Mechanical freezers function
by continuously circulating
cool air around the system, this
method uses refrigerants, pri-marily
natural gases, such as
ammonia or CO2. Mechanical
systems are usually character-ised
by lower lifecycle costs
with higher capital investment
and most often owned and op-erated
by the food processor.
Widely viewed as the long es-tablished,
traditional form of
freezing, however, recent IQF
technology advancements and
modern designs provide food
manufacturers with a new gen-eration
of mechanical freezing
and chilling equipment.
Why choose
mechanical freezing?
A food manufacturer’s primary
consideration when selecting
a freezing technique should
be based upon the food prod-uct
type and its characteristics,
in order to achieve the opti-mum
product quality, taste and
yield.
There is no single type of freez-er
that is best suited for all food
freezing applications. How-ever,
for a large segment of
the food processing industry,
mechanical freezing systems
are the logical, cost effective
option that will support a busi-ness’s
long term growth plan.
Modern day high tech me-chanical
IQF (Individual Quick
Freezing) tunnels, especial-ly
high speed air impinge-ment
systems, are capable of
extremely quick freezing of
small, flat, unpackaged food
Kryogene (Stickstoff-)Gefrier-geräte
verwenden Gase mit
sehr niedriger Temperatur, in
der Regel flüssigen Stickstoff
oder Kohlendioxid, die direkt
auf das Lebensmittel aufge-bracht
werden. Diese Systeme
bieten in der Regel niedrigere
Kosten für Investitionsgüter
mit hohen Betriebskosten und
werden üblicherweise vom
Gasversorger gemietet.
Mechanische Gefrierschränke
funktionieren durch kontinu-ierliche
Zirkulation von Kühl-luft
um das System herum,
bei diesem Verfahren werden
Kältemittel, hauptsächlich Erd-
gas, Ammoniak oder CO2, ver-wendet.
Mechanische Syste-me
zeichnen sich in der Regel
durch niedrigere Lebenszyk-luskosten
bei höheren Inves-titionen
aus und sind meist
im Besitz und Betrieb der Kü-chenmaschine.
Weit verbreitet
als die seit langem etablierte,
traditionelle Form des Gefrie-rens,
bieten die jüngsten Fort-schritte
der IQF-Technologie
Gefrieren
Freezing
und moderne Designs den Le-bensmittelherstellern
jedoch
eine neue Generation von me-chanischen
Gefrier- und Kühl-geräten.
Warum mechanisch
einfrieren?
Die primäre Überlegung eines
Lebensmittelherstellers bei der
Auswahl einer Gefriertechnik
sollte sich auf die Art des Le-bensmittels
und seine Eigen-schaften
stützen, um eine op-timale
Produktqualität, einen
optimalen Geschmack und
eine optimale Ausbeute zu er-reichen.
Es gibt keinen einzigen Ge-frierschrank,
der sich perfekt
für alle Anwendungen im Be-reich
der Lebensmittelgefrie-rung
eignet. Für ein großes
Segment der Lebensmittel-industrie
sind mechanische
Gefriersysteme jedoch die
logische und kostengünstige
Option, die den langfristigen
Wachstumsplan eines Unter-nehmens
unterstützen.
products such as burgers, sea-food
and fish.
Traditional mechanical sys-tems
utilise more convention-al
air speeds, with a naturally
slower freezing rate than cry-ogenic
systems. However, this
process is proven to be en-ergy
efficient and cost effec-tive,
highly capable for a wide
range of food products includ-ing
large portions, packaged
products, ice-cream or ready
meals. Generally, a cryogenic
system isn’t ideal for large or
packaged foods mainly due to
the high wastage of gas una-ble
to penetrate thick product
mass or packaging any quick-er
than conventional airflows.
The cryogenic freezers reduce
temperature through the direct
application of liquid nitrogen
or carbon dioxide within an
enclosure that contains the
food product. Due to the na-ture
of this injection and ex-haust
system, it can be difficult
to control cooling precisely
and evenly across and along
the product conveyor, thus re-ducing
efficient operation.
Mechanical IQF tunnels can
be designed with different
speeds for each belt and thus
each product, giving a food
manufacturer more flexibility
in comparison to a cryogenic
freezer. Furthermore, it is pos-sible
to switch products just as
quickly in mechanical IQF or
spiral systems with CIP (Clean
in Place) technology allowing
a fast turnaround.
Enhancing product quality
In the cryogenic system the
product conveyor is always a
stainless steel mesh belt due to
the extreme low temperature
of the freezer. The distinct ad-vantage
of a mechanical sys-tem
is that the conveyor belt
can also be manufactured from
food grade low temperature
plastic for applications that
would benefit from the attrib-utes
of this alternative materi-al.
For example, a hygienical-ly
designed plastic conveyor
belt provides simple release
for delicate or wet products,
which maintains product ap-pearance
and quality.
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