EPA/600/ETV-10/023
April 2010
Environmental Technology Verification
Baghouse Filtration Products
W.L. Gore & Associates, Inc.
L3650 Filtration Media
(Tested November-December 2009)
Prepared by
RTI International
HRTI
INTERNATIONAL
ETS Incorporated
Under a Cooperative Agreement with
U.S. Environmental Protection Agency
wEPA
ET/ ET/
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Environmental Technology Verification
Report
Baghouse Filtration Products
W.L. Gore & Associates, Inc.
L3650 Filtration Media
(Tested November-December 2009)
Prepared by
RTI International
ETS Incorporated
EPA Cooperative Agreement CR 831911 -01
EPA Project Manager
Michael Kosusko
Air Pollution Prevention and Control Division
National Risk Management Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
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THE ENVIRONMENTAL TECHNOLOGY VERIFICATION
PROGRAM
INTERNATIONAL
U.S. Environmental Protect'on Agency
ETV Joint Verification Statement
TECHNOLOGY TYPE:
APPLICATION:
TECHNOLOGY NAME:
COMPANY:
ADDRESS:
WEB SITE:
E-MAIL:
BAGHOUSE FILTRATION PRODUCTS
CONTROL OF PM2 5 EMISSIONS BY BAGHOUSE
FILTRATION PRODUCTS
L3650 Filtration Media
W.L. Gore & Associates, Inc.
101 Lewisville Road
Elkton,MD 21922
http ://www.gore.com
cpolizzi@wlgore.com
PHONE:
FAX:
(410) 392-3300
(410) 398-6624
The U.S. Environmental Protection Agency (EPA) created the Environmental Technology Verification
(ETV) Program to facilitate the deployment of innovative or improved environmental technologies
through performance verification and dissemination of information. The goal of the ETV Program is to
further environmental protection by accelerating the acceptance and use of improved and cost-effective
technologies. The ETV Program seeks to achieve this goal by providing high-quality, peer-reviewed data
on technology performance to those involved in the design, distribution, financing, permitting, purchase,
and use of environmental technologies.
The ETV Program works in partnership with recognized standards and testing organizations; stakeholder
groups, which consist of buyers, vendor organizations, permitters, and other interested parties; and with
the full participation of individual technology developers. The program evaluates the performance of
innovative technologies by developing test plans that are responsive to the needs of stakeholders,
conducting field or laboratory tests (as appropriate), collecting and analyzing data, and preparing peer-
reviewed reports. All evaluations are conducted in accordance with rigorous quality assurance (QA)
protocols to ensure that data of known and adequate quality are generated and that the results are
defensible.
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The Air Pollution Control Technology Center (APCT Center) is operated by RTI International* (RTI), in
cooperation with EPA's National Risk Management Research Laboratory (NRMRL). The APCT Center
evaluates the performance of baghouse filtration products (BFPs) used primarily to control PM25
emissions (i.e., particles 2.5 urn and smaller in aerodynamic diameter). This verification statement
summarizes the test results for W.L. Gore & Associates, Inc.'s L3650 filtration media.
VERIFICATION TEST DESCRIPTION
All tests were performed in accordance with the APCT Center draft Generic Verification Protocol for
Baghouse Filtration Products, available at http://www.epa.gov/etv/pubs/05_vp_bfp.pdf The protocol is
based on and describes modifications to the equipment and procedures described in Verein Deutscher
Ingenieure (VDI) 3926, Part 2, Testing of Filter Media for Cleanable Filters under Operational
Conditions, December 1994. The VDI document is available from Beuth Verlag GmbH, 10772 Berlin,
Germany. The protocol also includes requirements for quality management and QA, procedures for
product selection, auditing of the test laboratories, and the test reporting format.
Outlet particle concentrations from a test fabric were measured with an impactor equipped with
appropriate substrates to filter and measure PM2s within the dust flow. Outlet particle concentrations
were determined by weighing the mass increase of dust collected in each impactor filter stage and
dividing by the gas volumetric flow through the impactor.
Particle size was measured while injecting the test dust into the air upstream of the baghouse filter
sample. The test dust was dispersed into the flow using a brush-type dust feeder. The particle size
distributions in the air were determined both upstream and downstream of the test filter fabric to provide
accurate results for penetration through the test filter of PM25. All tests were performed using a constant
18.4 ± 3.6 g/dscm (8.0 ± 1.6 gr/dscf) loading rate, a 120 ± 6.0 m/h (6.6 ± 0.3 fpm) filtration velocity
[identical to gas-to-cloth ratio (G/C**)], and aluminum oxide test dust with a measured mass mean
aerodynamic diameter maximum of 1.5 um (average of three impactor runs). All BFPs are tested in their
initial (i.e., clean) condition.
