Dear Ray/ Mandeep,

I have stacked exchanger, i have modeled an exchanger in PVElite, but as it is stacked one, i have to consider loads due to upper shell while performing saddle analysis.

At present, I have to do it manually but Can it be automized in PVElite itself, via some check box and some additional inputs like weight, overall dimensions of the other shell etc?

Hi Purav

The best way of treating stacked vessels is to design the top vessel first. You will then get all the weights etc., to transfer to the bottom vessel. PV Elite can only handle one vesselat a time. This is the best we can offer.

As suggested by Ray you have to applied weights, moments etc of top exchanger on bottom exchanger as separate model in PV Elite. PV Elite at presently does not have staked unit modeling facility. Same is available in one other present software but it is really very costly.

Mukesh

Dear user,

rather then depending upon softwares sophistication & spilling more money its better to use certain human efforts & transfer loads.

What say mukesh.

& Mukesh, I guess You where speaking about MICROPROTOL & beleive me this software is so sophisticated that there is very little Human efforts are required.
Just few inputs & your design is ready to review.

Hello Tahir

This forum is really dedicated to Intergraph (Coade) products. This is not really the place to discuss our competitor's software.

Hi Ray/Mandeep,

How can we analyse the strength of the intermediate saddle support between the stacked exchangers (the one seated on the top surface of the bottom exchanger)?

Thanks.
Beh

Hi bsc00709!

Recently I had to face stacked exchangers and I did the following:

As Ray suggested above, I designed the upper exchanger, then I created a copy of the PVElite file and began to design the bottom exchanger (fortunately, both exchangers were similar).

Then, I put two masses in the same place where were placed the saddles of the bottom exchangers. Theese two masses had the value in Kg of the reaction of the upper exchanger. You must read theese values from teh "Horizontal Vessel Analysis" in operation, at the begining of each saddle calculation, you will read the following, as example:

Load Combination Results for Q + Wind or Seismic [Q]:
= Saddle Load + Max( Fwl, Fwt, Fsl, Fst )
= 4732 + Max( 1675 , 1688 , 1675 , 0 )
= 6421.1 Kgf

The mass should have a value of 4732 Kgf (that will be the vertical force). Then read this value in the other saddle!

If you have a great wind load, you should put two horizontal transversal force in the same place of the bottom exchanger saddles (plus the wind due to the bottom exchanger itself that will be automatically calculated)

It demans some more time but in this way I had good results and the purcharser of the equipment aprovved me the calculation. I didn´t show anything about the intermediate part between the base plate of the upper exchanger and the bottom exchanger in that calculation.

WARNING! some purcharsers specify to take into account the horizontal force of the bundle during extraction as a force of 100% the weight of the bundle. You can't put a moment in an horizontal vessel, so this force x center to center distance beteween exchangers shall be converted to two vertical loads (one upwards and the other downwards) acting in the saddles, wich can make the baseplate to have a higher thickness!!

There were something peculiar in the design of theese saddles. The circunferential wear plate was in contact and welded with the bottom exchanger shell only in the 120º bottom side. So the load of the upper exchanger were transfered to the base only by the saddle and not by the bottom exchanger. In the upper side, the wear plate was separated from the shell 5 mm.

It`s a pity that I can`t paste an image to make me understand.

Goodbye!