standard shell ID in heat exchanger 4

[Nasser D]

Hi everyone,

I am designing water to water heat exchanger, in my first try I have about 1000 tubes. The problem is in Kern book there is no shell ID match with this amount of tubes. Tube OD: 1 1/4 in. no of tube require 1070. Probably 2 passes tube. Thanks

 

You have the basic parameters. The answer is in the math.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[SnTMan]

Roll & weld shells can be made to nearly any diameter.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[georgeverghese]

For fouling service on shellside, use square(90deg) or rotated square(45deg) pattern to enable shellside cleaning. Tube pitch should be big enough to allow for cleaning also. Check Kern/Plant Owner design guidelines for min required pitch - typically tube pitch = 1.25 x tube od for cleaning.
Tables in Perry tell me you are looking at a 60inch OD shell for 1024tubes on 2pass with U tube bundle. Why not split the flow into 2nos. of 45inch shell OD HXs' operating in parallel? This should be easier to fabricate.

 

[Nasser D]

Thanks georgeverghese, Exactly I am looking for that table, but I can not find this table in Perry, could you please advise? Thanks

 

[Nasser D]

Hi Ironic metallurgist, Low design experience can be fixed by work and study. But, Clearly your level of courtesy is not enough to be able communicate with others with respect. I hope you also find a way to fix that. Have a great weekend.

 

Thanks, but I know I will not have a great weekend! I am overloaded with work reviewing shoddy, amateur documents provided by vendors who clearly don't have much expertise in the subject matter (but who are happy to take our money).

I am just stating what appears obvious, so you should not feel slighted. We were all in the same place at the start.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[EdStainless]

Those tubes sound awfully large for water to water.
I am much more accustomed to 3/4" with thin walls.
And flow velocity is your friend for heat transfer.
But shell side flow and the risk of vibration is a critical factor.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[MJCronin]

Yes Nasser, I agree ...

"Low design experience can be fixed by work and study." .... But not by work and study alone !!!....

You forgot to mention the long list of technical questions that must be asked to those with decades of experience and access to industry books, reports, codes and standards....

Then, and only then can your "Low design experience" be fixed ...

IMHO ....

MJCronin
Sr. Process Engineer

 

[georgeverghese]

Yes, those tables are in the 6th edition of Perry; they've scrubbed it out in the 7th edn.
Smaller shells are also easier to maintain - tube bundle weight must be within the crane capacity of your fabrication yard and your plant maintenance for pulling out the bundle.
Biggest problem with water is corrosion.
If this is in fouling service, welded plate frame HX would not be possible. Cleaning would be possible with gasketed plate frame HX, but leaks are very likely.
Take a look at spiral HX also, there is a good narrative on this in Perry 7th edn - cleanable and compact, much better temperature approach than shell and tube HX with 2 passes on tubeside, since it is pure countercurrent flow.

 

[GD2]

Nasser D,
Check the attached documents if this makes sense. Make sure that you take the responsibility of the design.



GDD
Canada

 

[Nasser D]

Thanks a lot everybody for great tips.