BS ISO 12500-2-2007 Filters for compressed air - Test methods - Oil vapours《压缩空气过滤器 试验方法 油蒸气》.pdf

1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58ICS 23.100.60; 71.100.20Filters for compressed air Test methods Part 2: Oil vapoursBRITISH STANDARD

2、BS ISO 12500-2:2007BS ISO 12500-2:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 July 2007 BSI 2007ISBN 978 0 580 53131 6Amendments issued since publicationAmd. No. Date Commentscontract. Users are responsible for its correct applicat

3、ion.Compliance with a British Standard cannot confer immunity from legal obligations.National forewordThis British Standard is the UK implementation of ISO 12500-2:2007.The UK participation in its preparation was entrusted to Technical Committee MCE/8, Compressors, pneumatic tools, pneumatic machine

4、s and vacuum technology.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a INTERNATIONALSTANDARDISO12500-2First edition2007-06-01Reference numberISO 12500-2:2007(E)Filters fo

5、r compressed air Test methods Part 2:Oil vapoursFiltres pour air comprim Mthodes dessai Partie 2: Vapeurs dhuileBS ISO 12500-2:2007iiiiiContents Page1 Scope 12 Normative references 13 Terms and definitions 14 Units and symbols . 25 Reference conditions 26 Test requirements 37 Test method 48 Uncertai

6、nty . 69 Test report 7Annex A (informative) Description and application of the test equipment . 8Annex B (informative) Sample test report form . 9Bibliography . 10BS ISO 12500-2:2007ivForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bod

7、ies(ISO member bodies). The work of preparing International Standards is normally carried out through ISOtechnical committees. Each member body interested in a subject for which a technical committee has beenestablished has the right to be represented on that committee. International organizations,

8、governmental andnon-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the InternationalElectrotechnical Commission (IEC) on all matters of electrotechnical standardization.International Standards are drafted in accordance with the rules given in the ISO/IEC

9、 Directives, Part 2.The main task of technical committees is to prepare International Standards. Draft International Standardsadopted by the technical committees are circulated to the member bodies for voting. Publication as anInternational Standard requires approval by at least 75 % of the member b

10、odies casting a vote.Attention is drawn to the possibility that some of the elements of this document may be the subject of patentrights. ISO shall not be held responsible for identifying any or all such patent rights.ISO 12500-2 was prepared by Technical Committee ISO/TC 118, Compressors and pneuma

11、tic tools, machinesand equipment, Subcommittee SC 4, Quality of compressed air.ISO 12500 consists of the following parts, under the general title Filters for compressed air Test methods: Part 1: Oil aerosols Part 2: Oil vapours Part 3: ParticulatesBS ISO 12500-2:2007vIntroductionOil adsorbent filter

12、s (e.g. activated carbon. etc.) are designed for the removal of oil vapours and odours fromcompressed air or gas streams.The most important performance characteristics of the filter are its ability to remove hydrocarbon vapours, itstotal adsorptive capacity and pressure drop.The aim of this part of

13、ISO 12500 is to define a method and test condition by which the above characteristicscan be measured and compared.BS ISO 12500-2:2007blank1Filters for compressed air Test methods Part 2:Oil vapours1ScopeThis part of ISO 12500 specifies the test layout and test procedures required for testing hydroca

14、rbon vapouradsorbent filters used in compressed-air systems to determine their effectiveness in removing hydrocarbonvapours. The performance characteristics to be identified are adsorptive capacity; pressure drop ( ).This part of ISO 12500 defines one method of presenting filter performance as hydro

15、carbon vapour capacity,expressed in milligrams, from results obtained under test conditions.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For datedreferences, only the edition cited applies. For undated references, the latest edition

16、 of the referenced document(including any amendments) applies.ISO 1219-1, Fluid power systems and components Graphic symbols and circuit diagrams Part 1: Graphicsymbols for conventional use and data-processing applicationsISO 2602, Statistical interpretation of test results Estimation of the mean Co

17、nfidence intervalISO 2854, Statistical interpretation of data Techniques of estimation and tests relating to means andvariancesISO 5598, Fluid power systems and components VocabularyISO 7000, Graphical symbols for use on equipment Index and synopsisISO 8573-1:2001, Compressed air Part 1: Contaminant

18、s and purity classesISO 8573-6, Compressed air Part 6: Test methods for gaseous contaminant content3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 5598 and the following apply.3.1 activated carboncharcoal which has an enhanced property of attracting c

