Heat Exchanger Design
Heat Exchanger Design
(OP)
I need 200 litre/hr liquid condensate at 170 Deg.F. steam available at 320 Deg.F and on other side, water (13 gpm) is available at 55 Deg.F.
Please help me how to design heat exchanger ?
Please help me how to design heat exchanger ?





RE: Heat Exchanger Design
You also have a cooling water flow rate and an inlet temperature. Since the heat given up by the condensing steam is picked up by the water, a thermal balance will give you the outlet water temperature.
Now, you have the duty and all the temperatures. Do you have a type of exchanger in mind? Shell and tube, plate, double pipe, etc or is this all part of your question?
RE: Heat Exchanger Design
I would like to go for plate and frame heat exchanger.
Sandy
RE: Heat Exchanger Design
One thing to check, you likely don't want the cooling water to be leaving at more than about 120F or you can have problems with calcium carbonate deposition and fouling. You can handle higher temperatures by playing around with your cooling water treating program but for one small exchanger, I doubt you will want to do that.
We just had Alfa-Laval in to do a presentation on plate and frame exchangers and I asked the question (wrt another process they were showing) whether it was possible to condense AND subcool in a single unit. They said it wasn't possible. No big problme, it just means you have one unit to condense the steam and another unit to subcool it. You can supply the cold cooling water to the subcooling unit and then use the warm cooling water from it to the condenser.
Coming up with a heat transfer area is a bit more tricky for plate and frame as the correlations aren't nearly as widely available (there have been some links and information posted on Eng-Tips, you might want to do some browsing). In any event, I'm not sure I would be actually determining how many plates I needed, I'd leave that up to the vendor though I might do some back checking to seee if the overall heat transfer coefficient looked reasonable (they'll be much higher than for a shell and tube obviously).
Have you looked on Alfa-Laval's or Trantor's web site to see what information might be available? I'd likely call up one of their technical people, explain what you are looking for and ask if they can give you some general information.
RE: Heat Exchanger Design
However, S&T HE's are more expensive than plate exchangers, so it may be cheaper to install multiple plate exchangers.
RE: Heat Exchanger Design
I suggest you ask Alfa Laval again . . about their TS6M and TS20M PHEs. These are designed specifically for steam primary use, and will allow the steam space to be flooded with sub-cooled condensate. Alfa laval should be able to predict your needs with their software.