Road vehicles -- Aerosol separator performance test for internal combustion engines

ISO 17536-1:2015 specifies general conditions, defines terms and establishes the basic principles for blowby oil aerosol separator performance tests by laboratory or engine and gravimetric or fractional test method.

Véhicules routiers -- Essai de performance du séparateur d'aérosols pour les moteurs à combustion interne

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Status
Published
Publication Date
18-Nov-2015
Current Stage
9092 - International Standard to be revised
Start Date
30-May-2021
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INTERNATIONAL ISO
STANDARD 17536-1
First edition
2015-12-01
Road vehicles — Aerosol separator
performance test for internal
combustion engines —
Part 1:
General
Véhicules routiers — Essai de performance du séparateur d’aérosols
pour les moteurs à combustion interne —
Partie 1: Généralités
Reference number
ISO 17536-1:2015(E)
ISO 2015
---------------------- Page: 1 ----------------------
ISO 17536-1:2015(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2015, Published in Switzerland

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form

or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior

written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of

the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2015 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 17536-1:2015(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Terms, definitions, symbols and units ........................................................................................................................................... 1

2.1 Terms and definitions ....................................................................................................................................................................... 1

2.2 Symbols and units ................................................................................................................................................................................ 4

3 Measurement equipment accuracy ................................................................................................................................................... 4

4 Absolute filter, wall flow trap and leakage ................................................................................................................................ 5

4.1 Absolute filter........................................................................................................................................................................................... 5

4.1.1 Absolute filter material .............................................................................................................................................. 5

4.1.2 Absolute filter mass measurement method ............................................................................................. 5

4.1.3 Absolute media measurement process validation .............................................................................. 5

4.2 Wall flow trap ........................................................................................................................................................................................... 5

4.2.1 Weight measurement ................................................................................................................................................... 5

4.2.2 Validation of wall flow trap liquid oil efficiency ................................................................................... 5

4.2.3 Validation of wall flow trap aerosol efficiency ....................................................................................... 6

4.3 Leakage .......................................................................................................................................................................................................... 6

5 Principles for aerosol separator performance tests ....................................................................................................... 6

5.1 General ........................................................................................................................................................................................................... 6

5.2 Test equipment ....................................................................................................................................................................................... 6

5.2.1 Grounding .............................................................................................................................................................................. 6

5.2.2 Upstream sample probe ............................................................................................................................................ 7

5.2.3 Upstream particle counter ...................................................................................................................................... 7

5.2.4 Particle counter calibration .................................................................................................................................... 7

5.2.5 Maximum particle concentration ...................................................................................................................... 7

5.2.6 Particle counter flow .................................................................................................................................................... 8

5.3 Determination of gravimetric separation efficiency .............................................................................................. 8

5.3.1 General...................................................................................................................................................................................... 8

5.3.2 Calculations .......................................................................................................................................................................... 8

Annex A (normative) Explanation of differential pressure and pressure loss of an

aerosol separator ..............................................................................................................................................................................................10

Annex B (normative) Test equipment ..............................................................................................................................................................11

Annex C (informative) Aerodynamic diameter .......................................................................................................................................13

Annex D (informative) Isokinetic sampling probes and information .............................................................................15

Annex E (informative) Life reference ................................................................................................................................................................18

Annex F (normative) Validation of the absolute filter media ..................................................................................................19

Annex G (normative) Leakage ..................................................................................................................................................................................20

Annex H (informative) Determination of maximum efficiency aerosol concentration ................................21

Annex I (informative) Test equipment — Wall flow trap design ..........................................................................................22

Bibliography .............................................................................................................................................................................................................................23

© ISO 2015 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO 17536-1:2015(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 Technical Committee ISO/TC 22, Road vehicles,

Subcommittee SC 34, Propulsion, powertrain and powertrain fluids.

ISO 17536 consists of the following parts, under the general title Road vehicles — Aerosol separator

performance test for internal combustion engines:
— Part 1: General
— Part 3: Method to perform engine gravimetric test [Technical Specification]
The following parts are under preparation:
— Part 2: Laboratory gravimetric test method [Technical Specification]
— Part 4: Laboratory fractional test method
— Part 5: Method to perform engine fractional test [Technical Specification]
iv © ISO 2015 – All rights reserved
---------------------- Page: 4 ----------------------
ISO 17536-1:2015(E)
Introduction

Engine crankcase blowby is composed of combustion exhaust gases which have escaped to the

crankcase via piston ring seals and lube oil aerosols generated by thermal and mechanical action within

the engine. These gases need to be vented from the crankcase to prevent a build-up of high pressure.

The constituents of vented engine blowby gases are recognized as an undesirable contaminant and

technology for their containment is therefore evolving.

The device used to separate oil aerosols from the blowby typically releases cleaned gases to atmosphere

or alternatively returns the cleaned product to the combustion process by feeding into the engine air

intake prior to the turbo compressor (if present). The latter has led to the requirement for a pressure

control device to isolate the engine crankcase from air intake pressure.

The engine test methods presented in ISO 17536 are general guidelines for performing an engine test.

Annexes A to I specify general and common provisions for aerosol separator performance test.

