1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationDD CEN/TS 15406:2010Solid recovered fuels Determination of bridgingproperties of bulk materialDD CEN/TS 15406:2010 DRAFT FOR DEVELOPMENTNational forewordThis Draft for Developmen
2、t is the UK implementation of CEN/TS 15406:2010. It supersedes DD CEN/TS 15406:2006 which iswithdrawn.This publication is not to be regarded as a British Standard.It is being issued in the Draft for Development series of publicationsand is of a provisional nature. It should be applied on thisprovisi
3、onal basis, so that information and experience of its practicalapplication can be obtained.Comments arising from the use of this Draft for Developmentare requested so that UK experience can be reported to theinternational organization responsible for its conversion toan international standard. A rev
4、iew of this publication willbe initiated not later than 3 years after its publication by theinternational organization so that a decision can be taken on itsstatus. Notification of the start of the review period will be made inan announcement in the appropriate issue of Update Standards.According to
5、 the replies received by the end of the review period,the responsible BSI Committee will decide whether to support theconversion into an international Standard, to extend the life of theTechnical Specification or to withdraw it. Comments should be sentto the Secretary of the responsible BSI Technica
6、l Committee at BritishStandards House, 389 Chiswick High Road, London W4 4AL.The UK participation in its preparation was entrusted to TechnicalCommittee PTI/17, Solid biofuels.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not p
7、urport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2010ISBN 978 0 580 69902 3ICS 75.160.10Compliance with a British Standard cannot confer immunity fromlegal obligations.This Draft for Development was published under the authority ofthe
8、 Standards Policy and Strategy Committee on 31 October 2010.Amendments issued since publicationDate Text affectedDD CEN/TS 15406:2010TECHNICAL SPECIFICATION SPCIFICATION TECHNIQUE TECHNISCHE SPEZIFIKATION CEN/TS 15406 September 2010 ICS 75.160.10 Supersedes CEN/TS 15406:2006English Version Solid rec
9、overed fuels - Determination of bridging properties of bulk material Combustibles solides de rcupration - Mthode de dtermination des proprits de formation de vote dans les matriaux en vrac Feste Sekundrbrennstoffe - Bestimmung der Neigung zur Brckenbildung von Schttgut This Technical Specification (
10、CEN/TS) was approved by CEN on 12 June 2010 for provisional application. The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their comments, particularly on the question whether the CEN/TS can be converted into a E
11、uropean Standard. CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS) until the
12、 final decision about the possible conversion of the CEN/TS into an EN is reached. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Lu
13、xembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2010 CEN All r
14、ights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. CEN/TS 15406:2010: EDD CEN/TS 15406:2010CEN/TS 15406:2010 (E) 2 Contents Page Foreword 3Introduction .41 Scope 52 Normative references 53 Terms and definitions .54 Determination of bridging prope
15、rties for non-coalescing materials 55 Determination of bridging properties for coalescing materials 96 Precision 117 Test report . 12Bibliography . 13DD CEN/TS 15406:2010CEN/TS 15406:2010 (E) 3 Foreword This document (CEN/TS 15406:2010) has been prepared by Technical Committee CEN/TC 343 “Solid reco
16、vered fuels”, the secretariat of which is held by SFS. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes CEN/TS
17、 15406:2006. CEN/TS 15406:2006 is not be converted into a European Standard as the test method specified in this document was not validated (see 1, 2). This document differs from CEN/TS 15406:2006 mainly as follows: a) Figures 1 and 2 replaced by new examples of figures for a bridging apparatus; b)
18、dimensions of the shear tester changed; c) automatic equipment allowed; d) repeatability limit specified; e) whole document editorially revised. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to announce this Technical Spe
19、cification: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the
20、United Kingdom. DD CEN/TS 15406:2010CEN/TS 15406:2010 (E) 4 Introduction This Technical Specification describes the determination of bridging properties of solid recovered fuels (SRF), which is conveyable in a continuous material flow. Bridging or arching is a complex parameter describing the situat
