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DCU Process Breakout

Facilitator: Evan Hyde – REFCOMM Inc.


What do you want to talk about? Bring your process and troubleshooting issues to this session. Discuss and collaborate with your DCU colleagues from around the globe.

This breakout session, held on 18 March 2021, hosted a lively discussion of process related topics. A sampling of topics and questions discussed is below:

How a Breakout Works
  1. After cutting the drum and removing the air from the drum with steam, which is the value you are increasing the pressure in the drum for the pressure test (leaks)?

2. We have TUD’s and BUD’s and we normally increase the pressure to 3 bar. We chose that value because it is the normal pressure we have during the cooling/quenching of the drum (we have back pressure control valve to blowdown system

3. Which is your criteria for this step of the cycle? Are you reducing that pressure in order to save time & steam? Any additional comments will be appreciated

4. We want to increase the HCGO endpoint from the present value of 532C to 560C and beyond. Presently we have optimized to 40 TPH HCGO wash over the shed deck in a 6.75 m dia column. How much we can go down in HCGO wash rate?

5. We have some very basic questions about sludge processing in a coker. How long would it take to dispose of sludge from say a crude tank and what is done to control odors from the sludge in storage prior to processing?

6. Our site currently has the highest HCGO metals based on Solomon. We have checked multiple sources for possible contamination with no success. Wilson-Snyders are leaking through bypasses based on temperatures. Can this be the main culprit?

7. What are the reasons for high back pressure in coke drum feed line during water quenching and how do we eliminate the issue?

8. What is the important role vapour heating temperature?? What should be maintained during normal operation??

9. How to avoid / minimize DCU coke Drum operational issues like hot spot , blow outs, coke bed collapse / kelly stuck up. Are the issues are due to low coke drum pressure operation or else?

10. Are some sites removing the insulation on drum overhead lines going to switch deck on Cokers to help with reducing overhead line coking?

11. Do you have any reference regarding usage of Antifoulant in DCU heaters to minimize fouling (Asphaltene stabilisation) and increase heater run length?

12. Literature says drum superficial velocity of approx. 0.3 ft/ sec for conventional coker units. Does it hold good for premium quality cokes as well. If not, What is the minimum drum superficial required. Kindly throw some light on this.

Join us for the next DCU Process Breakout on Thursday, 15 April 2021


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Posted by: Evan Hyde

Evan Hyde is the director of field services for He previously was president of C2 Nano Technology where they researched surface treatments to combat fouling & corrosion issues in cokers & other petrochemical process units. He was a Senior Engineering Advisor for Becht Engineering Co., Inc. and has consulted on processing improvement and reliability initiatives for coking clients around the world. Prior to joining Becht, Evan worked for ExxonMobil Research and Engineering, as a process engineer, with assignments in research, and troubleshooting for heavy oil upgrading equipment. He holds a B.S. of Chemical Engineering from Pennsylvania State University.

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