Molten sulfur line rupture

[srks]

For liquid sulfur line, using skin effect heat tracing, during shutdown for sulfur solidification case; during remelting process risks present are sulfur specific volume will expand and cause over pressure and line rupture.
a. What are precautions to be taken?
b. In case, if anyone faced such issue and how it resolved?
c. Identifying cold spots and depressurizing small sections pose more challenge, I guess.

Request Experts / members share experience.

 

[hacksaw]

You need to get a job in a sulfur processing facility. No simple forum answers.

 

[horacio Torres]

You heat the sulfur line with steam tracing until sulfur change to liquid phase before set it in service, it will not reach high pressure.

Horacio

https://www.linkedin.com/company/lagotuy/

 

[LittleInch]

srks,

As you seem to be aware, re melting sulphur lines which have gone solid is a very hazardous procedure and one which had casued ruptures on many previous occasions.

Therefore
a) put in place as many precautions as you can to prevent this happening. This could be spare heating cables / tubes, alternative heating systems such as steam as back up, some sort of flushing system to remove the sulphur before it gets solid, etc.

b) The only way to bring your line back to life is to do it very very slowly, allowing the sulphur to warm up and become slightly liquid to allow the expansion to take place. You really need to use temperature monitoring by fibre optic cable along the whole line to find those area which are taking longer to heat up and still solid.

c) in deed. Sometimes you may need to section your heating system into shorter lengths or lower voltage so that you can heat different parts at a different rate.

Try contacting a few vendors who do this like the lot attached.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[srks]

All,
Thanks for reply.
Using steam is difficult and not so useful process.
True, this is cumbersome job. Need to use electrical heating coil at different sections and move section by section. If we don't have fiber optic cable for temperature measurement, you are not sure of cold spots too..

In case if any have case studies, can you please share. I taken couple from net.
Request any process followed with such cases, pl share.

 

[3DDave]

Plan that the pipeline will rupture and at any and every point along the path. Fire, material collection, and any environmental considerations including evacuation if there's enough material to affect surrounding businesses or neighborhoods.

Set up a test section to try any procedure out before trying it on the installation.

Still, there's this report:

https://asmedigitalcollection.asme.org/IPC/proceedings-pdf/IPC1996/40214/785/2506970/785_1.pdf

which indicates that hot water tracing is expected to not rupture the line, but heat tracing runs a good chance of doing so if not careful, so be careful.

If it happens either the industry is really good at keeping it under wraps or there there is little off-site damage. I expected Google to find at least one report of a sulfur line rupture, but no such for me.

 

[pierreick]

Hi ,
What about a jacketed line ( pipe +valves )? my experience with product freezing above 190 Celsius.
Note : any possibilities to flush the line in case of shut down ?
Pierre

 

[srks]

Greetings.
.
3DDave, thanks for sharing this report. This one I already reffered from net., also similar line failure case study in Canada .
..
Need to address such issue section by section, I guess.

 

[Dhurjati Sen]

If the line is not too long and depending on material and man power availability, cutting and replacing is the best option.

The new line could be steam traced or jacketed, the former being cheaper.

DHURJATI SEN

 

[Pitta]

Dont warm the complete line in one stretch. Try to warm from last end where it is connected to tank.What happens here is that if pressure develops due to warming up it could easily be released into the tank and we could protect the line and flanges from leaking. Slowly warm till the end by lining up steam or power once warming completed in penultimate lines