CEMA 805-2004 Glossary of Pneumatic nConveying Terms.pdf

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1、GlossaryofPneumaticConveyingTermsPDF Version - 2004CEMASTANDARDNO. 805ISBN 1-891171-62-3Conveyor EquipmentManufacturers AssociationFor Information on Company Membershipvisit the CEMA Web Site athttp:/www.cemanet.orgCEMA ORGANIZATIONAL CHARTSAFETY NOTICEThe Conveyor Equipment Manufacturers Associatio

2、n has developed Industry Standard Safety Labelsfor use on the conveying equipment of its member companies.The purpose of the labels is to identify common and uncommon hazards, conditions, and unsafepractices which can injure, or cause the death of, the unwary or inattentive person who is working ato

3、r around conveying equipment.The labels are available for sale to member companies and non-member companies.A full description of the labels, their purpose, and guidelines on where to place the labels on typicalequipment, has been published in CEMAs Safety Label Brochure No. 201. The Brochure is ava

4、ilablefor purchase by members and non-members of the Association. Safety Labels and Safety LabelPlacement Guidelines, originally published in the Brochure, are also available free on the CEMA WebSite at http:/www.cemanet.org/CEMA_Safety_Pg.htmPLEASE NOTE: Should any of the safety labels supplied by

5、the equipment manufacturer becomeunreadable for any reason, the equipment USER is then responsible for replacement and location ofthese safety labels.Replacement labels and placement guidelines can be obtained by contacting your equipment supplieror CEMA.ConveyorChainControls PalletizersMeet in Marc

6、h and/or SeptemberConferenceStrategic PlanningInsuranceMeetingsMarketing/MembershipStatisticsFinance and BudgetPast PresidentsBulk HandlingSectionCommitteesUnit HandlingSectionEngineering ConferenceConveyor ChainPerformance TerminologyUnit Handling StandardsIdlersPulleysBeltSystemsScrewConveyorsBelt

7、 ManualAccessoriesSafety ControlsTerms andDefinitionsInternationalStandardsMeets Each JuneScrewConveyorsBulk HandlingComponentsand SystemsGeneral Bulk Handling SectionBulkAccessoriesUnit Handling Conveying SectionCOMMITTEES BOARD OF DIRECTORS OFFICERSFOREWORD AND ACKNOWLEDGMENTSThis standard, Glossa

8、ry of Pneumatic Conveying Terms, was prepared by the Pneumatic ConveyingSection of the Conveyor Equipment Manufacturers Association. The objectives and purposes for publishingthis standard include:A. Encourage uniform usage and understanding of performance terminology used in the conveyingfield.B. A

9、ssist in providing appropriate information for the selection and application of proper engineeringpractice in the field of materials handling as accomplished through usage of conveyor equipment.C. Provide a source or basis of information related to characteristics, features and conditionsinherent to

10、 the practices of materials handling through usage of conveying equipment.Throughout this standard, preferred terms are followed by their definitions. Alternate terms in commonusage are listed and cross-indexed back to the preferred term in each case.Utilitization of this Glossary of Pneumatic Conve

11、ying Terms, as published herein, is completely voluntary.This publication may be adhered to in its entirety, in part, or not at all, depending upon agreement of theparties involved.For definitions of terminology which are not included herein, review the following references:A. CEMA Terms and Definit

12、ions (Standard No. 102).B. CEMA Classification and Definitions of Bulk Materials (Book No. 550).C. ANSI/ASME B20.1, Safety Standard for Conveyors and Related Equipment.Legal terms and definitions are not within the scope of this publication.The Conveyor Equipment Manufacturers Association gratefully

13、 acknowledges the advice, assistance,and constructive criticisms afforded by the members of the committee and their companies. Without theirrespective contributions, preparation of this standard would not been have possible.CONVEYOR EQUIPMENT MANUFACTURERS ASSOCIATION6724 Lone Oak Blvd.Naples, Flori

14、da 34109(239) 514-3441Web SIte: http:/www.cemanet.orgDISCLAIMERThe information provided in this document is advisory only. These recommendationsare provided by CEMA in the interest of promoting safety in the work place. Theserecommendations are general in nature and are not intended as a substitute

15、for athorough safety program. Users should seek the advise, supervision or consultation ofqualified engineers or other safety professionals. Any use of this document, theinformation contained herein, or any other CEMA publication may only be made withthe agreement and understanding that the user and

16、 the users company assume fullresponsibility for the design, safety, specifications, suitability and adequacy of thesystem component, or mechanical or electrical device designed or manufactured usingthis information. The user and the users company understand and agree that CEMA,its member companies,

