1、BRITISH STANDARD BS 3928:1969 Method for Sodium flame test for air filters (Other than for air supply to I.C. engines and compressors) UDC 621.928.9.001.4BS3928:1969 Tins British Standard, having been approved by the Mechanical Engineering Industry Standards Committee, was published under the author
2、ity of the Executive Board on 29 August 1969 BSI 09-1999 First published September, 1965 First revision August, 1969 The following BSI references relate to the work on this standard: Committee references MEE/95 and MEE/95/3 Draft for comment 68/11604 ISBN 580 05740 2 Co-operating organizations The M
3、echanical Engineering Industry Standards Committee, under whose supervision this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations: Associated Offices Technical Committee Institute of Marine Engineers Asso
4、ciation of Consulting Engineers Institution of Civil Engineers Association of Mining Electrical and Mechanical Institution of Gas Engineers Engineers Institution of Heating and Ventilating Board of Trade Engineers* British Chemical Plant Manufacturers Institution of Mechanical Engineers Association
5、Institution of Mechanical Engineers British Compressed Air Society* (Automobile Division) British Electrical and Allied Manufacturers Institution of Production Engineers Association Locomotive and Allied Manufacturers British Gear Manufacturers Association Association of Great Britain British Intern
6、al Combustion Engine London Transport Board* Manufacturers Association Machine Tool Trades Association British Mechanical Engineering Confederation Ministry of Defence British Pump Manufacturers Association Ministry of Defence, Army Department* British Steel Industry Ministry of Power Crown Agents f
7、or Oversea Governments and Ministry of Public Building and Works* Administrations Ministry of Technology* Department of Employment and Productivity Ministry of Technology National (H.M. Factory Inspectorate)* Engineering Laboratory Electricity Council, the Central Electricity Ministry of Transport G
8、enerating Board and the Area Boards in National Coal Board England and Wales National Physical Laboratory (Ministry of Engineering Equipment Users Association Technology) Gas Council Royal Institute of British Architects The Government departments and scientific and industrial organizations marked w
9、ith an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this standard: Council of British Manufacturers of Petroleum Society of British Aerospace Companies Ltd Equipment Technical Section of the British Paper and Fa
10、n Manufacturers Association Ltd Board Makers Association Ministry of Public Building between 200 ft 3 /min (340 m 3 /h) and 500 ft 3 /min (850 m 3 /h) 2 atomizers; between 50 ft 3 /min (85 m 3 /h) and 200 ft 3 /min (340 m 3 /h) 1 atomizer, and below 50 ft 3 /min (85 m 3 /h) preferably a one hole ato
11、mizer. Each compressed air flowmeter shall be capable of measuring 3.3 ft 3 /min to 3.5 ft 3 /min (95 l/min to 100 l/min) of free air at a pressure of 100 lbf/in 2(7 bar 6) ). Alternatively, a single flowmeter capable of measuring the same total flow may be incorporated in the manifold (e.g.2 ft 3 /
12、min to 20 ft 3 /min (50 l/min to 500 l/min) range flowmeter for 4 atomizers), together with an isolating valve on each feedpipe. The constant pressure of 100 lbf/in 2(7 bar 6) ) may be obtained by the use of either a bleed-off valve or a regulating valve in the manifold. The valve shall be mounted n
13、ear the flame tube to facilitate operation of the rig, together with a pressure gauge and the flowmeter (ifa single one is used). The pressure gauge shall be of the Bourdon type with a dial of not less than6inches (150 mm) diameter, reading accurately to100 lbf/in 2(7 bar 6) ). 3.4 Ducting. The duct
14、ing B shall be of such diameter, D, that the linear speed of air shall not exceed 30 ft/s (9 m/s) and of such length that at least 2 seconds shall elapse for the passage of air between the atomizers and the filter under test, so that complete evaporation of water from the spray takes place before ar
15、rival at the filter. It shall be made of, or treated with, salt-resistant material such as polyvinyl chloride. A sump shall be provided on the underneath of the duct, placed at a distanceD from the spray box, to drain liquid carried over from the atomizers. The circular mixing baffle of diameter sit
16、uated at least 10 D from the spray box shall be supported centrally on wires or thin strips offering little resistance to flow. One axial sampling point E facing up-stream, at least5D from the baffle shall be provided in the inlet ducting, near the front face of the filter unit, for calibration purp
17、oses and r.h. measurements of the salt-laden air. The sampling orifice E shall have a sharp leading edge, and be of such a diameter that the sampling velocity is between ! and 4 times the duct velocity at a sampling flow rate of between1ft 3 /min and 2 ft 3 /min (28 l/min and56 l/min). Within these
18、limits, errors due to anisokinetic sampling are negligible. For a test rig handling 1000 ft 3 /min (1700 m 3 /h) ducting diameter D of 12 in (305mm) is suitable. 3.5 The filter housing. This shall consist of expanding sections from circular inlet to rectangular section, the cross-sectional area of t
19、he large end being not more than 50 % greater than that of the filter under test. Between the expanding sections there shall be a parallel section, of the same cross section as the rectangular ends, having a length between 10 % and 20 % greater than the depth of the filter under test, and within whi
20、ch the complete filter unit (including support and retaining frame) is to be mounted on a suitable supporting plate in accordance with the filter manufacturers normal method of installation. Static pressure taps shall be provided as near as practicable to the front and back faces of the filter. A su
21、itable differential manometer capable of being read to an accuracy of 0.05 in (0.1mm) water gauge (w.g.) shall be connected to the pressure taps. NOTEWhen the maximum face dimension of the filter exceeds say,3ft (915mm) the expander section on the upstream side becomes inconveniently long. Shorter expanders (but not less than1;X ) may be used if it is demonstrated that the dust distribution remains uniform over the face of the filter. 5) 1 bar = 10 5N/m 2 . 6) 1 bar = 10 5N/m 2 . D/2
