Hello everyone,

I am currently servicing a self cleaning (pulse) inlet air filter system that has been having some issues. Since being operation began in 2019 the self cleaning system has not been automatically activated once. In 2023 the filters were checked and upon visual inspection they were ready to be replaced, however the dp across the filters hadn't reached the threshold to activate the cleaning system. Since then the system has been ran manually every month for 2 hours.

The system is setup to activate at a dp of 3 inches of H2O and then turn off at 2.5 inches of H2O, but I can't seem to find where those numbers came from (I joined the company fairly recently). The filter is an altair PRO cartridge filter and it is a clearcurrent air pulse system.

I have been unable to find any information from the manufacturers on how often should the pulse system run? What should the setpoint be for the dp? How significant of a differential pressure drop across the filters is expected after the pulse system runs? what is the life expectancy of the altair pro cartridge filter? Should the system run during gas turbine operation or when the Turbine is not running?

If anyone has any relevant information I would appreciate the help. The manufactures have not been very helpful.

Thank you.

 

Check if the pulse system is disabled in PLC/HMI code, or if auto-mode is not configured.

 

@Ian B,

The environment where the machine is installed dictates when and how often the self-cleaning turbine inlet air filters will run. Dust, fumes from a nearby process, prevailing winds, nearby evaporative cooling system towers, exhaust from cars and trucks on a nearby road or highway which may or may not be paved--the list is almost endless and includes humidity, salt air and fog.

GE usually works with the filter supplier to determine the appropriate setting to automatically initiate the self-cleaning system. There are numerous types of filters for different application, and sometimes the filter house assemblies are smaller or larger than normal which can affect the anticipated usage of the automatic feature.

If the machine made it two years without a "blow" either the environment is very clean OR the switch to initiate automatic pulsing isn't connected or working properly. In any case, the operation of the switch should be verified no matter the problem.

Every GE heavy duty gas turbine (you didn't say which one, or how "young" it is and we can't read your mind or see what you see or know what you know--unless you tell us...) comes with either a document called the Device Summary or some kind of spreadsheet equivalent that lists most--but, sadly not all--of the settings of devices like the switch we are discussing. That is where you will find the factory settings for the switch to automatically initiate turbine inlet air filter pulsing/cleaning.

There will also be an Inlet & Exhaust System P&ID (GE usually calls them Piping Schematics). You may find some information in the NOTES section in the upper right corner of the first sheet of the drawing. [Bu the way, if you're new to GE gas turbines the P&IDs and the Device Summary are drawings you want to have your own copies of to read and refer to and make notes on. I always copy the device settings from the Device Summary to the relevant P&IDs--it's an excellent way to get to learn a lot about the machine, many of its control and protection settings and how the systems work and work together. HINT. HINT. REALLY BIG HINT.]

I am presuming there is no turbine inlet air filter differential pressure transmitter, but there should be a dp gauge on the filter control junction box. Sometimes, the dp gauge had two manually adjustable "needles", one to start the automatuc cleaning and one to stop it--but they often didn't work very well or last very long. I've also seen a couple of installations where the downstream low-pressure side sensing line was not connected (no one knew when it was disconnected or for how long it had been disconnected, or why it was not connected).

(By the way, when I started working for GE more than 40 years ago they stood us in front of a similar brick wall in a suit and tie for our training graduation photo. I am retired now, after having quit GE thrice.)

 

@Ian B,

Sorry; I missed the machine was commissioned in 2019.

Also, I don’t have any experience with that inlet filter or pulse system. But of the several designs I have worked on, they are all pretty much the same. The main difference being the control method, usually a proprietary printed circuit card system with dip switches or thumb wheels for parameters.