SIST EN ISO 16891:2016
(Main)Test methods for evaluating degradation of characteristics of cleanable filter media (ISO 16891:2016)
Test methods for evaluating degradation of characteristics of cleanable filter media (ISO 16891:2016)
This standard describes test methods useful to assess the relative change of properties of cleanable filter media for industrial applications by measuring the change of property of the media due to the exposure to hot and/or corrosive gases.
Prüfmethode zur Ermittlung der Abnahme der Wirksamkeit von abreinigbaren Filtermedien (ISO 16891:2016)
Diese Internationale Norm legt ein Bezugsprüfverfahren zur Bewertung der relativen Verschlechterung von Eigenschaften abreinigbarer Filtermedien zur industriellen Anwendung unter genormten, simulierten Prüfbedingungen fest. Der Hauptzweck der Prüfung besteht im Erlangen von Informationen zu Eigenschaften von Filtermedien, die dadurch, dass sie simulierten Gasbedingungen über einen längeren Zeitraum ausgesetzt sind, eine relative Änderung erfahren. Das Hauptaugenmerk dieser Internationalen Norm liegt auf der Eigenschaftsänderung von Filtern aus Vliesstoff, da diese häufig unter Bedingungen verwendet werden, die den in dieser Internationalen Norm beschriebenen Prüfgasbedingungen ähneln.
Die durch dieses Prüfverfahren erlangten Ergebnisse sind nicht dafür vorgesehen, die vollständigen Eigen-schaften kompletter Filteranlagen vorherzusagen. Dennoch unterstützen sie die Konstruktion von Taschenfiltern, die Auswahl und Entwicklung geeigneter abreinigbarer Filtermedien und die Identifizierung zweckmäßiger Betriebsparameter.
Méthodes d'essais pour l'évaluation de la dégradation des propriétés des medias filtrants décolmatables (ISO 16891:2016)
L'ISO 16891:2015 spécifie une méthode d'essai de référence standard utile pour évaluer les caractéristiques de dégradation relative des medias filtrants décolmatables pour des applications industrielles, dans un contexte simulant des conditions d'essai normalisées. L'objectif principal des essais est d'obtenir des informations sur l'évolution relative des propriétés des medias filtrants, suite à leur exposition prolongée à des gaz dans des conditions simulées. L'objectif principal de l'ISO 16891:2015 concerne les modifications des propriétés des filtres en textile non tissé, car ils sont fréquemment utilisés dans des circonstances similaires aux conditions d'utilisation des gaz d'essai décrites dans la présente Norme internationale.
Les résultats obtenus par cette méthode d'essai ne sont pas destinés à prédire les propriétés absolues d'installations de filtrage grande échelle. Toutefois, ils sont utiles pour la conception d'un filtre à poches ainsi que pour la sélection et le développement de medias filtrants décolmatables appropriés, et pour l'identification de paramètres d'exploitation appropriés.
Preskusne metode za ugotavljanje poslabšanja lastnosti filtrirnih sredstev, ki se lahko čistijo (ISO 16891:2016)
Ta standard opisuje preskusne metode za ugotavljanje relativne spremembe lastnosti čistilnih filtrirnih sredstev za industrijsko uporabo z merjenjem spremembe lastnosti sredstev zaradi izpostavljenosti vročini in/ali jedkim plinom.
