We noticed a tube rupture in the CCR reactor charge heater #1, the failure at the first tube of the heater.
Still up to date we are investigating the event. There is no final defined root cause for this failure.
In fact the failure occur after an emergency S/D due to power dip in the hole refinery.
Appreciate fast reply
Thanks,
Full Version: Ccr Charg Heater Tube Failure
Hi Maimani,
I am a process engineer for CCR Platforming unit and Naphtha Hydrotreating unit.
I am new to this forum. Eventhough, this item was posted one month ago, I would like to give my point of view.
In our refinery, the CCR Platforming unit has one charge heater and 3 interheaters, while we have four stacked reactors configuration. The charge heater is use to heat up the stream from the first reactor.
Charge heater no.1 is always the most problematic heater in CCR Platforming unit as it has to deliver the highest duty compared to other interheaters. Therefore, charge heater no.1 is always limiting in terms of Tube skin temperature.
When the firing is at maximum, the tube skin temperature will always have to be monitored closely to prevent it from exceeding the design value. Otherwise, once the design value is exceeded, the tube may rupture due to excessive thermal stress. This maybe the reason why your tube ruptured.
On another account, you also mention about the fact that the failure occured after an emergency shutdown due to power dip. The power dip has always caused many problems to refinery operation. For instance, the leaking of Packinox heat exchanger (feed-effluent heat exchanger) and scallop damage have always been attributed to the thermal shock caused power dip. Therefore, in this event, I believe that the power dip may have played a major role in the rupturing of the heater tubes. This is mainly because of thermal shock. During normal operation, the tube skin temperature for the charge heater is very high, and suddenly the temperature dropped rapidly during the power dip. This in turn caused the tube to be under massive thermal shock, which eventually leads to its failure. I hope this may provide some insight as to the reasons for the tube failure.
-Mohamed Azlan-
I am a process engineer for CCR Platforming unit and Naphtha Hydrotreating unit.
I am new to this forum. Eventhough, this item was posted one month ago, I would like to give my point of view.
In our refinery, the CCR Platforming unit has one charge heater and 3 interheaters, while we have four stacked reactors configuration. The charge heater is use to heat up the stream from the first reactor.
Charge heater no.1 is always the most problematic heater in CCR Platforming unit as it has to deliver the highest duty compared to other interheaters. Therefore, charge heater no.1 is always limiting in terms of Tube skin temperature.
When the firing is at maximum, the tube skin temperature will always have to be monitored closely to prevent it from exceeding the design value. Otherwise, once the design value is exceeded, the tube may rupture due to excessive thermal stress. This maybe the reason why your tube ruptured.
On another account, you also mention about the fact that the failure occured after an emergency shutdown due to power dip. The power dip has always caused many problems to refinery operation. For instance, the leaking of Packinox heat exchanger (feed-effluent heat exchanger) and scallop damage have always been attributed to the thermal shock caused power dip. Therefore, in this event, I believe that the power dip may have played a major role in the rupturing of the heater tubes. This is mainly because of thermal shock. During normal operation, the tube skin temperature for the charge heater is very high, and suddenly the temperature dropped rapidly during the power dip. This in turn caused the tube to be under massive thermal shock, which eventually leads to its failure. I hope this may provide some insight as to the reasons for the tube failure.
-Mohamed Azlan-
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