HI
I AM FACING FEW PROBLEM WHILE ANALYSING REBOILER PIPING

1)IF REBOILER SUPPORT IS HARD SUPPORT THEN IT WILL BE HOLD DOWN OR SIMPLE REST SUPPORT ? HOW TO AVOID UNBALANCED BETWEEN FOUR LUGS DUE PIPING EFFECTS.IT INCREASES NOZZLE LOADS ALSO IF HOLD DOWN SUPPORT.

2)ONE OF COLUMN IS HANGED(PLACED)BY LUGS ON STRUCTURE AND REBOLIER N PIPING IS BELOW THAT STRUCTURE, DUE TO THIS DISPLACEMENT ARE HIGH N NOZZLE LOADS INCRESRES DRASTICALLY EVEN PLACING THE SPRINGS(REBOILER PIPING IS STIFF N NOT POSSIBEL TO REROUT), HOW TO OVERCOME THIS PROBLEM?

EXPANSION JOINT

"Reboiler" that equals heat! No matter how you slice it heat does create problems with "Reboiler" piping.
That being said please don't over analyze the problem. Yes, you can prove that a bumble bee cannot fly but don't tell that to the Bumble Bee, he is quite happy flying around enjoying God's creation.

Also don't use an expansion joint. They are highly susceptible to failure, and you do not want a failure in "Reboiler" piping.

I got into the process plant design field more than fifty years ago and I worked on a lot of refinery projects with a lot of (vertical Thermo-siphon) Reboilers.

Most were supported from the tower at about the mid point of the Reboiler where the expansion was about equal above and below the support point. The bottom inlet piping from the tower bottoms to the Reboiler was always taken off the bottom head as far from the Reboiler as possible. This afforded a flexible leg in the configuration.

To be of any more help I would need to be standing right there beside you and be seeing the total design.

Sorry that I cannot do that, I have a tennis match here tomorrow.
Regards and good luck,

hi
thank you for your quick response but
1) In mine case we can not expansion joint. as space constraint
2) Reboiler is having independent structure, it can not be supported from column.

i have used springs also for that did't help that much ,

n we can not add more bend to system also.

This may help.

Sorry, somehow I am unable to upload a paper on vertical reboiler.If possible, pl. check a paper ( February 2007 Hydrocarbon processing) on the topic which I found very informative,

Regards

Check this thread.
http://www.coade.com/ubbthreads/ubbthrea...=true#Post19825

Dear Friends,
The drawing of a horizontal reboiler just beside the column show that both the supports are sliding. The inlet pipe from the column is making a header which is dividing into two branches that are connected to two nozzles in the shell side and similar is the case with the outlet pipes from reboiler to the column. The piping at inlet and outlet from the reboiler is of symmetrical design!
In my opinion the drawing is correct as the expansion in the incoming and outlet header will be equal in both directions, if one end is fixed the forces on the column nozzles would be high and the stresses on the inlet and outlet piping would also be high.
The stress engineer on the job insists that it is wrong!! One end has to be fixed.
Please share your experience and knowledge with us! What should be the case? Both ends sliding or one end has to be fixed?

Friends,

Checked at site and it is having both ends sliding!!

Any comments on this please?

Hopefully no earthquake or wind.

Other thing, do you expect that reboiler will have the displacements as
in the calculation?

Regards,

Dan,
The SEISMIC case is not taken in this region. The wind load is not applicable as the reboiler is installed at ground level and is (sort of) encircled by racks full of congested piping and structures with piping and equipment.

Remain the third thing. If it is a kettle reboiler, you have also steam and condensate lines at one end. Did you also consider their influence on the entire system?

Dan,

Of course, the stress engineer on the job would ensure all these important issues!!!!!

I want to know what is the opinion of experts on BOTH SUPPORTS SLIDING!.

BTW, it is not kettle type reboiler!

I do not know if it is possible to predict the real displacement of a heavy reboiler with both supports sliding. Maybe in theory you can solve the problem, but in reality, honestly I do not know. But passing this on stress engineer it is not really a good idea. Maybe the mechanical (static equipment) engineer can advise you.

Maybe somebody else can help you.

Regards,