19、ertain gases or vapours into the pore structure of itssurface layerpBS ISO 12500-2:200723.2 adsorbentsolid having the property of attracting gaseous or liquid molecules and causing them to adhere to its surface3.3 adsorptive capacitymass of a contaminant that can be adsorbed by tested filter3.4 ambi

20、ent temperaturetemperature of the air surrounding the filter housing under test3.5 breakthroughpoint when a determined amount of the test agent is detected downstream of the adsorbent filter3.6 equivalent rated flowflow at which, when the test filter is operated at a (e) test pressure, an equal gas

21、velocity to thatfor the device would be achieved were it to be operated at its rated pressure and flow3.7 filterapparatus for separation or removal of contamination from a compressed air or gas stream3.8 pressure dropdifferential pressuredifference between the inlet and outlet pressure of a componen

22、t, measured under specified conditions3.9 test agentn-hexane vapour used to challenge the filter under test4 Units and symbolsGeneral use of SI units (Systme international dunits; see ISO 1000) as given throughout this part ofISO 12500 is recommended. However, in agreement with accepted practice in

23、the pneumatic field, somenon-preferred SI units, accepted by ISO, are also used.NOTE bar (e) is used to indicate effective pressure above atmospheric.The graphic symbols on diagrams are in accordance with ISO 1219-1 and ISO 7000.5 Reference conditionsThe reference conditions for gas volumes shall be

24、:a) air temperature ;b) absolute air pressure (a);c) relative water vapour pressure 0.700 kPa 7 barp1 bar = 100 000 Pa1 l (litre) = 0,001 m320C100 kPa 1 barBS ISO 12500-2:200736 Test requirements6.1 Standard rating parametersThe standard rating parameters are as identified in Table 1.6.2 Inlet air f

25、lowTesting of hydrocarbon vapour adsorbent filters shall be carried out at the manufacturers equivalent rated flow.For the testing of filters that have their maximum flow rating quoted at a pressure other than (e)the measurement for hydrocarbon vapour removal can be made using equivalent flow veloci

26、ty at rated pressureidentified by the manufacturer for the filter under test.The test flow rate, , at reference conditions, expressed in cubic metres per second, is calculatedaccording to Equation (1):(1)whereis rated flow rate, at reference conditions, expressed in cubic metres per hour;is absolute

27、 test pressure, expressed in kPa bar (a);is absolute rated pressure, expressed in kPa bar (a);is the compressibility factor of air at rated pressure and , dimensionless.6.3 Test agentThe test agent used to challenge the adsorbent filters under investigation simulates operation with compressoroils.Ta

28、ble 1 Standard rating parametersReporting parameter Units Rating conditionsMaintain within actual gauge valueInstrument accuracy at test conditionsInlet temperature 20Inlet pressure kPa bar (e) 700 (7)() gauge readingAmbient temperature 20Test agent concentration in airamg/kg 1 000Minimum air purity

29、b ISO 8573-1:2001, Class 2 2 1cAir flow for testing m3/h rated flow gauge readingPressure drop Pa (mbar) Not applicable Not applicable() gauge readingaDensity of air is taken as bMinimum air purity to ensure that the filter under test is not affected by the presence of water vapour.cThe first number

30、 represents the solid-particle classification; the second, the humidity classification; and the third, the total oilclassification.C 5 2C 10 (0,1) 10 kPa 0,1 barC 5 2C 50 0,1 %100 % 2% 4% 1 kPa 10 mbar1,18 kg/m3.700 kPa 7 barqV e,REFqV e,REF=qV n,REFTpepnqV n,REFpepnT20CBS ISO 12500-2:20074The liqui

31、d n-hexane used as the test agent in this standard should have a purity of not less than (usuallyequating to a general-purpose laboratory reagent grade).Care should be taken not to contaminate the n-hexane with other chemicals or particulate matter.7 Test method7.1 Test equipment arrangementA schema

32、tic diagram of the test equipment is shown in Figure 1.A description of the test equipment is given in Annex A.7.2 Test parametersDuring the period of the test all the various parameters shall be maintained within the tolerances specified inTable 1.7.3 Determination of breakthrough concentrationMeas

33、urement of inlet/outlet challenge concentration shall be in accordance with ISO 8573-6; howeveriso-kinetic sampling is not required.Breakthrough of the test agent occurs when the downstream concentration of test agent reaches .A suitable instrument calibrated with the test agent in accordance with m

