Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations GregLocock on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Turbulators To Improve Heat Transfer 2

Status
Not open for further replies.

steamtech

Mechanical
Oct 4, 2002
3
I am looking for design data for the application of Turbulators (spiral section incerted into last section of third pass smoke tube)to improve heat transfer in the last tube pass of fire-tube boilers.
 
Replies continue below

Recommended for you

Steamtech

I have several papers, which I use when I design fire tube boilers for enhancing heat transfer in the convection tubes. I could scan them and send them to you if you want.

Bogu
 
Bogu, That sounds great, yes please scan and send me what you have. Also, do you get involved in coal firing of Fire tube boilers?
Steamtech
 
bogu, My email address is steamtech@pacific.net.au
 
i can speak from practical experience that they work and are beneficial; however, i've not been involved with the design/application of turbolators.
i know of a site that had bad boiler water, which led to tube replacement (firetube boiler). turbolators were a new product at that time (invented by a priest, i think!) and the boiler owner opted to have them installed in the boilers. within a couple of months after installation (now winter time), the gas company sent a couple of individuals to the owner's bldg to investigate for potential problems - i.e. why is gas consumption suddenly reduced? gas company reps found nothing wrong and everything seemed to be in good shape. so they inquired with the owner mentioning that gas consumption was reduced 50%. how come they asked? the owner was most pleased with the boiler retube and the installation of the turbolators. in fact these refurbished firetube boilers were operating signficantly better than originally designed.
-pmover
 
Steamtech / pmover

I have reduced stack temps from 310 deg c down to 180 deg c by fitting these items. Steamtech I have never designed a coal fired firetube I have only designed them for gas oil and sawdust. I will scan and email the papers in the next day or so.

Bogu
 
You might also check out retubing with X-ID tubes. These are a SA-178-A boiler tube with internal rifling embossed on the inside of the tube. They are made by a company called TEKtube in Tulsa, OK. They are generally willing to help with design information, too.
 
According to the papers published by Art Bergles, the turbulators will greatly increase the gas side pressure drop unless you design them to ensure a small gap exists between the turbulator and the tube ID. The spacing can be set with the attachment of a few buttons or nubs on the turbulator fins.
 
I've used the Wire wound turbolators in Heat Exchangers for years to improve performance of a particular unit. A function of the turbolator is to transmit heat from the tubeside fluid / gas to the tube wall any gap between the turbolator and the tube would drastically reduce this function.
ALL of the turbolators I've purchased over the years are designed to be an interferance fit into the bore of the tube.
Don't ever believe that you fit one of these items just to stir up the contents of the tube!
 
finman:
It is a good idea to review the published test data and draw engineering conclusions from the test data. If one doen't believe the test data, then all it takes is running your own test to prove or disprove the data.

The Bergles papers show very high increases in flue gas pressure drop when turbulators are installed in an interference fit, but if a slight gap is provided then the pressure drop does not increase as much and thre is subatantially the same improvement in heat transfer.
 
davefitz:

I stand by my comments!

I assume this data refers to spiral wound turbolators, in which case you may be correct, however with the more effective wire wound turbs you may find that I am correct.

Try using the information supplied by your peers as a basis for future development.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor