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Good Practices developed at Bottom of the Barrel's 2002 Coking.com Best Practices Seminar in Houston, TX.
HOT SPOT INDICATORS
1. Establish check list of indicators:
- Reduced quench time / channeling
- Total quench water usage below normal
- Total sour water - make below normal
- TI's normal
- Pressure spikes during quench
- Review checklist before proceeding with unheading
- Log any issues with cut.
2. If operational upset during drum coking that stops forward flow or heater trip that allows cold oil in drum: Return to target inlet and outlet temps for minimum for 3 to 4 hours. Cut feed if necessary to prevent overfill of drum.
3. When cutting: If you see steam huffing and puffing from top of drum, pull the stem up until huffing and puffing stops. Bathe coke bed to cool spot.
STUCK DRILL SYSTEMS
1. To prevent cave-ins
- Don't be aggressive with cutting pilot or
2. If stuck:
- Install bottom head, add quench water from bottom and float coke from around bit. Lift bit out, rotate if possible to help coke release.
TOP HEAD SAFETY
1. Steam eductor or air eductor to reduce coke drum pressure.
2. A fully automatic heading system.
3. PPE for pulling the top head
4. Half face respirator
5. Slicker suit or apron.
6. Personal H2S monitors
7. And/Or supplied fresh air.
8. Audio/Visual: simple microphone outside of drum, down by cone - plastic coasted. Listen for drill water on drum wall. Have sealed cabin with speaker - they use this with a drum cutting program.
Best Practices
1. Use the Coker community on these very unusual problems to help develop a game plan before ever taking off bottomhead!
Good Practices
1. Eliminate the feedline flanges or couplers.
2. Industry has moved to automating (Hydraulic cylinders for lifting and lowering chute - this gets rid of chain falls)
3. How do you deal with a drum that has started to fill, but did not coke:
- Maximum steam into drum, if you have steam.
- While steam system is sagging, it's time to put in steam water.
- Go back into the drum with feed, and you will get back in.
- Rock feedline, alternating steam/water, steam/water to open.
Common Practices
1. Half way switch on valve to start drum fill - reduces shock to drum.
... stay tuned, there's lots more to come.
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