|In the refrigeration cycle, for higher efficiency, the liquid
refrigerant condensed in the condenser and flowing in
the capillary tube towards the evaporator should be cooled,
while the vapour refrigerant sucked by the compressor
from the evaporator through the suction tube should be
heated up from saturated to superheated condition. Hence,
the two tubes are brought together to achieve both of
these objectives. This twin tube system is called the "heat
exchanger" or "suction tube assembly" of the refrigeration
To help the heat exchange, the two tubes can be soldered together as in the tube-on-tube copper heat exchangers, or the capillary tube can be passed through the suction tube as in the Al-Cu mono-tube heat exchangers.
KONVEYOR manufactures large quantities of both types as well as special ones for freezers like combi, frost-free, or home air conditioner.
Copper, capillary, and (partially) aluminium tubes are cut to lengths and brought together by using special machines.
Aluminium-copper connections of the mono-tube suction tubes may be made by different methods like, Zn-Al alloy brazing, ultrasonic soldering, or eutectic welding.