7 replies to this topic

[karzan]

Hi Dears,
I have a question about crude heaters, what is reason of medium steam connection to crude passes before entering
heater and when it is in service?
regards

Edited by karzan, 09 December 2009 - 03:16 AM.

[Padmakar Katre]

Dear,
The reason for steam (called coil steam) in refinery heaters is to increase/maintain the required velocity through heater coils.

[Zauberberg]

Actually, for Crude oil heaters in ADU the purpose of having MP Steam connection is to provide an option for quenching/cooling heater tubes in case of crude oil flow trip.

Once if the flow of crude oil completely stops (e.g. charge pump failure) the heater will be shut down as well - however the remaining radiant heat can cause overheating of tubes and, in certain occasions, failure of tube elements. MP steam is there to ensure adequate heat removal from the system.

Best regards,

[Root]

Actually, for Crude oil heaters in ADU the purpose of having MP Steam connection is to provide an option for quenching/cooling heater tubes in case of crude oil flow trip.

Once if the flow of crude oil completely stops (e.g. charge pump failure) the heater will be shut down as well - however the remaining radiant heat can cause overheating of tubes and, in certain occasions, failure of tube elements. MP steam is there to ensure adequate heat removal from the system.

Best regards,

Hi,
Inaddition to above this is called velocity steam steam and help for good heat transfer and most cases given in VDU and some time ADU.
Cheers

[djack77494]

By having the ability to add steam, it is possible to (within limits) extend a heater run before you need to take it offline and decoke. Of course, there is a price to be paid.

[iyer]

Hi Dears,
I have a question about crude heaters, what is reason of medium steam connection to crude passes before entering
heater and when it is in service?
regards

Medium pressure steam is added to induce a turbulence to flow. When it is known that the fluid through the tubes is susceptible to coking, we would prefer to create some sort of turbulence. It is kind of like adding a gas stream to fluid flow to prevent coking in heat exchangers. I do not totally agree with the radiation zone being protected due to loss of flow as, loss of flow would trigger the fuel gas/fuel oil shut down logic sequence.

Edited by iyer, 21 December 2009 - 10:52 PM.

[S.AHMAD]

Hi Dears,
I have a question about crude heaters, what is reason of medium steam connection to crude passes before entering
heater and when it is in service?
regards

Hi,

The others have given good reasons for the steam line. However, for sure it can be used for hydrocarbon free the system during shutdown since crude oil may still be left inside the coil.

[shammu]

Hi Dears,
I have a question about crude heaters, what is reason of medium steam connection to crude passes before entering
heater and when it is in service?
regards

velocity steam suppresses temperature peaking in the coils and thereby reducing the generation of cracked gases in the tubes which int urn reduces the load on the ejector condensers. Hence the ejector can pull a deeper vacuum

regards
shammu