RS COMPACT FREEZE TUNNEL, Руководство по эксплуатации и обслуживанию

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OPERATION & MAINTENANCE MANUAL
CompactFreezer
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3.2. COMPACT FREEZER PROCESS
The three basic principles of the Ultra ‐ Freeze® process are:
•
The use of fans (3module) to circulate the cold gases at high velocity. The one and two module units
use the pressure of the cryogenic tank to circulate the air. Fans can be added as an option to any
unit.
•
Accurate control of temperature
•
Belt speed control to set required “time exposure”, or “tunnel dwell time”
The Compact Freezer process utilizes the “wind chill” effect to increase the freeze rate for products. The
high velocity gas flow created by the circulating fans, continually removes the thin insulating envelope of
static gas that normally surrounds the product to be frozen. This allows the super cold nitrogen gases to
be in very close contact with the surface of the food product. The rapid freeze achieved by the high
velocity gas flow reduces product shrinkage and moisture loss, as well as maintains final quality of the
product.
The liquid nitrogen from the injection nozzles is rapidly converted to cold gas due to absorption of the
heat introduced by the food product. The secret to the efficient operation of the
Compact Freeze tunnel
is accurate temperature control of the modules and constant uninterrupted injection during the
processing period.
The Compact Freezer temperature controlled injection system keeps the liquid nitrogen consumption low
by matching the injection to the product heat load. If the product flow stops, the freezer automatically
reduces the liquid nitrogen injection rate to the minimum required to maintain the freezer operating
(set point) temperature.
A key error made by many operators of cryogenic freezers is improper managing of the freezing process.
Standards need to be set for various products (set point temperature and belt speed); in addition,
proper belt loading and proper belt speed (dwell time) must be maintained. There should be prompt
attention to changing conditions.
3.3. THE FREEZER
The Compact Freezer is an assembly of one, two or three modules joined together to form an insulated
tunnel that product is conveyed through. There is an entry and an exit vestibule bolted to the respective
end of the tunnel. The entry vestibule allows an area for loading the conveyor belt and has an exhaust
trough for collecting the cold exhaust vapors. The exit vestibule has the conveyor drive motor(s), the
exit exhaust trough and is the product discharge area.
The individual modules form natural zones that are used to efficiently control temperature of the freezing
process. Each module is equipped with two propeller
‐ type circulating fans mounted above the conveyor
that rapidly circulate the cold gases over the product. Product heat load variations cause the temperature
in each zone to change, which signals the cryogenic injection system to cycle off and on as required. This
insures the highest product freezing capacity with the optimal utilization of the cryogen cooling capacity.
Each module has stainless steel plates inside the sealed fiberglass skins. The Plates are located on the