17、 its officers, agents and employees shall not be liable in anymanner under any theory of liability for the user or users reliance on theserecommendations. The users and the users company agree to release, hold harmlessand indemnify CEMA, its member companies, successors, assigns, officers, agentsand

18、 employees from any and all claims of liability, costs, fees (including attorneysfees), or damages arising in any way out of the use of this information. CEMA and itsmember companies, successors, assigns, officers, agents and employees make norepresentations or warranties whatsoever, either express

19、or implied, about theinformation contained in this document, including, but not limited to, representationsor warranties that the information and recommendations contained herein conform toany federal, state or local laws, regulations, guidelines or ordinances.Glossary of Pneumatic Conveying TermsPr

20、epared byThe Pneumatic Conveying Sectionof theCEMA Engineering ConferenceCopyright 2004Conveyor Equipment Manufacturers Association1CEMA Standard 805 - Glossary of Pneumatic Conveying Terms - 2005PNEUMATIC CONVEYING TERMS AND DEFINITIONSThese terms and definitions were prepared by the Pneumatic Conv

21、eying Section of theConveyor Equipment Manufacturers Association as a service to users, designers, andspecifiers of pneumatic conveying equipment and were published in paper as CEMAStandard 805: Pocket Glossary of Pneumatic Conveying Terms.List of Pneumatic Conveying Terms Abrasiveness Actual Gas Ve

22、locity Adhesiveness Aeration Air Retention Angle of Repose Average Gas Velocity Bulk Material Composition Choking Velocity Cohesiveness Conveying Pressure Corrosiveness Dense Phase Conveying Dilute Phase Conveying Explosiveness Flotation Velocity Flowability Fluidized Fluidized Bulk Density Friabili

23、ty Hardness Hygroscopicity Loose Bulk Density Material Mass Flow Rate Material Temperature Material Temperature Sensitivity Material To Air Ratio Material Velocity Maximum Particle Size Median Particle Size Minimum Conveying Velocity Packed Bulk Density Particle Density Particle Shape Particle Size

24、Distribution Permeability Saltation Velocity Terminal Gas Velocity Two-Phase Flow Volumetric Gas FlowThe terms have been grouped into two sections:I. Material CharacterizationII. Basic Terms and DefinitionsI. MATERIAL CHARACTERIZATIONFluidized Bulk Density - is the apparent bulk density of a materia

25、l in its fluidized state. It isgenerally lower than either the packed or loose bulk density due to the air absorbed into the voids.Loose Bulk Density - (sometimes called the poured bulk density) of a bulk material is the weightper unit of volume (usually pounds per cubic foot) that has been measured

26、 when the sample is ina loose, non-compacted or poured condition. The loose bulk density may be close to the “asconveyed” bulk density and is preferred for the purposes of pneumatic conveying system design.Maximum Particle Size - is the maximum dimension in inches (in the case of lumpy materials) or

27、the maximum sieve size (in the case of powders and granules) of the largest lump or particle in thebulk material. Maximum particle size can be critical in the design of pneumatic conveying systems.Median Particle Size - is the median size or mid-point of the particle size distribution.2CEMA Standard

28、 805 - Glossary of Pneumatic Conveying Terms - 2005Packed Bulk Density - of a bulk material is the weight per unit volume (usually pounds per cubicfoot) that has been measured when the sample has been packed or compacted in, for instance, asilo or bin or after containerized transportation. The packe

29、d bulk density does not compare to theconditions that would be found in a pneumatic conveying system. It is for this reason that theloose bulk density is preferred for the purposes of conveying system design.Particle Density - is the mass of a particle divided by its volume. For a bulk material, ave

30、rageparticle density is used, found by dividing the mass of the material by its volume, excluding thevoids.Particle Shape - The shape and form of the particles of a bulk material can vary considerably. Thefollowing table specifically describes the individual particle shape only and not the bulk mate

31、rial asa whole.Term DefinitionAgglomerated Several individual particles bonded together.Angular Sharp-edged or having a multi-faced, irregular shape.Crystalline Of geometric shape or multi-faced regular shape.Cylindrical Cylinder-shaped.Dendritic Having a branched, crystalline shape with the branche

32、s extending from the facesof the body.Fibrous Regularly or irregularly thread like with a flexible structure.Flaky Plate-like.Needle-like Long, thin, rigid, straight, and pointed.Out-of-Round Similar to spherical but being somewhat deformed or elongated.Spherical Globe-like.Particle Size Distributio

