John Larson FMC FoodTech Frigoscandia Equipment Northfield

Frigoscandia Equipment
Northfield /Stein / DSI
John Larson
FMC FoodTech
Industrial Refrigeration Consortium’s
Research & Technology Forum
January 19-20, 2006 Madison Wisconsin
FMC FoodTech is a global, full-line food technology provider including harvesting, preparing, processing,
packaging and preservation systems. Market leading position in thermal processing, sterilization, cooking,
frying and freezing systems, citrus and tomato processing, vegetable harvesting and processing, conveying
and distribution systems.
TECHNOLOGIES OF OUR GROUP
First in Freezing
Northfield
Structure Supported Spiral Freezing
Technology
Leaders in Coating, Frying, and Cooking
Proven Specialists in Waterjet Cutting
Global Leader in Citrus Technology
Trusted Technology for Food Processors
Superior Aseptic Technology
Commanding the World’s Vegetable
Harvesting
Innovative Solutions from Processing
To Packaging
Experts in Potato and Snack Processing
2
GC27 - 05/00MC
3
The “Best” Food Freezing Technology Depends On a
Number of Factors - Tell Us About Your Product
• Unit Dimension - Range from 1/8” dia crumbles to 50 lb cases.
Required to determine tier space, belt style and belt loading.
• Unit Weight - Ranges from a few grams to 20 lbs or
more. Required to determine belt loading
• Packaging - Ranges from bare, raw products to fully
packaged cased products. Required to determine dwell time,
cleaning requirements, dehydration and belt style
• USDA/Cleanliness - Ranged from minimal cleaning requirements
needed to keep the machine operating properly to very stringent
HACCP microbial control for ready to eat, fully cooked products.
Affects spiral construction, materials of construction and choice of
cleaning system.
4
More about your Product
• Capacity - This is the primary concern when defining a
spiral. Ranges from less than 1,000 lbs. per hour to greater
than 15,000 lbs per hour. Affects spiral size, coil size, belt
speed
• Product Components - Primarily moisture content. If this
is a processed food with several different ingredients, such
as a pizza, it is important to know the various components
and the temperature and moisture content of each. Thermal
conductivity affects freezing time
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Still More about your Product
• Inlet Temperature - Affects refrigeration load and dehydration rate
• Outlet Temperature - Affects refrigeration load, freezer operating
temperature
• Loading Pattern - This can be regimented or random loaded. We
need to understand the loading pattern to size the spiral correctly.
• Constitution, Color, Etc. - Is it soft? Is it sticky? Is it white? Is it
crumbly? This will help define the cleaning system required, belt style
and a variety of design considerations
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Common goals:
freeze product quickly at a low cost
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What Factors Affect Freezing Duration?
• Product load
– Inlet temperature, moisture content, packaged/unpackaged
• Air Flow Configuration (freezer type)
— Vertical (up or down)
— Horizontal
— Impingement (Air Velocity)
• Heat Transfer Coefficient
— Ability of the freezer to remove heat from the product
— Conductive? Convective?
—Mechanism: Moving Water (280 – 17 000 W/m2 * k), Moving Air
(11 – 55 W/m2 * k), Still Air (3 – 23 W/m2 * k)
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Methods to Determine Freezing Duration
• Guess
• Mathematical estimation
– Must know heat transfer coefficient
• Trial and Error
– Vary hold time and measure out feed temp.
• Measure freezing curve
• Call your friendly equipment supplier
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Product Temperature Characteristics
Through Freezer
+68°F
Before
entering
+68°F
At freezer outfeed
-13°F
14°F
Half way through freezer
5°F
+40°F
Equalization
0°F
0°F
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Freezing Curve
Core
Surface
Average
Freezing
time
Time
32°F
0°F
Air temp.