21、ion when particles form a stable bridge over an opening that can be several times the length of the single particles. Bridging is dependent on several influencing factors, e.g. the conveying or transport system, particle size and shape, moisture content, bulk density, bed depth. The behaviour of SRF
22、 in bins, hoppers, feeders, and other handling equipment depends on bridging properties 3. Knowing these properties, already in phase of product development, is essential for avoiding flow problems. Bridging properties are also important for quality control. By checking the relative bridging propert
23、ies of a given bulk solid before it is placed into a system, unsatisfactory batches can be rejected or recycled, thereby preventing costly handling problems downstream. Bridging is not an absolute value and therefore there is a need for standardising the conditions for the determination of bridging
24、tendency in order to gain comparative measuring results. Bridging of solid recovered fuels is subject to variation due to several impacts such as filling layer, particle shape, and storage time in silos. Measured bridging values can therefore deviate from real conditions in silos and conveyer system
25、s. DD CEN/TS 15406:2010CEN/TS 15406:2010 (E) 5 1 Scope This Technical Specification specifies a method for the determination of bridging properties of solid recovered fuels using standard measuring equipment. The method is applicable to all solid recovered fuels with maximum dimensions of the partic
26、le of 100 mm. 2 Normative references The following referenced documents are indispensable for the application of this Technical Specification. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applie
27、s. prEN 15357:2008, Solid recovered fuels Terminology, definitions and descriptions prEN 15442, Solid recovered fuels Methods for sampling prEN 15443, Solid recovered fuels Methods for the preparation of the laboratory sample CEN/TS 15414-1, Solid recovered fuels Determination of moisture content us
28、ing the oven dry method Part 1: Determination of total moisture by a reference method CEN/TS 15414-2, Solid recovered fuels Determination of moisture content using the oven dry method Part 2: Determination of total moisture by a simplified method CEN/TS 15415, Solid recovered fuels Determination of
29、particle size and particle size distribution by screen method 3 Terms and definitions For the purposes of this document, the terms and definitions given in prEN 15357:2008 apply. 4 Determination of bridging properties for non-coalescing materials 4.1 Principle A sample is subjected to bridging by pl
30、acing it over an expandable slot opening in an equipment of standardised dimensions. By increasing the slot opening, the building of a bridge is facilitated which ultimately will collapse; the size of the slot opening at this time represents the bridging value of the fuel tested. 4.2 Apparatus 4.2.1
31、 Bridging apparatus, consisting of a container with an effective area of (1,1 0,01) (2 0,01) m2and a minimum height of (0,75 0,01) m, the sides of the container manufactured of oriented strand board (OSB) plates. (See Figure 1 and Figure 2.) DD CEN/TS 15406:2010CEN/TS 15406:2010 (E) 6 Dimensions in
32、millimetres a) Front view b) Side view Key 1 rubber mat 2 piston 3 spring 4 steel coil Figure 1 Example for an assembling of a bridging apparatus in front and side view DD CEN/TS 15406:2010CEN/TS 15406:2010 (E) 7 The bottom of the container shall be made of two solid rubber mats with the following d
33、imensions: width: (1,1 0,01) m minimum length: 2,2 m thickness: (0,01 0,001) m One end of each rubber mat (see positions 1 in Figure 1) shall be fixed to the lower edge of the end plate of the container. The opposite ends shall be fixed to the pneumatic pistons (see positions 2 in Figure 1), after t
34、urning around the steel coils (see positions 4 in Figure 1) situated below the bottom of the container. The steel coils shall have external diameters of (0,32 0,001) m. The centre of the coils shall be placed at a distance of (0,43 0,05) m below the horizontal plane of the container underside. The c
35、oils are rolled in the direction of the side surfaces of the container by the movement of the pistons, forming a slot opening in the bottom of the container from the middle outward. When the force of the pistons is released, a spring (see position 3 in Figure 1) causes the two steel coils to return