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 16891:2016
01-april-2016
3UHVNXVQHPHWRGH]DXJRWDYOMDQMHSRVODEãDQMDODVWQRVWLILOWULUQLKVUHGVWHYNLVH
ODKNRþLVWLMR ,62
Test methods for evaluating degradation of characteristics of cleanable filter media (ISO
16891:2016)
Prüfmethode zur Ermittlung der Abnahme der Wirksamkeit von abreinigbaren
Filtermedien (ISO 16891:2016)
Méthodes d'essais pour l'évaluation de la dégradation des propriétés des medias filtrants
décolmatables (ISO 16891:2016)
Ta slovenski standard je istoveten z: EN ISO 16891:2016
ICS:
91.140.30 3UH]UDþHYDOQLLQNOLPDWVNL Ventilation and air-
VLVWHPL conditioning
SIST EN ISO 16891:2016 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO 16891:2016
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SIST EN ISO 16891:2016
EN ISO 16891
EUROPEAN STANDARD
NORME EUROPÉENNE
February 2016
EUROPÄISCHE NORM
ICS 91.140.30
English Version
Test methods for evaluating degradation of characteristics
of cleanable filter media (ISO 16891:2016)
Méthodes d'essais pour l'évaluation de la dégradation Prüfmethode zur Ermittlung der Abnahme der
des propriétés des medias filtrants décolmatables (ISO Wirksamkeit von abreinigbaren Filtermedien (ISO
16891:2016) 16891:2016)
This European Standard was approved by CEN on 7 November 2015.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2016 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 16891:2016 E
worldwide for CEN national Members.
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SIST EN ISO 16891:2016
EN ISO 16891:2016 (E)
Contents Page
European foreword . 3
2
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SIST EN ISO 16891:2016
EN ISO 16891:2016 (E)
European foreword
This document (EN ISO 16891:2016) has been prepared by Technical Committee ISO/TC 142 "Cleaning
equipment for air and other gases" in collaboration with Technical Committee CEN/TC 195 “Air filters
for general air cleaning” the secretariat of which is held by UNI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by August 2016, and conflicting national standards shall
be withdrawn at the latest by August 2016.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent
rights.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands,
Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 16891:2016 has been approved by CEN as EN ISO 16891:2016 without any modification.
3
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SIST EN ISO 16891:2016
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SIST EN ISO 16891:2016
INTERNATIONAL ISO
STANDARD 16891
First edition
2016-01-15
Test methods for evaluating
degradation of characteristics of
cleanable filter media
Méthodes d’essais pour l’évaluation de la dégradation des propriétés
des medias filtrants décolmatables
Reference number
ISO 16891:2016(E)
©
ISO 2016
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SIST EN ISO 16891:2016
ISO 16891:2016(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2016, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
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copyright@iso.org
www.iso.org
ii © ISO 2016 – All rights reserved
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SIST EN ISO 16891:2016
ISO 16891:2016(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms . 4
5 Principle . 5
6 Test specimen, equipment and test procedure . 6
6.1 General . 6
6.2 Preparation of sheets for gas exposure. 7
6.2.1 Shape and size of tensile specimen . 7
6.2.2 Sample sheet for exposure . 7
6.2.3 Selection of sample sheet through air permeability measurement . 8
6.2.4 Filter media for exposure . 8
6.3 Sample preparation . 9
6.3.1 Exposure system . 9
6.3.2 Heating system .11
6.3.3 Test gas supply system.11
6.3.4 Gas analyzer .11
6.3.5 Gas treatment device .12
6.4 Exposure conditions and procedures .12
6.4.1 Exposure conditions .12
6.4.2 Exposure period and number of exposure .12
6.4.3 Attachment of filter sample sheets in the sample case .13
6.4.4 Implementation of the exposure .13
7 Tensile strength measurement of exposed specimen .14
7.1 Tensile test device .14
7.2 Preparation of a tensile test specimen .14
7.3 Method of tensile test .14
7.4 Characterization of the degradation.15
8 Test report .16
Annex A (informative) Causes and results of degradation of fabrics.17
Annex B (informative) Possible evaluation method for characteristic change of fabrics .18
Annex C (informative) Theoretical consideration of degradation mechanism .19
Annex D (informative) Determination of specimen size .22
Annex E (informative) Experimental setup for gas exposure.26
Annex F (informative) Service temperature of filter materials .30
Annex G (informative) Examples of measured data of fabric at different circumstances .31
Annex H (informative) Example of test report .37
Bibliography .41
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SIST EN ISO 16891:2016
ISO 16891:2016(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 142, Cleaning equipment for air and other gases.
iv © ISO 2016 – All rights reserved
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SIST EN ISO 16891:2016
ISO 16891:2016(E)
Introduction
The main purpose of using cleanable filter is, of course, to separate dust particles from dirty gases.
