Rating of Wet surface Air cooler
Rating of Wet surface Air cooler
(OP)
We have existing Wet surface air cooler but the calculations for the same are not available.
I am analysing to check wther the same exchanger can be used for higher heat load. The heat load is increased due to increase in preocess stream feed temperature. I need to keep the process stream outlet temperature same as before to keep same load on downstream hydrator.
Are there any methods for rating available? Can simulator be used for this purpose.
Breif description of Wet Surface air cooler.
The precess stream is in tubes. Water is sprayed on Tubes. The Air and water flows co currently as crossflow over the tubes. When air and water reaches basin the Air path is changed by 90 Degress. Induced fan removes the Air.
Therefore Air at ambient temperature ( Ranging 45 Deg in Summer to say 15 deg winter)mixes with water at Wet bulb temperature. Water picks up the heat from the process fliud flowing tubes. Air provides turbulance. The water evaporates into air and finally reaches the basin at wet bulb temperature. Therefore it is combination of Air cooler and cooling tower.
I am analysing to check wther the same exchanger can be used for higher heat load. The heat load is increased due to increase in preocess stream feed temperature. I need to keep the process stream outlet temperature same as before to keep same load on downstream hydrator.
Are there any methods for rating available? Can simulator be used for this purpose.
Breif description of Wet Surface air cooler.
The precess stream is in tubes. Water is sprayed on Tubes. The Air and water flows co currently as crossflow over the tubes. When air and water reaches basin the Air path is changed by 90 Degress. Induced fan removes the Air.
Therefore Air at ambient temperature ( Ranging 45 Deg in Summer to say 15 deg winter)mixes with water at Wet bulb temperature. Water picks up the heat from the process fliud flowing tubes. Air provides turbulance. The water evaporates into air and finally reaches the basin at wet bulb temperature. Therefore it is combination of Air cooler and cooling tower.





RE: Rating of Wet surface Air cooler
rmw
RE: Rating of Wet surface Air cooler
The wet bulb temperature of water leaving the basin is 22.8 deg C.
Aitr inlet is 45 deg C
The approach Process Gas outlet- water outlet is 29.4-22.8=6.6 deg C
Regards,
RE: Rating of Wet surface Air cooler
Cooling towers with the best technology can get to 3.88C of wet bulb. Frankly, I don't see why the WSAC Mfg'r doesn't use some cooling tower fill below the tube bundle (and before the 90 degree air turn) to get a closer approach to wet bulb, but that doesn't help you.
rmw
RE: Rating of Wet surface Air cooler
RE: Rating of Wet surface Air cooler
RE: Rating of Wet surface Air cooler
The process gas cooling comes from sensible heat transfer from the water flowing over the tube surface separating the water from the process. Since the theory is that the tube surface is constantly wetted, there should be no sensible heat transfer from the air.
In that process (not to be confused with your process process) the water gains heat. The air flowing down with the water is heated by the water through both evaporation and some sensible heat transfer if the water becomes hotter than the air. In the process of giving off its latent heat to evaporation, and the sensible heat transfer to the air, the water cools.
The heated and moist air is evacuated from the unit by the fans carrying the process heat rejection away.
rmw