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1、BRITISH STANDARD BS 3048:1958 Incorporating Amendment No. 1 Code for the Continuous Sampling and Automatic Analysis of Flue Gases: Indicators and Recorders UDC 662.613.5:543 Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 29 03:37:29 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 3048:1958 This B
2、ritish Standard, having been approved by the Instrument Industry Standards Committee and endorsed by the Chairman of the Engineering Divisional Council, was published under the authority of the General Council on 28 November 1958 BSI 10-1999 The following BSI references relate to the work on this st
3、andard: Committee reference INE/5/1 Draft for comment CW(INE) 9429 ISBN 0 580 3 5595 0 Co-operating organizations The Instrument Industry Standards Committee, under whose supervision this British Standard was prepared, consists of representatives from the following Government departments and scienti
4、fic and industrial organizations: The Government departments and scientific and industrial organizations marked with an asterisk in the above list, together with the following, were directly represented on the Committee entrusted with the preparation of this standard: Association of Scientific Worke
5、rsGauge and Tool Makers Association British Ceramic Research AssociationInstitute of Physics British Clock and Watch Manufacturers Institution of Chemical Engineers AssociationInstitution of Electrical Engineers British Electrical and Allied Industries Institution of Heating and Ventilating Research
6、 AssociationEngineers British Electrical and Allied Manufacturers Institution of Mechanical Engineers* AssociationIron and Steel Institute* British Industrial Measuring and Control Meteorological Office Apparatus Manufacturers Association*Ministry of Health British Iron and Steel Federation*Ministry
7、 of Housing and Local Government British Nautical Trade AssociationMinistry of Supply British Railways, The British Transport National Coal Board* CommissionNational Physical Laboratory (D.S.I.R.) British Scientific Instrument Research Oil Companies Materials Committee* Association*Radio Industry Co
8、uncil Council of British Manufacturers of Petroleum Scientific Instrument Manufacturers EquipmentAssociation Electricity Council, the Generating Board and Society of Instrument Technology the Area Boards in England and WalesWater-Tube Boilermakers Association Engineering Equipment Users Association
9、D.S.I.R. Fuel Research StationMinistry of Works Institution of Civil EngineersManufacturers of instruments for gas Ministry of Poweranalysis Amendments issued since publication Amd. No.Date of issueComments 7752August 1993Indicated by a sideline in the margin Licensed Copy: sheffieldun sheffieldun,
10、na, Wed Nov 29 03:37:29 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 3048:1958 BSI 10-1999i Contents Page Co-operating organizationsInside front cover Forewordiv Part 1. General Section 1. The significance of carbon dioxide and other measurements for combustion control1 1Flue gas analysis1 2Carbon
11、dioxide content of waste gases1 3Excess air requirements2 4Determination of excess air from oxygen measurements6 5Water vapour9 6Flue gas loss9 Section 2. Applications15 7Steam boilers15 8Continuous furnaces15 9Glass tank furnaces15 10High temperature intermittent furnaces16 11Gas producers16 12Blas
12、t furnaces16 13Regenerative furnaces17 Section 3. Installation, care and maintenance of sampling lines and instruments18 14General18 15Sampling system18 16Maintenance28 Section 4. Classification of types of instruments29 17General29 18Properties of gases which can be used for assessing composition29
13、 19Measurement of carbon dioxide30 20Choice of method for determining carbon dioxide30 21Measurement of carbon monoxide and combustible gases32 22Measurement of oxygen32 23Measurement of sulphur dioxide and sulphur trioxide33 24Measurement of smoke33 25Water vapour33 Part 2. Thermal conductivity ins
14、truments Section 1. General34 26Operating principle of thermal conductivity instruments34 27The conductivity cell34 28Electrical arrangements35 Section 2. Instruments and accessories36 29Indicators36 30Recorders36 31Use for measurement of oxygen37 32Instruments for measuring percentage of combustibl
15、e gases37 33Reference37 Part 3. Instruments depending upon chemical absorption and chemical reaction Section 1. Instruments measuring change in volume38 34Principles of operation38 Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 29 03:37:29 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 3048:1958
16、 ii BSI 10-1999 Page 35Solutions used and their renewal38 36Mechanical arrangements41 37The measurement of oxygen42 38The measurement of combustibles42 Section 2. Instruments measuring change of pressure 39General description43 Section 3. Instruments measuring change of temperature43 40General descr