They are usually designed to be usable for as long as two years to four years. However, it is very
hard to design and/or select filter media properly, since their important characteristics of collection
performance and residual pressure drop change with operation time. Physical and chemical properties
of filter media, such as degradation in tensile strength, tenacity and so on, also change with time. Those
changes can damage filter media and this can result in the breakage of bag filters and leakage of dust to
the atmosphere. Hence the evaluation of these performances is also important for the rational design
and the selection of appropriate filter media. ISO 11057:2011 has been published to meet the demand
for the evaluation of filtration characteristics.
Changes in physical and chemical properties of filter media are caused by many factors, such as heat,
corrosive gases, and mechanical reasons like clogging weave openings and increasing size of weave
openings, the combination of those factors and so on (see Annex A). These changes are mostly adverse
effects to filter media. Degradation proceeds very slowly, and thus, it takes a long time before recognizable
and/or measurable change appears. Furthermore, the appearance of change depends on the combination
of causes and fibre material. These facts are the main reason why mechanism of property changes has not
.[1]-[13]
been well understood despite its practical importance Hence, the characterization or evaluation
[14][15]
methods for filter media have not been established yet (see Annex B).
Nevertheless, there are demands for the establishment of a guideline for systematic characterization
and evaluation of property change of filter media with respect to their relevant long-time operation
not only from manufacturers of filter media, but also from producers and users of filter installations,
especially the users treating combustion exhaust gases.
To evaluate degradation of filter media in a laboratory, it is important that experiment can be done
in a relatively short time period by using controllable single or a small number of variables, i.e.
causes of change.
Furthermore, it is important that the resulting effects are measureable. From this point of view, heat
intensity is controllable by changing heating temperature and the intensity of corrosive gas is also
controllable by changing gas concentration. Thus, their effect is expected to be accelerated. Of course,
the effects can be evaluated by the degradation of tensile stress.
Evaluation of property change of filter media by corrosive gases can be done by contacting filter media
with those corrosive materials in any phases, i.e. gas, liquid and solid state. Testing by dipping filter
media into a solution of corrosive materials is easy and the resulting effects are expected to be obtained
[16]
in a short period of time. Chinese Standard, GB/T 6719:2009 adopts this method. Solid state testing
can be carried out by hard contact of filter media but it will take a long time and it is very hard to
control the intensity of corrosiveness.
Testing under the gaseous state takes much longer than a liquid type test but the intensity of
corrosiveness is controllable and it is much easier than the test under the solid state. Furthermore, test
temperature and gas conditions except corrosive gas concentrations, are similar to the actual operation
condition of filtration, which is suitable (see Annex B). Hence, in this International Standard, test
methods for evaluating degradation characteristics of cleanable unwoven filter media with synthetic
fibre by heat and corrosive gases are standardized because they are most widely used for bag filtration.
The major objective of this International Standard is to specify the testing method to assess the relative
change of physical performances of new and used cleanable filter media for industrial application, by
[17][18]
exposing it in hot and/or corrosive gas conditions .
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SIST EN ISO 16891:2016
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SIST EN ISO 16891:2016
INTERNATIONAL STANDARD ISO 16891:2016(E)
Test methods for evaluating degradation of characteristics
of cleanable filter media
1 Scope
This International Standard specifies a standard reference test method useful to assess the relative
degradation characteristics of cleanable filter media for industrial applications under standardized
simulated test conditions. The main purpose of testing is to obtain the information about relative
change of properties of filter media due to exposure to the simulated gas conditions for a long time. The
main target of this International Standard is the property change of nonwoven fabric filters because
they are frequently used under similar circumstances to the test gas conditions described in this
International Standard.
