Page 11
Page 11
The approximate heat transfer capacity for the
condenser selection is shown on the herebelow
table
The condenser is basically a heat exchanger
where the heat absorded by the refrigerant during
the evaporating process is given to the condensing
medium which could be the air or the water.
When using marine type condenser a marine
type, water regulating valve is requested as well
to modulate the cooling water flow within
condenser.
Recommendend valve is the pressure actuated
"PENN".
The Liquid receiver is a storage tank for liquid
refrigerant that can be useful on refrigeration
split installation to make the quantity of refrigerant
in the system less critical.
It is normally provided with two service valves
and occasionally can be built-in the bottom of
condenser. It is a common component used in
refrigeration plant and should be large enough to
hold all the refrigerant in the system.
The Oil separator should be filled with oil during
installation until the float valve just begins to
open. This oil quantity always remains in the
separator and would otherwise be taken from the
compressor.
It is well known that when the compressor
operates, small amount of oil is pumped out
along with the hot compressed vapor and to
prevent it from going any further in the system,
the oil separator traps it to return, upon opening
of its float valve, to the crankcase of the
compressor.
CONTROL DEVICES
The scale-ice maker system must be completed
with all the necessary safety devices and controls
in order to fully protect it and to minimize
operational checks and functions, however any
excess in using automatic controls and protections
may complicate the situation at the point that
some of the controls be eliminated later, by the
user.
In order to help the installator engineer to decide
with which controls he has to equip a given
system, we cover all the necessary ones
mentioning for each of them the positive factors
and eventually the negative ones.
High Pressure Control
Very important - No negative factors Set to
values shown on techn. spech. Not supplied.
Water Pressure Control
Very important - No negative factors Set to 0.8
atm-cut-in - 0.5 atm cut-out. Supplied.
Lo Pressure Control
Very important because in case of refrigerant
leaks at the evaporator, it prevents to draw in the
system some water from the drum reservoir. It
also prevents to draw air through the compressor
crank-shaft seal. This may occure during vacuum
operations of the system.
However, it may inopportunely trip-off at the
system start-up and if suction operating pressure,
on account of the excessive rotating speed of
compressor or excessive compressor capacity,
is very close and gets below its setting value,
which is 0.2 atm. Not supplied.
MAR 78 MAR 108 MAR 128 MAR 208 MAR 308
300 lt/hr 450 lt/hr 84*****h 1200 lt/hr 1600 lt/hr
Particular care must be deserved to the selection
of the water cooled condenser expecially the
marine type for fishing vessels installation.
They can be marine type (cupro-nickel) tube
within a tube condenser with plasticized heads.
With water inlet temperature of +20°C and outlet
of +30°C at condensing temperature of 32°C the
water consumption should be:
MAR 78 MAR 108 MAR 128 MAR 208 MAR 308
4900 Kcal/h 7500 Kcal/h 9750 Kcal/h 11000 Kcal/h 16200 Kcal/h
To Next Page
Loading...