Pre-cooling
Latent zone
Subcooling
Equalize
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Freezing Curve
Fully Cooked, Breaded 9-cut Chicken
190
170
130
110
90
70
50
30
10
-10
140
120
100
80
60
40
20
-30
0
o
Temperature ( F)
150
Time (minutes)
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Heat Transfer
• Valid for vertical airflow
• Double-sided action
Frigoscandia
Impingement
freezers
• Optimized technology to reach
acceptable power consumption
200
2
Heat transfer coefficient
[W/m2 ºC]
250
150
100
50
GyroCompact Spiral freezers
0
0
10
20
30
Air velocity m/s
40
50
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Other Considerations in Freezer Design
• Floor Space
• Headroom
• Indoor or Outdoor location
• Desired infeed and outfeed location
• Operation schedule
• Refrigeration available
• Utilities available (power, water, drains, steam)
• Noise limits
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Once the above factors are considered a
decision can be made as to the type of
freezer is best suited.
Far and away the most common type of
mechanical air blast selected is some type
of spiral freezer. The spiral has the most
flexibility of design and the ability to
handle virtually any product and
production rate.
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Technology Alternatives
• Spiral
– Self stacking spirals - GYRoCOMPACT Freezers
– Non-self stacking spirals (structure supported spirals) –
SuperTRAK, LST
• Impingment
– Advantec, FLoFREEZE
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Technology Alternatives
Dwell
times
Belt
Width
Belt
Speeds
Belt
Loading
[min]
[in]
[ft/min]
[lb/ft2]
Self stacking spiral
(Gyrocompact)
10-150
14– 40
1 – 98
Low Tension Spiral
(SuperTRAK)
15-500
12 – 60
Low tension Spiral
(LST)
15-500
Straight Impingement
(Advantec)
Straight
IQF(FLoFREEZE
Technology
Coil Size
TD
[tons]
[F]
1–2
60 – 370
15
1 – 150
1–7
60 – 300
10
12 – 60
1 – 150
5 – 10
60 – 300
10
1-5
49 – 70
2-78
1-2
40-200
15
6-12
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1-125
1-5
90-480
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Air Blast Spiral Freezer Belt Support Systems
Self stacking spiral
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GYRoCOMPACT® Spiral Freezer
Self-stacking belt
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Self Stacking Spiral Belt
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Vertical Airflow in a GYRoCOMPACT Freezer
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Northfield Spiral Belt Freezers
• Northfield SuperTRAK® Spiral
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Northfield Spiral Belt Freezers
• Northfield LST® Design (Large Spiral Technology)
Applications
•
•
•
•
•
•
Wide belt
High belt speed
Large tier spacing
Heavy loading
Sequential defrost
Multi-level decking
and baffling
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Impingement Freezing and Chilling
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Patented Impingement Technology
• Thousands of high velocity air
jets strip away the boundary of
air that holds heat around the
product, resulting in extremely
fast freezing time
Boundary of air
HOT PRODUCT
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ADVANTEC AIRFLOW PATTERN
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Frigoscandia ADVANTEC™ Freezer & Chiller
•
True impingement means no thermal
boundary layer
•
Retention time is now dependent upon heat
conductivity in the product
•
Product thickness plays important role and
there is a natural limit for freezing
applications of approx. 1 inch
•
The effects of cryogenics have been reached
and exceeded but with a completely
different level on costs and flexibility
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Air Distribution - FLoFREEZE M and S
5
1. IQF Track
2. Pulsator (optional equipment)
3. Fan
2
4. Evaporator
5. ADF
1
4
3
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Fluidization
1. Product infeed
1
2
2. Track 1
3
3. Weir
4
5
4. Track 2
5. Belt agitation
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Fluidization
Particles in natural repose
Particles in fluidized state
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Freezing green peas in FloFreeze M freezer
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Industry Trends in Food Freezing
• Belt width
– end-users are seeking wider belts to accommodate increased line capacity
• Plastic belts
– lower weights results in
• lighter and less costly freezer
• reduced parasitic power costs (reduced friction and lower belt tension)
• reduced product contamination “black specs”
• less product sticking
• Extended operating run time
– requires ability to manage coil frosting: air defrost, sequential defrost
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Industry Trends in Food Freezing
• Sealed enclosures
– fully welded enclosure construction
• Enhanced hygiene
– Clean-in-place designs
– Steam santization
• Extended operating run time
– requires ability to manage coil frosting: air defrost, sequential defrost
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ADF - Air Defrost System
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F.A.S.T™ Sequential Defrost System
• Isolates each freezer coil so it
can defrost individually with no
moving parts.
