19
Contractor’s manual
F15 - F30 Generators
Manual For F15 and F30 - Mill.: 2008 - 11 / Mod. : JPM 05
Page
F
E
D
C
B
A
L
K
J
P
O
N
H
G
I
M
D
R
S
B
Q
E
M
C1
C2
9. Operation
9.1 Principle of operation
9.1.1 Description of generator
Fig.1
Simplifi ed exploded view of a generator
Fig.2
Simplifi ed exploded view of a generator, and an illustration
of the water distribution seen from above.
The water distributed by the tray B fl ows copiously and
continuously over the internal surface of the stationary
drum F, inside which a low temperature refrigerant fl uid
circulates inside the double wall E. The insulation G of the
drum ensures heat exchanger withf the water only.
Part of this water M is frozen and the excess returns via
the lower water pan H into the base O, where the level
P is kept constant by means of a fl oat valve (not shown).
This water circulated by the pump N.
A helical reamer D, driven through a reduction gear A,
sweeps the surface L, when the coat of iceis thick enough,
the reamer starts rotating and harvesting the ice by ap-
plying pressure on it.
The torque limiter K switches off the electrical supply
to the motor-gearbox when in the event of mechanical
overbad.
The thickness and quantity of ice produced by the genera-
tor depends on :
-
The refrigerating power applied to the generator
-
The speed of rotation of the reamer.
Important
The thickness of the ice does not depend on the
spacing of the reamer from the drum. IT IS DANGER-
OUS TO SPACE THE REAMER AWAY FROM THE
DRUM this can cause : fatigue of the bearings, tripping
of the torque limiter, slugging and oil departure that
could destroy the compressor.
In the factory, the reamer is set as close as possible to
the drum : a distance of less than 0,4 mm, for a proper
operation.
The sprayed area Q is bounded by two wipers C1 and
C2, which surround the reamer D.
The purpose of wiper C1, situated before the reamer, is to
dry the ice before the latter reaches the subcooling zone
S. The area R for stripping the ice is located between one
blade of the reamer D and the rear wiper C2.
The purpose of this wiper is to remove the residues of ice
which may have remained on the drum after the passage
of the reamer.
There is no fl ow of water in the areas R and
S. So the perfectly dry ice I is stripped in the area R and
falls into the storage bin under the machine. However, for
the rear wiper to effectively clean the surface, it must be
adjusted in such a way that a thin trickle of water fl ows
along its forward face in contact with the surface (1 mm
approx.), as shown on fi g 2
Note
The reamer speed is set in the factory and cannot
be changed without the risk of causing operating
problems.
Operation
Thin trickle of water
