Alfa Laval Contherm 6X11, Инструкция по эксплуатации

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6 Installation
6.10 Installing an Ammonia for Freon: Full-Flooded Refrigeration System
The refrigeration system and related pipework should only be installed and tested by a qualified refrigeration technician. Ensure
that debris and contaminants associated with installing the refrigeration pipework are removed from piping and do not foul the
Contherm
™
or related components. Refer to Chapter 1 for any drawings and instructions specific to your order.
A typical refrigeration system configuration for a Contherm
™
is shown in Figure 6-19. Your installation may vary from what is
shown.
It is the end-user responsibility to ensure adequate refrigeration capacity to the Contherm
™
heat exchangers at all times. A
flooded system uses an accumulator of suitable size and positioning to provide a reservoir so that the entire media annulus of the
Contherm
™
is full of liquid refrigerant at all times.
An important optional feature available with Contherm
™
refrigeration systems using ammonia or Freon is the Maintain Status
feature. With proper system control, this feature will prevent complete freezing of the product in the Contherm
™
. If the flow
of product is interrupted long enough so that freezing of the product may occur, the Maintain Status feature will raise the
pressure of the refrigerant to a higher level than the normal operating pressures. This higher pressure will in turn raise the boiling
temperature of the refrigerant to a level above the freezing point of the product. Once the system has returned to within its
normal operating range, the pressure is reduced to continue the cooling of product. If freeze up does occur, emergency hot gas
will quickly flush the system and raise the temperature of the cooling media and the product.
6.10.1 Component Description
The following components are typical of those used in standard Contherm
™
refrigeration (ammonia and Freon) media packages.
Components in a Standard Ammonia Refrigeration Package include:
1
Ammonia accumulator.
2 Dual back pressure regulator.
3 Liquid feed line and Hand expansion valve.
4 Liquid level control.
5 Safety relief valve.
6 Purge valve.
7
Support leg.
8 Hot gas defrost.
A. Solenoid valve.
B. Hand valve.
C. Check valve.
9 Flanged connections to the Contherm
™
.
Freon systems use the same components as described for the ammonia package above with the addition of a sight glass and a
copper sniffer line for purging the system of oil.
Dual Back Pressure Regulator
The primary back pressure regulator valve controls the flow of refrigerant gas to maintain a constant upstream
pressure/temperature in the accumulator. It is the setting of this valve that determines the product temperature. If freeze up
of product occurs, an auxiliary back pressure regulator is utilized which is set at a higher pressure than the primary regulator.
This action is called “Maintain Status” because the auxiliary regulator maintains a high enough back pressure to raise the
product temperature above its freezing point in the Contherm
™
.
Liquid Level Control
The primary control for maintaining the liquid level in the accumulator is a float switch.
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