Each of the three test runs consisted of the following segments:
• Conditioning period—10,000 rapid-pulse cleaning cycles
• Recovery period—30 normal-pulse cleaning cycles
• Performance test period—6-hour filter fabric test period with impactor.
VERIFIED TECHNOLOGY DESCRIPTION
W.L. Gore & Associates, Inc. provided the following information about their product. The L3650 is a
membrane / fiberglass fabric laminate with a weight of 22 oz/yd2 (746 g/m2) and used in both GORE®
Filtration Products and PRISTYNE® Filter Media Type 6250. Figure 1 is a photograph of the fabric.
Sample material was received as nine 46 x 91 cm (18 x 36 in.) swatches marked with the manufacturer's
model number, year and month of manufacture, and cake side. Three of the swatches were selected at
random for preparing three test specimens 150 mm (5.9 in.) in diameter.
* RTI International is a trade name of Research Triangle Institute.
"Filtration velocity and gas-to-cloth ratio are used interchangeably and are defined as the gas flow rate divided by
the surface area of the cloth.
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W.L Gore
PC# L3650
Gore™ Membrane Fiberglass
Figure 1. Photograph of W.L. Gore & Associates, Inc.'s L3650 filtration media.
VERIFICATION OF PERFORMANCE
Verification testing of the W.L. Gore & Associates, Inc.'s L3650 filtration media was performed during
the period of November 30, 2009, to December 8, 2009, for standard test conditions at the test facility of
ETS Incorporated, 1401 Municipal Road NW, Roanoke, VA 24012. Test conditions are listed in Table 1.
The overall test results summarized in Table 2 represent the averages of three individual tests.
The APCT Center quality manager has reviewed the test results and the quality control (QC) data and has
concluded that the data quality objectives given in the generic verification protocol and test/QA plan have
been attained.
This verification statement addresses five aspects of filter fabric performance: filter outlet PM2s
concentration, filter outlet total mass concentration, pressure drop, filtration cycle time, and mass gain on
the filter fabric. Users may wish to consider other performance parameters, such as temperature, service
life, and cost when selecting a filter fabric for their application.
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Table 1. Test Conditions for Baghouse Filtration Products
Brand/Model: W.L. Gore & Associates, Inc.'s L3650 Filtration Media
Test Parameter
Dust concentration
Filtration velocity (G/C)
Pressure loss before cleaning
Tank pressure
Valve opening time
Air temperature
Relative humidity
Total raw gas stream flow rate
Sample gas stream flow rate
Number of cleaning cycles
During conditioning period
During recovery period
Performance test duration
Value
18.4 ± 3.6 g/dscm (8.0 ± 1 .6 gr/dscf)
120±6m/h(6.6±0.3fpm)
1, 000 ±12 Pa (4 ±0.05 in. w.g.)
0.5 ± 0.03 MPa (75 ± 5 psi)
50 ± 5 ms
25 ± 2 °C (77 ± 4 °F)
50 ± 1 0%
5.8 ± 0.3 m3/h (3.4 ± 0.2 cfm)
1.13 ± 0.06 m3/h (0.67 ± 0.03 cfm)
10,000 cycles
30 cycles
6h±1 s
Table 2. Baghouse Filtration Product Three-Run Average Test Results
for W.L. Gore & Associates, Inc.'s L3650 Filtration Media
Verification Parameter
Outlet particle concentration at standard conditions3
PM25, g/dscm
(gr/dscf)
Total mass, g/dscmb
(gr/dscf)
Average residual pressure drop (A P), cm w.g. (in. w.g.)
Initial residual A P, cm w.g. (in. w.g.)
Residual A P increase, cm w.g. (in. w.g.)
Filtration cycle time, s
Mass gain of test sample filter, g (gr)
Number of cleaning cycles
At Verification Test
Conditions
<0. 0000167°
(<0. 0000073)
<0. 0000167
(<0. 0000073)
2.72(1.07)
2.64(1.04)
0.21 (0.08)
180
0.08(1.29)
120
a Standard conditions: 101.3 kPa (14.7 psia) and 20 °C (68 °F). One or more of the impactor
substrate weight changes for these results were near the reproducibility of the balance.
b Total mass includes the mass of PM2 5 and larger particles that passed through the fabric.
meter. The detection limit is for a 6-hour test and based on VDI 3926.