17、iption43 Section 4. Diffusion instruments43 41Operating principles44 42Absorbents used and their renewal44 43Mechanical arrangements44 44The measurement of oxygen and combustibles44 Part 4. Viscosity and density instruments Section 1. Validity of inferential methods45 45Principle45 Section 2. Carbon
18、 dioxide recorders depending on gas density45 4645 47Direct weighing45 48Buoyancy46 49Effusion46 50Acoustic velocity46 51Dynamic method46 Part 5. Recent gas analysis instruments Section 1. General48 5248 Section 2. Oxygen meters depending directly upon the paramagnetism of oxygen48 53General48 54Dir
19、ect deflectional method48 55Method utilizing the loss of paramagnetism caused by heating50 Section 3. Oxygen meters depending indirectly upon the paramagnetism of oxygen51 5651 Section 4. Recording infra-red absorption instruments for gas analysis52 57General theory52 58Principle of method53 59Some
20、practical applications54 Part 6. Determination of dew point 6055 Part 7. Kindred subjects 61Sampling and analysis of fuel56 62Dust and smoke testing56 63Temperature measurement56 64Flow measurement56 65Smoke density indication and alarms56 66Instantaneous indication of combustion efficiency56 67Gene
21、ral references56 Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 29 03:37:29 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 3048:1958 BSI 10-1999iii Page Figure 1a Oxygen, nitrogen, air, carbon monoxide and carbon dioxide11 Figure 1b Hydrogen12 Figure 1c Water vapour13 Figure 2 Heat loss as a fun
22、ction of flue gas temperature and air/gas ratio 14 Figure 3a19 Figure 3b19 Figure 419 Figure 519 Figure 6a Water or mercury seal for breaking excessive vacuum21 Figure 6b Explanatory diagram of seal shown above22 Figure 7 Open vessel23 Figure 8 Closed vessel23 Figure 9 Continuous seal23 Figure 10 Wa
23、ter aspirator; water column type25 Figure 11 Water aspirator; injector type26 Figure 12 Venturi aspirator operated by chimney draught27 Figure 13 Electrical arrangement of thermal conductivity analyser, d.c. type35 Figure 14 Electrical arrangement of thermal conductivity analyser, a.c. type36 Figure
24、 15 Carbon dioxide absorption capacity of solutions of sodium hydroxide and of potassium hydroxide40 Figure 16 Determination of oxygen content from the magnetic susceptibility of oxygen. Direct deflectional method49 Figure 17 Determination of oxygen content from the magnetic susceptibility of oxygen
25、. Indirect method depending on the loss of paramagnetism on heating (magnetic wind method)50 Figure 18 Determination of oxygen content from the magnetic susceptibility of oxygen. Indirect method depending on the change in the viscosity of oxygen in a magnetic field52 Figure 19 Recording infra-red ab
26、sorption gas analyser53 Table 1 Theoretical carbon dioxide content of flue gases from typical fuels2 Table 2 Excess air required for complete combustion of typical fuels3 Table 3 Combustion air requirements and flue gas composition for typical fuels4 Table 4 Gaseous fuel5 Table 5 Loss of heat in flu
27、e gas, from bituminous coal, as derived from actual carbon dioxide analyses7 Table 6 Calorific values of fuel gas constituents10 Table 7 Approximate error in carbon dioxide reading32 Table 8 Relative thermal conductivities of certain gases35 Table 9 Specific gravities and relative viscosities of flu
28、e gas constituents45 Table 10 Magnetic susceptibility of some common gases48 Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 29 03:37:29 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 3048:1958 iv BSI 10-1999 Foreword This standard makes reference to the following British Standards: BS 526, Defin
29、itions of gross and net calorific value. BS 845, Code for commercial acceptance tests for steam boilers. BS 893, Method of testing dust extraction plant and the emission of solids from chimneys of electric power stations. BS 1016, Methods for the analysis and testing of coal and coke. BS 1017, The s
30、ampling of coal and coke. BS 1041, Code for temperature measurement. BS 1042, Code for flow measurement. BS 1756, Code for the sampling and analysis of flue gases. BS 2740, Simple smoke alarms and alarm metering devices. BS 2741, Recommendations for the construction of simple smoke viewers. BS 2742,
31、 Notes on the use of the Ringelmann Chart. BS 2742C, The Ringelmann Chart. BS 2811, Smoke density indicators and recorders. This British Standard Code is one of two prepared at the request of the Ministry of Power to assist in raising the general level of combustion efficiency in industry by the rig
32、ht understanding and use of flue gas analysis. This code does not concern itself with the selection of the point from which the sample should be taken or the kind of sampling tube which should be used, as these are dealt with in the British Standard Code on sampling and analysis.1) That code covers
33、all manually operated instruments for gas analysis and the necessary precautions to be taken with them, while this code deals with automatic instruments which give a direct indication or record of the gas composition. Since it is the policy of the Ministry to recommend the use of these instruments w
