1、Designation: E 790 08Standard Test Method forResidual Moisture in a Refuse-Derived Fuel AnalysisSample1This standard is issued under the fixed designation E 790; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revi
2、sion. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the measurement of the residualmoisture in an analysis sample of RDF. It is used to calculateto the dry
3、 basis other determinations performed on the analysissample. It is used with the air-dry moisture results to calculatetotal moisture (Note 1). The total moisture is used to calculateas-received values or other analyses performed on the sample.NOTE 1In some instances RDF moisture may change during th
4、esize-reduction steps of the analysis sample preparation procedure. Thismoisture change, unless suitable corrections are made, will affect theaccuracy of the total moisture value as calculated from the air-dry andresidual moisture results.1.2 The values stated in SI units are to be regarded asstanda
5、rd. No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applic
6、a-bility of regulatory limitations prior to use. For more specificprecautionary information see Section 7.2. Referenced Documents2.1 ASTM Standards:2D 3173 Test Method for Moisture in theAnalysis Sample ofCoal and CokeD 5681 Terminology for Waste and Waste ManagementE 180 Practice for Determining th
7、e Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals3. Terminology3.1 For definitions of terms used in this test method, refer toTerminology D 5681.4. Summary of Test Method4.1 This test method is based on the loss in weight of anair-dried analysis sample of RDF
8、 under rigidly controlledconditions of temperature, time, and air flow.4.2 The total moisture is calculated from the loss or gain inair drying and the residual moisture as determined by this testmethod.5. Significance and Use5.1 The treatment of the sample as specified herein isintended for the purp
9、ose of determining the residual moisturepresent in an analysis sample of RDF.5.2 The residual moisture value is used to convert as-determined analyses such as gross heating value, sulfur, andash to a dry sample basis.6. Apparatus6.1 Drying Oven:6.1.1 Referee TypeThe oven shall be so constructed as t
10、ohave a uniform temperature within the specimen chamber, havea minimum excess air volume, and be capable of constanttemperature regulation at 107 6 3C. Provision shall be madefor renewing the preheated air in the oven at the rate of two tofour times a minute, with the intake air dried by passing itt
11、hrough a desiccant. An oven similar to the one illustrated inFig. 1 of Test Method D 3173 is suitable.6.1.2 Routine TypeAdrying oven of either the mechanicalor natural circulation type which is capable of constant uniformtemperature within the specimen chamber regulated at 107 63C.NOTE 2Either type
12、of oven may be used for routine determinations.However, the referee-type oven shall be used to resolve differencesbetween determinations.6.2 ContainersA convenient form that allows the ashdetermination to be made on the same sample is a porcelaincapsule 22 mm in depth and 44 mm in diameter or a fuse
13、dsilica capsule of similar shape. This shall be used with awell-fitting flat aluminum cover. Platinum crucibles or glasscapsules with ground-glass caps may also be used. They shouldbe as shallow as possible consistent with convenient handle-ability.6.3 Analytical Balance, with 0.1 mg sensitivity.1Th
14、is test method is under the jurisdiction of ASTM Committee D34 on WasteManagement and is the direct responsibility of Subcommittee D34.03.02 onMunicipal Recovery and Reuse.Current edition approved Sept. 1, 2008. Published October 2008. Originallyapproved in 1981. Last previous edition approved in 20
15、04 as E 790 87(2004).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr
16、Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.4 Analysis Sample ContainersHeavy (minimum 4 mil),vapor-impervious bags, properly sealed; or noncorroding cans,glass jars, or plastic bottles with air-tight sealing covers to storeRDF samples for analysis. Containers shall
17、be checked forsuitability by measuring weight loss or gain of the sample andcontainer stored for 1 week under ambient laboratory condi-tions. The weight loss or gain should be less than 0.5 % of thesample weight stored in the container.7. Precautions7.1 Due to the origins of RDF in municipal waste,
18、commonsense dictates that some precautions should be observed whenconducting tests on the samples. Recommended hygienicpractices include use of gloves when handling RDF; wearingdust masks (NIOSH-approved type), especially when shred-ding RDF samples; conducting tests under negative pressurehood when
19、 possible; and washing hands before eating orsmoking.7.2 Laboratory sample handling shall be performed bytrained personnel. All operations shall be done rapidly aspossible to avoid sample moisture changes due to atmosphericexposure.7.3 Since heavy fine particles tend to segregate rapidly inthe RDF a
20、nalysis sample, the analyst should exercise care toassure that the analysis sample is well-mixed prior to perform-ing this determination.7.4 When the residual moisture is to be used for thedetermination of total moisture, special care shall be taken toavoid any change in sample moisture between the
21、completionof air drying and analysis for residual moisture. It is recom-mended that the delay between sample preparation and thedetermination of residual moisture be a maximum of 72 h.8. Sampling38.1 RDF products are frequently nonhomogeneous. For thisreason, significant care should be exercised to
22、obtain a repre-sentative laboratory sample from the RDF lot to be character-ized.8.2 The sample method for this procedure should be basedon agreement between the involved parties.8.3 The laboratory sample must be air-dried and particlesize reduced to pass a 0.5-mm screen for this analysis. Thisproce
23、dure must be performed carefully to preserve the sam-ples representative characteristics (other than particle size)while preparing the analysis sample to be used in this proce-dure.9. Procedure9.1 Heat the empty containers and covers under the condi-tions at which the sample is to be dried, place th
24、e stopper orcover on the container, cool over a desiccant for about 15 to 20min, and weigh. Mix the sample, if necessary, and dip out witha spoon or spatula from the sample bottle approximately1gofthe sample. Put the sample quickly into the container, cover,and weigh at once.NOTE 3If weighing bottle
25、s with air-tight covers are used, it may notbe necessary to preheat the moisture analysis container nor to desiccate itafter drying.9.2 Remove the cover and place in a desiccator. Quicklyplace the uncovered container into an oven preheated to 107 63C through which is passed a current of dry air. Clo
26、se theoven at once and heat for 1 hr. Open the oven, remove, coverthe container quickly, and cool in a desiccator over desiccant.Weigh the sample and container as soon as cooled toroom temperature.10. Calculation (see Note 1)10.1 Calculate the percent residual moisture, R,intheanalysis sample as fol
27、lows:R 5S 2 BS3 100 (1)where:S = grams of analysis sample used, andB = grams of sample after heating.10.2 Calculate the percent total moisture in the laboratorysample, as follows:M 5R 100 2 A!1001 A (2)where:R = residual moisture, %, andA = air dry loss determined during preparation of theanalysis s
28、ample, %.10.3 To convert other parameters determined on the analysissample, such as ash, sulfur, and gross calorific value, to a drysample basis, the following equation can be used:Pdry5Pad100!100 2 R(3)where:Pad= parameter, %“ as-determined” on the analysissample,R = residual moisture, % (see 10.1)
29、, andPdry= parameter, % expressed on a dry sample basis.11. Precision and Bias11.1 Precision:11.1.1 The standard deviations of individual determinations,in percent absolute are as follows:Typical AverageValueWithinLaboratoriesBetweenLaboratories2.54.5 % 0.15 % 0.50 %11.1.2 The above precision estima
30、tes are based on aninterlaboratory study conducted in accordance with PracticeE 180.11.2 BiasThe bias of this test method has not beendetermined due to a lack of a recognized standard referencematerial.3ASTM Subcommittee E38.01 is currently in the process of developingprocedures for sampling RDF and
31、 the preparation of an analysis sample. Thechairman of E38.01 should be contacted for details.E790082ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that det
32、ermination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved o
33、r withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel th
34、at your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).E790083
