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ASTM E1248-90(2004)

(Practice)

Standard Practice for Shredder Explosion Protection

Standard Practice for Shredder Explosion Protection

SIGNIFICANCE AND USE
Shredder explosions have occurred in most refuse processing plants with shredding facilities. Lessons learned in these incidents have been incorporated into this practice along with results of relevant test programs and general industrial explosion protection recommended practices. Recommendations in this practice cover explosion protection aspects of the design and operation of shredding facilities and equipment used therein.
This practice is not intended to be a substitute for an operating manual or a detailed set of design specifications. Rather, it represents general principles and guidelines to be addressed in detail in generating the operating manual and design specifications.
SCOPE
1.1 This practice covers general recommended design features and operating practices for shredder explosion protection in resource recovery plants and other refuse processing facilities.
1.2 Hammermills and other types of size reduction equipment (collectively termed shredders) are employed at many facilities that mechanically process solid wastes for resource recovery. Flammable or explosive materials (for example, gases, vapors, powders, and commercial and military explosives) may be present in the as-received waste stream. There is potential for these materials to be released, dispersed, and ignited within or near a shredder. Therefore, explosion prevention and damage amelioration provisions are required.

General Information

Status
Historical
Publication Date
27-Dec-1990
ICS
13.230 - Explosion protection
Technical Committee
D34 - Waste Management
Drafting Committee
D34.03 - Treatment, Recovery and Reuse
Current Stage
Ref Project

Relations

Replaces
ASTM E1248-90(1997) - Standard Practice for Shredder Explosion Protection
Effective Date
28-Dec-1990
Replaced By
ASTM E1248-90(2009) - Standard Practice for Shredder Explosion Protection
Effective Date
01-Sep-2009
Referred By
ASTM D5681-22e1 - Standard Terminology for Waste and Waste Management
Effective Date
28-Dec-1990

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ASTM E1248-90(2004) - Standard Practice for Shredder Explosion Protection
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Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: E1248 – 90 (Reapproved 2004)
Standard Practice for
1
Shredder Explosion Protection
This standard is issued under the fixed designation E1248; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3.1.4 explosion venting—the provision of an opening(s) in
the shredder enclosure and contiguous enclosed areas to allow
1.1 This practice covers general recommended design fea-
gases to escape during a deflagration and thus prevent pres-
tures and operating practices for shredder explosion protection
sures from reaching the damage threshold.
in resource recovery plants and other refuse processing facili-
3.1.5 explosionsuppression—thetechniqueofdetectingand
ties.
extinguishing incipient explosions in the shredder enclosure
1.2 Hammermills and other types of size reduction equip-
and contiguous enclosed areas before pressures exceed the
ment (collectively termed shredders) are employed at many
damage threshold.
facilities that mechanically process solid wastes for resource
3.1.6 inerting—the technique by which a combustible mix-
recovery. Flammable or explosive materials (for example,
tureisrenderednonflammablebyadditionofagasincapableof
gases, vapors, powders, and commercial and military explo-
supporting combustion.
sives) may be present in the as-received waste stream. There is
3.1.7 shredder—a size-reduction machine that tears or
potential for these materials to be released, dispersed, and
grinds materials to a smaller and more uniform particle size.
ignited within or near a shredder. Therefore, explosion preven-
tion and damage amelioration provisions are required.
4. Significance and Use
2. Referenced Documents 4.1 Shredder explosions have occurred in most refuse pro-
cessing plants with shredding facilities. Lessons learned in
2.1 National Fire Protection Association Standards:
these incidents have been incorporated into this practice along
National Electrical Code
with results of relevant test programs and general industrial
NFPA 13 Sprinkler Systems
explosion protection recommended practices. Recommenda-
NFPA 68 Guide for Explosion Venting
tions in this practice cover explosion protection aspects of the
NFPA 69 Explosion Prevention Systems
design and operation of shredding facilities and equipment
NFPA 497A ClassificationofClassIHazardous(Classified)
used therein.
Locations for Electrical Installations in Chemical Process
4.2 This practice is not intended to be a substitute for an
Areas
operating manual or a detailed set of design specifications.
3. Terminology
Rather, it represents general principles and guidelines to be
addressed in detail in generating the operating manual and
3.1 Definitions:
design specifications.
3.1.1 deflagration—an explosion in which the flame or
reaction front propagates at a speed well below the speed of
5. Design Practices
sound in the unburned medium, such that the pressure is
5.1 Design Rationale:
virtually uniform throughout the enclosure (shredder) at any
5.1.1 Each of the following design features is better suited
time during the explosion.
for some types of combustible/explosive materials and shred-
3.1.2 detonation—an explosion in which the flame or reac-
ders than for others. The selection of a particular combination
tion front propagates at a supersonic speed into the unburned
of explosion prevention features or damage control features, or
medium, such that pressure increases occur in the form of
both, should be made with an understanding of the types of
shock waves.
refuse entering the shredder, shredder operating conditions, the
3.1.3 explosion—a rapid release of energy (usually by
inherent strength of the shredder and surrounding structures,
means of combustion) with a corresponding pressure buildup
and the operating controls for screening input materials and
capable of damaging equipment and building structures.
restricting personnel access during shredding operations.
5.1.2 Several of the following explosion protection design
1
This practice is under the jurisdiction of ASTM Committee D34 on Waste
practices are effective for deflagrations but not for detonations.
Management and is the direct responsibility of Subcommittee D34.03 onTreatment,
Deflagrations usually result from accumulations of flammable
Recovery and Reuse.
gas-air,vapor-air,orpowder(dust)airmixturesinoraroundthe
Current edition approved Sept. 28, 2004. Published February 1991. DOI:
10.1520/E1248-90R04.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1

