Spider-Web®

Our fi lter media expertise

gives you power

Spider-Web is the fi rst fi lter media to effectivelycombine very high fi lter effi ciency with low airfl ow restriction both initially and throughout the life of the fi lter.

The result is better turbine protection, lower overall turbine operating costs and higher turbineavailability.

R

T RAD I T IONA LMED IA Dust

Particles

DustParticles Spider-Web

R

S P I D E R -WEBMED IA

Traditional Media (substrate)

Spider-WebSpider-Web aadvantagesdvantages

Surface fi ltration

Donaldson’s patented Spider-Web media technology consists of a “web” of sub-micron diameter fi bers bonded to a substrate of Donaldson cellulose or synthetic fi lter media. The nanofi ber web signifi cantly improves the media’s ability to collect dust particles on its surface, and minimizes the number of particles that penetrate into its depth. In traditional fi lter media without Spider-Web, particle ingress shortens fi lter service life.

Durability

The patented nanofi ber web is extremely durable, as well as resistant to moisture and high temperature. Spider-Web’s robust nanofi ber layer keeps protecting the turbine and delivering superior self-cleaning per-formance throughout the life of the fi lter.

Low pressure drop

Incoming air passes through the Spider-Web layer without increasing fi lter pressure drop. Spider-Web fi bers are very small compared to the airfl ow passages between media fi bers. Particles collect on the Spider-Web layer, keeping the media pores open. In traditional fi lter media, dust particles lodge in the pores between fi bers and become imbedded in the media depth. Eventually pores plug, causing fi lter pressure drop to increase.

High fi lter effi ciencyHigh fi lter effi ciencyhelps turbines run at helps turbines run at peak effi ciency, with peak effi ciency, with reduced maintenancereduced maintenance

Initially

Traditional fi lters have an initial period during which fi lter effi ciency must build up to peak levels, but Spider-Web fi lters are highly effi cient from the time they are installed. Spider-Web media accelerates the forming of a dust cake on the media surface, bringing the effi ciency to nearly 100% very quickly.Because its fi bers are less than 0,3µm in size, Spider-Web minimizes the number of fi ne particles that pass through the media during seasoning.

Throughout fi lter service life

Spider-Web’s unique surface loading capa-bilities cause incoming dust particles to con-tinuously build up on the media’s surface rather than its depth, thereby maintaining high effi ciency and extending fi lter service life.

On sub-micron particles

Another advantage of Spider-Web is its ability to capture sub-micron size particle. Because Spider-Web is made up of a tight web of sub-micron diameter fi bers, it is much more effi cient than traditional fi lter media at collecting dust particles less than one micron in diameter.

SSpider-Webpider-Web XP: XP:ppremium performanceremium performance

To further enhance fi lter effi ciency on sub- micron particulate Donaldson has developed and patented Spider-Web XP. Spider-Web XP features a web of sub-micron diameter fi bers on both sides of the fi lter media sub-strate. Thanks to this unique design initial fi lter effi ciency is improved. For urban and industrial locations with high concentra-tion of particles below one micron in size, Spider-Web XP offers best of its class tur-bine protection against fouling.

Look for improved Look for improved performance in these performance in these applications:applications:

All operating environments, including urban and industrial Static and pulse-clean fi lter systems

Spider-Web’s high effi ciency on sub- micron size dust particles benefi ts turbines operating in urban and industrial environments where a signifi cant portion of particles in the ambient air are less than one micron in size.

Dust particles load on the surface of Spider-Web fi lter media (below), rather than in its depth as in traditional media (above)

Spider-Web® Filter

0

0 0.5 1 1.5 2 32.5

102030405060708090

100

Synthetic Spider -Web XPSynthetic Spider -WebSyntheticCellulose

Particle size µm

Efficiency %

PerformancePerformanceimprovements forimprovements forpulse-clean fi lterspulse-clean fi lters

Better dust particle release

Dust particles are more easily dislodged during pulse cleaning, because they load on the surface of Spider-Web fi lter media rather than in its depth. In traditional fi lter media, dust particles become lodged in media pores; making it diffi cult to remove them during the pulse-cleaning process.

