2 replies to this topic

[sacc]

hi evvery body

it is beneficial to take tubes count in a given shell id ( as per tube count table)

or shall i consider more tubes than table gives
HTRI did not show any error for this ,so till error i can consider for increasing tubes ?

[srfish]

Needless to say but you need to be careful aqbout adding tubes on to the result of a tube count table. If the shell size is small and the nozzles are small adding tubes is not wise, particularly if the exchanger is to be built. If the shell is large with large nozzles, the tubes are probably removed for the bundle entrance and exit area. Tubes could be added but there would be a higher shell side pressure drop. If what your doing is an estimate there is no problem, otherwise get a tube count layout.

[Jiten_process]

@sacc

Firstly you have to specify what are you upto. Are you running HTRI in design mode or rating mode. HTRI calculates no. of tubes based on TEMA clearances required between OTL (outer tube limit) to shell ID. However tolerance to some extent is allowed in this TEMA clearances. you can then specify manually no. of tubes in HTRI and theoratically it takes the same no. of tubes for thermal calculations. It also checks vibration for the specified no. of tubes, nevertheless by saying theroratically i wanted to point out mechanical constraints with respect to fabrication of an exchanger. So it is always advisable to follow tube count table until you have a strong reason of not doing so.

Let us have others' view on the same.