© ISO 2015 – All rights reserved v
---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 17536-1:2015(E)
Road vehicles — Aerosol separator performance test for
internal combustion engines —
Part 1:
General
1 Scope

This part of ISO 17536 specifies general conditions, defines terms and establishes the basic principles

for blowby oil aerosol separator performance tests by laboratory or engine and gravimetric or

fractional test method.
2 Terms, definitions, symbols and units
2.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1.1
blowby
aerosol produced from engines and released through a crankcase vent
2.1.2
oil carryover
total amount of liquid oil captured in the downstream wall flow trap
2.1.3
filter element

replaceable part of the crankcase system, consisting of the filter material and carrying frame

2.1.4
crankcase ventilation system

device which separates oil and particles from the engine blowby before venting to either the engine

(closed crankcase ventilation, CCV) or the environment (open crankcase ventilation, OCV)

2.1.5
differential pressure

difference in static pressure measured immediately upstream and downstream of the unit under test

2.1.6
pressure loss

measure of the loss of aerodynamic energy caused by an aerosol separator at the observed air flow rate

due to different flow velocities at the measuring point.

Note 1 to entry: It is expressed as the differential pressure corrected for any difference in the dynamic head at

the measuring points
Note 2 to entry: For further information, see Annex A.
2.1.7
wall flow trap
device to capture oil that is flowing along the walls
Note 1 to entry: The wall flow trap design is drawn in Figure I.2.
© ISO 2015 – All rights reserved 1
---------------------- Page: 6 ----------------------
ISO 17536-1:2015(E)
2.1.8
absolute filter

filter downstream of the unit under test to retain the contaminant passed by the unit under test

2.1.9
piezometer tube
duct that has a hole or holes drilled in the wall to obtain a pressure reading
Note 1 to entry: For further information, see Figure B.2.
2.1.10
separator efficiency

ability of the aerosol separator or the unit under test to remove contaminant under specified test

conditions
2.1.11
optical diameter
optical equivalent diameter
o,i

diameter of a particle of the type used to calibrate an optical sizing instrument that scatters the same

amount of light as the particle being measured

Note 1 to entry: Optical diameter depends on the instrument, the type of particle used to calibrate the instrument

(usually polystyrene latex spheres), and the optical properties of the particle being measured.

2.1.12
aerodynamic diameter
aerodynamic equivalent diameter

diameter of a sphere of density 1 g/cm with the same terminal velocity due to gravitational force in

calm air, as the particle being measured

Note 1 to entry: Annex C provides additional information about aerodynamic diameter.

Note 2 to entry: Aerodynamic diameter depends on the instrument, the type of particle used to calibrate the

instrument (usually polystyrene latex spheres), and the properties of the particle being measured.

2.1.13
pressure regulator

device between the outlet of the aerosol separator and air intake to regulate the crankcase pressure in

high vacuum conditions
2.1.14
mass oil flow
mass amount of oil per unit time
2.1.15
relief valve

device to direct a portion of the flow around a separation device due to a pressure difference, usually

venting to the atmosphere
2.1.16
bypass valve

device to direct a portion of the flow around a separation device due to pressure difference, usually

venting downstream of the bypassed separation device
2.1.17
challenge aerosol

output from the aerosol generator or engine which corresponds to the distribution in testing and with

the amount of the mass feed rate

Note 1 to entry: The aerosol distribution by mass is prescribed in ISO/TS 17536-2.

2 © ISO 2015 – All rights reserved
---------------------- Page: 7 ----------------------
ISO 17536-1:2015(E)
2.1.18
particle size
polystyrene latex equivalent size expressed as a diameter in micrometers
2.1.19
isokinetic sampling

sampling in which the flow in the sampler inlet is moving at the same velocity and direction as the flow

being sampled

Note 1 to entry: Annex D provides additional information about isokinetic sampling.

2.1.20
particle counter
instrument for sizing and/or counting aerosol particles

Note 1 to entry: Recommended particle counters are optical particle counters (in accordance with ISO 21501-1) or

other counters demonstrating good correlation in measuring particle sizes such as aerodynamic particle counters.

2.1.21
coefficient of variation
COV
standard deviation of a group of measurements divided by the mean
2.1.22
unit under test
UUT

either a single aerosol separator element or a complete crankcase ventilation system

2.1.23
open crankcase ventilation
OCV

aerosol separator system that is attached to the crankcase and is vented to the environment

2.1.24
closed crankcase ventilation
CCV
aerosol separator system that is attached between the crankcase and the engine
2.1.25
aerosol separator
device that separates oil from the blowby stream or test stand airstream
2.1.26
high efficiency particulate air filter
HEPA filter

filter having 99,95 % efficiency at most penetrating particle size (class H13 in accordance with EN 1822),

or 99,97 % (or higher) fractional efficiency at 0,3 μm using dispersed oil particulate (DOP) aerosol as

defined by IEST RP-CC001 recommended practice
2.1.27
inertial separator
device that separates oil from the blowby stream using inertia
2.1.28
combination separator

device that separates oil from the blowby stream using inertia as well as a filter element

2.1.29
rated air flow
flow rate specified by the user or manufacturer
Note 1 to entry: The rated air flow is usually used as the test air flow.
© ISO 2015 – All rights reserved 3
---------------------- Page: 8 ----------------------
ISO 17536-1:2015(E)
2.1.30
test air flow

measure of the quantity of air pushed or drawn through the aerosol separator per unit time

2.1.31
aerosol generator

laboratory equipment that can produce a simulated blowby particle distribution from oil and

compressed air

Note 1 to entry: The aerosol distribution by mass is prescribed in ISO/TS 17536-2.