The results obtained from this test method are not intended for predicting the absolute properties of full
scale filter facilities. However, they are helpful for the design of a bag filter and selection and development
of appropriate cleanable filter media, and for the identification of suitable operating parameters.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for the application of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 4606, Textile glass — Woven fabrics — Determination of tensile breaking force and elongation at
breaking by strip method
ISO 13934-1, Textiles — Tensile properties of fabrics — Part 1: Determination of maximum force and
1)
elongation at maximum force using the strip method
ISO 29464:2011,Cleaning equipment for air and other gases — Terminology
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 29464:2011 and the
following apply.
3.1
aged filter sheet
filter sheet exposed under simulated hot and corrosive gas conditions for a preset period of time to
evaluate the change of filter properties
3.2
air permeability
gas volume flow rate per unit filtration area at pressure drop of 124,5 Pa
3.3
average gas concentration
mean concentration of test gases during the exposure
1) This International Standard replaced ISO 5081, Textiles — Woven fabrics — Determination of breaking strength
and elongation (Strip method).
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SIST EN ISO 16891:2016
ISO 16891:2016(E)
3.4
batch type exposure chamber
chamber in which filter sheets are exposed to stationary test gas mixture
3.5
chemical degradation
degradation of chemical properties of filter media by the interaction with test gases
3.6
cleanable filter
filter designed to enable the removal of collected dust by appropriate technique
[SOURCE: ISO 29464:2011; 3.1.77]
3.7
continuous-flow-method
exposing method of filter sheet, which is exposed in a continuous flow of test gas mixture
3.8
corrosive gas
chemicals which react with filter media and change its chemical and physical properties
3.9
degradation
change in physical and chemical performances of filter media by the interaction with corrosive gases
3.10
elongation
incremental change in length of test specimen by tensile test
3.11
elongation at maximum load
incremental change in length of test specimen at maximum load in tensile test
3.12
elongation ratio
ratio of elongation of test specimen to its initial length between holders or its percentage
3.13
elongation ratio at maximum load
ratio of elongation of test specimen at maximum load in tensile test to its initial length between holders
3.14
exposure chamber
chamber to expose test filter sheet to corrosive gases
3.15
filter media
material separating particulate matter from gases and characterized by its separating structure and its
structural and/or textile-technological characteristics
3.16
flow-through type replacement
method to replace test gas in the batch type exposure chamber by introducing test gas continuously
to the chamber
3.17
initial load
initial load applied on the test specimen at the start of tensile test
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SIST EN ISO 16891:2016
ISO 16891:2016(E)
3.18
length between holders
length between holders of top and bottom holding chucks positioned at the start of the tensile test
Note 1 to entry: See Figure 3.
3.19
load
tensile strength of test specimen observed in the tensile test
3.20
non-continuous-flow-method
exposing method of filter sheet, which is exposed in still test gas mixture
3.21
nonwoven fabric
filter media using fabric made from long fibres, bonded together with each other by chemical,
mechanical, heat or solvent treatment
3.22
number of replacement
number of test gas replacement for whole heating space volume of the test chamber
3.23
replacement of gas
exchange gas to maintain test gas concentration within certain concentration range
3.24
retention of tensile strength
ratio of tensile strength of the test specimen subjected to thermal and/or acid gas exposure to that of
the test specimen without the exposure
3.25
strip method
method of implementing tensile test with holding whole width of the test specimen with a holding device
3.26
tensile speed
speed to pull a test specimen in tensile test
3.27
tensile strength
value of the maximum load divided by the width of test specimen
3.28
test gas
gas which may cause changes in physical propertied of filter media to be used for tensile test
3.29
vacuum replacement
method to replace test gas in the batch type exposure chamber by the use of vacuum
