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Crude Preheat Hot Exchanger Fouling Reasons Required.

  • 1.  Crude Preheat Hot Exchanger Fouling Reasons Required.

    Posted 02-08-2019 12:02
    What do you think? Is the most acceptable thought of fouling of crude preheat heat exchanger? Usually it is observed that after desalter hot train exchanger when temperatures reaches to 130-150 C. Fouling normally occurs.

    Shahzeb Hassan ME,BE Process Engineering
    Executive Process engineer, PRL

  • 2.  RE: Crude Preheat Hot Exchanger Fouling Reasons Required.

    Posted 29 days ago
    The crude exchanger network is normally designed to supplement the amount of heat going into the first crude distillation tower.  The final addition of heat prior to that tower is the fired heater.  Normally you want to adjust the firing rate to achieve some target overflash (the amount of crude that doesn't end up in the tower bottoms).  This drives motor fuel fractions (naphtha, kerosene, and diesel) overhead where they can end up in fuel blendstocks.  So, until the fired heater reaches its maximum limit, the incremental cost of fuel is the only driver for improved preheat performance.  Once the heater is at its limit, the penalty of lower overflash is more complicated to quantify (lower fuel yields), but eventually will limit crude oil refinery throughput.  An older technology for evaluating heat exchanger network performance (to identify best candidates for shutdown and cleaning) was Hextran.  This was not trivial to run and did require a lot of individual heat exchanger temperature data that is not always available using day to day operating data.  I think that most of the challenges even today for crude preheat exchanger train evaluations center around obtaining sufficient operating temperature (and flow) data.

    Scott Love PE
    Bartlesville OK
    [ConocoPhillips (retired)]