Antifoam on Drum Level Control

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Antifoam on Drum Level Control

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Antifoam on Drum Level Control - 1/9/2005 3:23:29 AM

Coker Squirrel

Posts: 59
Joined: 1/9/2005
Status: offline

Are there any Cokers running antifoam on Coke Drum level control? It would probably be more efficient way to control antifoam usage. The antifoam should be injected at the top of the Coke Drum 180 degrees from the vapor line. It would work better to have the antifoam tank located on top deck so that response time with an antifoam knock would be more responsive. This would also reduce antifoam usage and would be more effective. CHGO should be used as a carrier. It is heavier than CLGO and would tend to not flash as easy.

Post #: 1

RE: Antifoam on Drum Level Control - 2/3/2005 2:26:35 PM

garypitman

Posts: 4
Joined: 9/21/2004
Status: offline

Having the anti-foam controlled by level does work. We have had this control system for many years. Anti-foam rate is controlled through a metering pump and then injected into the CLGO carrier. The line to the drum is packed and the response time is immediate.
We can run either CHGO or CLGO we prefer CLGO.
I would not want any storage of anti-foam on the structure.

(in reply to Coker Squirrel)

Post #: 2

RE: Antifoam on Drum Level Control - 2/3/2005 10:49:50 PM

Coker Squirrel

Posts: 59
Joined: 1/9/2005
Status: offline

That is pretty much the same system we have in place right now with the exception of the automatic drum level control. I was looking to improve on this system. It is difficult for us to set up a reliable auto-controlled antifoam injection system. We have to add antifoam as needed with a flow controller. I want a reliable automatically Drum Level Control system. Currently, the Console Operator has to focus his attention on the Drum Level to inject additional antifoam when it is needed. If we had a level controller that would do this, I think that we could possibly minimize our antifoam usage.

(in reply to garypitman)

Post #: 3

RE: Antifoam on Drum Level Control - 5/2/2005 4:55:49 PM

sangu

Posts: 2
Joined: 3/29/2005
Status: offline

What type of level measurement are you using? Is it Neutron back scatter or other radiation types? Is there any advantage in using one over the other?

(in reply to Coker Squirrel)

Post #: 4

RE: Antifoam on Drum Level Control - 6/10/2005 2:20:49 PM

Guest

Neutron backscatter is a a proactive sensor that operates on the prescence of radiaton. It reads the density of the foam and ,therfore, lets you know the proper time to anti-foam.
Gamma is more re-active and works on the principal of the absence of radiation and, therefore, has difficulty in defining the type of foam. The best solution is a combination of using neutron backscatter (three to four units) on a drum with gamma level at the top (typically ten feet) for foam over prevention. This combination also allows for monitoring closer to the chord line.

(in reply to sangu)

Post #: 5

RE: Antifoam on Drum Level Control - 12/17/2005 10:37:56 PM

Guest

You have to remember that Neutron back scatter units measure the hydrogen density so it is not really measuring the top of the foam. The gamma detectors will respond to anything that is in between the gauge and the radiation source (ie. the top of the foam). The gamma system is better in determining exactly where the top of the foam is actually located.

(in reply to Guest)

Post #: 6

RE: Antifoam on Drum Level Control - 2/28/2006 9:10:23 PM

Guest

quote:

ORIGINAL: garypitman

Having the anti-foam controlled by level does work. We have had this control system for many years. Anti-foam rate is controlled through a metering pump and then injected into the CLGO carrier. The line to the drum is packed and the response time is immediate.
We can run either CHGO or CLGO we prefer CLGO.
I would not want any storage of anti-foam on the structure.

(in reply to garypitman)

Post #: 7

RE: Antifoam on Drum Level Control - 3/15/2010 11:07:51 AM

Guest

we have gamma levels. but i want to now haw to determinate the real fom level using gamma. i have a difference of 5 feet betwen the reactive and real level, is correct? or should i inyect more antifoam? this question do not permit me to control antifoam inyeccion

(in reply to Guest)

Post #: 8

RE: Antifoam on Drum Level Control - 6/3/2010 4:02:42 PM

Guest

When using anti-foam, you are never going to get rid of all the foam no matter how much anti foam you use. The idea is to try and control the amount with the least amount of anti-foam as possible and makes sure that you don't have a "fluff" up after switch that causes a foam over. By using the gamma level, you can determine approzimately how much foam you have by tracking the differences from the level at switch to after switching. This will show you the amount of foam that you had present at switch time. Normally (depending on types of crude and charge rates) you can have anywhere from 2 feet of foam to 10 feet of foam at switch time even with the full amount of anti-foam being injected. Remember some crudes are bad about foaming after switch.

(in reply to Guest)

Post #: 9