Home › Forums › Coking › Design and Reliability › Cokedrums, Structure, Inspection › Drums › Drum obstrution
This topic contains 9 replies, has 4 voices, and was last updated by Anonymous 11 years, 11 months ago.
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February 28, 2011 at 8:25 am #2365
If I have a drum obstrution during thw water quench, what I would do ? Returning the steam injection in the drum ?
What is it the best procedure to solve a drum obstrution ? -
February 28, 2011 at 9:07 am #5239
AnonymousIn our case, after we finished the drum feed, we did not inject steam because a power failure. We did not have done the water quench and the drum became plugged. What is it the procedure for solve this ? Our drum
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February 28, 2011 at 9:27 am #5238
I think returning to steam injection is the best way to make through the passage. Coke particles may obstructing the path if steam flow is became normal let it run for few monutes after that water injection to be such a way so that there is contious flow through the path that closing steam same time opening water injection . There will be hammering for few seccond after that it will be ok
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February 28, 2011 at 9:29 am #5237
Open all the flanges of reactor clean it by hydroblasting other than this I think no way.
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February 28, 2011 at 12:57 pm #5236
AnonymousThe drum is still hot. We have tried to inject steam, but the flowrate is low.How can I open the drum safely and hidroblasting it ?
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March 2, 2011 at 5:00 am #5229
Anonymousthis mighte be a late replay….
try to put water from the top in small quantities (5-10 m3/hr), and account the sour water generated from the blow down. Do heat balance for the drum, if >90% heat is recovered then go for cutting. -
March 3, 2011 at 12:40 am #5228
Anonymousone of the recent accidents in recent years has been for this event of a loss of injection drum (plugged channel), the drum was ketp 5 days with out nothing (steam or water) the operators thought that the drum would be cold, after the accident was estimated that a drum of coke may take 15 to 27 days to cool a temperature below 100 C
when the maintenance staff opened the bottom flange was an explosion, two people died at the bottom of the drum
after this accident we suffer this plugging and based on this experience we apply the following procedure
we inject water from the top (alternate quench) until it had a water level above the bed of coke, as the water enters the water perchlorate and vaporizes
-Foam was injected (via a fire truck) through the top line
-we opened the flanges (we kept a team a group of firefighters around the bottom drum) and proceeded to cut the hole pilot ( speed was 2 to 3 feet per minute ) all the personal was protected (EPP)Remember that when you open the bottom of the drum (depending on what type of unheading devide you have install) drum will have accumulated hot water , for that reason open partially the drum and let it drain
espana2005
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March 3, 2011 at 12:51 am #5226
AnonymousYou can read this event
http://www.historylink.org/index.cfm?DisplayPage=output.cfm&file_id=5618espana2005
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March 10, 2011 at 6:15 pm #5214
AnonymousThanks for the answers. We have solved our problem (drum obstrution) by injecting water in the feed pipe on the drum bottom by a hose in a small flow because the obstrution. When we observed that the water reach the drum top we wait 4-6 hours (hot soaking). The temperature on the wall was below 110 degree C and the pressure below 0.1 Kgf/cm2. We opened the drum and we decoked it with no problem (hot spot). The water even in a small quantity cooled the drum.
Thanks by the helping -
March 16, 2011 at 2:38 pm #5201
I am glad the worked out for you. Keep in mind the outside drum wall temperatures are a poor indicator of the temperature in the drum especially in a plugged hot drum. Coke and/or pitch is an excelent insulator so a few feet of coke or pitch on the wall can give you a false sence of security.
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