2.1.32
drainage vessel

device that captures the separated oil from the crankcase separation system, not to include oil carryover

Note 1 to entry: Filter life is not used in all parts of ISO 17536. Life reference is given in Annex E.

2.1.33
mass feed rate

mass amount of challenge aerosol or liquid subjected to the unit under test per unit time

Note 1 to entry: Filter life is not used in all parts of ISO 17536. Life reference is given in Annex E.

2.2 Symbols and units
Quantity Symbol Unit
Volume flow rate q l/min
Velocity v m/s
Density ρ kg/m
Mass flow rate q g/h
Pressure p Pa
Differential pressure Δp Pa
Pressure loss Δp Pa
Mass m g
Time t s
Speed N rev/min
Torque T N-m
3 Measurement equipment accuracy
Air flow rate to within ± 5 % of reading.
Differential pressure to within ± 25 Pa of reading.
Temperature to within ± 1,5 °C of reading.

Mass to within 0,1 g except for absolute filter mass and downstream wall flow trap.

Mass to within 0,01 g for absolute filter mass and downstream wall flow trap.
Relative humidity (RH) with an accuracy of ± 2 % RH.
Barometric pressure to within ± 3 hPa.
Crankcase pressure to within ± 25 Pa of reading
4 © ISO 2015 – All rights reserved
---------------------- Page: 9 ----------------------
ISO 17536-1:2015(E)
RPM to within ± 0,5 % of maximum engine speed
Torque within ± 2 % of operating torque
Leak rate shall be < 1 % of the air flow rate.

The measurement equipment shall be calibrated at regular intervals to ensure the required accuracy.

4 Absolute filter, wall flow trap and leakage
4.1 Absolute filter
4.1.1 Absolute filter material

Separation efficiency of the absolute filter shall be equal to or greater than 97 % for the challenge

aerosol based on the calculation in Annex F. The absolute filter shall be stable up to temperatures equal

or greater than 105 °C, and resistant to oil, all kind of fuels, water, and other components of blowby.

The validation of absolute filter media efficiency is given in Annex F.
NOTE The use of an absolute filter with a backing will minimize fibre loss.
4.1.2 Absolute filter mass measurement method

The absolute filter shall be weighed, at least to the nearest 0,01 g, after the mass has stabilized.

Weigh stabilization may be achieved for water removal and minimal volatile content loss by storage

in a ventilated oven at a constant temperature of 65,5 °C. Other temperatures may be used to meet

customer requirements. Alternatively, place absolute filter in an ambient temperature and humidity

controlled enclosure.

The absolute filter shall be weighed in the same environment as at the beginning of the test. Heated

weighing should be in an enclosed heated chamber.
NOTE See Annex F for the validation process and 4.1.3 for process control.
4.1.3 Absolute media measurement process validation

Using the method of choice, the absolute pad weight method shall be performed once each day for three

days and have no more than ± 0,03 g variation between measurements.
4.2 Wall flow trap
NOTE An example of the wall flow trap design is given in Figure I.2.
4.2.1 Weight measurement

The wall flow trap shall be weighed, to the nearest 0,01 g, after the mass has stabilized.

The wall flow trap should be weighed in the same environment as at the beginning of the test. Heated

weighing should be in an enclosed heated chamber.
4.2.2 Validation of wall flow trap liquid oil efficiency

Arrange two wall flow traps in series. Challenge the wall flow trap with a high mass flow rate to

determine gravimetric efficiency according to the test procedure given in the corresponding clauses in

the relevant part of ISO 17536. Wall flow trap efficiency from the validation setup shall be equal to or

greater than 97 % for the challenge aerosol with a minimum of 1 g gained in the upstream wall flow trap.

Challenge the wall flow trap with a high mass flow rate to determine gravimetric efficiency test.

© ISO 2015 – All rights reserved 5
---------------------- Page: 10 ----------------------
ISO 17536-1:2015(E)
The wall flow trap efficiency, E , shall be calculated as shown in Formula (1):
100 (1)
E = ×
Δ+mmΔ
where
Δm is the mass increase of upstream wall flow trap;
Δm is the mass increase of downstream wall flow trap.
4.2.3 Validation of wall flow trap aerosol efficiency

Conduct a test similar to the method explained in Annex F, to obtain an aerosol efficiency value using

the specified challenge aerosol. The test setup shall consist of an oil mist generator, wall flow trap, and

an absolute filter to measure the aerosol. The absolute filter shall meet the requirements in 4.1.1. A

minimum of 3 g shall be subjected to the wall flow trap during this efficiency test. The wall flow trap

shall meet an efficiency of less than 1 %.
4.3 Leakage

It is important to minimize leakage into the test system to obtain good data. Depending on where the

leakage occurs, it can cause major errors in particle counting.

As a minimum all connections and joints should be checked for visual leakage using soap bubbles or

smoke. Any known soap solution can be used for the test. Preferably, the soap solution (foam) will be

applied using a brush at all connections and joints. Leaks are especially important on the clean side of

the oil separator.
Leakage shall be evaluated according to Annex G.
5 Principles for aerosol separator performance tests
5.1 General

Performance tests shall be performed on a complete aerosol separator assembly. The tests may consist

of one or more of the following: laboratory gravimetric test (see ISO/TS 17536-2), an engine gravimetric

test (see ISO/TS 17536-3), a laboratory fractional test method (see ISO/TS 17536-4) and an engine

fractional method (see ISO/TS 17536-5).