Lower, stabilized pressure drop

Spider-Web’s improved dust particle release capabilities result in a lower, stabilized fi lter pressure drop. The pressure drop of a pulse-clean fi lter system with Spider-Web fi l-ters stabilizes at a lower level than the same fi lter system with traditional fi lters, because the media’s surface loading properties greatly improve dust particle release during the pulse-cleaning operation.

Improved turbine availability

The improved pulse cleaning performance of Spider-Web fi lters results in fewer planned and unplanned maintenance outages for fi lter replacement. This extended fi lter life, and the reduction in the amount and frequency of turbine cleaning provides improved turbine availability.

How to assessHow to assessfi lter performance testsfi lter performance tests

How to comparefi lter effi ciency data

Different fi lter tests provide different types of stated fi lter effi ciency. Most people consider the air that we breathe to be relatively clean when in fact, each breath contains thousands of tiny “dust” particles. Most of these parti-cles are so small (less than 25µm) that they cannot be seen with the naked eye. Because a turbine “breathes” considerably more air than we do, it is much more susceptible to the negative effects of these dust particles.

There are three basic types of fi lter effi ciency that are refer-enced in fi lter data reports:

ArrestanceArrestance the ratio of the weight of dust particles captured to the total weight of dust exposed to the fi lter.

Dust spotDust spot (or ASHRAE 52.1) which relates to the relative “staining” characteristics of the dust that passes through a fi lter.

Fractional efficiencyFractional efficiency (or ASHRAE 52.2)the discrete measure of the number of parti-cles of a specifi c size down-stream of a fi lter compared to a measure of the number of par-ticles of the same size upstream of the fi lter.

Media Technology

Fractional effi ciency tests show that on 0.5 µm size particles, the initial effi ciency of Donald-son Spider-Web XP is twice that of our regular Spider-Web ! (26% of 0.5 µm-size particles are left to pass through vs. only 13%). And this is just about three times better than com-petitive offerings. Stopping more of the dust particles in the 0 to 2 µm in size range reduces compressor fouling and improves heat rate.

Initial fractional effi ciencyInitial fractional effi ciency teststestsAll tests were conducted on conical/cylindrical fi lter pairs (as in a GDX system)by a test laboratory independent of Donaldson.

Donaldson’s Spider-Web fi lter media technology, sloading and thereby minimize the penetration of p

How are these measurementsHow are these measurementsimportant in gas turbine fi lters?important in gas turbine fi lters?

Although “small” particles in the air outnumber “large” particles by a ratio in the range of a million to one, the large particles account for most of the weight. Large particles (>5µm) are what cause erosion on turbine blades, and if a fi lter’s effi ciency did not quickly approach 99+% on these particles, that fi lter would not be used for a turbine application. For this reason, arrestance effi ciency is of little signifi -cance for turbine fi lters.Dust spot effi ciency is a signifi cant test because it measures a fi lter’s ability to remove smaller micron particles that will adhere to turbine compressor blades or deposit inside cooling passages.These small particles(<5µm) will foul the compressor over time and result in reduced turbine performance. The ability of a fi lter to pre-vent this fouling will result in increased turbine performance and a reduction in the amount and frequency of cleaning.Particle count is a signifi cant test, especially on smaller particulate sizes, because it is a method for comparing different fi lter element effi ciencies on specifi c particle sizes. This test shows differences in effi ciency performance of ‘similar’ types of fi lter media, and for the most part will show the same effi ciency relationship between fi lters as shown by the dust spot.

