×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

How to clean liquid fuel nozzle lines for 7ea gas turbine.

How to clean liquid fuel nozzle lines for 7ea gas turbine.

How to clean liquid fuel nozzle lines for 7ea gas turbine.

(OP)
We have a duel fuel combined cycle unit here in Florida. How ever we cannot run on #2 diesel because of coking deposits in the fuel lines. I would like to get some input as to go about correcting this problem. Any thoughts?

RE: How to clean liquid fuel nozzle lines for 7ea gas turbine.

To prevent coking in the first place, keep the lines cooler, e.g. by putting a radiation shield between the lines and whatever heat source is nearby.

To dissolve coke that's already present without disassembling anything, run a few gallons of Marvel Mystery Oil through the lines, e.g. by adding it to the fuel supply. Directions for dosing are on the bright red can, ~$10/gal at Pep Boys.

Mike Halloran
Pembroke Pines, FL, USA

RE: How to clean liquid fuel nozzle lines for 7ea gas turbine.

Dual fuel units are known for having this problem. Is this a DLN unit or Std. Combustor? recommendations differ
The only way to clean the lines is:
Disassembly
Thorough cleaning with steam or another product that will dislodge the coke lumps
Inspection with borescope where possible.
Otherwise, you will push the dirt into the combustion chamber.

The recommendation for GE units is to run the liquid fuel system once a week (TIL 1107) also not running below 50% liquid as this may cause overheating of the main fuel oil pump.

If the liquid fuel is used sparingly (e.g. once a year or so, when there is no gas available) several users have opted to remove the liquid fuel lines from the tee where it connects to the purge air line, cap off the unused tee branch (careful, that is a SAE thread with an o-ring) and leave the purge air line only for normal operation.

The other end of the liquid fuel line also needs a cap (regular threaded connection).

For long periods in stand-by the flow divider will also need to be drained of liquid fuel and filled with an oil recommended by the flow divider manufacturer and changed with the frequency recommended by the flow divider manufacturer (typically once a month).

It is also advisable to drain all the liquid fuel piping and pressurize it with Nitrogen to avoid precipitation in the diesel fuel or rust formation (when empty).

The fuel oil tanks will also need to be drained of the water accumulation at the bottom.

The water injection system also needs to be drained and maintained.

A full system by system review is needed to assess the particular requirements at your site.

Should you need more detailed advise, please let me know.




saludos.
a.

RE: How to clean liquid fuel nozzle lines for 7ea gas turbine.

(OP)
Thanks for the replies. It is a DLN unit, it hasn't run in the thirteen years I have been with the company. Can you give me the recommendations for sparingly used liquid fuel systems.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Resources

eBook - 10 Reasons to Choose CATIA on the Cloud
To compete in today’s fast-paced and competitive market, smaller and newer firms need a powerful platform that will enable them to compete with bigger players, without the heavy investments needed in computer hardware, software and personnel. Download Now
White Paper - Smart Manufacturing for Electronics
This white paper describes a transformative approach to electronics manufacturing made possible by the addition of Mentor Graphics to the Siemens family. It describes a completely digitalized strategy that supports both printed circuit board (PCB) and mechanical design and manufacturing, uniting the entire product lifecycle – from idea and production to customers and back. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close