For performance tests which require pressure reading to be measured, either static or differential, this

shall be done in accordance with Annex A.

The test equipment used to measure pressure readings shall be as specified in Annex B.

5.2 Test equipment
5.2.1 Grounding

Grounding is required for all test apparatus to reduce the effects of static charges and to improve the

consistency of the test results. Grounding of metallic and non-metallic surfaces, housings, transport

tubes, injectors and associated hardware is recommended.
6 © ISO 2015 – All rights reserved
---------------------- Page: 11 ----------------------
ISO 17536-1:2015(E)
5.2.2 Upstream sample probe

Sampling probe shall be isokinetic (average local velocity of duct and probe to be equal) to within

+0 % and −10 %. The same probe design should be used before the oil separator. Sampling probe shall

be located on the centreline of the test duct. Sample probes shall be located at least seven diameters

downstream of any bends, reducers, expanders, etc. The sampling probe shall be at least four diameters

upstream of any bends, reducers, expanders, etc. The sampler will also be located in the centre of duct.

The probes shall be made of electrically conductive metallic tubing with a smooth inside surface. The

design of the probe and sampling line will reduce particle losses. The inlet of the sampling probe shall

be sharp edged and shall be located near the centre of the duct. The tube shall be straight, (or no more

than one bend) and as short as possible. See Annex D for details on isokinetic sampling. A short flexible

connection to the particle counter may be used to allow some flexibility and reduce stress on the

counter inlet. Polytetrafluoroethylene (PTFE) may not be used as flexible tubing. Use conductive tubing

[e.g. plasticized polyvinyl chloride (PVC)] instead.

Sampling probe ducting to the particle counter shall be set up in a way that no sedimentation of large

particles takes place while paying attention to the following.
— vertical orientation of the tubing;
— sufficient flow velocity;
— short connection length between particle counter and sampling probe;
— avoidance of bends in the tubing;
— no sharp angles if bends are necessary.
5.2.3 Upstream particle counter

The airborne particle counter shall be capable of counting particles in the 0,35 µm to 55 µm optical

size range and 0,5 µm to 10,0 µm aerodynamic size range. It is also desirable for the Particle Counter

to have a design incorporating clean sheath air to protect the optics and keep the optics clean. The

particle counters may also need to be adapted with an exhaust port that can be routed back to the test

system vacuum. Without this exhaust set up the particle counter may not be able to perform at the

rated flow. Counters shall be calibrated using accredited lot traceable polystyrene latex (PSL) spheres

(see ISO 21501-1 calibration procedure.). Data should also be reported in equivalent aerodynamic size

ranges. Most laboratories currently use optical particle counters, however the technical advantages of

using aerodynamic particle counters is also well recognized.

The particle counter shall be able at a minimum, to discriminate eight logarithmically spaced particle

size classes.
5.2.4 Particle counter calibration

The particle counters shall be calibrated with polystyrene latex particles of appropriate size prior to

system start-up and a minimum of once a year to verify that the size calibration has not changed. It is

recommended that the particle counter calibration be verified periodically during the year between

calibrations.
5.2.5 Maximum particle concentration

The maximum total particle concentration shall be established to prevent coincidence counting, (i.e.

counting more than one particle at a time). A recommended method for establishing this limit is to

conduct oil separator gravimetric efficiency tests at a series of different concentrations and compare

the results. The maximum concentration is determined at the point where increasing the concentration

by a factor of two causes the fractional efficiency in the smallest size range at the higher concentration

to be more than 5 % less than the fractional efficiency at the lower concentration. Another method is

to increase the concentration in steps (e.g. by using a diluted and an undiluted aerosol) and determine

© ISO 2015 – All rights reserved 7
---------------------- Page: 12 ----------------------
ISO 17536-1:2015(E)

the concentration where the particle counter starts showing significant deviation from the expected

concentration in the smallest size range. An example is given in Annex H.
5.2.6 Particle counter flow

The particle counter flow rate shall remain constant within ± 5 % for the duration of a test including

the correlation done before the test.
5.3 Determination of gravimetric separation efficiency
5.3.1 General

The purpose is to determine the gravimetric separation efficiency. The device should be operated at the

prescribed air flow rate and oil flow rate. The weight changes of the component parts and the absolute

filter during the test period shall be used to calculate the gravimetric efficiency.

The weight increase of the absolute filter after conditioning for a gravimetric efficiency test shall be

greater than 0,05 g.
5.3.2 Calculations
Calculate the aerosol efficiency, E , by the method shown in Formula (2):
Δ+mmΔ+Δm
uD d
E = ×100 (2)
Δ+mmΔ+Δ+mmΔ
uF Dd

Calculate the total efficiency, E , by the method shown in Formula (3) and Formula (4):

Δ+mmΔ
E = ×100 (3)
Δ+mmΔ
...

DRAFT INTERNATIONAL STANDARD
ISO/DIS 17536-1
ISO/TC 22/SC 5 Secretariat: AFNOR
Voting begins on: Voting terminates on:
2014-08-13 2014-11-13
Road vehicles — Aerosol separator performance test for
internal combustion engines —
Part 1:
General

Véhicules routiers — Essai de performance du séparateur d’aérosols pour les moteurs à combustion

interne —
Partie 1: Généralités
ICS: 43.060.20
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 17536-1:2014(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION. ISO 2014
---------------------- Page: 1 ----------------------
ISO/DIS 17536-1:2014(E)
Copyright notice

This ISO document is a Draft International Standard and is copyright-protected by ISO. Except as

permitted under the applicable laws of the user’s country, neither this ISO draft nor any extract

from it may be reproduced, stored in a retrieval system or transmitted in any form or by any means,

electronic, photocopying, recording or otherwise, without prior written permission being secured.

