《BS-7881-1997.pdf》由会员分享，可在线阅读，更多相关《BS-7881-1997.pdf（30页珍藏版）》请在三一文库上搜索。
1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS 7881 : 1997 ICS 43.060
2、.40; 47.020.20 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Method of test for Petrol filters Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 12:59:02 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7881 : 1997 This British Standard, havi
3、ng been prepared under the direction of the Engineering Sector Board, was published under the authority of the Standards Board and comes into effect on 15 June 1997 BSI 1997 The following BSI references relate to the work on this standard: Committee reference MCE/21/6 Draft for comment 93/712281 DC
4、ISBN 0 580 26818 7 Amendments issued since publication Amd. No.DateText affected Committees responsible for this British Standard The preparation of this British Standard was entrusted by Technical Committee MCE/21, Filters for gases and liquids, to Subcommittee MCE/21/6, Filters for volatile liquid
5、 fuels, upon which the following bodies were represented: Motor Industry Research Association Society of Motor Manufacturers and Traders Limited Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 12:59:02 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7881 : 1997 BS
6、I 1997i Contents Page Committees responsibleInside front cover Forewordii Method 1Scope1 2Normative references1 3Test to determine flow rate versus pressure drop1 4Test to determine single pass efficiency and micrometre rating3 5Test to determine filter life, cumulative efficiency and dust holding c
7、apacity8 Annexes A(normative) Test liquid for fuel filter tests13 B(informative) Specification for test dusts15 C(informative) Example of graph of efficiency from HIAC particle count method17 D(informative) Worked example of the method of determination of filter efficiency (single pass efficiency)18
8、 E(informative) Example of graph of efficiency from gravimetric method19 F(informative) Worked example of the method of determination of filter efficiency (cumulative efficiency)20 G(informative) Example of graph of pressure drop versus life21 H(informative) Example of graph of efficiency versus lif
9、e22 J(informative) Example of graph of pressure drop versus efficiency23 Tables A.1 Test liquid for fuel filter tests13 B.1Particle size distribution of SAE fine test dust15 B.2Typical chemical composition of SAE fine test dust15 B.3Particle size distribution of MIRA M1 test dust15 B.4Particle size
10、distribution of MIRA M2 test dust15 B.5Particle size distribution of MIRA M3 test dust16 B.6Particle size distribution of MIRA M4 test dust16 Figures 1Test rig for determination of flow rate versus pressure drop2 2Test rig for determination of single pass efficiency and micrometre rating4 3Typical 1
11、40 mm diameter filter disc holder assembly5 4Vacuum flask and pump for filter discs6 5Test filter for determination of life and cumulative efficiency10 6Typical 47 mm diameter filter disc holder assembly11 A.1 Typical viscosity/temperature curve for test liquid14 C.1Graph of efficiency from HIAC par
12、ticle count method17 E.1Graph of efficiency from gravimetric method19 G.1Graph of pressure drop versus life21 H.1 Graph of efficiency versus life22 J.1Graph of pressure drop versus efficiency23 List of referencesInside back cover Licensed Copy: London South Bank University, London South Bank Univers
13、ity, Fri Dec 08 12:59:02 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ii BSI 1997 BS 7881 : 1997 Foreword This British Standard has been prepared by Subcommittee MCE/21/6. The methods described in this standard do not cover all the desired fields and further methods may be added to future revisions of
14、 this standard. Appropriate precautions are necessary to ensure the safety of personnel carrying out the tests in this standard. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover
15、, pages i and ii, pages 1 to 24, an inside back cover and a back cover. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 12:59:02 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BSI 19971 BS 7881 : 1997 Method 1 Scope This British Standard describes methods for determ
16、ination of flow rate versus pressure drop, single pass efficiency and micrometre rating, and rig life, cumulative efficiency and dust holding capacity of petrol filters intended for automotive and marine internal combustion engines. 2 Normative references This British Standard incorporates, by dated
17、 or undated reference, provisions from other publications. These normative references are made at the appropriate places in the text and the cited publications are listed on the inside back cover. For dated references, only the edition cited applies; any subsequent amendments to or revisions of the
18、cited publications apply to this British Standard only when incorporated in the reference by amendment or revision. For undated references, the latest edition of the cited publication applies, together with any amendments. 3 Test to determine flow rate versus pressure drop 3.1 Principle Liquid is pa
19、ssed through a filter at various flow rates and the resistance of the filter at each flow rate is measured. 3.2 Test liquid The test liquid shall be a straight mineral oil with properties as given in annex A. 3.3 Apparatus 3.3.1 Test rig assembly, comprising components 3.3.2 to 3.3.8. NOTE. A diagra
20、m of the test rig assembly is shown in figure 1. 3.3.2 Reservoir, of 5 l minimum capacity. 3.3.3 Electric diaphragm pump, of 6 l/min maximum flow and of 35 m maximum head. 3.3.4 Flow control valve. 3.3.5 Differential pressure gauge, capable of reading in excess of 70 kPa. 3.3.6 Thermometer. 3.3.7 Fl
21、ow meter. 3.3.8 Piping, of inside diameter (i.d.) 6 mm smooth bore tube provided with an upstream pressure tapping 50 mm from the test filter inlet and a downstream pressure tapping 80 mm from the test filter outlet. 3.4 Mounting of test filters 3.4.1 Mount axial flow filters vertically with the out
22、let uppermost. 3.4.2 Mount other types of filter as appropriate to their manner of operation. 3.5 Procedure NOTE. The numbers that appear in brackets in this clause relate to the numbers in figure 1. 3.5.1 Place 5 l of clean test liquid into the test rig reservoir (1), install a clean up filter, sim
23、ilar to the filter to be tested, in the test filter position (4), start the pump (2) and circulate the test liquid through the clean up filter for 15 min. 3.5.2 Remove the clean up filter and replace with the test filter, ensuring that air is removed from the test filter prior to starting the test.