---------------------- Page: 1 ----------------------
E1248 – 90 (2
...

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4.1 Shredder explosions have occurred in most refuse processing plants with shredding facilities. Lessons learned in these incidents have been incorporated into this practice along with results of relevant test programs and general industrial explosion protection recommended practices. Recommendations in this practice cover explosion protection aspects of the design and operation of shredding facilities and equipment used therein.  
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5.1 This test method is applicable to dusts and powders, and provides a procedure for performing laboratory tests to evaluate hot-surface ignition temperatures of dust layers.  
5.2 The test data can be of value in determining safe operating conditions in industrial plants, mines, manufacturing processes, and locations of material usage and storage.  
5.3 Due to variation of ignition temperature with layer thickness, the test data at one thickness may not be applicable to all industrial situations (see Appendix X1). Tests at various layer thicknesses may provide a means for extrapolation to thicker layers, as listed in the following for pulverized Pittsburgh bituminous coal dust (2). Mathematical modeling of layer ignition at various layer thicknesses is described in Ref. (3).
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5.4 This hot plate test method allows for loss of heat from the top surface of the dust layer, and therefore generally gives a higher ignition temperature for a material than Test Method E771, which is a more adiabatic system.  
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Note 1: Much of the literature data for layer ignition is actually from a basket in a heated furnace (4), known as the modified Godbert-Greenwald furnace test. Other data are from nonstandardized hot plates (5-9).  
5.6 Additional information on the significance and use of this test method may be found in Ref. (10).
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1.1 This test method covers a laboratory procedure to determine the hot-surface ignition temperature of dust layers, that is, measuring the minimum temperature at which a dust layer will self-heat. The test consists of a dust layer heated on a hot plate.2,3  
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ASTM E1515-14(2022)(Test Method)
Standard Test Method for Minimum Explosible Concentration of Combustible Dusts