Requests for permission to reproduce should be addressed to either ISO at the address below or ISO’s

member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Reproduction may be subject to royalty payments or a licensing agreement.
Violators may be prosecuted.
ii © ISO 2014 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/DIS 17536-1
Contents Page

1 Scope ...................................................................................................................................................... 1

2 Terms, definitions, symbols and units ................................................................................................ 1

2.1 Terms and definitions ........................................................................................................................... 1

2.2 Symbols and units ................................................................................................................................. 4

3 Measurement equipment accuracy ..................................................................................................... 4

4 Absolute filter, wall flow trap and leakage .......................................................................................... 5

4.1 Absolute filter ........................................................................................................................................ 5

4.2 Wall flow trap ......................................................................................................................................... 5

4.3 Leakage .................................................................................................................................................. 6

5 Principles for aerosol separator performance tests .......................................................................... 7

5.1 General ................................................................................................................................................... 7

5.2 Test equipment ...................................................................................................................................... 7

5.3 Determination of gravimetric separation efficiency .......................................................................... 8

Annex A (normative) Explanation of differential pressure and pressure loss of an aerosol

separator .............................................................................................................................................. 10

Annex B (normative) Test equipment ............................................................................................................. 11

Annex C (informative) Aerodynamic diameter ............................................................................................... 13

Annex D (informative) Isokinetic sampling probes and information ........................................................... 15

Annex E (informative) Life reference .............................................................................................................. 18

Annex F (normative) Validation of the absolute filter media ........................................................................ 19

Annex G (normative) Leakage ......................................................................................................................... 20

Annex H (informative) Determination of maximum efficiency aerosol concentration ............................... 21

Annex I (informative) Test Equipment 2 ......................................................................................................... 22

© ISO 2014 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO/DIS 17536-1
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.

International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.

The main task of technical committees is to prepare International Standards. Draft International Standards

adopted by the technical committees are circulated to the member bodies for voting. Publication as an

International Standard requires approval by at least 75 % of the member bodies casting a vote.

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.

ISO 17536-1 was prepared by Technical Committee ISO/TC 22, Road Vehicles, Subcommittee SC 5, Aerosol

Separator performance for internal combustion engines.

ISO 17536 consists of the following parts, under the general title Road Vehicles — Aerosol separator

performance test for internal combustion engines:
 Part 1: General
 Part 2: Laboratory gravimetric test method[To be published]
 Part 3: Method to perform engine gravimetric test [To be published]
 Part 4: Laboratory fractional test method [To be published]

 Part 5: Method to perform engine fractional test[To be published, Technical Specification]

iv © ISO 2014 – All rights reserved
---------------------- Page: 4 ----------------------
ISO/DIS 17536-1
Introduction

Engine crankcase blow-by is composed of combustion exhaust gases which have escaped to the crankcase

via piston ring seals and lube oil aerosols generated by thermal and mechanical action within the engine.

These gases must be vented from the crankcase to prevent a build-up of high pressure. The constituents of

vented engine blow-by gases are recognized as an undesirable contaminant and technology for their

containment is therefore evolving.

The device used to separate oil aerosols from the blow-by typically releases cleaned gases to atmosphere or

alternatively returns the cleaned product to the combustion process by feeding into the air inlet prior to the

turbo compressor. The latter has lead to the requirement for a pressure control device to isolate the engine

from turbo inlet suction.

The engine test methods presented in ISO 17536 are general guidelines for performing an engine test.

Annexes A ~ I of this part of ISO 17536 specify general and common provisions for aerosol separator

performance test.
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DRAFT INTERNATIONAL STANDARD ISO/DIS 17536-1
Road Vehicles — Aerosol separator performance test for
internal combustion engines — Part 1: General
1 Scope

This part of ISO 17536 specifies general conditions, defines terms and establishes the basic principles for

blow-by oil aerosol separator performance tests by laboratory or engine and gravimetric or fractional test

method.

Conformance of a device to legislation is outside of the scope of this standard and the appropriate regulations

must be consulted.
2 Terms, definitions, symbols and units

For the purposes of all parts of ISO 17536, the following terms and definitions apply.

2.1 Terms and definitions
2.1.1
blowby
aerosol produced from engines and released through a crankcase vent
2.1.2
oil carryover
total amount of liquid oil captured in the downstream wall flow trap
2.1.3
filter element

replaceable part of the crankcase system, consisting of the filter material and carrying frame

2.1.4
crankcase ventilation system

device which separates oil and particles from the engine blowby before venting to either the engine (CCV) or

the environment (OCV)
2.1.5
differential pressure

difference in static pressure measured immediately upstream and downstream of the unit under test

2.1.6
pressure loss

measure of the loss of aerodynamic energy caused by an aerosol separator at the observed air flow rate due

to different flow velocities at the measuring point.