24、3.5.3 Circulate the test liquid through the test filter and note the pressure differential Dp at 50 %, 75 %, 100 % and 125 % of the rated flow of the filter. 3.6 Expression of results Plot a graph of differential pressure Dp versus flow rate. 3.7 Test report The test report shall include at least th
25、e following information: a) the name of the organization conducting the test; b) the date of the test; c) the make and model number of the filter; d) a description of the filter; e) the rated flow of the filter; f) the test flow rates and the corresponding differential pressures; g) the type of test
26、 liquid; h) the test temperature. NOTE. The graph (see 3.6) should also be included if required by the purchaser. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 12:59:02 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 2 BSI 1997 BS 7881 : 1997 3 2 5 7 6 1 4 9 8 290
27、8080 300300 Key: 1.Reservoir6Thermometer 2.Electric diaphragm pump7Flow meter 3.Flow control valve8Inlet pressure tapping 4.Filter under test9Outlet pressure tapping 5.Differential pressure gauge Dimensions in millimetres Figure 1. Test rig for determination of flow rate versus pressure drop License
28、d Copy: London South Bank University, London South Bank University, Fri Dec 08 12:59:02 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BSI 19973 BS 7881 : 1997 1) For this standard the HIAC particle counter (Pacific Scientific Ltd., 11801 Tech Road, Maryland 20904-1909, USA) was used. Other instruments
29、employing the light extinction principle described in BS 3406 : Part 7 may be used, but the results may not correlate with those of this standard. 2)For information on the availability of SAE (Society of Automotive Engineers) and MIRA (Motor Industry Research Association) test dusts, contact the BSI
30、 library, BSI Head Office, 389 Chiswick High Road, London W4 4AL. 4 Test to determine single pass efficiency and micrometre rating NOTE. Two test procedures are described as follows. 1) Test procedure A: Analysis of samples by HIAC particle counter1), using SAE test dust2); 2) Test procedure B: Anal
31、ysis of samples gravimetrically and by ashing, using MIRA test dusts2). Both procedures are suitable for obtaining a filter micrometre rating result. Procedure A is the preferred procedure and this procedure should be used wherever possible. 4.1 Principle Particles of known sizes are offered to a fi
32、lter and the efficiency of their removal is measured. 4.2 Materials 4.2.1 Test liquid, a straight mineral oil with properties as given in annex A. 4.2.2 Test dusts a) For procedure A: SAE fine test dust2). b) For procedure B: MIRA test dusts M1, M2, M32). NOTE 1. MIRA M4 test dust may be required fo
33、r testing very coarse filters. NOTE 2. Specifications for the test dusts are given in annex B. 4.2.3 Dispersant, oil-based, ashless. 4.2.4 Membrane filter discs, of diameter 140 mm, and 0.8 mm mean pore size. 4.2.5 Petroleum distillate, (required for procedure B only), analytical grade, filtered thr
34、ough a 0.45 mm pore size membrane. 4.2.6 Distilled water. 4.3 Apparatus 4.3.1 Test rig assembly, comprising components 4.3.2 to 4.3.10. NOTE. A diagram of the test rig assembly is shown in figure 2. 4.3.2 Funnel. 4.3.3 Stirrer, rated at approximately 1000 r/min. 4.3.4 Spherical separating flask, of
35、2 l capacity. 4.3.5 Stopcock. 4.3.6 Influent sampling point pinchcock. 4.3.7 Flow control cock. 4.3.8 Isolating cock. 4.3.9 Effluent sampling point pinchcock. 4.3.10 Tubing, of i.d. 5.5 mm glass with clear PVC tubing used for joining sections, where required. 4.3.11 Membrane filter disc holder, as s
36、hown in figure 3. 4.3.12 Vacuum flask and pump, as shown in figure 4. 4.3.13 Hot air oven, capable of maintaining a temperature of 140 C20 C. 4.3.14 Desiccator. 4.3.15 Analytical balance, having0.1 mg readability. 4.3.16 Stop watch. 4.3.17 Measuring cylinder, of 500 ml capacity. 4.3.18 Beaker, of 80
