Rapid Hardening Systems

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Rapid Hardening Systems

• By R.C.Greener

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Which Would You Rather Buy?

• A or B

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Benefits of Quick Hardening

• Better Freshness and Quality
• Smoother Ice Cream Texture
• Less Carton Damage in Storage and Distribution
  Process
• Less Chance of Product Skinning
• Better Ice Cream Consistency Regardless of
  Package Size or Shape
• Lower Labor and Handling Costs
• Inventory reduction - Ship directly from
  Hardener

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Costs to Harden Rapidly

• More energy
• Higher Capital Investment
• Increased product shrinkage if design improper

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Percentage of H2O Frozen at Various Draw/Fill
Temperatures

• Draw Temp H2O Frozen
• 25oF 33.0
• 24oF 41.0
• 23oF 47.0
• 22oF 52.0
• 21oF 56.0
• 20oF 59.0
• -15oF 90.0

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Two Types of Hardening
Open Loop
Closed Loop
Ice Cream Manufacturer Purchases Refrigeration
Ice Cream Manufacturer Refrigerates with Self
Contained System
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Open Loop
Closed Loop
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Advantages of Cryogenic Hardening

• Lowest retention time for ice cream novelties
  cakes
• Excellent ice cream texture
• Allows surface setting of novelty item prior to
  wrapping
• Superior overall quality for cake items

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Disadvantages of Cryogenic Hardening

• Very expensive on a cost/lb basis
• Cost is proportional to location cryogenic medium
  processing
• Unit must meet sanitation demands
• Process requires expensive production room area

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How Immersion Plate Systems Harden
Ice Cream
Evaporative Condenser
Mechanical Refrigeration System
Heat Transferred by Direct Conduction from
Product to Refrigerant
Energy Transferred from Refrigerant to Atmosphere
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Advantages of Immersion Hardening

• Best method to harden stick novelties
• Rapid hardening with resultant minimum retention
  times
• Automation allows high production rates
• High product quality
• Efficient heat removal process

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Disadvantages of Immersion Hardening

• Single item process
• Requires expensive production room area
• Must meet sanitation requirements
• Some units subject to high waste water demands
• Product shrinkage through process is relatively
  high
• High capital expense for single item manufacture

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Advantages of Plate Hardener

• Makes near perfect squares and rectangles on 95
  of production
• Rapid hardening with resultant minimum retention
  times
• Heat removal via conduction is very efficient
• Requires minimal space in low cost ambient
  warehouse environment
• Low production shrinkage through hardening process

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Disadvantages of Plate Hardener

• Very limited item utility
• Approximately 5 of product has shape
  irregularities
• High capital cost in plants where all volume can
  not be hardened by plate process
• Safety issue because refrigerant is in moving
  hollow plate
• Requires low refrigerant temperature

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How Air Convection Hardens
Cold Air
Ice Cream
Mechanical Refrigeration System
Evaporative Condenser
Coil
Warm Air
Conduction from Refrigerant to Atmosphere
Conduction from Product to Air
Conduction From Product to Refrigerant
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Air Convection Significance

• Used for Hardening over 85 of Ice Cream in US.
• Used by over 95 of Ice Cream Manufacturers in US

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Important Facts about Convection Hardening

• Product Draw or Fill Temperature
• Package Orientation during Hardening Process.
• Laminar Air Flow Vs. Turbulent air flow
• Air Vs. Heat Removal Index Temperature
• Product Spacing

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Importance of Draw/Fill Temperatures

• Draw Temp H2O Frozen
• 25oF 33.0
• 24oF 41.0
• 23oF 47.0
• 22oF 52.0
• 21oF 56.0
• 20oF 59.0
• -15oF 90.0

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Air Flow Perpendicular to Pak Length

• Package 4 56 oz.
• Flavor Choc. Peanut butter cup.
• Air Temp. -25o F
• Air Velocity 1000 FPM
• Core Temp In 20.3o F
• Core Temp Out -0.4o F
• Retention Time
• 5 Hr 48 Min

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Air Flow Parallel to Pak Length

• Package 4 56 oz.
• Flavor Choc. Peanut butter cup.
• Air Temp. -25o F
• Air Velocity 1000 FPM
• Core Temp In 19.8o F
• Core Temp Out -1.3o F
• Retention Time
• 4 Hr 18 Min

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Draw Temp vs. Hardening Times

• Package 4 56 oz. SqRd
• Flavor Pumpkin Crème
• Air Temp. -23o F
• Air Velocity 1000 FPM
• Core Temp In 23.2o F
• Core Temp Out -0.1o F
• Retention Time
• 5 Hr 28 Min

• Package 4 56 oz. SqRd
• Flavor Pumpkin Crème
• Air Temp. -23o F
• Air Velocity 1000 FPM
• Core Temp In 19.3o F
• Core Temp Out -0.2o F
• Retention Time
• 4 Hr 4 Min

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Laminar vs Turbulent Air Flow

• Definitions
• Laminar Flow Streamline flow in a viscous
  fluid near a solid boundary.
• Turbulent Flow Fluid flow in which the
  velocity at a given point varies erratically in
  magnitude and direction.

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The requirement for an efficient air distribution
system is

• Conversion from Turbulent Flow
• to
• Laminar Flow

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What Causes Turbulent Flow?

• Fans and other mechanical methods of moving air.
• Obstructions to normal air flow.
• Merging air patterns.

Advantages

• Can provide excellent heat removal when
  hardening.

