WATER COOLED HEAT EXCHANGER TEMPERATURE LIMITATIONS

[roker]

Hello all,

Are there any limitations for the process fluid inlet temperature to be cooled with cooling tower water, for example can we cool a process stream at 120 C with water at 30 C ?

regards,
roker

 

[TBP]

Heat exchangers are routinely used to heat water - or some other liquid using steam at far higher temperatures than you have. The only limitation I can think of is not to heat the tower water too much - you may have plastic piping or tower fill to consider. But that's easily dealt with - just have the tower water flow sufficient to keep the delta-T within acceptable limits.

 

[Jason5000]

roker,

Hot cooling water exchangers can foul faster. From my experience 120 C is a little hot for process inlet to a cooling water exchanger, but I have seen it done with good long term reliability.

This is highly dependent on your water chemistry. If you run too many cycles hot exchangers are more susceptible to plating out scale.

 

[ayoyo]

Jason is right, check you water quality. The film temperature at your water side maybe higher than you think, and caused fouling to your heat exchanger.

 

[srfish]

Calculate the tube wall temperature at the hottest point. The Heat Exchanger Design Handbook in the section on recommrnded fouling resistances for design says " For cooling waters from which calcium carbonate may deposited, a heat transfer surface temperature above 60 degrees C(140 F) should be avoided".

 

[HeinrichK]

Usually it is cheaper to install an aircooler with a small watercooler behind it. (Of course depending on the size of the process flow you want to cool)