I've a problem with my air filter for GE-7EA equipped with self cleaning pulsation method. The rate of increase in DP is high even though we run the manual online pulsation throughout the year. And once the DP reaches a point it won't drop down no matter how often you do the pulsing we have to change some filter elements. Can anyone give me a comprehensive method to analyze the degradation of the filter and comparison to turbine perfomance? And can any one give some recommendation or ideas to keep up with this problem?

 

This is one of the most frustrating questions for me (this one and, "How often should we water wash the unit?"). *EVERY* installation is different; every environment is different; every atmosphere is different. Do you have fine dust or sand? How much humidity does the site normally experience? Is there any un-natural source of humidity being ingested into the turbine through the inlet filters? Is the site on a coastal location where there is more humidity than an inland location might be? Are there dirt roads which have a lot of traffic nearby? Your site is not like 99.87% of the other sites in the world; it's unique, just like you.

This is a really good question for filter manufacturers. You can search the Internet for gas turbine inlet filters and come up with many different manufacturers and sales rep's--and they will be very happy to show you their wares and explain why there product is better than others.

Have you investigated "pre-filters"? Several manufacturers have different types of outer coverings which can be placed over the pleated filter elements and changed periodically to help reduce the mail filter element changes.

I've also seen improperly adjusted pulsing mechanisms, and pulse intervals which don't let the air pressure properly build up between pulses. Personally, I'm *not* a fan of using compressor discharge pressure through an air dryer skid (most of which aren't adjusted or maintained properly and so don't work anyway, and can let wet air get into the pulsing system). A large AC motor-driven compressor with a large receiver/tank is best. I also believe in pulsing the filters when the unit is not running, not just when it's running.

But, the biggest factor affecting filter life is site conditions. I know of one site which is located 100 yards from the ocean which changes filters every six months, and has had to do so for more than 20 years. It's located near a farming/agricultural area and there is a lot of dust as well as the nightly fog and high humidity. They've tried everything, and they've just resigned themselves to the fact that they have to change their filters about every six months. There's a sister site about 20 miles inland which doesn't change their filters but about every 18-20 months. They don't have the fog, humidity, or dust from the farming activity.

I've seen some owners that have built barriers around the unit to try to keep dust from getting to filters; some work, some don't. There are lots of possible solutions, and possible problems. Try contacting inlet filter manufacturer for some guidance with pulse mechanism settings.