3M DUOFLO Specifications

a 3M company

DuoFLO Filter Systems

Filter Cartridge Benefits...

...Filter Bag Economy

Easily retrofits standard bag filter housings

Provides up to 4 times or more life than conventional bag filters

Eliminates filter media rupture, contaminant by-pass and unloading

Simplifies filter installation, removal,and disposal

Reduces hold-up volume by up to 67% or more

The CUNO DuoFLO filter system is an advanced proven alternative to the use of standard bag filters. Developed using CUNO's extensive depth filtration experience, the DuoFLO filter features a true graded-porosity media structure and a 62 % increase in filter surface area. Compared to conventional felt filter bags, DuoFLO filters provide:

up to 4 times or more the service life

superior contaminant removal efficiency

enhanced flow per filter element

reduced loses associated with frequent filter change-outs (production

downtime, disposal, and labor costs)

The DuoFLO filter will easily retrofit most existing bag filter housings. To take advantage of the DuoFLO system in applications where bag filter housings are currently in use, simply remove the existing bag support basket, replace it with a DuoFLO support basket, and insert the DuoFLO filter. For new installations, CUNO offers a full line of DuoFLO filter housings (page 5).

The DuoFLO element is comprised of two cylinders bonded to a top plate and a lower seal plate. As shown in Figure 1, the fluid enters the top of the filter through flow channels located in the DuoFLO filter top plate. The fluid flows between the inner and outer media cylinders, and then passes through the media and support basket into the clean chamber of the filter housing.

Top P lat e

Flow Channels

The DuoFLO design incorporates an innovative new geometry of both filter element and restrainer basket which provides 100% 3 dimensional support of the DuoFLO media. This eliminates the potential for filter element rupture and the resulting gross contamination of the downstream effluent with previously

Inner Media

Cylinder

Outer Media

Cylinder

removed particles. The design of the DuoFLO element also reduces filter element hold-up fluid volume by 67% compared to conventional bags, minimizing worker exposure to process fluids.

Filter design combining a graded-porosity media with 62% greater filter surface area

Hold-up volume reduced by 67% compared to conventional bag filters.

100%, downstream support of the filter element

Superior flow characteristics

Longer Service Life – up to 4 times or more that of conventional felt filter bags

Reduced Filter Usage - minimizes product loss, labor, disposal costs, and operator exposure

Increased productivity - less down time for filter change-out

Reduced product loss & related disposal costs

Used element retains less fluid, making it lighter weight for easier removal

Eliminates displacement balloons and associated spillage during change-out

Eliminates filter rupture, contaminant bypass and unloading

Allows operation to higher differential pressures before filter change-out

Maximizes utilization of filter surface area and maintains low operating pressure drop

Reduces flow per unit area (flux) for improved effluent quality

Lower Seal

Plate

CUNO utilizes state-of-the-art technology to produce the DuoFLO filter element optimizing both performance and filtrate quality to ensure customer satisfaction. DuoFLO filter elements are sized to replace conventional # 1and # 2 bag filters and are available in both polypropylene and polyester materials (including 21 CFR listed materials) with nominal ratings from 1 to 200 micron.

The DuoFLO filter design provides an increase in filter surface area of 62% when compared to commonly used #1 and #2 bag filters. This additional surface area provides the following benefits

Lower flux (flow rate per unit area): Since filter

life is inversely proportional to flux, reducing the flux by 50% can achieve up to a three-fold increase in filter life. Additionally, lower flux improves the retention efficiency of the element.

Lower initial pressure drop: This increases the

time before the recommended change-out pressure is reached

DuoFLO filters are offered in a graded porosity filter media where two media layers of different porosities are combined. The result is superior contaminant holding capacity. The added capacity is achieved by removing the larger contaminants in the first layer and the finer contaminants in the tighter, downstream layer (see Figure 2). The configurations of each nominally rated filter media have been optimized to achieve the longest service life. Media Migration is eliminated by thermally bonding the exterior surface of the downstream media layer.

Extensive testing, supported by field results, has demonstrated the superior life advantage achieved by DuoFLO elements while obtaining superior efficiencies. As shown in Graph 1, DuoFLO elements provide for up to 4 times the throughput compared to equivalently rated conventional bag filters (the life of the filters were measured to the same terminal differential pressure).

100

Throughput (Percent)

1 micron 5 micron 10 micron 25 micron

CUNO DuoFLO Elements

Competitor F

* Polypropylene media

Competitor FEX Competitor H

Competitor HEX

DuoFLO Filter Elements

Simple Filter Removal - Simply insert the CUNO removal tool into the top plate and lift the filter from the housing.

Easy Filter Installation -.The

DuoFLO filter element is a rigid cylinder that easily slides into the support basket

Graded Porosity Media DuoFLO media consists of 2 layers. The first layer or upstream zone is “open” to remove the larger contaminant while the downstream zone is “tighter” to remove the smaller contaminant. This design provides greater contaminant holding capacity and longer life than conventional single layer media.

Reduced Hold-Up Volume A 67% reduction in hold-up volume significantly decreases lost product and disposal costs.

Superior Sealing Collar Constructed from molded polypropylene or polyester with an advanced sealing lip that provides a dynamic spring-like seal, the DuoFLO design eliminates contaminant bypass.

Size Hold-Up Volume (gallons)

#2 DuoFLO 1.4 #2 Standard bag

Support Basket - Full Support

of the filter element ensures filter integrity even under the most demanding conditions by eliminating the potential for media stretching which can open the pore structure and allow larger particles to pass.

4.3

Increased Surface Area -The

unique design provides 62% more area than typical bag filters for longer life and fewer filter change-outs.

Size Filter Area (ft )

#2 DuoFLO 6.7 #2 Standard Bags 4.1

Singed Media Surface - Many

filter bags release fibers that end up in the filtered product. The DuoFLO filter media is thermally treated to eliminate loose fibers.

The unique DuoFLO element design - 62% greater area and a unique

graded-porosity media structure - provides a service life advantage of up to 4 times greater than conventional filter bags. Other features media treatment, thermal seaming, ultrasonic bonding ensure that the

DuoFLO filter is unsurpassed in quality and performance.

Thermal Side Seam - Using advanced thermal sealing processes, the DuoFLO seam eliminates the problem of contaminants passing through large needle holes.

Integral Media to Plate Seal an integral seal between the plastic components and the filter media is ensured by using state-of-the-art ultrasonic welding techniques.

(sealing collar

of plastic parts to media)

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