Air Filtration - Life-cycle analysis aids filter review process
A life-cycle cost (LCC) system devel-oped by Camfil Industrifilter will help offshore operators assess how filter efficiency affects the perfor-mance of their plant.
Filter efficiency has a big impact on plant performance, according to Peter Sandberg, managing director of Camfil Industrifilter. The more dust, dirt, and moisture that gets through the filter, causing fouling on the machinery it is meant to protect, the more performance suffers.
Plant efficiency is also directly affected by the pressure drop through the filter system – the greater the pressure drop, the more efficiency suffers. Pressure drop occurs at all four stages of the filtration system: at the air intake, at the pre-filters, the fine filters and the silencers.
Camfil Industrifilter has developed products and systems that limit pressure drop. For example, the old type of pre-filter, a pad placed across the path of the air flow, has been replaced with filters consisting of angled, pleated media. These filter more effectively and present a greater surface area to the air flow, which reduces the pressure drop and extends the product's life.
Camfil's deliveries to Snøhvit included air intakes with snow hoods for five LM6000 gas turbines.
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The company has also replaced the old type of silencer with a more modular design that substitutes the parallel splitters previously used. The new design provides an open area of 50%, compared with around 33% for the old type, thereby reducing both the velocity and the pressure drop.
If sufficient data is available, the LCC system can be used to compare different types of gas turbines, which tend to differ in their sensitivity to fouling. Generally speaking, higher efficiency turbines, for example, are more sensitive to fouling. So an assessment of performance in relation to the filter system could provide valuable input to the combination of equipment selected, Sandberg says.
Camfil Industri-filter recently made two deliveries to the Snøhvit LNG plant in northern Norway. One comprised the air intakes for five 43-MW LM6000 gas turbines to Nuovo Pignone. This delivery included snow hoods capable of handling wet and dry snow. Although the turbines are located on land, the delivery was basically an offshore system derived from the company's CamGT prime filters. The company was able to comply with the fast-track schedule required – it received the order last November and delivered the equipment in February.
The company also supplied air intake systems and ancillary equipment for three LM2500+ turbines to Dresser Rand for Statoil's Kristin platform, and to Nuovo Pignone for a compressor set for Statoil's Visund gas export project.
For more information, contact Peter Sandberg, Camfil Industrifilter. Tel +46 33 17 85 75, fax +46 33 17 85 55, [email protected], www.camfilfarr.com