33、n - of a bulk material is a tabulation of the percentage of particles bymass in each particle size range. The percentage described is either that passing or being retainedon a specific screen size. In the United States, the screens used are “U.S. Standard Screens” or“Tyler Test Screens”. Other metho

34、ds of size analysis may be used, particularly in the case of veryfine and/or cohesive powders. These methods include photo sedimentation, optical microscopy,electrical sensing zone techniques (such as the Coulter counter), and laser diffraction spectrometry.Bulk Material CompositionThe following tab

35、le describes the general compositions that may be found in a bulk material.Term DefinitionUniform A single bulk material whose particles possess the same size and shape.Non-Uniform A single bulk material whose particle size and shape may vary.Granular A bulk material comprised of individual particle

36、s which can be visibly discerned.Powder A bulk material comprised of individual particles which cannot be visibly discernedMixed Two or more different bulk materials which have been combined.3CEMA Standard 805 - Glossary of Pneumatic Conveying Terms - 2005Bulk Material CharacteristicsAbrasiveness -

37、of a material is determined by its hardness factor and the shape of itsparticles. A material which has, for instance, a high Mohs hardness factor and has sharp,angular-shaped particles will be considered highly abrasive.Adhesiveness - can be described as “external cohesiveness” that is, the ability

38、of amaterial to adhere to other surfaces.Aeration - is the action of introducing air (or gas) to a bulk material by any means. Aerationmay cause the material to become fluidized or agitated.Air Retention - is the ability of a material to retain air (or other gas) in the void spaces ofthe material af

39、ter the air (or gas) supply to it has been terminated. Air retention capabilitycan vary between almost zero and several days, depending upon the materials otherphysical characteristics.Angle of Repose - of a bulk material is the angle between the horizontal and the slopingsurface of a heap of the ma

40、terial which has been allowed to form naturally without anyconditioning, usually by gravity flow from a funnel or other similar device.Cohesiveness - describes the tendency of a material to adhere to itself. The cohesive-ness of a bulk solid material can be caused by any and sometimes by all of seve

41、ral factors.These include electrostatic charging, surface tension effects, and interlocking of certainparticle shapes, particularly fibrous types of materials. Cohesiveness in bulk solids causeserratic flow from bins, pipeline feeding problems, and adverse effects in certain kinds ofvalves.Corrosive

42、ness - Some materials have chemical properties which will, when combinedwith other materials such as moisture and air, cause chemical deterioration to materials ofconstruction.Explosiveness - In certain conditions, some bulk materials can form potentially explosivemixtures when combined with air. Th

43、ese conditions depend on (a) the nature of the mate-rial itself, which would include its ignition temperature, its chemical reaction with oxygen,its particle size distribution, and so on; and (b) the nature of the operation involving thematerial. Details of explosion risk, reactivity, and fire hazar

44、d are now required by law inmost states in the U. S. to be listed on the Material Safety Data Sheet (MSDS). The MSDSmust accompany any material which is transported, stored or tested. In all cases involvingexplosive materials, reference should be made to NFPA classifications.Flowability - is the eas

45、e with which a bulk material flows under the influence of gravityonly.Fluidized - describes the state some bulk materials achieve when a gas has been en-trained into the void spaces between the particles of the material. Material in a highlyfluidized state tends to behave more like a fluid (as the t

46、erm implies) than a solid bulkmaterial.4CEMA Standard 805 - Glossary of Pneumatic Conveying Terms - 2005Friability - describes a bulk material where particles are easily crumbled or pulverized.Hardness - is a property of a solid material which contributes to its overall abrasiveness.The harder a mat

47、erial is, generally, the greater the erosion for a given velocity on a pipe-line. Hardness is difficult to quantify and is somewhat subjective when described. MohsScale of Hardness is used to describe the materials when designing pneumatic conveyingsystems.Hygroscopicity is the ability of a material

48、 to absorb moisture from its surroundings.Moisture may be absorbed from either the ambient air (especially during high humidityconditions) or the conveying air of the pneumatic system.MaterialTemperature - Generally, most bulk materials are handled at ambient tempera-ture conditions. However, in som

49、e cases, the material may be at an elevated temperature.Elevated temperature can affect both the condition of the material itself and its surround-ings -particularly the equipment that is being used to convey it. Care should be taken,when considering high temperature materials, that the temperature range is clearly andaccurately stated, and any effects on the material (particularly its handling characteristics)should be noted.The temperature of the bulk material, measured in O F. or O C., for purposes of pneumaticconveying design, is th