Noise from shell and tube evaporator

[wilsoncheung]

Hello,you guys!
I came across a problem. When testing a screw water cooled chiller,we heard noise from the evaporator. It sounds like some small things hitting the copper tubes or the copper vibration makes them hit each other, which makes noise.

The noise is not very loud, but enough for you to hear without too much attention.

This a DX evaporator, U-tube type.

Have you ever come across such kind of problem, pls let me know.

I am waiting for you answer... thanks!

[US Iceman]

This may be due to vibration induced by flow through the baffles. The tube holes in the baffles may be too big or the baffles themselves improperly sized to the shell. There is a section of the TEMA code that deals with this I believe.

[wilsoncheung]

Hello,you guys!
I came across a problem. When testing a screw water cooled chiller,we heard noise from the evaporator. It sounds like some small things hitting the copper tubes or the copper vibration makes them hit each other, which makes noise.

The noise is not very loud, but enough for you to hear without too much attention.

This a DX evaporator, U-tube type.

Have you ever come across such kind of problem, pls let me know.

I am waiting for you answer... thanks!

[wilsoncheung]

Thanks, US Iceman!

This is stand product and we have manufactured many similar products for many years. And we come across this problem for the first time.

The holes in baffle or the baffle cut is quite mature. I don't think there design problem with the baffle problem.

[desA]

Can you take a pic of the application?

Is the pump pushing water into the tubes, or sucking it out? (There is a reason I'm asking) In other words is your pump connected correctly?

What is the water entry flowrate?
Water-side flow arrangement for the tube-pass?
Water inside, or outside the tubes?

Give us as much info as you can & I'm sure we'll be able to work it out.

Sounds like water-side cavitation, or similar.

[Tesla]

Hi Wilson
I had a simmilar prob on a Luke centrif chiller. We cut open the vessel and found broken welds on horrizontal plates which were welded. You could use a pipe camera to help locate problem. First check for design flow rates and cavitation.

[NoNickName]

Yes, it's the distributor plate, a small pierced plate welded in front of the liquid manifold, which came loose or was damaged by a liquid hit and it's bouncing inside.

[wilsoncheung]

Thanks, you guys!
For Tesla, I guess we may have the same problem. Fortunately we have three identical chillers. The first one, as stated above have the noise problem, but the second one is normal. So desA, I don't think there is problem with testing platform. And the design is no problem.

[desA]

^ So you've gone out to physically check all the connections since the start of the thread?

If everything is sorted on the connection side - then you may have to look into the 'loose baffle' idea. Are you planning to cut it open?