NOTE 1 It is expressed as the differential pressure corrected for any difference in the dynamic head at the measuring

points
NOTE 2 For further information, See Annex A.
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ISO/DIS 17536-1
2.1.7
wall flow trap
device to capture oil that is flowing along the walls
NOTE The wall flow trap design is drawn in Figure I.2.
2.1.8
absolute filter

filter downstream of the unit under test to retain the contaminant passed by the unit under test

2.1.9
piezometer tube
duct that has a hole or holes drilled in the wall to obtain a pressure reading
NOTE For further information, see Annex B, Figure B.2.
2.1.10
separator efficiency

ability of the aerosol separator or the unit under test to remove contaminant under specified test conditions

2.1.11
optical (equivalent) diameter
Do,i

diameter of a particle of the type used to calibrate an optical sizing instrument that scatters the same amount

of light as the particle being measured

NOTE Optical diameter depends on the instrument, the type of particle used to calibrate the instrument (usually

polystyrene latex spheres), and the optical properties of the particle being measured.

2.1.12
aerodynamic (equivalent) diameter
Dae

diameter of a sphere of density 1 g/cm with the same terminal velocity due to gravitational force in calm air,

as the particle being measured
NOTE 1 Annex C provides additional information about aerodynamic diameter.

NOTE 2 Aerodynamic diameter depends on the instrument, the type of particle used to calibrate the instrument (usually

polystyrene latex spheres), and the properties of the particle being measured.
2.1.13
pressure regulator

device between the outlet of the aerosol separator and air intake to regulate the crankcase pressure in high

vacuum conditions
2.1.14
mass oil flow
mass amount of oil per unit time
2.1.15
relief valve

device to direct a portion of the flow around a separation device due to a pressure difference, usually venting

to the atmosphere
2.1.16
bypass valve

device to direct a portion of the flow around a separation device due to pressure difference, usually venting

downstream of the bypassed separation device
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ISO/DIS 17536-1
2.1.17
challenge aerosol

output from the aerosol generator or engine which corresponds to the distribution in testing and with the

amount of the mass feed rate.
NOTE The aerosol distribution by mass is prescribed in ISO 17536-2.
2.1.18
particle size
polystyrene latex (PSL) equivalent size expressed as a diameter in micrometers
2.1.19
isokinetic sampling

sampling in which the flow in the sampler inlet is moving at the same velocity and direction as the flow being

sampled.
NOTE Annex D provides additional information about isokinetic sampling.
2.1.20
particle counter
instrument for sizing and/or counting aerosol particles

NOTE 1 Recommended particle counters are optical particle counters (OPC/OAS as per ISO 21501-1) or other counters

demonstrating good correlation in measuring particle sizes such as aerodynamic particle counters (APC).

2.1.21
coefficient of variation
COV
standard deviation of a group of measurements divided by the mean
2.1.22
unit under test
UUT

either a single aerosol separator element or a complete crankcase ventilation system

2.1.23
open crankcase ventilation
OCV

aerosol separator system that is attached to the crankcase and is vented to the environment

2.1.24
closed crankcase ventilation
CCV
aerosol separator system that is attached between the crankcase and the engine
2.1.25
aerosol separator
device that separates oil from the blowby stream or test stand airstream
2.1.26
high efficiency particular air filter
HEPA filter

filter having 99,95 % efficiency at most penetrating particle size (class H13 in accordance with EN 1822), or

99,97 % (or higher) fractional efficiency at 0,3μm using DOP aerosol as defined by IEST RP-CC001

recommended practice
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ISO/DIS 17536-1
2.1.27
inertial separator
device that separates oil from the blowby stream using inertia
2.1.28
combination separator

device that separates oil from the blowby stream using inertia as well as a filter element

2.1.29
rated air flow
flow rate specified by the user or manufacturer
NOTE The rated air flow is usually used as the test air flow.
2.1.30
test air flow

measure of the quantity of air pushed or drawn through the aerosol separator per unit time

2.1.31
aerosol generator

laboratory equipment that can produce a simulated blowby particle distribution from oil and compressed air

NOTE The aerosol distribution by mass will be prescribed in ISO 17536-2.
2.1.32
drainage vessel

device that captures the separated oil from the crankcase separation system, not to include oil carryover

NOTE Filter life is not used in all parts of ISO 17536. Life reference is given in Annex E.

2.1.33
mass feed rate

mass amount of challenge aerosol or liquid subjected to the unit under test per unit time

NOTE Filter life is not used in all parts of ISO 17536. Life reference is given in Annex E.

2.2 Symbols and units
Table 1—Symbols and units
Quantity Symbol Unit
Volume flow rate V l/min
Velocity m/s
Density kg/m
Mass flow rate m g/hr
Pressure Pa
Differential pressure d Pa
Pressure loss l Pa
Mass g
Time s
Speed rev/min
Torque N-m
3 Measurement equipment accuracy
Air flow rate to within ± 5 % of reading.
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ISO/DIS 17536-1
Differential pressure to within ± 25 Pa of reading.
Temperature to within ± 1.5° C of reading.

Mass to within 0,1 g except for absolute filter mass and downstream wall flow trap.

Mass to within 0,01 g for absolute filter mass and downstream wall flow trap.
Relative humidity (RH) with an accuracy of ± 2% RH.
Barometric pressure to within ± 3 hPa.
Crankcase pressure to within ± 25 Pa of reading
RPM to within ± 50 r/min.
Torque within ± 100 N-m.
Leak rate shall be < 1% of the air flow rate.

The measurement equipment shall be calibrated at regular intervals to ensure the required accuracy.