• Automatically controlled by the
freezers PLC.
• Preprogrammed sequence
defrosts during normal freezer
operation.
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Welded Enclosure, GYRoCOMPACT M-series
freezers
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Hygiene
GYRoCOMPACT
Clean In Place (CIP)
38
Hygiene
Run Cold
Belt Washer
Recirculating Cleaning System
Rail & Drum
Cleaning
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Questions or comments?
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www.fmcfoodtech.com
Additional Information
Horizontal Air Flow
–
–
–
–
–
–
Large coil face proportional to spiral cross section
Can accumulate frost for a long time between defrosts
Little air baffling required
Low cost axial fans
Good for flat and heavily packaged products
Can defrost with Hot Gas only
Vertical Air Flow
–
–
–
–
–
–
–
Gives highest heat transfer at given air velocity
Creates higher pressure drop
Good for most bare products
Reduces dehydration losses
Quiet backwardly inclined cetrifugal fans
Helps prevent light products from lifting off belt (SVAD)
HAF - Horizontal Air Flow
SVAU or SVAD - Single
Vertical Air Flow, Upwards
or Downwards
DVA – Dual Vertical Air Flow
Spiral Design Constraints
• Conveyor belt must adequately support product and leave
no unacceptable markings or damage product. Belt and
drive system must be strong enough. to sustain the
system tension (radius weight) or the stack weight.
BELT
TENSION RATING
Flat Wire Belt w/heavy duty double bar links
300 lbs.
Leading Edge Performance Grid
300 lbs.
Fatigue Resistant Omni-Flex
400 lbs.
Leading Edge Performance Link
700 lbs.
Plastic Belts
400 lbs
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Spiral Design Constraints
• Must have adequate belt and coil, fans and refrigeration supply
to meet capacity requirements while freezing product to the
specified temperature without product damage or shrink.
• Coil must be designed to collect frost while running at design
capacity for the required number of hours
• Must fit in the space allowed
• Tier pitch or link height must allow adequate space for product
clearance and mechanical clearance with enough safety factor
to prevent product jams
46
Plastic Spiral belts from all the major suppliers of modular belting,
KVP, Intralox, Habasit as well as from Ashworth, the originator of
the low tension spiral belt.
Acetal now is the material of choice for most spiral applications. All
vendors continuing to develop new products to meet various
product requirements.
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Advantages of Plastic Belts
•Lower weights results in lighter and less costly freezer
•Lower weight results in lower power costs
•Reduced friction results in lower belt tensions
•Easily repairable
•Reduced product contamination “black specs”
•Less product sticking
•In certain applications allows elimination of UHMW wear
strips
48
Disadvantages of plastic belts
•Reduced thermal conductivity results in longer freezing time
for some products
•The materials which make the best belts (acetal) are
extremely flammable and give off toxic fumes
•Slightly less cleanable than metal and more prone to surface
scratching
•Difficult to detect broken belt pieces in product stream with
existing equipment
•Higher initial belt cost
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Extended Freezer Run Times
Changes in USDA rules are allowing and
encouraging plants to keep freezers cold
longer and run for longer production runs
between freezer cleanup. The only way to
achieve this is to find ways to remove
accumulated frost from the coils to maintain
performance. For example a freezer running
15,000 lbs per hour of a hot product could
generate 300 lbs of frost per hour.
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Enclosure and floor development.
In the US there has been great interest in
using enclosure with urethane foam cores
and stainless steel on both the inside and
outside surfaces. These enclosures are
designed for all interior and exterior joints
to be fully welded. All penetrations through
the enclosure for refrigeration lines,
conduit, conveyor openings are also fully
seam welded.
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Freezer Steam Sanitation
• Desire on the part of users to raise temperatures in freezers
to above 150 F and hold them for 15 minutes as a kill step
against bacteria.
• Need specially designed enclosures and equipment to
withstand enormous temperature swings
• Provide instrumentation in freezer to verify that all surfaces
reach required temperatures.
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