For over a decade, Camfil and gas turbine OEMs have worked together to design optimum solutions for offshore, coastal, and harsh environment applications. An OEM major approached Camfil with the need for a high efficiency compact solution. The idea was to have a product with a footprint identical to the existing high velocity filter houses while ensuring longer filter replacement intervals, lower initial pressure drop (dP), greater hydrophobicity characteristics, and EPA efficiency for particulate removal (especially salt).
THE CASE
Foxtrot International, an upstream oil and gas player, manages a gas exporting platform situated offshore Ivory Coast, Africa, where they operate two mechanical drive gas turbine units (5MW each) that drive compressors with high availability requirements.
Units A and B are exposed to harsh environmental conditions that led to spikes in dP, and excessive engine degradation from fouling and corrosion. Consequently, Foxtrot was forced to schedule unwanted shutdowns for maintenance.
ORIGINAL FILTER CONFIGURATION
The original intake system was a high velocity (31,298 CFM) configuration with nine M6 efficiency final filters (3W x 3H) per turbine.
MAINTENANCE REQUIREMENTS
Due to the extreme site conditions, Unit B's turbine performance significantly decreased.
- High dP across the system required four shutdowns per year for filter replacement.
- The engine required four offline washes per year due to fouling; and,
- A boroscope inspection showed signs of corrosion on the engines, which requires costly repairs.
SITE INSPECTION
Camfil sent technical site representatives to evaluate the existing air inlet systems and their surroundings. Due to Camfil’s track record of successful offshore filtration systems, the OEM awarded Camfil with the project.
PROPOSED FILTER CONFIGURATION
Foxtrot’s objectives were to eliminate degradation and minimize maintenance requirements to once per year. To achieve this, Camfil recommended redesigning the filter house to the Compact EPA Filter solution consisting of:
- CamVanes
- Pre filter CamGTR 3V-600 F8 according to EN779:2012 that can be changed during operation (nine pcs)
- Final barrier filter CamGT 3V-600 E10 according to EN1822:2009 (nine pcs)
The new filter house uses nine prefilters back to back with nine high efficiency filters to fit in the existing footprint.
RETROFIT SITE SUPERVISION
To minimize downtime during the installation process, coordination effort was key. The Camfil team went onsite to supervise the installation work and on-the-spot troubleshooting. They assessed the equipment required and the manpower needed.
TAKEAWAY
The results are impressive since the upgraded solution delivers lower dP while offering EPA efficiency versus the original M6 efficiency. A typical E10 EPA filter solution is expected to have a higher dP than an M6 filter solution when using the same housing size. The Compact Static EPA filter solution is able to deliver an EPA efficiency performance at a lower dP and with a longer service life, resulting in safer, more reliable, and more productive operations.
The site manager further confirmed a significant improvement in engine performance, allowing them to run a full year without any unwanted shutdowns that were previously caused by fouling and corrosion with the original system.
Results
- From four to one filter changes per year
- From four to one water washes per year
- Corrosion issues eliminated
- Same footprint
additional predicted savings - carbon emissions
Compared to the original M6 solution, Camfil estimates that the CamGT 3V-600 solution could reduce CO2 emissions by 1000 tonnes per turbine, per year.
By limiting salt ingestion, higher efficiency systems reduce the thermal corrosion risk and fouling of the compressor, resulting in higher power output and increased turbine availability.
Africa (French)
