8 replies to this topic

[Dmitry]

Dear all,


Please help with next issue:

Numbers of shell passes is 1
Numbers of shells in series is 2
Number of shells in parallel is 1
Tube passes per shell is 2

Am I right with this data? Please see attached file

Dmitry

Attached Thumbnails

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[Art Montemayor]

Dmitry:

I may be wrong – mainly because at 75 years, my eyes aren’t what they used to be – but I believe what I can make out in your scanned General Arrangement drawing is two, identical, BEM stacked heat exchangers operating as one unit with each having:

• One pass per shell; and
• One tube pass per shell.

I hope my eyes haven’t failed me. This is the usual way to configure a heat transfer application where the total area is relatively large for the tube side application and a temperature cross is to be avoided by using pure counter-flow. By using identical stacked exchangers you can control the shell diameter – and consequently, the Reynolds number in the tube side because you control the number of tubes. The net effect is that you have, in effect, lengthened the tube path and established the required heat transfer area in an economical counter-flow configuration.

[srfish]

Dmitry,

You were correct except for the number of tube passes. Art caught this tube pass error correctly. They are one(1) tube pass heat exchangers.

[Bobby Strain]

Dmitry,
You usually have a view of the tubsheets and heads. Consult them to be sure. Both the responses above are from old guys, and they are not necessarily getting a complete picture either.

Bobby

[Art Montemayor]

El diablo no es peligroso porque es diablo;
Es peligroso porque es viejo.

[Dipankarc84]

Hi Dmitry,
Mr. Montemayor has already answered your question. Just an additional suggestion from my side. You can distinguish between even and odd tube passes by looking at the location of the channel side nozzles. If the nozzles are at opposite ends (as is the case in your drawing), it has to be odd no. of tube passes and hence 2 tube passes are not possible.

Regards
Dipankar

[Dmitry]

Thanks for reply,

Could you give a link or some document where I can find explanation how to define heat exchangers details.

Dmitry

[srfish]

Dmitry,

Here are some literature sources that give detailed mechanical information on shell-and tube heat exchangers:
Serth,R.W., Process Heat Transfer
Cao, E., Heat Transfer in Process Engineering
Heat Exchanger Design Handbook
TEMA (shows nomenclature)

[Dmitry]

Dmitry,

Here are some literature sources that give detailed mechanical information on shell-and tube heat exchangers:
Serth,R.W., Process Heat Transfer
Cao, E., Heat Transfer in Process Engineering
Heat Exchanger Design Handbook
TEMA (shows nomenclature)

Than you for help, I wil try to find these books

Dmitry