BROCHURE

The Munters differencein process freezing
Eliminate ice and frost, increase
throughput, and secure quality

Humidity control helps
optimize process
High volume, round-the-clock, fast-paced production systems are the norm
when it comes to process freezing operations. But uncontrolled humidity in foodproduction facilities can lead to expensive downtime when evaporators need to
be defrosted and ice must be removed from conveyors, floors, and walls.
Desiccant dehumidification removes moisture from the air before it can form
into frost and ice on equipment. With ice build-up and defrost cycles significantly
reduced, process freezing operations can run smoothly at maximum capacity –throughout the entire year.

2Desiccant dehumidification
for blast and spiral freezers
A blast or spiral freezer is a critical component in most frozen food production
processes. One of the greatest challenges manufacturers face is frost build-up in
freezer units and evaporator coils. But when a Munters desiccant dehumidification
system delivers dry air to blast and spiral freezers manufacturers get the following
benefits:• Improved freezer cooling performance – less or no ice or frost means lessor no defrost cycles.
• Higher cooling capacity – frost-free evaporator coils offer consistent and better
product flow through the freezer since cooling coils are more efficient.
• Better product quality – frost-free freezer inlets, outlets, and conveyors will notdamage product and conveyors don´t malfunction due to frost build-up.
• Improved productivity – staff don´t have to manually remove frost and there´sno longer a need for total defrost shutdowns• Significantly reduced staff injuries - falls and slips are no longer a worry since
there´s no more frost or ice.

Munters MX2

Munters DSS Pro

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Moisture infiltration anddew point control
The two most important factors in food freezer design are moisture infiltration andcontrol dew point.
If the installation is already in place, the designer must simply take surface
temperature readings on the walls, floor, and conveyor supports to ensure ice
formation is kept to a minimum. The control dew point will be slightly below that
surface temperature.
Sometimes temperatures are so low that it wouldn´t be practical to maintaina dew point low enough to prevent all ice formation. It may be necessary to
determine what temperature makes the most economic sense and accept minimal
ice formation.
The lower the dew point, the more efficient the refrigeration system becomes,
which means less frost on ceilings and conveyors. By removing moisture at its
source – before entering the cold space – the system operates more efficiently.

Determine moisture loads
Moisture loads come from air getting by doors and conveyor openings, andproduct evaporation.
Infiltration air – Factory or outdoor air entering the space has the highest moistureload. Air enters when a door is opened, or continuously flows through openings
around conveyors. No matter how it gets in, it´s important to reduce this load to aminimum with entry tunnels and vestibules. Any door openings inside the freezer
should also be kept to a minimum.
Product moisture – Product water vapor is easy to calculate by simply weighing
the product entering and exiting the freezer. The difference in weight is largely
moisture. If the product is wrapped before freezing, this load will be close to zero.

4The Munters Solution
Munters dehumidifiers have a desiccant wheel that rotates slowly between two
primary airstreams, process, and reactivation. In the process airstream water vapor
is removed as it passes through the desiccant wheel. This dehumidified air is thendelivered to a manufacturing process or space. The wheel then rotates into thereactivation sector where a heated airstream is passed through the wheel. The
desiccant wheel releases the water vapor to this airstream.
The desiccant process becomes more efficient as air temperature decreases.
Munters dehumidification solutions can produce air dew points of -34°C andlower so you can have dry, wintertime moisture conditions, even in the summer.
Since the Munters dehumidification unit removes moisture from the air to levels
below the evaporator’s temperature, moisture no longer freezes on cold surfaces
and refrigeration equipment operates more efficiently, with fewer evaporator defrost
cycles, fewer conveyor jams due to ice build-up and safer, less slippery floors.
Munters has spent decades improving and optimizing the desiccantdehumidification process including patenting technologies like PowerPurge®,
which reduces energy consumption by up to 30%.

Munters Honeycombe® Wheel Technology
Patented HoneyCombe® wheel
design provides a vast surface
area for desiccant5

Honeycombe®
Dehumidifier

Wet Air
Outlet

Wet Air
OutletHoneycombe®
Dehumidifier

Reactivation
Inlet AirDry Air
SupplyAir from
Plant or OA

Dry Air
SupplyCoils

Return Air

Coils

Conveyor

Reactivation
Inlet Air

Tunnels Added atFreezer Openings

Conveyor
Openings
or Doors

Process Freezer

Return Air

Conveyor
Openings
or Doors

Process FreezerFigure 1. Makeup air system with tunnels

Figure 2. Air system with vestibule

Process freezer types
No vestibule (figure 1) – Usually a spiral freezer or blast freezer is built without avestibule. While vestibules are often impossible to install, due to lack of space,conveyor tunnels help mitigate icing inside the freezer.
Air is taken from the ambient plant (or outside air if the plant has negative
pressure), processed through the dehumidifier and supplied to the conveyor
tunnels. This air should be enough to maintain a minimum of 0.508 m/s air velocity
for the conveyor openings.
Vestibule system (figure 2) – The vestibule system may be all that´s needed tominimize moisture in the process freezer if space allows. It´s low cost and simple
to install.
Air is taken from the vestibule, processed through the dehumidifier and returnedto the vestibule area, just in front of the freezer conveyor entrance. The only air thatgets into the freezer is dry air with a moisture level below the temperature of theevaporators. The dehumidifier can be switched on by a conde nsation controller,
set to maintain the air at a specific dew point.

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Conventional systems
can´t remove moistureefficiently
Process freezing systems are designed to remove sensible heat from a productrapidly and efficiently. However, they are not designed to efficiently remove latentheat/moisture from the air inside the freezing chamber.
While cooling coils can be automatically defrosted, ice on conveyors andfloors must be manually removed, causing production to slow down or stop. Coildefrosting also adds a heat load to the freezer and puts the coil offline, which
reduces the freeze´s ability to keep temperatures cold.
The cooling capacity of the evaporator coil is also significantly reduced since
the coil builds up frost, so product cooling is reduced. This means that productcooling rates can vary with coil frost, yielding uneven production quality andthroughput. For some freezers, defrost cycles causes production to stop or slow
down, causing expensive and unnecessary delays.
To reduce icing, the moisture in the air must be reduced. Refrigeration systems
lack the cooling capacity to produce low air dew points when humidity ishigh. The coils freeze with condensed moisture before a low dew point can beachieved. And when you use an evaporator coil to remove moisture, it discharges
air at saturation, which means that it cannot absorb any additional product orinfiltration moisture.

7Munters Services –With you all the way
With Munters as your service partner, your air treatment equipment will receive theattention, care and maintenance needed to reach its maximum life expectancy.
Throughout each phase of the equipment life cycle, the knowledge and expertiseof Munters Services will insure optimal operation, minimum energy consumption,and extension of the life of your investment.
Our range of services available through our global network of Munters
Services Engineers and Technicians include:• Comprehensive installation and start-up services• PrimaCaire™ (extended warranty) agreement• Flexible ServiceCaire™ maintenance agreements to fit your specific needs• Performance checks and optimization• Numerous upgrade options for substantial energy savings and improved
performance

BR-X X X X X-202110 -EN

Being a global provider of air treatment solutions means our product andservice portfolio may vary depending on climate conditions, regional demand,applications and industries.

Find your nearest Munters office at www.munters.com
Munters reserves the right to make alterations to specifications, quantities, etc., for production
or other reasons, subsequent to publication. © Munters AB, 2021