SIGNIFICANCE AND USE
5.1 This test method provides a procedure for performing laboratory tests to evaluate relative deflagration parameters of dusts.  
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4.1 This test standard describes how to evaluate the relative sensitivity of materials and components to dynamic pressure impacts by various gaseous fluid media (can include gas mixtures).  
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5.1 Commercial trace detectors are used by first responders, security screeners, the military, and law enforcement to detect and identify explosive threats and drugs of interest quickly. These trace detectors typically operate by detecting chemical agents in residues and particles sampled from surfaces and can have detection limits for some compounds extending below 1 ng. A trace detector is set to alarm when its response to any target analyte exceeds a programmed threshold level for that analyte. Factory settings of such levels typically balance sensitivity and selectivity assuming standard operating and deployment conditions.  
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SCOPE
1.1 In harmony with the Joint Committee for Guides in Metrology (JCGM) and detection concepts of the International Union of Pure and Applied Chemistry (IUPAC) (1, 2)2, this test method uses a series of replicated measurements of an analyte at dosage levels giving instrumental responses that bracket the critical value, a truncated normal distribution model, and confidence bounds to establish a standard for estimating practical and statistically robust limits of detection.
Note 1: Other standards are available that evaluate the general performance of detection technologies for various analytes in complex matrices (for example, Practice E2520).  
1.2 Here, the limit of detection (LOD90) for a compound is defined to be the lowest mass of that compound deposited on a sampling swab for which there is 90 % confidence that a single measurement in a particular trace detector will have a true detection probability of at least 90 % and a true nondetection probability of at least 90 % when measuring a process blank sample.  
1.3 This particular test method was chosen on the basis of reliability, practicability, and comprehensiveness across tested trace detectors, analytes, and deployment conditions. The calculations involved in this test method are published elsewhere (3), and are performed through an interactive web-based calculator available on the National Institute of Standards and Technology (NIST) site: https://www-s.nist.gov/loda.  
1.4 Intended Users—Trace detector developers and manufacturers, vendors, testing laboratories, and agencies responsible for public safety and enabling effective deterrents to terrorism.  
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SIGNIFICANCE AND USE
5.1 This test method provides a procedure for performing laboratory tests to evaluate deflagration parameters of dusts.  
5.2 The data developed by this test method may be used for the purpose of sizing deflagration vents in conjunction with the nomographs and equations published in NFPA 68, ISO 6184/1, or VDI 3673.  
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Note 5: Ref (2) concluded that dusts with KSt values below 45 bar m/s when measured in a 20-L chamber with a 10 000-J ignitor, may not be explosible when tested in a 1-m3 chamber with a 10 000-J ignitor. Ref (2) and unpublished testing has also shown that in some cases the KSt values measured in the 20-L chamber can be lower than those measured in the 1-m3 chamber. Refs (1) and (3) found that for some dusts, it was necessary to use lower ignition energy in the 20-L chamber in order to match MEC or MIC test data in a 1-m3 chamber. If a dust has measurable (nonzero) Pmax and KSt values with a 5000 or 10 000-J ignitor when tested in a 20-L chamber but no measurable Pmax and ...
SCOPE
1.1 Purpose. The purpose of this test method is to provide standard test methods for characterizing the “explosibility” of dust clouds in two ways, first by determining if a dust is “explosible,” meaning a cloud of dust dispersed in air is capable of propagating a deflagration, which could cause a flash fire or explosion; or, if explosible, determining the degree of “explosibility,” meaning the potential explosion hazard of a dust cloud as characterized by the dust explosibility parameters, maximum explosion pressure, Pmax; maximum rate of pressure rise, (dP/dt)max; and explosibility index, KSt.  
1.2 Limitations. Results obtained by the application of the methods of this standard pertain only to certain combustion characteristics of dispersed dust clouds. No inference should be drawn from such results relating to the combustion characteristics of dusts in other forms or conditions (for example, ignition temperature or spark ignition energy of dust clouds, ignition properties of dust layers on hot surfaces, ignition of bulk dust in heated environments, etc.)  
1.3 Use. It is intended that results obtained by application of this test be used as elements of a dust hazard analysis (DHA) that takes into account other pertinent risk factors; and in the specification of explosion prevention systems (see, for example NFPA 68, NFPA 69, and NFPA 652) when used in conjunction with approved or recognized design methods by those skilled in the art.
Note 1: Historically, the evaluation of the deflagration parameters of maximum pressure and maximum rate of pressure rise has been performed using a 1.2-L Hartmann Apparatus. Test Method E789, which describes this method, has been withdrawn. The use of data obtained from the test method in the design of explosion protection systems is not recommended.  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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Standard Practice for Calculation of Hazard Potential Figures of Merit for Thermally Unstable Materials