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In accordance with the generic verification protocol, this verification statement is applicable to filter
media manufactured between the signature date of the verification statement and 3 years thereafter.
signed by Sally Gutierrez 5/7/2010 signed by Jason Hill 4/5/2010
Sally Gutierrez Date Jason Hill Date
Director Director
National Risk Management Research Laboratory Air Pollution Control Technology Center
Office of Research and Development RTI International
United States Environmental Protection Agency
NOTICE: ETV verifications are based on an evaluation of technology performance under specific, predetermined
criteria and the appropriate quality assurance procedures. EPA and RTI make no express or implied warranties as to
the performance of the technology and do not certify that a technology will always operate as verified. The end user
is solely responsible for complying with any and all applicable federal, state, and local requirements. Mention of
commercial product names does not imply endorsement.
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Environmental Technology Verification Report W.L. Gore & Associates, Inc. L3650
Notice
This document was prepared by RTI International* (RTI) and its subcontractor ETS Incorporated (ETS)
with partial funding from Cooperative Agreement No. CR 831911-01 with the U.S. Environmental
Protection Agency (EPA). The document has been subjected to RTI/EPA's peer and administrative
reviews and has been approved for publication. Mention of corporation names, trade names, or
commercial products does not constitute endorsement or recommendation for use of specific products.
RTI International is a trade name of Research Triangle Institute.
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Environmental Technology Verification Report W.L. Gore & Associates, Inc. L3650
Foreword
The Environmental Technology Verification (ETV) Program, established by the U.S. Environmental
Protection Agency (EPA), is designed to accelerate the development and commercialization of new or
improved technologies through third-party verification and reporting of performance. The goal of the
ETV Program is to verify the performance of commercially ready environmental technologies through the
evaluation of objective and quality-assured data in order to provide potential purchasers and permitters an
independent, credible assessment of the technology that they are buying or permitting.
The Air Pollution Control Technology Center (APCT Center) is part of the EPA's ETV Program and is
operated as a partnership between RTI International (RTI) and EPA. The APCT Center verifies the
performance of commercially ready air pollution control technologies. Verification tests use approved
protocols, and verified performance is reported in verification statements signed by EPA and RTI
officials. RTI contracts with ETS Incorporated (ETS) to perform verification tests on baghouse filtration
products, including filter media.
Baghouses are air pollution control devices used to control particulate emissions from stationary sources
and are among the technologies evaluated by the APCT Center. The APCT Center developed (and EPA
approved) the Generic Verification Protocol for Baghouse Filtration Products to provide guidance on
these verification tests.
The following report reviews the performance of W.L. Gore & Associates, Inc.'s L3650 filtration media.
ETV testing of this technology was conducted during November and December 2009 at ETS. All testing
was performed in accordance with an approved test/quality assurance (QA) plan that implements the
requirements of the generic verification protocol at the test laboratory.
