes & Scales
Tote Transfer

11. Batching Sequence Major Scale:
Computer draws multiple bins to the major scale.
Computer switches to one bin and jogs at the end of the each ingredient.
Batching System
Micro Scale
Minor
Scale
Major Scale
Major Ingredients
Corn/Wheat
SBM
Midds
DDGS

12. Batching Sequence Minor Scale Fill:
Batching System
Minor Scale Fill:
Computer draws single bins to the minor scale and jogs at the end of the each ingredient.
Major Scale
Minor
Scale
Micro Scale
Minor Ingredients
Dical
Limestone
Salt
Lysine

13. Batching Sequence Micro Scale Fill:
Batching System
Micro Scale Fill:
Computer draws single bins to the micro scale and jogs at the end of the each ingredient.
Micro Scale
Minor
Scale
Major Scale
Micro Ingredients
Vitamins
Trace Minerals
Medications
Amino Acids

14. Batching Sequence Scale Considerations: Major Scale 80-90%
Batching System
Scale Considerations:
Major Scale 80-90%
Minor Scale 10-15%
Micro Scale < 5%
Micro Scale
Minor
Scale
Major Scale

15. Batching Sequence Major Scale Discharges First
Batching System
Major Scale Discharges First
Fills the dead space between the ribbons and tub.
Micro Scale
Minor
Scale
Major Scale

16. Batching Sequence Minor Scale Discharges after a 5-10 second delay
Batching System
Minor Scale Discharges after a 5-10 second delay
Minor ingredients mix with the major ingredients
Micro Scale
Minor
Scale
Major Scale

17. Batching Sequence Micro Scale Discharges after a 0-5 second delay
Batching System
Micro Scale Discharges after a 0-5 second delay
Micro tub or scales open and the material is transferred with a drag conveyor
Micro Scale
Minor
Scale
Major Scale

18. Batching Mixing Time Horizontal Double Ribbon 30-60 second Dry Mix
second Wet Mix
Batching
Batching System
Micro Scale
Minor
Scale
Liquid Addition
Volumetric (meter)
Gravimetric (weighed)
Liquid Ingredients:
Fat
Molasses
Choline
Amino acids
Major Scale

19. Batching Sequence Discharge Process
Mixer opens and material drops to a surge hopper
Batching/Mixing System
Micro Scale
Minor
Scale
Major Scale

20. Batch Cycle Batch Cycle – 4 mins Weighing 2 min Mixing 3 min
Discharge 1 min
Mixing 3 min
Weighing 2 min
Discharge 1 min
Mixing 3 min

21. Automation System

22. Batch Production Report

23. Mixing equipment

24. Horizontal Ribbon Mixer

25. Double Ribbon Mixer – Mixing Zones
Feed Flow
Main Mixing Zone
Main Mixing Zone
Typical mix time = 3-4 min

26. Double Ribbon Horizontal Mixer

27. Paddle Mixer

28. Paddle Mixer – Mixing Zones
Feed Flow
Main Mixing
Main Mixing
Some
Mixing
Some
Mixing
Main Mixing
Main Mixing

29. Horizontal Paddle Mixer

30. Rotating Drum Mixer – Mixing Zones
Main Mixing Zone

31. Drum Mixer

32. Ribbon Mixer - Counterpoise

33. Ribbon Mixer – Counterpoise Mixing Zone

34. Forberg Fluid Bed Mixer

35. Forberg Mixer

36. Vertical Mixer

37. Vertical Mixer – Mixing Zones
Main
Mixing
Zone
Main
Mixing
Zone
Main
Mixing
Zone

38. Vertical Mixer

39. Mixer Problems
Material on ribbons
Material on paddles

40. Batching & Mixing Problems
Fat sprayed on ribbon and shaft
Fat lumps created by poor liquid application and mixing

41. Mixer uniformity analysis

42. Factors Affecting Uniformity
Particle Shape
Spherical, square, flat
Particle Size
Different particle size can separate during the handling process
Density
Heavy particles may settle out during conveying and discharge to a bin
Static Charge
Particles will adhere to equipment if not properly grounded
Hydroscopicity
Vitamins or Feed Additives may absorb water
Adhesiveness
Fats or molasses may adhere to equipment

