[Lucibar Davalillo]

Sure, it can be done, or at least minimized by compressing blowdown gases using ejector system. Look for further information at Encon-Jamnagar Refinery. I haven’t heard this being done at US Cokers.  

[Lucibar Davalillo]

Carlos,
There is no such thing as “puncturing” recommended in any of the decoking procedures i have read; it seems to be just a poor practice from old dogs, which must likely may be due to lack of follow-up and/or maintenance of cutting equipments; it cuoud be due to low cutting pressure, damaged nozzles, between others. Procedures vary for different cokers depending on the available system, either hydraulic or air driven, but frequent preventive maintenance is a constant for all.
 
Lucky 

[Lucibar Davalillo]

All these fires are happening after big refineries profits because their ambition to take the opportunity of the boom do not allow a chance for fixing what is wrong. No doubt measuring is required, but nothing changes without an assessment plan and responsible implementation in timely manner; operational excellence means that team understands how to make their equipment more reliable and safer, even before thinking on making money; having reliable equipment and trained teams will lead to increased safer production by itself.

[Lucibar Davalillo]

if you got lucky and have a slide valve, then you got a fixed chute and no major problems, other than keeping bolts in place.
for must of us still dealing with telecopic chutes, then dealing with chute unbalance due to lost guides (pieces of metal ending on coke pit), chute hydraulics failing, etc, wish you best luck.
Just one more thing, either fix or telescopic chute, it is not the part will take out your breath, so hold it until you get your coker going….

[Lucibar Davalillo]

Anybody using new Delta valve Isolation valves? They claim none steam consumption, although their GV850 call for steam purge.
 
I heard about Chevron Coker trying it

[Lucibar Davalillo]

Hey Ely,
What happened? Isn’t Lawrance pumps working as expected?
 
No many Cokers have coke domes, but its water quality should not be much different from the one recovered from coke pit. If I remember right those little pumps are of sumergible type.
 
Glad hearing from you,
Lucky 

[Lucibar Davalillo]

I would not try anything more expensive if wedge meters work well, as you said.
 
You will need more room to accomodate ultrasonic, so it will have some additional plot plan impact
 
Just my thoughts..
Lucky

[Lucibar Davalillo]

A good start could be this link:
http://www.deltavalve.com
 
Just get enrrolled and they will fullfill you with answers

[Lucibar Davalillo]

Sure
150# superheated steam is much better option for initial drum warm-up; , but your going to be it can be done for as long as needed, while heating up main fractionator and drying out the whole system with hot oil circulation at the same time.

[Lucibar Davalillo]

I personally believe every coker behaves different, depending on many factors, being most evident: feed quality, heaters efficiency, fractionator wash oil section design, TPR, and T,P conditions, etc..others less evident are, additional steam consumption, additional flush oil consumption, blowdown limitations, HKGO filters operation, and in general everything may affect your coke drum superficial velocity.
Only after doing a concious review of design parameters and making sure everything is running to the optimum, then ramping heaters at the end of the cycle may help mitigate foaming issues. I have found similar problems due to excessive steam velocity in heaters and just adjusting back values to normal design was enough to get out of the foaming problems.
Lucky 

[Lucibar Davalillo]

In cokers always pay giving up something to increase throughput; it has been my way of running cokers. If heaters safety limits are not exceeded, then go for it. Typically Coke drums are the limitations, especially in latest designs where overdesign hardly gets to 110%. Also feedstock is getting worse and most likely will eat that extra 10%.
In summary, make sure maximizing your heaters and everything else, but watch closely your drums; you will recover faster from heater tubes fouling and even plugging, but coke drum foamover would be a killer.
Just my thoughts..
Lucky 

[Lucibar Davalillo]

I have not heard many having such problem; of course, it may happen due to different reasons; poor vent design may be one, but it would have to happen for every single drum, rather than an isolated case; others come to my mind are followings:
i) isolation valves at psv inadvertely left open or large leaks, ii) very rear long enough coke bed chanelling, which would evident if lot clean cold water is being drained, iii) if slides valves installed, opening too fast and draining through it; iv) almost forgot the possibility of starting draining at very low pressure due to: a) blowdown drum vapors line up to flare, b) blowdown vapors recovered by ejectors or ring compressors, in order to meet new environmental regulations set by NSPS CFR 60 Subpart Ja, which establishes lowering drum pressure below 5 psig before venting.
 
Is there any coker following such regulation (believe applies for new construction since May 2007 ?
 
   

[Lucibar Davalillo]

Following References are kind of old, but very good…
Brown, J. W., W., Schuette, W. L., and Sherman, L. G., Latest Developments in Flexicoking. Presented at the AIChE Meeting, March 19, 1975
 
Anonymous, Flexicoking Passes Major Test, Oil Gas J., 73(10), 53-56 (March 10, 1975)
 
Blaser, D. E., Rionda, J. A., and Saxton, A. L., Combine Desulfurizing and Coking, Hydrocarbon process., 50(9), 137-141 (1971)
 
Lucky

[Lucibar Davalillo]

Is there any other coker, besides Reliance Jamnagar in India, using ejectors to recover coke drum vents to blowdown?
 
What’s the lowest pressure can get at coke drum before venting to atm., after quench, without using ejectors at blowdown?
 
  

[Lucibar Davalillo]

Thanks
It helped a lot

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