The Art Of Providing A Complete Package: Camfil Farr is a supplier of a complete filtration and acoustic package for the new Siemens SGT-750 gas turbine
by bo svensson

In the early days of gas turbines, the importance of clean combustion air and noise reduction was not as well understood as it is today. The lack of proper air filter systems resulted in fouling of compressor sections, which resulted in a drop of the plant’s efficiency. Engine degradation resulting from compressor fouling is still a significant cost driver when it comes to inlet filtration-related issues.

Camfil Farr has, in close cooperation with Siemens, designed the entire filtration and acoustic package for the new SGT-750 gas turbine from Siemens, which was introduced in November 2010.

Even worse can be the effect of salt sucked into the hot sections of the turbines. The airborne salt from the sea or in the desert areas causes hot section corrosion, called sulfidation. The result of this is a drop of efficiency, in addition to the reduction of the lifetime of hot parts. One company that understood the importance of air filtration was Industrifilter. Initially they were manufacturing air filter systems and noise abatement for intake and exhaust systems of gas turbines. In the late 1990s the company was acquired by Camfil, a Swedish manufacturer of filter material.

In 2000, Camfil also acquired another filter manufacturer, the American company Farr, followed by an acquisition of Kaefer Raco Engineering, Bremen, Germany, in 2006. “Today’s Camfil Farr Power Systems has extensive experience in sizing, designing and manufacturing different system solutions in all conceivable environments,” said Peter Sandberg, CEO of Camfil Farr Power Systems. “With our complete product and system offering, we can provide the right solution, including everything from the inlet system, enclosure and ventilation, to exhaust and damper systems.”  Sandberg said, “We are used to leading and managing projects and performing all contracts in close collaboration with our customers. Each project has its own project manager, who ensures that the customer’s requirements and preferences are met throughout the course of the project.”

One recent success of Camfil Farr Power Systems is its contract with Siemens Industrial Turbomachinery in Finspong, Sweden. Camfil Farr has, in close cooperation with Siemens, designed the package for the new Siemens SGT-750 gas turbine introduced in November. The contract covers the design and production of the complete package including the air intake system with filter and noise abatement, in addition to the engine enclosure, including gearbox and generator compartments, where applicable, and exhaust duct and silencing system. The work has resulted in a development and supply contract for Camfil Farr for units initially sold by Siemens.

“Enclosures are designed with efficient ventilation to keep the temperature on a required level. In this particular case, the ventilation system for the enclosure is made in accordance with a patented solution we have,” said Sandberg. “For the Siemens SGT-750 we are using the filtered air after the main air intake filters, instead of making a separate ventilation air filter system. This saves both space and, in the longer perspective, maintenance costs.”

The “HemiPleat” technology utilizes an optimized pleating technology, which keeps the media pack open to breath, hence reducing pressure drop.

The general product portfolio offered by Camfil Farr, i.e., inlet systems, enclosures and exhaust systems, are designed to include piping, cabling racks and lots of smaller details and components all completely installed when delivered from Camfil Farr’s works. This way, time is saved once the final assembly of a complete package is done in the works of the gas turbine manufacturer or at the final installation site.

The material used for manufacturing of the inlet, enclosure and exhaust varies with the requirements of the final location of the plant. Coated carbon steel, marine-grade aluminum and stainless steel are available materials used for manufacturing of the structural parts. An inlet system is adapted to meet countless requirements. Besides a suitable filter combination, the system also needs to be supplemented with weather protection devices and, if necessary, anti-icing systems or insect guards. If the machine is installed in an area with high temperatures, inlet cooling is an option that increases the machine’s performance.

Details such as water separation and drainage are vital to a well-functioning inlet system and, in particular, for offshore installations. And a system must be simple to assemble and maintain. A number of filter types are available. The CamGT product family is the core of Camfil Farr’s static or barrier systems. It is available in single header or the “Box Type Green” version and is a high-efficiency filter designed with vertical pleating for humid or wet conditions. Efficiency levels are available in five different grades from F7 up to and including the HEPA grade E12.

To act as a first or pre-filter stage in the static systems, Camfil Farr has recently launched the CamFlo XMGT. This is a heavy-duty bag filter with a new synthetic filter media combining high dust-holding capacity with durability and stable, nondeclining efficiency. For the pulsejet systems, the Cam-Pulse GT HemiPleat filter is designed for high dust-loaded environments. The HemiPleat technology utilizes an optimized pleating technology, designed to keep the media pack open to breath, reducing pressure drop and improving “cleanability,” said the company. A gas turbine and its auxiliary systems need to be protected against weather and excessive temperatures.

The enclosure provides effective protection against fire and varying weather conditions. It takes care of the noise and can be delivered skid mounted or as a free-standing module.

The surrounding environment must also be protected from the high noise levels generated by the machinery. An enclosure provides effective protection against fire and varying weather conditions. The noise is taken care of by this enclosure and by silencers installed in the inlet and outlet openings. “Our enclosures are built as an integrated part of the system. Lighting, easy to-open doors, lifting beams and service areas are just some of the features inherent in our designs,” said Sandberg. “The enclosures can be delivered skid mounted or as freestanding modules, and the systems are effectively insulated against vibrations. The enclosures are designed with efficient ventilation.”

Exhaust systems for simple-cycle and combined-cycle installations are mandatory, as the exhaust flue gases have temperatures of 400° to 650°C. The noise emitted by gas turbines is reduced through the installation of an absorbing silencer splitter in the bypass stack. “Our advantage is that we are a complete supplier, who can design and deliver the whole inlet and acoustic systems, from the inlet opening to gas turbine’s bell-mouth and from the exhaust collector flange to the connecting flange of the heat recovery steam generator or top of stack,” said Sandberg. “That is including exhaust diffuser, diverter damper and a bypass stack with silencer. We do this on a turnkey basis worldwide, if required.”

Source: Diesel & Gas Turbine Worldwide

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