37、0 ml capacity. 4.3.19 HIAC particle size analyser (required for procedure A only, complete with high concentration sensor and calibration chart. 4.3.20 Magnetic stirrer and follower (required for procedure A only). 4.3.21 Sample bottles (required for procedure A only), of 120 ml capacity to suit HIA
38、C particle size analyser. 4.3.22 Wash bottle (required for procedure A only), of 250 ml capacity for test liquid. 4.3.23 Muffle furnace (required for procedure B only) capable of maintaining a minimum temperature of 800 C50 C. 4.3.24 Seven crucibles (required for procedure B only), of 40 mm diameter
39、 3 30 mm depth with lids. 4.3.25 Tongs (required for procedure B only), with extended handles for use in muffle furnace. 4.3.26 Beaker (required for procedure B only), of 2 l capacity. 4.3.27 Beaker (required for procedure B only), of 250 ml capacity. 4.3.28 Coarse/fast filter discs (required for pr
40、ocedure B only). 4.3.29 Wash bottle (required for procedure B only), of 200 ml capacity for petroleum distillate. 4.4 Preparation of test contaminant suspensions for use in procedures A and B 4.4.1 Place sufficient test dust or powder in a hot air oven at 140 C20 C for 2 h, then allow it to cool and
41、 store it in a desiccator. 4.4.2 Filter approximately 2 l of test liquid through a membrane filter disc (see figures 3 and 4). 4.4.3 Weigh out, using an analytical balance, between 25 mg and 30 mg of test material, record its exact weight, and mix with approximately 100 mg of dispersant on the watch
42、 glass. Wash it into an 800 ml beaker with a small quantity taken from 500 ml of pre-filtered test liquid. 4.4.4 Add the remainder of the pre-filtered test liquid to the test dust and stir at approximately 1000 r/min for 15 min. Licensed Copy: London South Bank University, London South Bank Universi
43、ty, Fri Dec 08 12:59:02 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 4 BSI 1997 BS 7881 : 1997 Key 1.Funnel 2.Stirrer 3.Spherical separating flask (2 l) 4.Stopcock 5.Influent sampling point pinchcock 6.Test filter 7.Flow control cock 8.Isolating cock 9.Effluent sampling point pinchcock Figure 2. Test
44、rig for determination of single pass efficiency and micrometre rating Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 12:59:02 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BSI 19975 BS 7881 : 1997 Key 1.Position of filter disc 2.Drainage channel 3.Concentric rings
45、 4.Six clamp bolts 5.Static earth point 6.Bung to suit flask Figure 3. Typical 140 mm diameter filter disc holder assembly Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 12:59:02 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 6 BSI 1997 BS 7881 : 1997 Key 1.Filter
46、disc holder 2.Rubber bung 3.PVC tubing 4.Vacuum flask 5.Vacuum pump Figure 4. Vacuum flask and pump for filter discs 4.5 Calibration of test rig NOTE. The numbers that appear in brackets in this clause relate to the numbers in figure 2. 4.5.1 Calibrate the flow rate of the test rig with a filter of
47、similar construction. 4.5.2 Prime the rig by pouring test liquid into the funnel (1) with isolating cock (8), flow control cock (7) and stopcock (4) open, and pinchcocks (5) and (9) closed, and allow the liquid to flow slowly up through the filter until all the air has been eliminated, controlling t
48、he rate of flow with the flow control cock (7). When the separating flask (3) is full, close the isolating cock (8). 4.5.3 With the stopcock (4) and pinchcock (9) fully open, adjust the flow control cock (7) to give a flow of 0.9 l to 1.1 l/min by use of the measuring cylinder and stop watch, refill
49、ing to the top mark before the start of each test. 4.5.4 Remove and discard the filter. 4.6 Test procedure for HIAC particle count method (procedure A) NOTE. The numbers that appear in brackets in this clause relate to the numbers quoted in figure 2. 4.6.1 Install the filter to be tested in the clean test rig and prime the rig with membrane filtered test liquid as described in 4.5.2, except that the flow control cock (7) is left in the calibrated position specified in 4.5.3. 4.6.2 Allow the liquid to flow out of the separating flask (3) and close the effluent pinc