Disadvantages

• Consumes greater amount energy (Fan BHP).
• Increases static pressure resulting in reduced
  air flow (CFM) with existing equipment.

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Package Spacing

• Package Rows should have a minimum of 2.00 inch
  space between rows for air flow.

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Advantages of Pallet Hardener

• More mechanical simplicity than all other air
  convection hardeners
• Low capital investment
• Hardens multiple package sizes
• Low maintenance costs

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Disadvantages of Pallet Hardener

• Mediocre to poor hardening results
• Requires conscientious operator to insure product
  quality
• High labor costs
• High product shrinkage
• Can result in unattractive packaging

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Advantages of Spiral Belt Hardener

• Highest degree of mechanical simplicity of
  automated air convection hardeners
• Good hardening when operated within design
  parameters
• Low to moderate capital investment
• Hardens multiple package sizes simultaneously
• Low production shrinkage through hardening
  process
• Available in system sizes from 250 GPH

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Disadvantages of Spiral Belt Hardener

• Belt loading limited to 10 lbs/ft of belt for
  good belt life
• High fan horsepower results in high energy
  demands and cost
• Requires low refrigerant temperatures
• Very difficult to automate package handling in
  high output plants
• High maintenance costs (belt cost represents 35
  of typical system cost)

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Advantages of Tray between Continuous Chain

• Highest degree of mechanical simplicity of
  automated tray type air convection hardeners
• Double pass air system insures very good
  hardening
• Moderate capital investment
• Hardens multiple package sizes simultaneously
• Low production shrinkage through hardening
  process
• Very good package orientation adapts to
  automation
• Efficient air system reduces energy requirement
  and cost
• Available in systems as small as 250 GPH

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Disadvantages of Tray between Continuous Chain

• Feed rates less than 2500 GPH
• Not very suitable for simultaneous multiple line
  productions
• Higher maintenance costs than tray/transport type
  systems

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Advantages of Variable Retention Time (VRT)
Hardener

• Allows variable retention time for different size
  items
• Easily adapts to line automation
• Maintains package orientation through the
  hardening process
• Hardens multiple package sizes simultaneously
• Handles high production rates (up to 10,000 GPH)

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Disadvantages of Variable Retention Time (VRT)
Hardener

• Highest cost hardener
• Complex program and operation
• Higher product shrinkage through system
• High static pressures require higher HP and
  energy requirements longer retention times
• Inherent design results in higher maintenance
  costs
• Minimum size system is approx 1500 GPH

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Multiple Tray Transport
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Heart of the Multiple Tray Transport
The Transport
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Advantages of Multiple Tray Transport

• Double pass air system insures very good
  hardening
• Hardens multiple package sizes simultaneously
• Very low production shrinkage through hardening
  process w/ good design
• Moderate mechanical simplicity of automated tray
  type air convection hardeners
• Moderate capital investment
• Very low maintenance cost with long service life
  (40 years)
• Very good package orientation adapts to
  automation
• Efficient air system reduces energy requirement
  and cost
• Available in sizes to 10,000 GPH

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Disadvantages of Multiple Tray Transport

• No multiple retention time in standard form
• Minimum size system is 750 GPH
• More complex than spiral belt system
• Higher product shrinkage w/ poor design

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Advantages of Fusion Cell

• Combination conduction/convection system hardens
  faster than any air convection system
• Most efficient air hardening system -- rivals
  that of plate hardener
• Hardens multiple package sizes simultaneously
• Very low production shrinkage through hardening
  process
• Moderate mechanical simplicity of automated tray
  type air convection hardeners
• Overall capital investment lower than most air
  systems
• Very low maintenance cost with long service life
  (30 years)
• Very good package orientation adapts to
  automation
• Available in sizes to 10,000 GPH
• Most compact of air convection hardeners
• Allows same refrigerant suction temp for both
  freezer and hardener

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Disadvantages of Fusion Cell

• No multiple retention time in standard form
• Minimum size system is 750 GPH
• More complex than spiral belt system
• Higher floor loadings than other air convection
  types

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Manual Hardener Design
Fan Coil
Air Plenum
Carts or Wire Baskets w/ Rows of Ice Cream
Paks Laminar Flow
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Energy Consumption in Average Ice Cream Plant

• Mix Processing 5
• Freezing 35
• Hardening 45
• Storage 15
• Total 100

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Real Energy Costs

• 1.0 HP motor w/ 16 Hr on/8 Hr off Cycle
• 8 Hr off .746 x .08 x 8 Hr x 250 da
• 119.36
• 115 off day .746 x .08 x 24 Hr x 115 da
• 164.72
• Total Annual Energy Waste 284.08
• Total Waste for 25 Motors 7,102.00
• Does not include refrigeration losses

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Individual Carton vs

• Over Wrapped Package

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TRI-Tray Hardening Test w/ Individual Sqround
Retention Time 2 Hr. 13 Min.
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TRI-Tray Hardening Test w/ (6) Overwrapped Sqrds
Retention Time 4 Hr. 33 Min.
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Design Objectives of Fast Hardener

• Rapid hardening to achieve uniform ice
  crystallization and improve quality.
• Improve package quality.
• Ability to adapt to future packaging/marketing
  changes.
• Lowest possible product shrinkage thru hardening
  process.
• Low energy demand.
• Low power (kwh) requirement.
• Low direct labor.
• Low maintenance cost.
• Adaptability to Automation.
• Capital cost commensurate with operational
  savings.

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Any Question?

• Thank You!
• If you have any future question, please contact
  dgreener_at_freestech.com