4 Absolute filter, wall flow trap and leakage
4.1 Absolute filter
4.1.1 Absolute filter material

Separation efficiency of the absolute filter shall be equal to or greater than 97 % for the challenge aerosol

based on the calculation in Annex F. The absolute filter shall be stable up to temperatures equal or greater

than 105°C, and resistant to oil, all kind of fuels, water, and other components of blowby.

The validation of absolute filter media efficiency is given in Annex F.
NOTE The use of an absolute filter with a backing will minimize fibre loss.
4.1.2 Absolute filter mass measurement method

The absolute filter shall be weighed, at least to the nearest 0,01 g, after the mass has stabilized. Stabilization may

be achieved by storage in a ventilated oven at a constant temperature of 65,5 °C ± 1,5 °C. The absolute filter

shall be weighed inside the oven. Alternatively, place absolute filter in an ambient temperature and humidity controlled

enclosure. Repeat this procedure until the mass has stabilized.

The absolute filter shall be weighed in the same environment as at the beginning of the test. Heated weighing

should be in an enclosed heated chamber.
NOTE See Annex F for the validation process and 4.1.3 for process control.
4.1.3 Absolute media measurement process validation

Using the method of choice, the absolute pad weight shall have no more than ± 0,03 grams variation over

three days.
4.2 Wall flow trap
NOTE An example of the wall flow trap design is given in Figure I.2.
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ISO/DIS 17536-1
4.2.1 Weight measurement

The wall flow trap shall be weighed, to the nearest 0,01 g, after the mass has stabilized.

The wall flow trap should be weighed in the same environment as at the beginning of the test. Heated

weighing should be in an enclosed heated chamber.
4.2.2 Validation of wall flow trap liquid oil efficiency

Arrange two wall flow traps in series. Challenge the wall flow trap with a high mass flow rate to determine

gravimetric efficiency according to the test procedure given in the corresponding sections in each concerned

part of ISO 17536. Wall flow trap efficiency from the validation setup shall be equal to or greater than 97,0 %

for the challenge aerosol with a minimum of 1.0 gram gained in the upstream wall flow trap.

Challenge the wall flow trap with a high mass flow rate to determine gravimetric efficiency test

The wall flow trap efficiency, E shall be calculated as follows:
E  100 (1)
m m
C D
where
E is the wall flow trap efficiency system in series;
m is the mass increase of upstream wall flow trap;
m is the mass increase of downstream wall flow trap.
4.2.3 Validation of wall flow trap aerosol efficiency

Conduct a test similar to the method explained in Annex F, to obtain an aerosol efficiency value using the

specified challenge aerosol. The test setup shall consist of an oil mist generator, wall flow trap, and an

absolute filter to measure the aerosol. The absolute filter shall meet the requirements in 4.1.1. A minimum of

3 grams shall be subjected to the wall flow trap during this efficiency test. The wall flow trap shall meet an

efficiency of less than 1%.
4.3 Leakage

It is important to minimize leakage into the test system to obtain good data. Depending on where the leakage

occurs, it can cause major errors in particle counting.

As a minimum all connections and joints should be checked for visual leakage using soap bubbles or smoke.

Any known soap solution can be used for the test. Preferably, the soap solution [foam] will be applied using a

brush at all connections and joints. Leaks are especially important on the clean side of the oil separator.

Leakage shall be evaluated according to Annex G.
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ISO/DIS 17536-1
5 Principles for aerosol separator performance tests
5.1 General

Performance tests shall be performed on a complete aerosol separator assembly. The tests may consist of

one or more of the following: laboratory gravimetric test (see ISO 17536-2 ), an engine gravimetric test (see

ISO/TS 17536-3), a laboratory fractional test method (see ISO 17536-4 ) and an engine fractional method

(see ISO/TS 17536-5 ).
5.2 Test equipment
5.2.1 Grounding

Grounding is required for all test apparatus to reduce the effects of static charges and to improve the

consistency of the test results. Grounding of metallic and non-metallic surfaces, housings, transport tubes,

injectors and associated hardware is recommended.
5.2.2 Upstream sample probe

Sampling probe shall be isokinetic (average local velocity of duct and probe to be equal) to within +0% and -

10%. The same probe design should be used before the oil separator. Sampling probe shall be located on the

centreline of the test duct. Sample probes shall be located at least 7 diameters downstream of any bends,

reducers, expanders etc. The sampling probe shall be at least 4 diameters upstream of any bends, reducers,

expanders etc. The sampler will also be located in the centre of duct. The probes shall be made of electrically

conductive metallic tubing with a smooth inside surface. The design of the probe and sampling line will reduce

particle losses. The inlet of the sampling probe shall be sharp edged and shall be located near the centre of

the duct. The tube shall be straight, (or no more than one bend) and as short as possible. Refer to Annex D

for details on isokinetic sampling. A short flexible connection to the particle counter may be used to allow

some flexibility and reduce stress on the counter inlet. PTFE may not be used as flexible tubing. Use

conductive tubing [e.g. plasticized PVC] instead.