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Environmental Technology Verification Report W.L. Gore & Associates, Inc. L3650
Availability of Verification Statement and Report
Copies of this verification report are available from the following:
• RTI International
Engineering and Technology Unit
P.O. Box 12194
Research Triangle Park, NC 27709-2194
• U.S. Environmental Protection Agency
Air Pollution Prevention and Control Division (E343-02)
109 T. W. Alexander Drive
Research Triangle Park, NC 27711
Web Site: http://www.epa.gov/etv/vt-apc.html (electronic copies)
in
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Environmental Technology Verification Report W.L. Gore & Associates, Inc. L3650
Table of Contents
age
Notice i
Foreword ii
Availability of Verification Statement and Report iii
List of Figures v
List of Tables v
List of Abbreviations and Acronyms vi
Acknowledgments viii
1.0 Introduction 1
2.0 Verification Test Description 2
2.1 Description of the Test Rig and Methodology 2
2.2 Selection of Filtration Sample for Testing 4
2.3 Control Tests 4
2.4 Analysis 5
3.0 Description of Filter Fabric 7
4.0 Verification of Performance 8
4.1 Quality Assurance 8
4.2 Results 8
4.3 Limitations and Applications 9
5.0 References 10
IV
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Environmental Technology Verification Report W.L. Gore & Associates, Inc. L3650
List of Figures
aee
Figure 1. Diagram of filtration efficiency media analyzer test apparatus 3
Figure 1. Photograph of W.L. Gore & Associates, Inc. L3650 filtration media 7
List of Tables
Table 1. Summary of Control Test Results 5
Table 2. Summary of Verification Results for W.L. Gore & Associates, Inc. L3650 Filtration Media 9
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Environmental Technology Verification Report
W.L. Gore & Associates, Inc. L3650
List of Abbreviations and Acronyms
APCT Center Air Pollution Control Technology Center
BFP baghouse filtration product
cfm cubic feet per minute
cm centimeters
cm w.g. centimeters of water gauge
dia. diameter
AP pressure drop
dscmh dry standard cubic meters per hour
EPA U.S. Environmental Protection Agency
ETS ETS Incorporated
ETV Environmental Technology Verification
FEMA filtration efficiency media analyzer
fpm feet per minute
g grams
g/dscm grams per dry standard cubic meter
g/m3 grams per cubic meter
G/C gas-to-cloth ratio (filtration velocity)
gr grains
gr/dscf grains per dry standard cubic foot
h hours
in. inches
in. w.g. inches of water gauge
kPa kilopascals
m meters
VI
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Environmental Technology Verification Report W.L. Gore & Associates, Inc. L3650
m/h meters per hour
m3/h cubic meters per hour
mbar millibars
min. minutes
mm millimeters
Mpa megapascals
ms milliseconds
NA not applicable
Pa pascals
PM particulate matter
PM2.5 particulate matter 2.5 micrometers in aerodynamic diameter or smaller
psi pounds per square inch
psia pounds per square inch absolute
QA quality assurance
QC quality control
RTI RTI International
s seconds
scf standard cubic feet
t time
VDI Verein Deutscher Ingenieure
w.g. water gauge
um micrometers
°C degrees Celsius
°F degrees Fahrenheit
vn
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Environmental Technology Verification Report W.L. Gore & Associates, Inc. L3650
Acknowledgments
The authors acknowledge the support of all those who helped plan and conduct the verification activities.
In particular, we would like to thank Michael Kosusko, U.S. Environmental Protection Agency's (EPA's)
Project Officer, and Bob Wright, EPA's Quality Manager, who both work as part of EPA's National Risk
Management Research Laboratory in Research Triangle Park, NC. Finally, we would like to acknowledge
the assistance and participation of W.L. Gore & Associates, Inc. personnel, who supported the test effort.
For more information on W.L. Gore & Associates, Inc.'s L3650, contact the following:
Chris Polizzi
W.L. Gore & Associates, Inc.
101 Lewisville Road
Elkton, MD 21922
(410) 506-3529
cpolizzi@wlRore.com
For more information on verification testing of baghouse filtration products, contact the following:
Jason Hill
RTI International
P.O. Box 12194
Research Triangle Park, NC 27709-2194
(919) 541-7443
APCTVC@rti.org
Vlll
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Environmental Technology Verification Report W.L. Gore & Associates, Inc. L3650
1.0 INTRODUCTION
This report reviews the pressure drop (AP) and filtration performance of W.L. Gore & Associates, Inc.'s
L3650 filtration media. Environmental Technology Verification (ETV) testing of this technology/product
was conducted during a series of tests in November and December 2009 by ETS Incorporated (ETS),
under contract with the Air Pollution Control Technology Center (APCT Center). The objective of the
APCT Center and the ETV Program is to verify, with high data quality, the performance of air pollution
control technologies. Control of fine-particle emissions from various industrial and electric utility sources
employing baghouse control technology is within the scope of the APCT Center. An APCT Center
program area was designed by RTI International (RTI) and a technical panel of experts to evaluate the
performance of particulate filters for fine-particle (i.e., PM25) emission control. Based on the activities of
this technical panel, the Generic Verification Protocol for Baghouse Filtration Products was developed.
This protocol was chosen as the best guide to verify the filtration performance of baghouse filtration
products (BFPs). The specific test/quality assurance (QA) plan for the ETV test of the technology was
developed and approved in May 2000, followed by an approved update in February 2006. The goal of the
test was to measure filtration performance of both PM2.5 and total particulate matter (PM), as well as the
AP characteristics of the W.L. Gore & Associates, Inc. technology identified above.