When analyzing fi lter test data

Not only is it important to recognize that there are different types of effi ciency, it is also important to recognize that fi lter data being compared must be from tests performed at similar airfl ow rates. It is also important to look at all of the data in a fi lter test. If a fi lter element has an effi ciency of 99.5% on a particular micron size after it has been loaded with 100 grams of dust, the average effi ciency from start-up to that point will be signifi cantly less, and the 99.5% effi ciency is of little value to a turbine operator unless the fi lter ele-ment is loaded with dust before it is installed in the air fi lter. The “Average Effi ciency” from start-up to any point on a loading curve should be the only effi ciency data that is compared and is determined by the ratio of the area under the effi ciency curve to the total area of the graph. This is the same method employed when a fi lter is rated with an (average) ASHRAE Effi ciency.Finally, it is important to recognize that effi ciency data shows how much dust a fi lter media has captured rather than how much dust has passed through (penetrated) the fi lter media. It is the comparison of dust penetration that should be of interest to turbine users, because it is only the dust that passes through a fi lter that affects the performance of the turbine. For example, although there doesn’t appear to be much difference between 94% fi lter effi -ciency and 96% fi lter effi ciency, the 94% effi cient fi lter allows 50% more dust to pass through (penetrate) the fi lter media.shown here at 2500X magnifi cation, uses a web of nanofi bers to enhance surface

particles into the depth of the media.

All Donaldsonfi lter cartridges feature:

All Donaldson XLRfi lter panels feature:

Metallic inner and outer liner for fi lter sturdiness Pleatloc for optimum pleat spacing

and long fi lter life Beading for media stability and

safe pulse cleaning

Unique PowerCore media packaging Moulded heavy duty frame

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1

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Spider-Web filter mediaStandard filter media

Time in hours

WHY LOW WHY LOW P IS IMPORTANTP IS IMPORTANT

Generally accepted industry guidelines suggest that for each 100 mm of pressure drop, a power plant can experience a loss in turbine output power of somewhere between 1% and 1.4%. Based on this guideline, if a base load system (running at about 8000 hours per year) experiences an incremental pressure drop of 25 mm WG (1” WG), that pressure drop would translate into a loss of output of 0.25%.The edge you get with Donaldson Spider-Web fi lters is worth their premium price. As nanofi ber media technology, Spider-Web helps maintain lower average P over the life of the fi lter. And Spider-Web fi lters keep performing and delivering higher turbine output throughout their 2 to 3 year (or longer) lifespan!

Example:

For a plant that operates at 8000 hours per year, each 25 mm WG (1” WG) pressure drop would result in the loss of 0,25% of operating output. Using an engine with a 150 MW output, each 25 mm WG (1” WG) incremental pressure drop per year (8000/hours)

Pressure drop stabilizationPressure drop stabilization

This chart compares the pressure drop of a GDX pulse clean fi lter using Spider-Web fi lters to that of the identical GDX using traditional fi lters. Spider-Web media stabilize at a lower

P over the life of the fi lters. Results are from an accelerated test under simulated dust storm conditions in the laboratory.

Media

Regional Headquarters

Europe, Middle East and Africa

Donaldson Europe b.v.b.a.

Research Park Zone 1

Interleuvenlaan 1

B-3001 Leuven

Belgium

Tel. + 32 16 38 39 40

Fax + 32 16 38 39 39

Email: GTS-europe@emea.donaldson.com

Regional Headquarters-Asia Pacifi c

Donaldson Filtration Pte. Ltd.

No.3, Changi Business Park Vista #02-00

Singapore 486051

Tel. + 65 6311 7373

Fax + 65 6311 7398

Email:gts-asiapacifi c@donaldson.com.sg

Worldwide Headquarters

Donaldson Company Inc.

1400 W. 94th Street

PO Box 1299

Minneapolis

Minnesota 55440

USA

Tel. + 1 952 887 3131

Fax + 1 952 887 3843

Email: fi lterinfo@mail.donaldson.com

www.donaldson.com

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Spider-Web GTS-210