Steam Water Exchanger 1

[Nik456]

I have steam/water Shell and Tube exchanger and my flowrate for steam is 6500 lb/hr and water is 55,000 lb/hr.

I would like to have your inputs for the desired location for Water and Steam. As water flowrate is higher, I thought of placing the water at shell side.

 

[ash9144]

You want to condense on the shell side, so steam on shell side.

Also assuming your water is cooling water, it is prone to fouling. If you get fouling inside your tubes you can clean them. Foul your shell side and you need new HEX.

 

[sshep]

Hey Nik,

Definitely put the most fouling fluid (water) on the tubes. High tubewall temperatures make scaling and fouling very likely on the water side. If you make the tubes an even number of passes, then you can use a floating head design (or even fixed tubesheet) in order to get straight tubes to clean. Include chemical cleaning nozzles to give that option also.

Although it doesn't apply to your case, a secondary consideration for chosing side is to put the lowest allowable pressure drop on the shell. This gives flexibility in chosing baffle spacing to meet allowable pressure drop criteria. The flowrate itself is rarely a consideration for chosing sides in my experience.

Is there any chance you can heat your water by direct steam injection. It could be a very problem free option in some cases- not sure of your process application.

best wishes,
sshep

 

[rmw]

Sshep, a great suggestion and a star for you.

rmw

 

[MJCronin]

Another consideration in a heat exchanger of this type is a phenomena called "surging"

This occurs when there is an interuption in the smooth flow of condensate out of the HX. (This assumes that the steam is on the shellside of the HX)

Condensate flows suddenly when the liquid collects within the HX and surface area is reduced to a point where a control valve suddenly opens.

Ensure that you have a "condensate pot" or similar available volume if you place steam on the shellside of thiss HX.

Regards

-MJC