Power Turbine - Diesel System Cleanliness 2

[JamesDUK]

Hello,
Not sure this is the correct forum for this, if not let me know if there is a more appropriate one.
Am working on a offshore platform where we are having serious power turbine reliability problems (on gas/diesel dual fuel machines) traced to dirty diesel.
The diesel piping is around 2m3 total volume with 200 m3of storage, we have a single nominal 1 micron filter and coalescer in the system. The turbine vendor is asking for NO particles greater than 3 micron in the supply to his machines. I cannot see this being at all practical. Latest particle analysis give a result of about 23/21/18 to BS ISO 4406 so absolutly nowhere near and we've been flushing for weeks. We're calling out filter specialist. Does anyone has any feel for what achievable or advise?
Thanks

 

[dwedel]

I am interested in hearing what you find out. However our little babies, are single fuel NG, so I can't help you out much. There is a new industrial engine forum, under the Mechanical Engineers, but we are a small group yet. If you don't get answers here, maybe the ChemE's can help.

dwedel
Hotrod Big Engines!
For site policies and guidelines
see faq731-376

 

[abeltio]

liquid fuel requires at least 24 hs (preferably 48 to 72hs)of settling before using in the unit.
the suction should be floating (suction from the top, against suction from the bottom).

to do this, you usually have a bulk tank and 2 daily tanks that have capacity for 72hs and are used alternatively, this gives the required settling time.
HTH

saludos.
a.

 

[ApC2Kp]

JamesDUk,
There are two problems to deal with for the sources of diesel fuel particulate contamination. First, the storage tanks and piping may have corrosion and rust. Either lined carbon steel tanks or stainless steel tanks could eliminate the corrosion particles from them. Piping of stainless steel, fabricated with low spatter TIG welding process, and cleaned with a pickling acid solution, will minimize any particles from piping. That leaves only the diesel fuel itself as a source of particulate. The grade of fuel needs to specify a maximum ash content, etc. Diesel #2 / Jet 'A' will be a lot better than No. 6 bunker fuel oil!
There was a turbine at APS utility with fuel oil backup to its normal natural gas supply. They found turbine blades gone after a month burning fuel oil, while natural gas had no observable wear on blades. Your offshore platform location has intake air with particles from salt spray. Use and check the air filters along with the fuel filters.

 

[MikeHalloran]

After Hurricane Andrew, my then employer rented a refrigerated trailer for communal food storage by affected families. I was occasionally tasked with refueling the trailer's little Diesel. We used translucent polypropylene 5 gal acid carboys to carry fuel from the next county. I couldn't believe the quantity of water and crud that came in Diesel fuel, regardless of source; usually 5 to 10 percent by volume was something other than fuel.

Nowadays I work on yachts, and the one thing they all have in common, big or small, high budget or pig boat, is multiply redundant multiple stage fuel filters. Some have polishing filter systems running 24/7 even when the boat is idle.

I.e., if you've got just one filter, or just one filter system, you haven't a chance of getting or keeping that fuel supply clean.




Mike Halloran
NOT speaking for
DeAngelo Marine Exhaust Inc.
Ft. Lauderdale, FL, USA

 

[aviat]

3 microns is quite small for main filter. A couple of things. Do not use galvanized tanks for diesel because it comes off and gets into the filter. Another thing that would be very applicable to your situation are microbes that grow in diesel and jet A fuel. These things look like coffee grounds and will plug fuel filters. Once it gets into fuel it is hard to get rid of unless you drain and clean tank. To prevent them growing you should drain water daily, because they need water to grow, and use a microbiocidal agent.

 

[orenda1168]

JamesDUK:

Are you sure the problem is with diesel particulate? Any turbine operation ingesting salt-laden combustion air is potentially subject to sulfidation attack of the blades.

Orenda

 

[JamesDUK]

Thanks for the posts guys, a good sanity check for me. We have 2 tanks so one settling, piping is stainless, storage is treatement carbon steel so pretty sure contamination is by source, we're in the FSU and the quality isn't really there.
Mikehalloran, very interesting comments we're on a mutli billion dollar job and yet can't afford a decent filter. I'm off to source a new one and see how we go, will post an update once I get the filters sorted but that'll be 8 weeks minimum.

 

[JamesDUK]

Orenda,
We have turbine trips traced had fuel valve failures (valve not opening enough when power demand increases), the valve vendor has dismantled them and is blaming large quantities of small particles deposited on some of the valve components.

I have found some very useful information on hydraulic filtration on the parker website

http://www.parker.com/hydraulicfilter/cat/htm-3.pdf.

 

[unclesyd]

In addition to all the good information above and the referenced thread here is a type filter that you may want to investigate as a prefilter. We used this type filter in any number of applications in our process.

http://www.cuno.com/industrial/general.shtml

Look at these models or better yey give them a call.

Auto-Klean Models EG/EGS The AUTO-KLEAN MODEL EG and SUPER AUTO-KLEAN MODEL EGS are all metal cleanable edge filters that can be cleaned without interrupting flow.

Auto-Klean Model G The AUTO-KLEAN MODEL G is an all metal cleanable edge filter. The cast iron head is gasket sealed to the sump by a reinforcing ring and screws to allow sump removal without disturbing pipe connections.