SIGNIFICANCE AND USE
5.1 This practice provides nine figures of merit which may be used to estimate the relative thermal hazard of thermally unstable materials. Since numerous assumptions must be made in order to obtain these figures of merit, care must be exercised to avoid too rigorous interpretation (or even misapplication) of the results.  
5.2 This practice may be used for comparative purposes, specification acceptance, and research. It should not be used to predict actual performance.
SCOPE
1.1 This practice covers the calculation of hazard potential figures of merit for exothermic reactions, including:
(1) Time-to-thermal-runaway,
(2) Time-to-maximum-rate,
(3) Critical half thickness,
(4) Critical temperature,
(5) Adiabatic decomposition temperature rise,
(6) Explosion potential,
(7) Shock sensitivity,
(8) Instantaneous power density, and
(9) National Fire Protection Association (NFPA) instability rating.  
1.2 The kinetic parameters needed in this calculation may be obtained from differential scanning calorimetry (DSC) curves by methods described in other documents.  
1.3 This technique is the best applicable to simple, single reactions whose behavior can be described by the Arrhenius equation and the general rate law. For reactions which do not meet these conditions, this technique may, with caution, serve as an approximation.  
1.4 The calculations and results of this practice might be used to estimate the relative degree of hazard for experimental and research quantities of thermally unstable materials for which little experience and few data are available. Comparable calculations and results performed with data developed for well characterized materials in identical equipment, environment, and geometry are key to the ability to estimate relative hazard.  
1.5 The figures of merit calculated as described in this practice are intended to be used only as a guide for the estimation of the relative thermal hazard potential of a system (materials, container, and surroundings). They are not intended to predict actual thermokinetic performance. The calculated errors for these parameters are an intimate part of this practice and must be provided to stress this. It is strongly recommended that those using the data provided by this practice seek the consultation of qualified personnel for proper interpretation.  
1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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ASTM
ASTM E2931-13(2019)(Test Method)
Standard Test Method for Limiting Oxygen (Oxidant) Concentration of Combustible Dust Clouds

SIGNIFICANCE AND USE
5.1 This test method provides a procedure for performing laboratory tests to evaluate relative deflagration parameters of dusts.  
5.2 Knowledge of the limiting oxygen (oxidant) concentration is needed for safe operation of some chemical processes. This information may be needed in order to start up, shut down or operate a process while avoiding the creation of flammable dust-gas atmospheres therein, or to pneumatically transport materials safely. NFPA 69 provides guidance for the practical use of LOC data, including the appropriate safety margin to use.  
5.3 Since the LOC as measured by this method may vary with the energy of the ignitor and the propagation criteria, the LOC should be considered a relative rather than absolute measurement.  
5.4 If too weak an ignition source is used, the measured LOC would be higher than the “true” value and would not be sufficiently conservative. This is an ignitability limit rather than a flammability limit, and the test could be described as “underdriven.” Ideally, the ignition energy is increased until the measured LOC is independent of ignition energy (that is, the “true” value). However, at some point the ignition energy may become too strong for the size of the test chamber, and the system becomes “overdriven.” When the ignitor flame becomes too large relative to the chamber volume, a test could appear to result in an explosion, while it is actually just dust burning in the ignitor flame with no real propagation beyond the ignitor (1-3).5 This LOC value would be overly conservative.  
5.5 The recommended ignition source for measuring the LOC of dusts in 20-L chambers is a 2500-J pyrotechnic ignitor.6 This ignitor contains 0.6 g of a powder mixture of 40 % zirconium, 30 % barium nitrate, and 30 % barium peroxide. Measuring the LOC at several ignition energies will provide information on the possible overdriving of the system to evaluate the effect of possible overdriving in a 20-L chamber, comparison tests may also be m...
SCOPE
1.1 This test method is designed to determine the limiting oxygen concentration of a combustible dust dispersed in a mixture of air with an inert/nonflammable gas in a near-spherical closed vessel of 20 L or greater volume.  
1.2 Data obtained from this method provide a relative measure of the deflagration characteristics of dust clouds.  
1.3 This test method should be used to measure and describe the properties of materials in response to heat and flame under controlled laboratory conditions and should not be used to describe or appraise the fire hazard or fire risk of materials, products, or assemblies under actual fire conditions. However, results of this test may be used as elements of a fire risk assessment that takes into account all of the factors that are pertinent to an assessment of the fire hazard of a particular end use.  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in Section 8.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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