We have a number of gas turbine units installed at our gas processing plant in Pakistan. The site has high humidity & fog in the months of December and January. Due to high humidity/fog, DP (differential pressure) across filters increase particularly in colder hours (after midnight and early morning) which also results into shutdown when exceeded the trip limit.

Would you please share your experience operating gas turbine units and type of filtration (element type, inlet air treatment, self cleaning practices, alert/trip limits, pulse clean start/stop dp setpoints etc). Have you adjusted alert/trip & self clean dp start/stop on dp switch across filters or across ambient and compressor inlet (considering duct losses).

Appreciate valuable comments.

 

You do really need to check previous posts before you post. Use the search, it will give you a lot of information. If you look above in the Forum you will see a post by Nawaz started on Nov. 11th. and continuing to now. take a look, it may answer some of your questions.

Can you give some more details on what kind of filter system you have and what model of filter you are using?

 

Thanks Bob. I will check the previous posts.

Reply to your queries is as follows:
We are using Donaldson TTD and GDX. The filter element is Donaldson Synthetic Spiderweb (standard and XP).

 

The issue of high humidity or rain fall on self cleaning filters has always been a bit controversial. Typically, if you try and pulse clean the filters when they are wet, you can damage the filters. If you are getting high DP trips during high humidity periods it tells me that either your filters are dirty or your instrument settings are low, both for alarm & trip and maybe also for auto-cleaning start/stop. How regularly do you pulse your filters? Do you only do it on DP or do you also pulse by time?

If you have Donaldson filters, Donaldson should be able to advise on these issues. Simply, you should be checking the DP with brand new, clean filters and the Donaldson should be able to look at your fillter house/ductwork configuration and determine what the Alarm/Trip and self cleaning start/stop limits are.

 

Pulse filter cleaning an auto should be the following condition
1.pulse filter dp reached 3mbar or
2.every 24 hours or
3.humudity 65%

GT Trip will be following condition

Total air intake DP 12mbar with 30secs time delay alarm
Total air intake DP 15mbar protection shutdown

Total air intake DP 16mbar GT trip

 

self cleaning timer intervals shall be minimum& filter control system shall be in in AUTO

dp OF FILTER READING SHALL BE CHECKED AND CLEANING SHALL BE DONE ON REGULAR BASIS

YOU CAN AVOID YOUR AIR INTAKE FILTER PROBLEM
WE ARE ALSO USING SAME TYPE FILTERS