Sampling probe ducting to the particle counter must be set up in a way that no sedimentation of large particles

takes place while paying attention to the following.
- vertical orientation of the tubing;
- sufficient flow velocity;
- short connection length between particle counter and sampling probe;
- avoidance of bends in the tubing;
- no sharp angles if bends are necessary.
5.2.3 Upstream particle counter

The airborne particle counter shall be capable of counting particles in the 0,3 to 5 µm optical size range and

0,5 to 10,0 µm aerodynamic size range. It is also desirable for the Particle Counter to have a design

incorporating clean sheath air to protect the optics and keep the optics clean. The Particle Counters may also

need to be adapted with an exhaust port that can be routed back to the test system vacuum. Without this

exhaust set up the Particle Counter may not be able to perform at the rated flow. Counters must be calibrated

1) To be published
2) To be published
3) To be published
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ISO/DIS 17536-1

using accredited lot traceable PSL (polystyrene latex) spheres (Reference ISO 21501-1 calibration

procedure.). Data should also be reported in equivalent aerodynamic size ranges. Most laboratories currently

use optical particle counters, however the technical advantages of using aerodynamic particle counters is also

well recognized.

The particle counter shall be able at a minimum, to discriminate 8 logarithmically spaced particle size classes.

5.2.4 Particle counter calibration

The particle counters shall be calibrated with polystyrene latex particles of appropriate size prior to system

start-up and a minimum of once a year to verify that the size calibration has not changed. It is recommended

that the particle counter calibration be verified periodically during the year between calibrations.

5.2.5 Maximum particle concentration

The maximum total particle concentration shall be established to prevent coincidence counting, (i.e. counting

more than one particle at a time). A recommended method for establishing this limit is to conduct oil separator

gravimetric efficiency tests at a series of different concentrations and compare the results. The maximum

concentration is determined at the point where increasing the concentration by a factor of 2 causes the

fractional efficiency in the smallest size range at the higher concentration to be more than 5 % less than the

fractional efficiency at the lower concentration. Another method is to increase the concentration in steps (e.g.

by using a diluted and an undiluted aerosol) and determine the concentration where the particle counter starts

showing significant deviation from the expected concentration in the smallest size range. An example is given

in Annex H.
5.2.6 Particle counter flow

The particle counter flow rate shall remain constant within  5 % for the duration of a test including the

correlation done before the test.
5.3 Determination of gravimetric separation efficiency
5.3.1 General

The purpose is to determine the gravimetric separation efficiency. The device should be operated at the

prescribed air flow rate and oil flow rate. The weight changes of the component parts and the absolute filter

during the test period shall be used to calculate the gravimetric efficiency.

The weight increase of the absolute filter after conditioning for a gravimetric efficiency test shall be greater

than 0,05 grams.
5.3.2 Calculations
Calculate the aerosol efficiency,E , by the following method:
Δm Δm Δm
u D d
(2)
E  100
Δm Δm Δm Δm
u F D d
Calculate the total efficiency, , by the following method:
Δm Δm
u d
(3)
E  100
Δm Δm Δm Δm
u F D d
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ISO/DIS 17536-1
Δm Δm
T F
(4)
E  100

Formula 4 shall be used only for calculating Total efficiency in ISO TS 17536-3 gravimetric tests.

NOTE If a wall flow trap is not used, aerosol efficiency cannot be measured, only total efficiency is recorded.

Calculate the liquid penetration per unit time, , by the following method:
(5)
P 
Calculate the mass feed rate, by the following method:
Δm Δm Δm Δm
u F D d
O  (6)
where
is the efficiency of the unit under test;
t is the test time in hours;
E is the total efficiency (liquid and aerosol) of the unit under test;

E is the total efficiency (liquid and aerosol) of the unit under test for engine gravimetric;

is the liquid penetration of the unit under test;
is the mass increase of the unit under test;
is the mass increase of the absolute filter;
is the mass increase of the downstream wall flow trap;
is the mass increase of the drain;

is the mass increase of the alternative method of capturing the total challenge (absolute filter

method).
O is the mass feed rate to the unit under test.
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ISO/DIS 17536-1
Annex A
(normative)
Explanation of differential pressure and pressure loss of an aerosol
separator

When differential pressure across a separator has been measured (p – p in Table A.1), any difference in the

2 1

cross-sectional area of the ducts at the upstream and downstream pressure tapping points shall be taken into

account in determining the differential pressure across the separator. The differential pressure across the

separator is given by the formula:
(A.1)
Δp Δp Δp
l d c
where
is the measured differential pressure.
2 2
ρ *ν ρ *ν
2 1
2 1
(A.2)
Δp  
2 2
where
is the density of the air at the upstream pressure tapping point;
ρ is the density of the air at the downstream pressure tapping point;
is the velocity of the air in the duct at the upstream pressure tapping point;

is the velocity of the air in the duct at the downstream pressure tapping point..

Table A.1 – Illustration of differential pressure, pressure loss of an aerosol separator

Term Air being pushed through the separator Explanation
Differential pressure Used with normally equal diameter
Δp  p  p
d 2 1
piezometers.
See Figure B.1.
Pressure loss Δp Δp Δp Used when the inlet and outlet
l d c
piezometers have different diameters
2 2
(ρ ν ) (ρ ν )
2 1
2 1
(p  p )
2 1
Where
is the pressure measured at the upstream pressure tapping point;
p is the pressure measured at the downstream pressure tapping point.
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ISO/DIS 17536-1
Annex B
(normative)
Test equipment

The test equipment shall consist of a wall flow trap (see Annex I) and an inlet/outlet piezometer tube. Typical

set-up for differential pressure test, wall flow trap design (see Annex I) and the inlet/outlet piezometer tube

dimensions are shown in Figures B.1, I.1 and I.2 and B.2 respectively.
...

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