34、anufacturers instructions shall be usedto measure the test agent concentration, e.g. flame-ionization detector or infra-red analyser.7.4 Test durationMeasure the time from the introduction of the vapour to the filter under test until breakthrough is detected. Atleast three examples of each model sha

35、ll be tested and the results averaged.7.5 Differential pressureMeasure and record the pressure drop across the filter under test.7.6 Calculation of adsorbed test agentThe mass, expressed in milligrams, of test agent, , adsorbed by the test filter shall be calculated as given inEquation (2):(2)wherei

36、s inlet concentration of the test agent, expressed in milligrams per kilogram;is air flow rate used during test, expressed in cubic metres per hour;is the time to achieve the breakthrough of the activated carbon element under test, expressed inhours98 %1 mg/kgMTAMTA= wTA,iqairt 1,18wTA,iqairtBS ISO

37、12500-2:20075Key1 compressed air supply2 full-flow ball valve3 pressure regulator4 pressure sensing/measuring5 pressure regulator6 non-return valve7 temperature sensing/measuring8 full-flow ball valve9 dewpoint sensing/measuring10 pressure sensing/measuring11 pressure differential gauge12 temperatur

38、e sensing/measuring13 full-flow ball valve14 pressure measuring tube15 filter under test16 by-pass full-flow ball valve17 activated carbon filter (with sufficient capacity to protect against release of n-hexane)18 multi-turn flow control valve19 flow sensing/measuring20 silencer21 full-flow ball val

39、ve22 test agent reservoir23 multi-turn flow control valve (coarse flow)24 flow sensing/measuring25 multi-turn flow control valve (fine flow)26 flow sensing/measuring27 evaporator28 heated pressure regulator and line to 2929 hydrocarbon vapour detector30 data recorder31 ambient temperature sensing/me

40、asuringaDetails of the construction of the measuring tubes are given in ISO 7183.Figure 1 Typical layout of test equipmentBS ISO 12500-2:200767.7 Test procedureTest procedure shall be done in the following order.a) Stabilize all test equipment at constant operating temperature, pressure and flow con

41、ditions. Commencedata recording.b) Establish the background level of ambient methane by using the hydrocarbon vapour detector (HVD)(typically ). This level can either be zeroed off on the HVD or added to the breakthroughconcentration for the time to breakthrough measurement.c) Establish the level an

42、d stability of the upstream test agent concentration by adjustment of the liquid-feedcontrol valves on the evaporator apparatus while checking the concentration with the HVD with the test filterbypass line open and the valves on both sides of the test filter closed.d) Install the test filter, open t

43、he inlet valve to the test filter followed by the outlet valve and simultaneously closethe bypass valve. The downstream concentration measured by the HVD should return to a level less thanthe specified breakthrough concentration. Record the time at which this level is reached.e) Record the test filt

44、er differential pressure.f) Monitor the downstream concentration with the HVD until such time as the measured value exceeds thespecified breakthrough concentration. The exact time to breakthrough can be determined from the trenddata which have been recorded by the data recorder.g) Close the evaporat

45、or supply valves and isolate the evaporator from the main line. Open the bypass valveand close both test filter isolation valves.h) Following the conclusion of the test, all air-supply valves should be closed and the pressure within the testapparatus allowed to safely decay to (e).8 UncertaintyNOTE

46、A calculation of the probable error, according to this clause is not always necessary.Due to the very nature of physical measurements, it is impossible to measure a physical quantity without erroror, in fact, to determine the true error of any one particular measurement. However, if the conditions o

47、f themeasurement are sufficiently well known, it is possible to estimate or calculate a characteristic deviation of themeasured value from the true value, such that it can be asserted with a certain degree of confidence that thetrue error is less than the said deviation. The value of such a deviatio

48、n (normally a confidence limit)constitutes a criterion for the accuracy of the particular measurement.It is assumed that compensation can be made by corrections for all systematic errors that can occur in themeasurement of the individual quantities measured and of the characteristics of the air. A f

49、urther assumption isthat the confidence limits in errors in reading and integration errors are negligible if the number of readings issufficient.The (small) systematic errors that can occur are covered by the inaccuracy of measurements.Quality classifications and limits of error are often invoked for ascertaining the uncertainty of individualmeasurement because apart from the exceptions (e.g. electrical transducers), they constitute only a fr