feed surge drum 2

[kagadpencil]

In a refining operation, what does feed surge drum do?
What is blanketing gas? What is its purpose?
On a drawing (roungh sketch really) for a Feed surge drum I see a nozzle connection for steam out, but I dont see steam in - Is there something wrong? Or is it for the steam that is removed from the naphtha?
At an outlet nozzle connection I see a vortex breaker - What is its purpose? What if the fabricator does not provide it - Is it an absolute must?

 

[jte]

kagad-

I agree with Guidoo in another one of your posts. These types of questions really should be answered internally by some of your senior mechanical and/or process engineers. However, I've nothing else to do during the rest of my lunchtime, so (from a mechanical engineer's perspective)...

A feed surge drum allows you to keep a constant feed. Please tell me that you get your hands dirty changing your own oil in your car. It'll make me feel better. When you're pouring several quarts of oil into your car using a funnel, you can pour a quart into the funnel and it will slowly continue on into the engine. While you put the first quart down and pick up the second one the liquid level in the funnel will go down. Then you refill it with the next quart. All the while, the flow rate of oil into your engine will remain more or less constant. Same concept for the feed surge drum. It allows you to maintain relatively constant flow into your system while your supply can vary a bit.

Blanketing gas covers a liquid to reduce the liquid from flashing as much. Process engineers might fill this one in better.

Steam out connections are used when the vessel is out of service. You are "steaming out" the crud left in the vessel to prepare it for entry, as mentioned in a reply to one of your other posts. Often you will see vessels which will be steamed out designed for 1/2 or full vacuum 'cus if the vessel is blocked in the steam can condense and implode the vessel if it isn't capable of withstanding the vacuum.

Vortex breakers break the vortex. You know, that conical shape the water takes when you pull the plug on the bathtub... What you are trying to avoid here is sucking vapor in with the liquid which could cause a downstream pump to become unhappy. If your process folks called for a VB on their specification, it is most likely because the line feeds a pump. If the fabricator does not install the vortex breaker, the rotating equipment engineers at the refinery will be unhappy.

jt

 

[Guidoo]

jte,

I wish I had such long lunch breaks... By the way, Kagad was also advised in another post to look for a mentor. His reply was that he did have a mentor but that this mentor was always busy (nice mentor so to say). So because of this lousy mentor he is going to keep the Internet community busy...

Tank or vessel blanketing is another word for inerting. It is done to prevent having a flammable atmosphere in the tank/vessel. See section "interting" in article in Chemical Engineering Progress:

http://www.cepmagazine.org/pdf/020157.pdf

 

[Guidoo]

I found another article on blanketing, just by doing a Google search with "tank blanketing". It can be found on

http://www.cheresources.com/blanketzz.shtml

and this has a link to another article on

http://www.flowcontrolnetwork.com/PastIssues/jun2003/1.asp