Section 2 of this report documents the procedures used for the test and the conditions over which the test
was conducted. A description of W.L. Gore & Associates, Inc.'s L3650 filtration media is presented in
Section 3. The results of the test are summarized and discussed in Section 4, and references are presented
in Section 5.
This report contains summary information and data from the test and the verification statement. Complete
documentation of the test results is provided in a separate data package report and an audit of data quality
report. These reports include the raw test data from product testing and supplemental testing, equipment
calibrations results, and QA and quality control (QC) activities and results. Complete documentation of
QA/QC activities and results, raw test data, and equipment calibrations results are retained in ETS's files
for 7 years.
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Environmental Technology Verification Report W.L. Gore & Associates, Inc. L3650
2.0 VERIFICATION TEST DESCRIPTION
The BFPs were tested in accordance with the APCT Center Generic Verification Protocol for Baghouse
Filtration Products1 and the Test/QA Plan for the Verification Testing of Baghouse Filtration Products.2
These documents incorporate all the requirements for quality management, QA, procedures for product
selection, auditing of the test laboratories, and reporting format. The Generic Verification Protocol (GVP)
describes the overall procedures used for verification testing and defines the data quality objectives. The
values for inlet dust concentration, raw gas flow rate, and filtration velocity used for current verification
testing have been revised in consultation with the technical panel since posting of the GVP. These
revisions are documented in Section 4.1. The test/QA plan details how the test laboratory at ETS
implemented and met the requirements of the GVP.
2.1 Description of the Test Rig and Methodology
The tests were conducted in ETS's filtration efficiency media analyzer (FEMA) test apparatus (Figure 1).
The test apparatus consists of a brush-type dust feeder that disperses test dust into a vertical rectangular
duct (raw-gas channel). The dust feed rate is continuously measured and recorded via an electronic scale
located beneath the dust feed mechanism. The scale has a continuous readout with a resolution of 10 g. A
radioactive polonium-210 alpha source is used to neutralize the dust electrically before its entry into the
raw-gas channel. An optical photo sensor monitors the concentration of dust and ensures that the flow is
stable for the entire duration of the test. The optical photo sensor does not measure absolute
concentration, and is, therefore, not the primary concentration measurement for the test. A portion of the
gas flow is extracted from the raw-gas channel through the test filter, which is mounted vertically at the
entrance to a horizontal duct (clean-gas channel). The clean-gas channel flow is separated in two gas
streams, a sample stream and a bypass stream. An aerodynamic "Y" is used for this purpose. The
aerodynamic " Y" is designed for isokinetic separation of the clean gas with 40% of the clean gas entering
the sample-gas channel without change in gas velocity. The sample-gas channel contains an Andersen
impactor for particle separation and measurement. The bypass channel contains an absolute filter. The
flow within the two segments of the "Y" is continuously monitored and maintained at selected rates by
adjustable valves. Two vacuum pumps maintain air flow through the raw-gas and clean-gas channels. The
flow rates, and thus the gas-to-cloth ratio (G/C) through the test filter, are kept constant and measured
using mass flow controllers. A pressure transducer is used to measure the average residual AP of the filter
sample. The pressure transducer measures the differential pressure across the filter samples every 3
seconds; the residual AP measurements are those taken 3 seconds after the cleaning pulse. The AP
measurements are then averaged, as described in Appendix C, Section 4.4.1 of the GVP. High-efficiency
filters are installed upstream of the flow controllers and pumps to prevent contamination or damage
caused by the dust. The cleaning system consists of a compressed-air tank set at 0.5 MPa (75 psi), a
quick-action diaphragm valve, and a blow tube [25.4 mm (1.0 in.) dia.] with a nozzle [3 mm (0.12 in.)
dia.] facing the downstream side of the test filter.
Mean outlet particle concentration is determined when a portion of the gas flow is extracted from the raw-
gas channel through the test filter, which is mounted vertically at the entrance to a horizontal duct (clean-
gas channel). The clean-gas flow is separated using an aerodynamic "Y" so that a representative sample
of the clean gas flows through an Andersen impactor that determines the outlet particle concentration.
Outlet particle concentrations were determined by weighing the mass increase of dust collected in each
impactor filter stage and dividing by the gas volumetric flow through the impactor.
The particle size was measured while a fine dust was injected into the air stream upstream of the filter
fabric sample. The particle size distributions in the air were determined both upstream and downstream
of the test filter fabric to provide accurate results for penetration through the test filter of PM2.5.
