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I have a titanium tube bundle which has been in service in a cooling water heat exchanger for the past 6 years. Process side contains LPG service with several ppm of chlorides. Tube side contains seawater. The exchanger is a trim condenser. Process temperature and pressure is ~55C and 1950 kPag...

1. Is the feed to the splitter hydrotreated? 2. Any history of fouling and corrosion in the unit? 3. Any analysis on water accumulated in overhead receiver if any?

Thank you patrica, More questions: I was doing calculations for the heat exchanger and then I have to determine the Reynolds number on the shell side. In that case, can i write Re as (mass flowrate/Ac) * tube_diameter / viscosity? Secondly, what fraction of the flow on the shellside would we...

I am very confused. It seems that there can be many different definition for the area for crossflow within the shell of a HX. What should be the more representative intepretion for the flow area under cross flow. Currently, I have always assumed it to be Ac = (Shell_Dia * (Tube_pitch -...

quark, unfortunately, when the HX was originally designed for, the piping was such that the hot oil flows from the top down. In additionm the return piping does not go upwards after the heat exchanger and therefore we might expect a low pressure zone and therefore accumulation of vapours on the...

My exact suspicion as well!!! But how would the gases get dissolved into the hot oil? that would be really difficult to prove? There was a venting exercise done in the plant a few years ago. apparently, when the HX was vented, the heat transfer seems to have improved, indicating a better heat...

i have a vertical shell and tube HX with a hot oil heating medium flowing on the shell side downwards. The HX was quite poorly designed, with baffles cuts of <10% and relatively small baffle spacing. My suspicion is that the shell side is not properly filled with the heating medium during...

25362, This is one interesting finding. I'm not sure whether I get it intepreted correctly though. Are you saying that for cross-flow HX, it would not be advantageous to operate the shell side at higher RE because thermal effectiveness decreases? What do you mean by the temperature profile...

joerd, It's interesting how you mentioned the possibility of dead zones within the shell side of the reactor, because I do have exactly the same suspicions. However, I have been cracking on head on how I can actually prove this. Do you have any ideas on this? Anyone else? Montemayor, i must...

have anyone come across the phenomenon of a 'cold spot' within a enothermic multitubular non-isothermal reactor. The idea is that the temperatures within the reactor drops to a very low temperature in the front section of the reactor, somewhat like the reversible of the hot spot of an exothermic...

Hacksaw, I'm still pretty confused about the understanding of the thermocouples in a packed tubes. What should the thermocouples within the tubes read? The bulk averaged temperature? The center-bed temperature? Then the next question comes: How do we read when we are reading is true or the...

The heating medium on teh shellside is a commercial heating oil, Sandotherm while the tubeside is basically a vapour phase mixture of primarily methyl phenyl carbinol and water.

25362, I guess u can look at the problem from teh other side as well and reason that the heat transfer problem, if there is one, could occur on the tube side. In fact, i do have a working reactor and we do suspect that fouling could occur as a result of condensation of the vapour phase, leading...

sorry guys, have been out for quite some time...here goes... 22082002, the baffles are ~10% horizontal cuts. I really don't recall any notch in the middle...i've look through the mechanical drawings and found nothing...could u describe it in details? 25362, Yes, i have actually suspected...

25362, I do have the similar sentiments as u, that the possibility of a reduced HTC as a result of some vapour-liquid mixture within the HX. In fact, I am in the midst of doing some testing on this possibility for one of the HX in the plant i'm working in. Any comments on this subject, anyone...

Hi all, I have a multitubular catalytic reactor where an endothermic reaction is taking place on the tube side and a heating oil is flowing cocurrently in the shell side of the reactor. Recently, I have seen a suspected reduced heat transfer coefficient which lead to a significant temperature...

22082002, I totally agree with you on the part of which side the hotter fluid should flow in. Unfortunately, the HE is already in place and therefore process modifications to it could be difficult. Anyway, what are the possiblities of developing vapour pockets on the shell side of the...

Hacksaw, Does that mean there is no way I can validate the readings obtained from the thermocouples, except to perhaps reinstall the thermocouples and perform calibrations etc or even install new or better thermomeasuring devices? How about doing a simple model to estimate the skin temperature...

I have a catalytic fixed bed reactor with approximately 2400 tubes. There are several thermowells in the tubes of the reactor which measures the temperature along the bed. The question is, How i can ensure that the temperature measured by these thermocouples representative of the rest of the...

When considering the operation of a shell and tube heat exchanger, where a heating medium (hot oil) flows in the shell side of the exchanger, is it necessary that the pipings to the inlet and outlet to the HE be such that the outlet piping rises to a level higher than that of the inlet. I...