Larger Kettle Re-boilers 2

[Inchtain]

Good morning,

During our last overhauling of the Kettle Reboiler, we encountered many difficulties in dismantling and re-installing the heavy U-bundle.

I wonder if someone has an experience on them and has a typical procedure for extracting and returning back the bundle!

Sincerely,

 

[CuMo]

Maybe you could hire a company with an extractor to do it for you next time.
There are extractors out there than can pull out quite heavy bundles.

https://www.youtube.com/results?search_query=bundle+extractor

Some of them are quite flexible and can reach you in hours.

https://www.youtube.com/watch?v=6TQF21WrBJ0

 

[r6155]

May be the out of roundness of the shell side, short part. Try with smooth grinding of shell inside.

Regards

 

[Inchtain]

Hello,

I highly appreciate your reply.

Actually, what made the operation difficult were: 1 Heavy U-bundle, 2-Kettle Re-boiler shape (Not U-Bundle HX), 3 location high at the 3rd store platform.

The most critical job was the final stage of inserting the bundle as it was difficult to push inside and keep the tube sheet leveled with the shell flange without damaging the gasket in-between.

When pushing the bundle inside, it inclined and was resting on the shell with small upward rise of the tube sheet. We made many modification using cables, bolts with beams, hand jacks and took about 2 days to fix it properly.

So, any better and easier alternative?

Best wishes,

 

[r6155]

Some drawing, photos ?. Please

Regards

 

[Inchtain]

Good afternoon,

I am attaching the following for your reference.

Regards,

 

[r6155]

1)did you measure the out of roundness of the shell?
2)can you grinding the thickness of the shell 0,5 mm?

Regards

 

[Inchtain]

No out-of-roundness and we wouldn't like to grind the shell.

In fact, the tube bundle is heavy and long and it didn't remain straight when inserted.

Regards,

 

[r6155]

1)Try lubrication with heavy grease.
2)Are you using one or two cranes?

Regards

 

[Inchtain]

Lubrication sounds brilliant, but do you think the used grease can affect the process fluid in the shell (Condensate) and/or the heat transfer efficiency?

It was easy sliding the bundle with one crane at the beginning and it got harder when the mating flanges got closer where the heavy weight held the bundle down at its rear inside the shell and little up outside at tube sheet and the shell flanges.

Best wishes,

 

[r6155]

After installing the bundle you can enter and clean with hot water and drain.

See youtube as say Cumo 18 May 21. You need a bed structure to avoid bending of bundle.

Regards

 

[Inchtain]

I am afraid access to clean the bundle after installing through the shell nozzles is quite difficult. Besides, water might create problems in the system as it is absolutely difficult to dry completely.

On the other hand, using the special equipment will safe a lot of effort. But, what to do in their absence?

Regards,

 

[r6155]

You can use 2 cranes with 2 spreader bar, 4 points for lifting. This 4 points reduce bending of the bundle.

Regards

 

[Inchtain]

Hello again,

Can you please provide even a simplified sketch for such lifting by 2 cranes?

Mind you, the problem is at the final stage when no place for even a rope wrapping because almost all the bundle is inside the shell

Thanks

 

[r6155]

I have little information (close to zero) that makes it impossible to continue helping you. Lifting to 20 m is a high risk.
I suggest contacting a lifting company.
Also, can you contact the manufacturer?
This is an interesting topic for me.
Sorry Inchtain

Regards

 

[Christine74]

If I understand you correctly and the problem is that bundle wasn't going straight into the shell when you were installing it, there are a number of things you can do:

1) Install 2 guides made from inverted angles or bar stock along the bottom of the kettle to act as rails that keep the tube bundle from veering sideways during installation.
2) Install hold-downs inside the kettle to keep the bundle from veering upward during installation.
3) Redesign the kettle. Instead of having the cone welded directly to the shell flange, weld a short cylinder to the shell before attaching the cone. The cylinder will keep the tube bundle centered during installation.


-Christine

 

[Inchtain]

Hello Christine,

I like your approach to the issue. Any illustrative drawings or sketches from you is highly appreciable where they can help us understand the ideas better.

Thanks

 

[Christine74]

See Section RCB-4.9 of the 10th edition of TEMA for details of bundle hold-downs and bundle skid rail alignment devices.

Here's a link the only photo I could find of a kettle shell that includes a short cylinder that would help with alignment of the tube bundle:

https://heatexchangersindia.com/kettle-reboiler-type-heat-exchanger.html

-Christine