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Environmental Technology Verification Report
W.L. Gore & Associates, Inc. L3650
f
DUST FEED FROM EXTERNAL HOPPER
DUST CHARGE NEUTRALIZER
RECTANGULAR CHANNEL
111 x 292 mm (4-3/8x11-1/2")
PHOTOMETER
FILTER FIXTURE AND TEST FILTER
CYLINDRICAL EXTRACTION TUBE
CLEAN-GAS SAMPLE PORT
RAW-GAS SAMPLE PORT
CLEANING SYSTEM
ABSOLUTE FILTER AND
ANDERSENIMPACTOR
BACKUP
FILTER
MASS FLOW
CONTROLLER
MASS FLOW
CONTROLLER
CALIBRATED
ORIFICE
Figure 1. Diagram of filtration efficiency media analyzer test apparatus.
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Environmental Technology Verification Report W.L. Gore & Associates, Inc. L3650
The following series of tests was performed on three separate, randomly selected filter fabric samples:
• Conditioning period
• Recovery period
• Performance test period.
To simulate long-term operation, the test filter was first subjected to a conditioning period, which consists
of 10,000 rapid-pulse cleaning cycles under continuous dust loading. During this period, the time between
cleaning pulses was maintained at 3 seconds. No filter performance parameters are measured in this
period.
The conditioning period is immediately followed by a recovery period, which allowed the test filter fabric
to recover from rapid pulsing. The recovery period consists of 30 normal filtration cycles under
continuous and constant dust loading. During a normal filtration cycle, the dust cake is allowed to form
on the test filter until a differential pressure of 1,000 Pa (4.0 in. w.g.) is reached. At this point, the test
filter is cleaned by a pulse of compressed air from the clean-gas side of the fabric. The next filtration
cycle begins immediately after the cleaning is complete.
Performance testing occurred for a 6-hour period immediately following the recovery period (a
cumulative total of 10,030 filtration cycles after the test filter had been installed in the test apparatus).
During the performance test period, normal filtration cycles are maintained and, as in the case of the
conditioning and recovery periods, the test filter is subjected to continuous and constant dust loading.
The filtration velocity (G/C) and inlet dust concentrations were maintained at 120 ± 6 m/h (6.6 ± 0.3 fpm)
and 18.4 ± 3.6 g/dscm (8.0 ± 1.6 gr/dscf), respectively, throughout all phases of the test.
2.2 Selection of Filtration Sample for Testing
Filter fabric samples of L3650 filtration media were supplied to ETS directly from the manufacturer
(W.L. Gore & Associates, Inc.), with a letter signed by John McMillan, Business Leader, W.L. Gore &
Associates, Inc., attesting that the filter media were selected at random in an unbiased manner from
commercial-grade media and were not treated in any manner different from the media provided to
customers. The manufacturer supplied the test laboratory with nine 46x91 cm (18 x 36 in.) filter
samples. The test laboratory randomly selected three samples and prepared them for testing by cutting one
test specimen of 150 mm (5.9 in.) diameter from each selected sample for insertion in the test rig sample
holder. The sample holder has an opening 140 mm (5.5 in.) in diameter, which is the dimension used to
calculate the face area of the tested specimen.
2.3 Control Tests
Two types of control tests were performed during the verification test series. The first was a dust
characterization, which is performed monthly. The reference dust used during the verification tests was
Pural NF aluminum oxide dust. The Pural NF dust was oven dried for 2 hours and sealed in an airtight
container prior to its insertion into the FEMA apparatus. The criteria for the dust characterization test are
a maximum mass mean diameter of 1.5 ± 1.0 um and a concentration between 40% and 90% of particles
less than 2.5 jm. These criteria must be met in order to continue the verification test series.
The second control test, the reference value test, is performed quarterly using the reference fabric and the
FEMA apparatus. The reference value test determines the weight gain of the reference fabric, as well as
the maximum AP (final residual pressure drop) . The results of the test verified that the FEMA apparatus
was operating consistently within the required parameters. The average fabric maximum AP (average of
the repeated measurements of final residual pressure drop conducted during the quarter applicable to this
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Environmental Technology Verification Report
W.L. Gore & Associates, Inc. L3650
test) in a reference value test must be 0.60 cm w.g. ± 40%, and the fabric weight gain average must be
1.12 g ± 40%. Three reference value control test runs were conducted. The results of the control tests are
summarized in Table 1.
