1592006207 XB570L GB r1.1 23.03.2015 XB570L
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11.3 EXAMPLE OF A BLAST CHILLER CYCLE
The following drawing explains how a Blast Chiller cycle can be done
.
iS1
iS2
iS3
0
-5
-10
-15
-20
-25
-30
5
10
15
20
FIRST PHASE:
HARD CHILL
2 PHASE
SOFT CHILL
3 PHASE
FREEZING CYCLE
rS2
rS1
rS3
Time
Temper.
°C
Insert probe
Room Probe
11.3.1 First phase: “Hard chill”.
It is normally used to fast chill hot foods. E.g. from 80°C / 170°F to 20°C / 70°F
During “
Hard Chill
”, both compressor and fan are always on until the
rS1
temperature is reached. At
this point compressor is turned on end off so as to keep the temperature of the room at the
rS1
value.
“Hard Chill” ends when the temperature measured by the 3 insert probes reach the
iS1
value.
11.3.2 Second phase: “Soft chill”.
The
Soft Chill
starts when the Hard Chill ends. It is used to prevent thin layer of ice from forming on the
product. The Soft Chill lasts until the temperature measured by the 3 insert probes reach the set point
iS2
(usually 4 or 5°C).
During Soft Chill the temperature of the room is regulated by the ambient probe with the set point
rS2
(normally at 0 or 1 °C / 32 or 34°F). When the box temperature reaches the
rS2
value compressor is
turned on end off so as to keep the temperature of the box at this value.
11.3.3 Third phase: “Freezing cycle”.
Freezing Cycle: used to fast freeze foods.
The Freezing Cycle starts when the Soft Chill ends. During the “Freezing Cycle” both compressor and
fan are always on until the
rS3
temperature is reached. At this point compressor and fans are turned on
end off so as to keep the temperature of the room at the
rS3
value (normally some degrees below
iS3)
.
Freezing Cycle ends when the temperature measured by the 3 insert probes reach the
iS3
value
(normally -18°C / 0°F), in any case it ends when the maximum time
Pd1 + Pd2 + Pd3
has expired.
11.3.4 End of the Blast Chill cycle and starting of the Hold Mode.
When one of the three insert probes reaches the iS3 value the values End followed by the i1P or i2P or
i3P are shown on the display.
Cycle ends when all the probes have reached the iS3 value. A signal is generated: buzzer and alarm
relay is turned ON, the display shows the message “End” alternating with the room temperature.
The alarm automatically stops after the “
but
” time or by pressing any keys.
At the end of the cycle the controller can start the “Hold mode” keeping the room temperature at the
value set in HdS parameter.
If HdS = OFF, the machine is turned OFF.
