Parallel condensers Shell and tube paralle with Evaporative Condenser

[Herschmidt]

Hi :

I´m currently working in a refrigeration plant in Argentina, the plant has one tube and shell condenser and a evaporative condenser working in parallel, what caugh my attention is that the evaporative condenser is sitting on the floor and there is not high difference between the evaportive condenser outlet and the shell and tube outlet.

I know that in order to make them work, we have to raise the evaporative condenser, but the question is how high?

The evaportive condenser is a SEMCOBAC VXC135, it has an output of 315000 Kcal/h or 366 Kw, working with 35ºC condensation temperature, and the refrigerant is ammonia.



Thanks in advance.

Hernan

[PVA]

The main problem is that we need to balance the condensers, and this is solved by several methods, in your case, you need more specific look at the PID diagram (scheme) of installation.

[charlie n]

The height of the condenser is not always the issue. You do, however, need at least a 1 meter high liquid drain leg with an inverted trap at the bottom or the liquid drain needs to enter the bottom of the high pressure receiver. The purpose of the liquid column is to build up a pressure head of liquid refrigerant equal or a little greater than the pressure drop through the evap. condenser at design flow. There is almost no pressure drop through the S & T condenser so the outlet pressure will be much higher than the outlet pressure of the evap. therefore there is a very small flow through the evap. cond. unless you provide this pressure increase by means of a liquid column.