1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58gaseous fluoride contentICS 13.040.40Stationary source emissions Sampling and determination of BRIT
2、ISH STANDARDBS ISO 15713:2006BS ISO 15713:2006This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 June 2006 BSI 2006ISBN 0 580 48774 1Cross-referencesThe British Standards which implement international publications referred to in this document
3、 may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online.This publication does not purport to include all the necessary provisions of a contract. User
4、s are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations.Summary of pagesThis document comprises a front cover, an inside front cover, the ISO title page, pages ii to v, a blank page, pages 1 to 14, an inside back cov
5、er and a back cover.The BSI copyright notice displayed in this document indicates when the document was last issued.Amendments issued since publicationAmd. No. Date CommentsA list of organizations represented on this subcommittee can be obtained on request to its secretary. present to the responsibl
6、e international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK.National forewordThis British Standard reproduces verbatim ISO 15713:2006 and impleme
7、nts it as the UK national standard.The UK participation in its preparation was entrusted by Technical Committee EH/2, Air quality, to Subcommittee EH/2/1, Stationary source emissions, which has the responsibility to: aid enquirers to understand the text;Reference numberISO 15713:2006(E)INTERNATIONAL
8、 STANDARD ISO15713First edition2006-06-01Stationary source emissions Sampling and determination of gaseous fluoride content missions de sources fixes chantillonnage et dtermination de la teneur en fluorure gazeux BS ISO 15713:2006ii iiiContents Page Foreword iv Introduction . iv 1 Scope 1 2 Normativ
9、e references 1 3 Terms and definitions .1 4 Principle2 5 Reagents.2 6 Apparatus .3 7 Sampling.5 8 Analytical procedure by ion selective electrode 9 9 Expression of results 11 10 Performance characteristics 13 11 Test report 13 BS ISO 15713:2006iv Foreword ISO (the International Organization for Stan
10、dardization) 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
11、 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 S
12、tandards 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
13、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 15
14、713 was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 1, Stationary source emissions. BS ISO 15713:2006vIntroduction This International Standard describes a method for the measurement of the concentration of gaseous fluoride compounds in flue gas passing through ducts or c
15、himneys. The effects of fluoride containing species are of concern as irritants to humans when inhaled at high concentration and because of the potential for adverse effects on vegetation. For the purposes of this International Standard, the fluoride measured is quoted as hydrogen fluoride. The aim
16、of the method is to measure hydrogen fluoride, but, in practice, the parameter assessed is operationally defined. The fluoride measured is from those compounds that pass through a filter and dissolve in dilute sodium hydroxide and which produce fluoride ions which remain present in solution when ana
17、lysed. BS ISO 15713:2006blank1Stationary source emissions Sampling and determination of gaseous fluoride content 1 Scope This International Standard is applicable to the measurement of the gaseous fluorides that are entrained in gases carried in stacks or ducts. The gaseous fluoride content is expre
18、ssed as a mass of hydrogen fluoride in the stack gas. This International Standard is applicable to all stacks emitting gases with fluoride concentrations of below 200 mg/m3. It can be used for higher concentrations, but then the absorption efficiency of the bubblers should be checked before the resu
19、lts can be regarded as valid. The detection limit of the method is estimated as 0,1 mg m3, based on a sample volume of 0,1 m3. All compounds that are volatile at the filtration temperature and produce soluble fluoride compounds upon reaction with water are measured by this method. The method does no
20、t measure fluorocarbons. The concentration of fluoride in the adsorbent solution is then measured using an ion selective electrode. The amount of fluoride measured is then expressed as hydrogen fluoride by convention, though this may not reflect the chemical nature of the compounds, which are measur
21、ed. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 9096:2003, Station
22、ary source emissions Manual determination of mass concentration of particulate matter ISO 10780, Stationary source emissions Measurement of velocity and volume flowrate of gas streams in ducts 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 i
23、sokinetic sampling sampling at a flowrate such that the velocity and direction of the gas entering the sampling nozzle is the same as that of the gas in the duct at the sampling point ISO 9096:2003 3.2 sampling point specific position on the sampling section at which a sample is extracted NOTE Sampl
24、ing points are spread out over the sampling section in order to be representative of subsections of equal areas. BS ISO 15713:20062 3.3 STP standard conditions for temperature, 273,15 K, and pressure, 101,325 kPa 4 Principle As a result of the high reactivity and solubility of hydrogen fluoride, par
25、ticular precautions are required to minimize irreversible loss of the species of interest and to take a representative sample. Firstly, if incorrect materials are selected for the sampling probe, impingers and connecting tubing they could react irreversibly with the species of interest. Secondly, if
26、 condensed liquid droplets are present in the probe before the impingers the species of interest may dissolve in them and so not be included in the measurement. Further, where droplets are present in the flue, if the sample is not taken isokinetically, then it may not be representative. The flow con
27、ditions at a sampling plane are determined before sampling. If there are droplets present, then isokinetic sampling at a number of sampling points is necessary. The homogeneity of the spatial profiles of the flue gas velocity, temperature and oxygen concentration is investigated. If there is signifi
28、cant variability in any of these parameters, but no droplets, then sampling is carried out at a number of sampling points but at a constant flow rate. If these parameters exhibit homogeneity, then sampling is carried out at a single point at a constant flow rate. To determine the gaseous fluoride co
