Alfa Laval Contherm 6X11, Инструкция по эксплуатации

Страница: 44 / 124

6 Installation
Safety Relief Valve
The refrigeration safety relief valve prevents pressure in the accumulator from rising above a safe limit.
Purge Valve
A refrigeration system that uses ammonia must have a purge valve located at a low point so that the oil that accumulates in the
refrigerant line can be drained from the system.
Hot Gas Defrost
The hot gas defrost consists of the following valves:
1. The hot gas solenoid valve is an on/off valve that allows hot gas to get piped into the refrigeration system. When energized,
the hot gas will flow into the Contherms
™
media annulus and accumulator to prevent product freeze-up.
2. The hand valve is used to control the flow of hot gas into the refrigeration system.
3. The check valve prevents liquid from flowing back into the hot gas line.
Suction Line Installation
1. Do not connect the suction line header to a pre-existing header already in use as this could produce varying refrigeration
loads to the Contherm
™
.
2. Size the header for 50% or more above the rated capacity of the Contherm(s
™
).
3. Keep suction pressure at compressor as low as possible to allow for greatest cooling capacity at the Contherm
™
.
Sniffer Line
A sniffer line is used with Freon refrigeration systems to purge oil from the accumulator.
The following paragraphs identify several precautionary steps that you should take when installing and piping your refrigeration
system.
1. Pipe lengths to be kept to a minimum to not create restriction of liquid to Contherm
™
.
2. Install a hand expansion valve in the liquid feed line between the solenoid and accumulator to control the flow of liquid
refrigerant. This valve should be adjusted so that the solenoid remains open roughly 70% of the time during operation.
3. Install an indicator lamp to show when the liquid line solenoid is open.
4. Install a relief valve and ensure that it is properly vented. The purge valve should be located at the low point of the system to
permit the removal of oil contamination from the ammonia refrigerant. The system should be purged regularly to prevent
oil from blanketing the heat exchanger surface and reducing thermal efficiency.
5. Install a Sniffer Line if your refrigeration system is using Freon. This line should be connected as shown in Figure 6-19. When
installed correctly, a small, but constant, amount of liquid flow will be maintained thereby ensuring the removal of the oil,
which floats on top of the Freon refrigerant.
44