43. What Represents the Goal of Mixing?
Segregated Mix
Perfect Mix
Random Mix

44. Weighing Ingredients Correctly?
Weighing Accuracy
Feed mills overdose their ingredients by about 1.5%
Average inaccuracy in dosing within feed mills ranges from %
About 85% of the calls are weighted with an error of ± 5% and about 90% are within ± 10% of called weight

45. Distribution of weighing errors

46. Overdosing and weighing errors error within mill (a-n) across all observations

47. Are You Weighing Ingredients Correctly?
Weighing Precision
Variation in weighing within ingredients, expressed as Coefficient of Variation (CV)
Weighing CV ranges on average of about 5% ( % CV)

48. Causes of Weighing Variation
Hand-weighing ingredients
People tend to overdose by about 1% when ingredients are weighed by hand
Micro-ingredients and premix dose errors
Micro-ingredients scales seem to be more variable than macro-ingredient scales because of the size of the call
Descrepancies between call size and scale resolution
Average weighing discrepancies in feed mill is about 2% but can range up to 20%
For example, requesting 11.3 lbs of an ingredient when the scale has a resolution of only 2 lbs.
Ratio of call size to scale resolution
Weighing errors and CV decreases as the call size to scale resolution increases. For example, a call for 100 lbs to be weighed on a scale with a resolution of 5 lbs gives a call/scale resolution of 20, where as a call for the same 100 lbs on a scale with a resolution of 2 lbs gives a ratio of 50.

49. Weighing errors and CVs for different call size to scale resolutions
Call Size:Scale
Resolution Ratio
Weighing Error, %
CV, % 10
4.0
11.4
100
1.0
3.6
1000
0.3
1.1

50. Mixer Uniformity Analysis
Mixer Markers
Single nutrient/ingredient
Salt
Synthetic Amino Acids (Lysine or Methonine) Dry Mix Uniformity
Economical
Accurate and precise at inclusion level
Test twice per year
Ten samples from the same batch of feed
Sample mixer or a point closest to the discharge

51. Mixer Uniformity Analysis
Sampling Points
Mixer or Surge samples provides information on dead spots in the mixer or mixer maintenance issues
Sampling during the discharge process provides representative samples of the feed as it moves through the system.

52. Feed Quality Assurance – Mixer Test
Sample mixer OR
Sample surge
Sample discharge conveyor

53. Mixer Uniformity Analysis - Quantab™

54. Mixer Uniformity Analysis - Quantab™
Weigh 10 gram sample of feed into a dish
Scale +/- 0.1 g

55. Mixer Uniformity Analysis - Quantab™
Fold filter paper to create a cone

56. Mixer Uniformity Analysis - Quantab™
Measure out 90 ml of HOT distilled water
SAFETY
Hot Water Burns!!

57. Mixer Uniformity Analysis
Mix sample and water for 30 sec wait and re-mix for 30 sec.
Place filter paper cone in cup
Place Quantab strip into the filter cone
Indicator strip at the top will turn black when complete

58. Mixer Uniformity Analysis - Quantab™
Read highest point on the strip
Determine NaCl level based on the calibration chart on the bottle.
Multiple by 10
(10:1 dilution)

59. Mixer Uniformity Analysis Calculations
Calculation of Mixer CV
Mean of samples
Standard deviation of samples
CV % = standard deviation x 100
mean

60. Mixer Uniformity Analysis Calculations

61. Mixer Uniformity EvaluationCV
RATING
CORRECTIVE ACTION
< 10%
Excellent
None
10-15%
Good
Increase mixing time by 25-30%
15-20%
Fair
Increase mixing time by 50%, look for worn equipment, overfilling, or sequence of ingredient addition
20% +
Poor
Possible combination of all the above
Consults extension personnel or feed equipment manufacturer

62. Double Ribbon Mixer – RPM’s

63. Double Ribbon Mixer – Worn Ribbons

64. Double Ribbon Mixer – Wrong Rotation

65. Double Ribbon Mixer – Build-Up

66. Questions