29、ntent of the flue gas, a representative metered sample of that gas is drawn through a heated sampling probe and filter. Any droplets, which may contain dissolved gaseous fluoride compounds, are evaporated in the heated probe. Particulate bound fluoride species that may be present as solid materials
30、are removed by filtration of particulates at a controlled temperature. Gaseous fluoride compounds or more precisely those water-soluble fluoride compounds that pass through the filter are absorbed using a sampling train made up of a series of impingers containing a sodium hydroxide solution. The con
31、centrations of dissolved fluoride ions in the collected solutions are measured using the ion selective electrode technique. 5 Reagents To carry out the method, the following reagents are required to be of a recognized analytical grade. If they have changed visibly, they should be discarded. 5.1 Abso
32、rber solution, 0,1 mol/l NaOH solution. 5.2 Sample gas drying agent, self-indicating coarse grade silica gel. 5.3 Total ionic strength adjustment buffer (TISAB). Sodium chloride Sodium acetate trihydrate Trisodium citrate monohydrate Glacial acetic acid Deionized or distilled water 5,0 mol/l NaOH BS
33、 ISO 15713:200635.4 Calibration solutions. Deionized or distilled water Sodium fluoride 6 Apparatus 6.1 Introduction A schematic diagram of the equipment for the sampling of gaseous fluorides is given in Figure 1. The apparatus consists of a sampling probe and filter assembly that may be heated if r
34、equired, an impinger train containing sodium hydroxide solution to capture gaseous fluorides, a pressure gauge, a suction control valve, a suction pump, a gas meter, and a sample gas volume flow rate measurement system. A thermometer and manometer shall be included in the sample train to allow the t
35、emperature and relative pressure of the metered gas to be determined. A barometer shall be used to measure atmospheric pressure during the test in order that the volume of the gas sampled can be normalized to standard conditions of 273,15 K and 101,325 kPa. 6.2 Probe The probe shall be a length of r
36、igid tubing and shall be capable of withstanding the temperature within the duct. It shall be resistant to chemical attack from the various pollutants in the duct. In particular, the probe shall be resistant to fluoride attack to avoid sample loss. Suitable materials for fluoride sampling are silica
37、 or Moneltype alloys1). The probe shall have a heating system capable of maintaining a gas temperature at its exit of at least 423 K or 20 K 5 K above the dew point temperature, whichever is the higher. The internal surfaces of the sample probe shall be cleaned thoroughly before each sample run by r
38、insing it with deionized water. Between samples, it will first be necessary to allow the probe to cool. The probe rinse shall be repeated until the rinse water shows no evidence of particulate matter. 6.3 Filter and filter housing A filter shall be used to capture particulate material to prevent dis
39、solution of any soluble particulate fluoride. Filters can be placed in the duct between the nozzle and the probe only if there are no droplets present, or out of the duct before the first impinger. If a filter is used outside the duct, it shall be heated to a temperature of at least 423 K or 20 K 5
40、K above the dew point temperature, whichever is the higher, to avoid condensation. If the amount of particulate fluoride within the sample is below 10 % of the total, then the filter can be omitted. Filters and filter holders shall be made of material resistant to attack by fluorides; for example, g
41、lass frits will remove gaseous fluoride and therefore cannot be used as filter supports. Filter holders shall have an airtight seal against leakage from outside or around the filter. The filter shall be capable of withstanding prolonged exposures up to 40 K above the temperature setting and have at
42、least 99,5 % collection efficiency for 0,3 m diameter particles. The filter housing shall be cleaned thoroughly prior to use and before each sample run using deionized distilled water until no particulate matter is present on the inner surfaces of the filter holder. 1) Moneltype alloys is an example
43、 of a suitable product(s) available commercially. This information is given for the convenience of users of this International Standard and does not constitute an endorsement by ISO of this product. BS ISO 15713:20064 6.4 Sampling train The impingers shall be connected to the sampling probe using HF
44、 resistant materials. Suitable materials are polypropylene, polyethylene or Vitontubing 2). The sampling train consists of a series of four impingers through which the sample gases are passed and the fluorides are removed into solution. The impingers can be made of quartz, polypropylene or polyethyl
45、ene. Convenient sizes for impingers are 125 ml to 250 ml. The first two impingers shall contain between 50 ml and 100 ml of 0,1 mol/l NaOH solution of analytical grade. The third impinger shall be left empty to catch any carryover of the absorption solution. The fourth impinger shall be used a dryin
46、g unit. Its materials of construction need not be resistant to HF. It shall be filled with silica gel to dry the sample gas prior to the suction unit, gas meter and volume flow meter. Prior to use, the impingers shall all be rinsed and cleaned with distilled or deionized water and a bottlebrush. Dur
47、ing sampling, the gases shall enter the first impinger at its base and bubble up through the sodium hydroxide solution before entering the second impinger at its base. The geometry of the impingers and quantity of absorbing solution employed shall be such that a gaseous fluoride absorbance efficienc
48、y of not less than 95 % is achieved at the chosen sampling flow rate and in the concentration range examined. Evidence that this criteria is met shall be demonstrated on at least one occasion at the maximum flow rate used with that design of equipment. 6.5 Suction unit The pump is used to draw the s
49、ample through the sampling train. It shall be an airtight pump capable of maintaining the selected sampling flow rate throughout the sampling period and shall be adjusted using a flow regulator. 6.6 Thermometer An airtight thermometer shall be fitted into the sample line after the drying unit and before the gas meter. The thermometer shall be capable of measuring absolute temperature to within 1 % of the absolute temperature. 6.7 Differential pressure gauge The differential pressure gauge shall be used to measure the differen