3.30
thermal exposure
expose filter media at an elevated temperature to accelerate the change of its physical properties
3.31
woven fabric
filter media using a fabric formed by weaving
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SIST EN ISO 16891:2016
ISO 16891:2016(E)
4 Symbols and abbreviated terms
2
A total surface area in a filter media (m )
APA nonwoven fabric with Aromatic Polyamide fibres
−3
C gas concentration (mg•m )
−1
F(A) constant related to total surface area of filter media (N•mm )
Glass fabric with Glass fibres
−1
K effective reaction constant (s )
3 −1 −1
k reaction constant (m •mg •s )
L length of specimen (mm)
1
L length between holders (mm)
2
L length of holder (mm)
3
MD machine direction
P load (N)
P maximum load (N)
max
p pressure (Pa)
PI nonwoven fabric with Polyimide
PPS nonwoven fabric with Polyphenylene Sulfide
PTFE nonwoven fabric with Polytetrafluoroethylene
−1
Q flow rate of test gas (l•min )
3 −1 −2
q air permeability of filter [(cm •s ) •cm ]
−1
S tensile speed (mm•min )
T temperature (°C)
TD transverse direction
t exposure time (s),(h)
V volume of the exposure chamber (l)
w width of holder (mm)
δ elongation (mm)
δ elongation at maximum load (mm)
max
ε elongation ratio (%)
ε maximum elongation ratio (%)
max
−1
τ tensile strength (N•mm )
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SIST EN ISO 16891:2016
ISO 16891:2016(E)
−1
τ tensile strength of the filter media without exposure (N•mm )
0
−1
Δτ tensile strength difference between after and before (N•mm )
exposure
5 Principle
Physical performance of filter media mostly degrades with time because of long time exposure under
severe gas conditions, such as hot and/or corrosive gas conditions. When filter media is exposed to hot
and/or corrosive gas atmospheres such as NOx, SOx, HCl and moisture etc., those gases are considered to
interact with materials in fibres and thus affect crystallinity and/or other bonding of molecules in fibres,
i.e., they decompose fibre in the media to some extent. Hence, these conditions result in irreversible
damage to media and weaken physical performances like tensile strength, elongation and so on.
Details of the above mentioned process have not been understood well yet, but tensile strength after
filter media is exposed to corrosive gases and/or high temperature is expressible by the following
formula with the assumption that degradation reaction between corrosive gas and some reactive
component in a fibre is pseudo linear.
ττ0=− tFΔτ =1AK−exp − t (1)
() () () ()
where
Τ(t) tensile strength of filter media;
F(A) unknown constant related to total surface area of filter media;
K effective reaction constant and is related to the degradation of media.
The first derivative of Formula (1) becomes,
dΔττd
=- =eKF AKxp − t (2)
() ()
dt dt
Similar formula can be obtained applying Hooke’s law between tensile strength and elongation as:
dΔδ
∝KF AKexp − t (3)
() ()
dt
Formula (2) and Formula (3) suggest that a straight line is obtained when the logarithm of first
derivative of tensile strength of filter media and elongation is plotted against exposure time t in a semi-
log paper, as shown in Figure 1. The slope of the line in Figure 1 gives K [see the details of the derivation
of Formula (2) and Formula (3) in Annex C].
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SIST EN ISO 16891:2016
ISO 16891:2016(E)
Key
t exposure time (h)
y lg(-dτ/dt)
Figure 1 — Relation between gradient of tensile strength of filter media and exposure time to
corrosive gas
The degradation process is usually very slow, and thus, measurable changes in the physical properties
(like tensile strength and elongation) usually appear after filter media has been exposed for a very long
time period. Hence, it shall be accelerated by some means to evaluate the effect through an experiment.
In this International Standard, degradation is accelerated by exposing filter media to a higher corrosive
gas concentration and higher gas temperature.
6 Test specimen, equipment and test procedure
6.1 General
The test specimen, equipment and procedure at each step shall be chosen so as to ensure good
reproducibility and repeatability of the test. The equipment to prepare the samples for the measurement
generally consists of the following main components: gas supply system; exposure chamber and
heating system; exhaust gas treatment unit; vacuum pump; and gas analysing system. Figure 2 shows a
schematic diagram
...
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