tube bundles 1

[AO1958]

Hi everybody,

hope somebody could help me.
I am designing an heat exchanger composed by bare tubes, and I'd need to find a reference formula for heat transfer and pressure drop.

I am reconnecting to following thread
thread378-170854

I have the possibility to
Heat Transfer - J.P. Holman
nevertheless I cannot find any reference to this topic.

Please, could anybody of you tell me if this issue is present in the most recent versions ?

Could anybody of you give me some other literature or web references ?

Many thanks

 

[gr2vessels]

AO 1958,
It seems a bit naive your request for help in the design of heat exchangers. This type of the equipment requires highly specialized engineering knowledge, experience, to not mention the software at the cost of tens of thousands of dollars. The thermal design and the mechanical design of a heat exchanger is the product of several competent engineers hard work, at the cost of many thousand of dollars. You might as well ask for help to build a rocket, to have a short trip to the Moon.
However, if you know what type of shell and tube heat exchanger you need, if you know the both process fluid properties, flow, pressure, temperature data, plus many other details at a later stage, them we might be able to guide you step by step in your endeavour.
Cheers.
gr2vessels

 

[MikeHalloran]

I think he's trying to say 'no shell', i.e. a tank heater.



Mike Halloran
Pembroke Pines, FL, USA

 

[TBP]

Assuming that Mike has correctly described AO1958's problem, why not use an off the shelf unit from a heat exchanger manufacturer? I've done that. Buy a shell & tube, remove the shell, cut the flange off, along with a few inches of shell. Cut a corresponding hole at the location required in the tank, and weld the shell flange & stub on. Stab the tube bundle in, and bolt the head on. The tank is now the shell. Pipe up the head, and you're in business.

 

[AO1958]

Hi All, and thanks for your answers.

Just some clarifications:

to Mr.gr2vessels
in my opinion, even a rocket has to be designed considering element by element.
In shorts:
there is a bank of tubes.
I have to realize a calculation of an heat transfer coefficient.
Internal side convective coefficient and pressure drop are known.
I need to know external convective coefficient.
Therefore I need a correlation to calculate it.


according to the quoted thread it would be present in J.P. Holman book, but I am not able to find any evidence.

Therefore, I kindly ask if somebody of you knows some correlations or could recommend me some literature reference.
I don't think that this request is so different from the others I can read in the forum

that's the basis of my thread.

to Mr.TBP
Unfortunately at the moment I am not able to realize any practical experimentation, but I'd need to realize a theoretical one.

Many thanks

 

[rmw]

Yes, a rocket does have to be designed element by element, but that process is usually done by Rocket Scientists.

With no disrespect meant, for you to have the task that you have before you and to have to ask the questions that you are asking, you are way out of your league.

Hx design is not just one correlation, but many, and even the "rocket scientists" of the Hx world have to work hard to get it right.

Sorry, but JP Holman isn't even close. I design Hx's as part of my day job and my JP Holman usually just gathers dust on the shelf.

I recommend that you get an expert or consult with some possible vendors of this type equipment. Give them your requirements and let them do the sizing for you and than analyze their choices with what you can find in JP Holman.

rmw

 

[SNORGY]

I am not a heat transfer equipment designer, but when I do get into some "rough technical justice" kind of situations, it is my opinion that Kearns is about the best reference out there for "the rest of us".

With all due respect to the detailed designers of specialized equipment, sometimes "the rest of us" just have to take the plunge and take a shot at something, due to a myriad of constraints and reasons.

After all, for everything, I knew nothing about anything the first time I tried something.

Regards,

SNORGY.

 

[vpl]

I don't design heat exchangers for a living, but occasionally have had to verify that they were meeting their design requirements. You have to really dig deep into most heat transfer books, but there is usually a chapter or two on heat exchanger desgin.

This is one such book, available for free on the web:

http://web.mit.edu/lienhard/

http://www/ahtt.html

I use Thomas: "Heat Transfer - Professional Version" and Kreith: "Principles of Heat Transfer. In both books, I recommend reading Chapter 11.

But frankly AO1958 and SNORGY, it's not an easy subject and not one where you can really expect people who do it for a living to do it for you for free.

Patricia Lougheed

Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of the Eng-Tips Forums.

 

[TBP]

To me, this is like designing your own valve. Unless you work for a valve company, why would you beat your brains out trying to do this yourself?

I'd call a couple of HX manufacturers, give them the background info, and let THEM do the heavy lifting on the design-end.

 

[SNORGY]

Thanks VPL...

However, in reading my post I don't think there was any suggestion of expecting a specialist or consultant to perform a complex design for anyone for free. My message, in point of fact, was quite to the contrary. It simply stated that, in the absence of better resources, if one needs to do it on one's own, Kearns is a good resource, and that further, there is a first time for everything for everybody.

Regards,

SNORGY.

 

[pastyl]

Bell-Delaware method is suitable for calculating shell side heat transfer coefficient and pressure drop of shell & tube heat exchanger. Once you do that, then you can find easily overall thermal rating.
You can find method in Perry's Ch.Engineer Handbook or wolverine tube mfr. site downloading wolverine book.
If concerns one application you can send me the process data and heat exchanger geometry for proceeding to the calculation.