T&S GX vibrations

[MortenA]

Generally speaking: What are the most common "tricks" to reduce vibration in a TEMA type S&T HX?

I know this may be a "too general" question - but lets say a BEM type 1 or 2 passes. What would help here, e.g. with high shell side fluid flow?

Best regards

Morten

 

[speco]

MortenA,

Since nobody else as responded, I'll throw what I have seen done in the past. I understand that vibration is often the result of high inlet velocity where the shellside fluid impinges on the tube bundle.

1. Use an impingement plate at the inlet shell nozzle. Often used in steam shellside applications.

2. Change to a BEU type and put the inlet shell nozzle beyond the tube return bends at the back end of the shell. Obviously, you can't do this with a BEM type.

3. Use a larger inlet nozzle to reduce the Rho-V^2 effect.

Regards,

Speco (

http://www.stoneprocess.com)

 

[srfish]

On

http://www.gulleyassociates.com

website there are 4 tips. Click engineering tips and look under the section: Vibration of bundles.

 

[rmw]

Wow, whoever put that site together had some time on their hands.

Vibration is caused by either too high of a velocity or too wide of a space between baffles or support plates.

One of the tips in the link in the above post alluded to what is called "staking" in the large condenser world where a lot of condensers were made in a day before a lot of stuff was discovered about hydrodynamic whip caused by high velocity. It has to do with the vortex shedding frequencies caused by the flow over the tubes. The stakes help dampen it. Stakes are flexible metal or plastic strips inserted into several rows of tubes. Your stake material has to be compatible with the process fluid on the shell side.

The best remedy is to design where it won't happen. I think HEI has publications where the formula is given to determine baffle (support spacing) to prevent vibration.

rmw

 

[MortenA]

Actually im only costing, using TACS/HYSYS to get an idear about the price. So some warning pop up, and i try my best to adapt the design

Thats for the help so far.

Best regards

Morten