34、here the size of the installation justifies it, it has been thought helpful to preface the code by some notes on the value of automatic instruments for combustion control. The remainder of this first part gives some general notes on the use of indicating and recording instruments, while in the subse
35、quent parts of the code different types of instruments are considered together with points relevant to their use. This procedure naturally involves a certain amount of repetition but has the advantage that each part is complete in itself. A British Standard does not purport to include all the necess
36、ary provisions of a contract. Users of British Standards are responsible for their correct application. 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, pages i to iv, pages 1
37、to 56, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. 1) BS 1756:1952, “Code for the sampling and analysis of flue gases”. Licensed Copy: she
38、ffieldun sheffieldun, na, Wed Nov 29 03:37:29 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 3048:1958 BSI 10-19991 Part 1. General Section 1. The significance of carbon dioxide and other measurements for combustion control 1 Flue gas analysis Analysis of flue gases from industrial plant serves four
39、main purposes. First, it indicates whether the general conditions for efficient running have been fulfilled; second, it forms a useful check on the continuance of these conditions and draws attention to any need for maintenance of the plant; third, it provides the necessary information for a full he
40、at balance to be calculated; and lastly, it gives an indication of the type of atmosphere present in the furnace. Since fuels consist mainly of compounds of carbon, hydrogen and oxygen, together with smaller amounts of sulphur, instruments used for flue gas analysis are confined to those which will
41、measure the products of their combustion. The latter are the gases carbon dioxide, carbon monoxide, water vapour, sulphur dioxide and sulphur trioxide. Provision for the measurement of oxygen from any excess air and for unconsumed gases such as hydrogen, carbon monoxide, methane and other hydrocarbo
42、ns, is also made, since these gases are liable to occur if insufficient air has been used, or if a reducing atmosphere is dictated by the process requirements. When a fuel is burnt the products of combustion are necessarily heated and, therefore, to obtain the highest thermal efficiency these gases
43、should not be excessively diluted with air, and on their final emergence to the atmosphere should be at as low a temperature as practicable. 2 Carbon dioxide content of waste gases From the analysis of a fuel, the resultant theoretical air requirements for complete combustion may be calculated, and
44、from this the analysis of the resultant theoretical flue gases. In practice, the most commonly determined component of the flue gases is carbon dioxide. Oxygen may also be determined and frequently the combustible gases (carbon monoxide, hydrogen, etc.) are measured. Where there are no special condi
45、tions it is usually sufficient to measure the carbon dioxide. (See Clause 4 for applications where oxygen measurements are desirable because carbon dioxide measurements are meaningless.) Table 1 shows the theoretical percentage of carbon dioxide for perfect combustion, with no excess air, for a numb
46、er of fuels. These figures are necessarily approximate, depending as they do on the hydrogen content of the particular fuel. When flue gases are to be analysed, they are first cooled, and in consequence almost all the water vapour is condensed and does not appear in the final analysis. The figures a
47、re, therefore, for dry gases at 60 F. The fact that water vapour is not usually determined in the analysis of flue gases does not imply that its quantity is unimportant. Water vapour contains 1 055 B.t.u. of latent heat per pound apart from the sensible heat it may contain by virtue of its temperatu
48、re in excess of 60 F, and in preparing a heat balance its effect must be considered. The usual method is to determine the total moisture in the original fuel and to add to this the amount of water in the combustion air and the water produced by combustion of the hydrogen (i.e. 9 times the weight of
49、hydrogen per pound of fuel), and also the weight of water supplied as steam for forced draught or firebar cooling or as water spray for ash quenching and also any other steam, such as that supplied in the blast to a gas producer. The heat loss in water vapour per pound of fuel may be calculated as follows: Loss = W1 055 + 0.45 (T 60) B.t.u. per lb of fuel where W = weight of water in pounds (as calculated) per pound of fuel and T = temperature of flue gas (F). The figures in Table 1 are sufficiently accurat
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