Table 1. Summary of Control Test Results
Mass mean diameter, urn
% Less than 2.5 um
Weight gain, g
Maximum pressure drop, cm w.g.
Requirement
1.5± 1.0
40%-90%
1.1 2 ±40%
0.60 ± 40%
Measured Value
1.28
74.27%
0.76
0.54
Criteria Met
Yes
Yes
Yes
Yes
2.4 Analysis
The equations used for verification analysis are described below.
Af
Cds
C2.5ds
dia.
Fa
Fs
G/C
Mt
M2.5
N
Pavg
Pi
PS
Qa
Qds
Q2.5ds
Qst
t
tc
Ts
Wf
Exposed area of sample filter, m2
Dry standard outlet particulate concentration of total mass, g/dscm
Dry standard outlet particulate concentration of PM2.5, g/dscm
Diameter of exposed area of sample filter, m
Dust feed concentration corrected for actual conditions, g/m3
Dust feed concentration corrected for standard conditions, g/dscm
Gas-to-cloth ratio, m/h
Total mass gain from Andersen impactor, g
Total mass gain of particles equal to or less than 2.5 um diameter from Andersen
impactor, g. This value may need to be linearly interpolated from test data.
Number of filtration cycles in a given performance test period
Average residual AP, cm w.g.
Residual AP for rth filtration cycle, cm w.g.
Absolute gas pressure as measured in the raw-gas channel, mbar
Actual gas flow rate, m3/h
Dry standard gas flow rate, dscmh
Dry standard gas flow rate for 2.5 um particles, dscmh
Standard gas flow rate for a specific averaging time, t, dscmh
Specified averaging time or sampling time, s
Average filtration cycle time, s
Raw-gas channel temperature, °F
Weight of dust in feed hopper following specified time, g. Because of vibrations causing
short-term fluctuations to the feed hopper, this value is measured as a 1-min. average.
Weight of dust in feed hopper at the beginning of the specified time, g. Due to vibrations
causing short-term fluctuations to the feed hopper, this value is measured as a 1-min.
average.
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Environmental Technology Verification Report
W.L. Gore & Associates, Inc. L3650
Conversion factors and standard values used in the equations are listed below.
460 = 0 °F, in °R
1,013 = Standard atmospheric pressure, mbar
528 = Standard temperature, °R
Area of Sample Fabric, Af
Af =
Actual Gas Flow Rate, Qa
"(?;+460)* 1013
Qa=Q**
Gas-to-Cloth Ratio, G/C
P * 528
C~Af
Standard Dust Feed Concentration, Fs, for a specified time, t
_
~
Actual Raw Gas Dust Concentration, Fa
F -F Jfc±460)*1013~
s [ Ps*528
Dry Standard Clean Gas Particulate Concentration, Total Mass, Cds
M.
L %H20
Q *t*\\ —
Vds I
Dry Standard Clean Gas Particulate Concentration, PM2.5, C2.5ds
C
- 2.5
2.5 ds
100
Filtration Cycle Time, tc
Average Residual Pressure Drop, Pavg
p -^
** N
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Environmental Technology Verification Report
W.L. Gore & Associates, Inc. L3650
3.0 DESCRIPTION OF FILTER FABRIC
The W.L. Gore & Associates, Inc. L3650 is a membrane / fiberglass fabric laminate with a weight of 22
oz/yd2 (746 g/m2) and used in both GORE® Filtration Products and PRISTYNE® Filter Media Type 6250.
Figure 2 is a photograph of the fabric. Sample material was received as nine 46 x 91 cm (18 x 36 in.)
swatches marked with the manufacturer's model number, year and month of manufacture, and cake side.
Three of the swatches were selected at random for preparing three test specimens 150 mm (5.9 in.) in
diameter.
W.L Gore
PC# L3650
Gore™ Membrane Fiberglass
Figure 2. Photograph of W.L. Gore & Associates, Inc.'s L3650 filtration media.
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Environmental Technology Verification Report W.L. Gore & Associates, Inc. L3650
4.0 VERIFICATION OF PERFORMANCE
4.1 Quality Assurance
The verification tests were conducted in accordance with an approved test/QA plan.2 The EPA quality
manager conducted an independent assessment of the test laboratory in June 2005 and found that the test
laboratory was equipped and operated as specified in the test/QA plan.
