8 replies to this topic

[masweber]

How do I determine the flow requirements for a tube rupture case? In an exchanger with 100 tubes, do I use 1/100th of the normal flow? Do I treat the combined tube end areas as an orifice and calculate flow? We typically design to the 2/3rds rule, so I would typically not see this case.

[Art Montemayor]

msb119:

API Recommended Practice 521 cites the following references for determining both the transient and steady-state flows in a ruptured tube within a shell & tube exchanger:

1) D. W. Fowler, T. R. Herndon, & R. C. Wahrmund; "An Analysisi of Potential Overpressure of Heat Exchanger Shell Due to a Ruptured Tube"; paper presented at the ASME Petroleum Division Conference; September 22-25, 1968.

2) R. C. Case; "A Method to Determine Exchanger Relief Valve Requirements"; Proceedings - Division of Refining; 1970; Volume 50; API, NY; pp. 1082 - 1092.

3) V. H. Sumaria, J. A. Rovnak, I. Heitner, & R. J. Herbert; "Model to Predict transient Consequences of a Heat Exchanger Tube Rupture"; Proceedings - Refining Department; 1976; Volume 55; API, Washington, DC; pp 631-654.

I recommend you follow these guidelines and detail your reference source when applying the appropriate algorithm unless you intend to develop your own analysis and algorithm.

I also recommend you read the discussion on this subject in API 521.

Art Montemayor

How do I purchase/find a copy of the 3 papers? I have been looking for them and have not had any luck.

[gvdlans]

Art,

I have the same question as Joey: Do you have any suggestions on how to obtain these references? In the past I have tried to get a copy of the Sumaria paper but with no success. It was not available in my companies library and also the university libraries in The Netherlands did not have a copy...

By the way, the relevant section in API RP521 is section 3.18 on pages 23-24 of the 4th edition.

I was able to purchase a copy of the articles from the Linda Hall Library of Science, Engineering and Technology, Kansas City, Missouri, USA.

website:http://www.lhl.lib.mo.us
email: requests@lhl.lib.mo.us
phone 816-363-4600 for int'l 800-662-1545

[Art Montemayor]

Joey:

Thank you very much for sharing this important information with all of us. This is a very important subject and it deserves the attention you and Guido have given it.



Guido:

Please receive my apologies for not acting on your request any faster. I and my wife are packing and preparing to travel to be with our grandchildren for Thanksgiving and Christmas and have been very disorganized due to the need to do our Christmas shopping now in order to take the kids their presents. Additionally, my wife packed a lot of my books and engineering references in boxes that she stored in our attic. She did this in order to clean up my library that is getting overrun with books, files, catalogs, and calculations of many years. Needless to say, my wife (who is not an engineer) has very little interest and respect for engineering calculations and references. Knowing the distaste she has for engineering and the fact and we will celebrate our 42nd wedding anniversary next week, I have to admit that our marriage was put together by a much higher power and I never criticize her actions. I continue to look through all the stuff and haven't found the ruptured tube analysis and references yet. I know it's there - in some box - and I'll keep looking. I promise you that as soon as I find it, I'll publish it or find some manner or way to have it available to everyone on the Forum.

Like you, I've had to confront this type of PSV problem before and I've also been fortunate to participate in some projects where the issue was handled directly and with the aid of some notable experts. I led a 20+ member task force on reviewing the PSVs for Union Carbide in various US process plants. In that project, we confronted this issue often. I worked with Union Carbide-developed software and had the direct consultation of their "Guru", Larry Simpson. Larry was a renowned Process Engineer who has authored a lot of papers and work on FLuid Flow and PSV. He wrote the software we used on that project and his algorithms were put together in expert manner. I've also worked on DuPont projects, so I'm familiar with the procedures and algorithms they have employed in the past as well. I consider this a very important subject and will continue to look for all materials I may still have on the subject. Please bear with me and I'll try to contribute something positive.

Have a bountiful and pleasant set of Holidays.

Art Montemayor

[gvdlans]

Art,

Thank you for your reply. Don't worry, there is no immediate hurry here, so please enjoy your holidays and time with your family.

Point is that I have interest in the dynamic phenomena that may occur during a tube failure scenario. This is one of the subjects where the approach is not very clear. One of our clients even states that the pressure spikes will not occur in practice but only in calculations where an instantaneous tube rupture is assumed. In reality, the tube rupture is not instanteneous but takes a few milliseconds.

There is not a lot publicised, or it is publicised in papers that are difficult to get. API refers to the Sumaria paper, but I could not get a copy of it. I will try the link suggested by Joey.

Talking of Larry Simpson, I also found another reference interesting reference (but not the paper itself...) from him:

Simpson, L.L., AIChE Loss Prevention Symposium, Vol. 6, 1972.

[gvdlans]

I just received an electronic copy of the Article from Sumaria et al., from the Linda Hall Library as Joey suggested. Thank you for the hint! This library has an excellent and fast service.

Guys,

I would like to get a copy of paper on exchanger tube rupture.
if you have one please send it to amit.joshi@cdicorp.com

Thanks,

Amit