36、in the initial position, closing the slot opening. This arrangement allows a constant opening movement minimizing the friction with the particles of the material. To facilitate the handling, the container may be equipped with wheeled legs. Figure 2 shows a section of Figure 1 to demonstrate the oper
37、ation principle of the bridging apparatus more detailed. Key 1 rubber mat 2 spring 3 steel coil in initial position 4 steel coil in opening phase Figure 2 Operation principle of the bridging apparatus DD CEN/TS 15406:2010CEN/TS 15406:2010 (E) 8 Figures 3 to 5 give pictorial representations of a brid
38、ging apparatus. Figure 3 Pictorial presentation of the front of a bridging apparatus Figure 4 Pictorial presentation of the operation principle of a bridging apparatus Figure 5 Pictorial presentation of the side of a bridging apparatus DD CEN/TS 15406:2010CEN/TS 15406:2010 (E) 9 4.2.2 Metric steel r
39、ule with a scale gradation of 1 mm, for measuring the distance between the coils after the bridge is collapsed. 4.2.3 Shovel, to homogenise the sample. 4.3 Sampling and sample preparation The sample shall be taken and prepared in accordance with prEN 15442 and prEN 15443. The minimum volume of the t
40、est portion shall be 1,1 m3loose volume. The particle size distribution of the material on a separate sub-sample shall be determined following the procedures given in prEN 15443 and CEN/TS 15415. The particle size shall be reported together with the result of the bridging test. The moisture content
41、of the material on a separate sub-sample shall be determined following the procedures given in prEN 15443 and CEN/TS 15414-1 or CEN/TS 15414-2. The moisture content shall be reported together with the result of the bridging test and at least the minimum sample size in accordance with prEN 15442. 4.4
42、 Procedure Place the bridging apparatus (4.2.1) horizontally on a clean, solid concrete floor. A distance shall exist between the floor and to the underside of the apparatus to allow a free fall of the sample material. The container of the bridging apparatus (4.2.1) shall be dry and empty. Load the
43、sample into this container of the bridging apparatus (4.2.1). Level out the upper surface of the sample so that a layer of 0,5 m thickness is evenly spread in the container. The loading of the container with the sample may be performed, for example, using a wheel loader. Roll the rubber mats slowly
44、by activating the pneumatic piston devices, thus generating a slot opening under the sample. As soon as the bridge collapses, stop the opening process and measure the shortest distance between the surface of the coils with the metric steel rule (4.2.2) to the nearest 1 mm. After the measurement is f
45、ully performed, open the bottom of the sample container by reactivating the piston devices and allow the container so to be completely cleared. Unify all the sample and repeat the test after rehomogenisation. The test shall be repeated ten times. NOTE The test should be performed preferably at the s
46、ite of SRF production or use since the test portion shall have a minimum volume of 1,1 m3(see 4.3). 4.5 Calculation Calculate the relative bridging property as the arithmetic mean of the ten repetitions. 5 Determination of bridging properties for coalescing materials 5.1 Principle For coalescing mat
47、erials, the minimum shear that causes the collapse of a consolidated sample is assumed as an index of bridging properties 4. DD CEN/TS 15406:2010CEN/TS 15406:2010 (E) 10 5.2 Apparatus 5.2.1 Shear tester, mainly consisting of a test chamber and a cover plate (see Figure 6). Dimensions in millimetres
48、Key 1 force gauge Figure 6 Schematic diagram of the shear tester (5.2.1) (longitudinal section) The chamber shall have a circular section. The inside dimensions of this cylinder shall be (150 5) mm width and (100 10) mm high. The bottom of the cylinder shall have a circular hole with a dimension of
49、(110 0,5) mm. The test sample shall be covered by a planar plate with a size of (90 0,5) mm; the plate shall be exactly positioned at the centre line of the test chamber. The plate shall be connected with a force gauge. Both the test chamber and cover plate shall be made of polished stainless steel. 5.2.2 Shovel, to homogenise the sample. 5.3 Sampling and sample preparation The sample shall be taken and prepared in accordance with prEN 15442 and prEN 15443. If necessar
