BEM heat exchanger. 2 tubeside nozzles welded to the front head. head welded to main flange?

[seamantgn]

I'm designing a vertical BEM 1000x6096 mm - 2 passes HE.
Process guys gave me a Tema sheet of the exchanger showing a sketch with the nozzles fixed to the low head.
For me was odd but i performed the calculation with that arrange.
After i talked with a experieced colleague and he suggest me why not weld the heads to the main flanges to save the material and weld of the intermediate shells.
I perform the calculations again and for me look very odd. The reason it's i never saw a horizontal 2 passes BEM with this type of design; the rear end with the main flange welded to the head. In the TEMA std the examples have a intermedia te shell.

I ask to a process guy if will work well. The guy said me that was ok but he din't simulate it in his HTRI....

I work in engineering company then i don't know if this type of design will have manufacturing problems. I think may be weld 2 - 10 nps noozles without pad to a 1000 mm head, and weld the partion plate and the main flange must be up to make a pwht. Or if are some manufacturing problem.

Also i don't perform the thermal calculations. I ask to my self if with this design don't have problems due to hidráulic losses or other issues.

I think if it's rare this design will have reasons to not use it.

Some experienced heat exchanger designer can give me a hand o view point.

Thanks

Regards

 

[racookpe1978]

Show a sketch to clarify what you intend.

 

[mechanical2014]

I hope my below understanding is correct, in absence of drawing.
1. Nozzles (Inlet and outlet) fixed to the bottom head (vertical HE) and 2 passes on tube side HE. ?
2. In the lower head there must be a partition plate separating the inlet and outlet. ?

Now with the above understanding you colleague suggestion of "weld the heads to the main flanges" holds true if
A. Use a U tube bundle.
B. Weld the upper head with the shell i,e, Body flange will have shell welded on one side and bonnet welded on other side.
C. Bottom head can be welded in the same way, if chemical cleaning is envisaged for HE or there is no issue of fouling.

 

[SnTMan]

seamantgn, nozzles may be placed in the head, head welded to body flange and cylinder omitted if it works thermally, hydraulically (check w/ the process guy) and mechanically. That would be on you.

Typically, it makes no difference, from a ratings standpoint, where the channel nozzles are located. Mechanically, you must be able to fit nozzles and required reinforcement, pass plate, any vents / drains, etc into the available head diameter. Note that adding a reinforcement pad to a formed head is difficult and is usually to be avoided.

mechanical2014, a TEMA BEM is by definition a fixed-tubesheeet, straight tube exchanger with removable bonnet-type channels.

Regards,

Mike