The ETS QA officer and the APCT Center's QA staff have reviewed the results of this test and have
found that the results meet the overall data quality objectives as stated in the test/QA plan. It should be
noted that, because of the highly efficient nature of the filter medium being tested, the impactor substrate
weighings for these results were below the reproducibility of the balance. The relative percent error in the
post-filter weighing measurements cannot be computed because most of the values were near zero. As a
result of this occurrence, the tests do not meet the data quality objectives (DQOs) stated in the test/QA
plan for mass gain associated with outlet concentrations. However, as stated in the test protocol, "for
highly efficient fabrics, the mass gains stated for these quality objectives may not be achieved in the
specified test duration. For these tests it is acceptable for the indicated DQO not to be met."
Data on calibration certificates for the flow meters, flow transducers, weights, low- and high-resolution
balances, thermometer, and humidity logger are maintained at ETS in a separate data package.
Deviations from the test plan include organizational personnel changes.
The ETS QA officer and the APCT Center's QA staff have also reviewed the results of the control tests,
which are summarized in Section 2.3, Table 1. The dust characterization control test met the appropriate
requirements of the test/QA plan and verification protocol. The reference fabric tests met maximum AP
and weight gain requirements established for reference fabric performance in the GVP, indicating the
measurement system is operating in control.
4.2 Results
Table 2 summarizes the mean outlet particle concentration measurements for the verification test periods.
Measurements were conducted during the 6-hour performance test period. The performance test period
followed a 10,000-cycle conditioning period and a 30-cycle recovery period.
Table 2 summarizes the three verification tests that were performed under standard verification test
conditions. The average residual AP across each filter sample at the nominal 120 m/h (6.6 fpm) filtration
velocity [for a flow rate of 5.8 m3/h (3.4 cfm)] is also shown in Table 2. This AP ranged from 2.58 to 2.79
cm w.g. (1.02 to 1.10 in. w.g.) for the three filter samples tested. The residual AP increase ranged from
0.18 to 0.25 cm w.g. (0.07 to 0.10 in. w.g.) for the samples tested. All three standard condition
verification runs were used to compute the averages given in Table 2. The PM25 outlet particle
concentration average for the three runs is <0.0000167 g/dscm. The total PM concentration average for
the three runs is <0.0000167 g/dscm.
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Environmental Technology Verification Report
W.L. Gore & Associates, Inc. L3650
Table 2. Summary of Verification Results for W.L. Gore & Associates, Inc.'s L3650 Filtration Media
Test Run Number
PM2.5 (g/dscm)b
Total PM (g/dscm)
Average residual A P (cm w.g.)
Initial residual A P (cm w.g.)
Residual A P increase (cm w.g.)
Mass gain of sample filter (g)
Average filtration cycle time (s)
Number of cleaning cycles
4V11-R1
<0. 0000167°
<0. 0000167°
2.79
2.69
0.19
0.06
168
128
4V11-R2
<0. 0000167
<0. 0000167
2.58
2.48
0.18
0.09
205
105
4V11-R3
<0. 0000167
<0. 0000167
2.79
2.75
0.25
0.10
168
128
Average3
<0. 00001 67
<0. 00001 67
2.72
2.64
0.21
0.08
180
120
a All three verification runs were used to compute averages.
b One or more of the impactor substrate weight changes for these results was near the reproducibility limit of the
balance.
c The measured value was determined to be below the detection limit of 0.0000167 grams per cubic meter. The
detection limit is for a six-hour test and based on VDI 3926.
4.3 Limitations and Applications
This verification report addresses two aspects of BFP performance: outlet particle concentration and AP.
Users may wish to consider other performance parameters, such as service life and cost, when selecting a
baghouse filtration fabric for their application.
In accordance with the GVP, this verification statement is applicable to BFPs manufactured between the
signature date of the verification statement and three years thereafter.
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Environmental Technology Verification Report W.L. Gore & Associates, Inc. L3650
5.0 REFERENCES
1. RTI International. 2001. Generic Verification Protocol for Baghouse Filtration Products, RTI
International, Research Triangle Park, NC, February. Available at
http://www.epa.gov/etv/pubs/05 vp bfp.pdf.
2. ETS Incorporated and RTI International. 2006. Test/QA Plan for the Verification Testing of
Baghouse Filtration Products (Revision 2), ETS Incorporated, Roanoke, VA, and RTI
International, Research Triangle Park, NC, February. Available at
http://www.epa.gov/etv/pubs/600etv06095.pdf.
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