Dust Control Handbook for Industrial Minerals Mining and Processing

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Clothes Cleaning BoothThe clothes cleaning booth is 48 by 42 inches which provides the worker with sufficient space torotate in front of the air nozzles to perform the cleaning process. Intake air enters the booththrough a 2-foot opening in the roof, then flows down through the enclosure before exitingthrough an air plenum on the bottom back wall of the booth. As this intake air flows through thebooth, it entrains dust removed from the worker's clothing during the cleaning process andforces it down towards the air plenum and away from the worker's breathing zone. Theexhausted dust-laden air then travels from this air plenum at the base of the booth to the exhaustventilation system.Air ReservoirThe air reservoir is necessary to supply the required air volume to the air nozzles used in thespray manifold. The size requirement for the reservoir was calculated based upon the design ofthe manifold. Either a 120- or 240-gallon reservoir should be used, depending on the number ofworkers needing to clean their clothes in sequence. The average cleaning time required duringfield testing was about 18 seconds, and the 120-gallon reservoir provides approximately22 seconds of air capacity. If multiple individuals will be using the booth one after another, thenthe 240-gallon reservoir should be used. This reservoir should be pressurized to at least 150 psiand it should be located close to the cleaning booth and hard-piped to the air spray manifoldlocated in the booth. A pressure regulator must be installed immediately before the air spraymanifold to regulate the nozzle pressure to a maximum of 30 psi.Air Spray ManifoldFigure 8.2 represents the air spray manifold design. The air spray manifold is composed of26 spray nozzles spaced 2 inches apart. The bottom nozzle is located 6 inches from the floor andis a circular designed nozzle for cleaning the worker's boots. This nozzle is used in conjunctionwith an adjustable ball-type fitting so that it can be directed downward. The other 25 air spraynozzles are flat fan sprays, which lab testing proved to be the most effective for cleaning at closedistances. The air spray nozzles deliver slightly less than 500 cfm of air.The original air spray manifold was designed for an individual around 5 feet 10 inches, theaverage height for a male worker in the United States. For shorter workers, a sliding mechanismis used to cover the top air nozzles to prevent discharged air from directly hitting the individual'sface.An in-line filter should also be incorporated between the compressed air supply and the air spraymanifold. This filter substantially reduces the potential that foreign material such as a metal burror rust particle could be blown from an air spray nozzle during cleaning.Controls for Secondary Sources 203
Figure 8.2. Air spray manifold design with 26 nozzles spaced 2 inches apart.Exhaust VentilationFor effective dust removal, it is critical that the cleaning booth be ventilated under negativepressure at all times so as to not allow any dust liberated from the clothing to escape from thebooth and into the work environment. In the design stage of this technology, testing validatedthat an exhaust volume of 2,000 cfm was sufficient to maintain a negative pressure throughoutthe entire clothes cleaning cycle. A pressure control switch is also incorporated into the systemwhich will not allow the air spray manifold to activate unless an acceptable negative pressure ismaintained within the cleaning booth.To exhaust the dust-laden air from the cleaning booth, there are two recommended methods:(1) the dust can be vented to a dust collector system (e.g., baghouse [Cecala et al. 2007]), or(2) the dust can be vented to an area outside the plant where it will not contaminate otherworkers nor be entrained back into the plant [Cecala et al. 2008]. There are many dust sources204 Controls for Secondary Sources
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Report of Investigations 9689Dust C
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FUNDAMENTALS OF DUSTCOLLECTION SYST
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Minimizing Field Fits and Welds ...
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Recommendations for Proper Wet Dril
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CONTROL TECHNOLOGIES FOR FILLING 50
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Effective Filtration ..............
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ILLUSTRATIONSFigure 1.1. Relationsh
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Figure 3.2. The air and water flow
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Figure 9.5. Problem created by heat
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UNIT OF MEASURE ABBREVIATIONSUSED I
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Robert J. Franta, Quotation Enginee
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silica. Quartz is the most common s
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DUST CONTROL HANDBOOK FOR INDUSTRIA
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CHAPTER 1: FUNDAMENTALS OFDUST COLL
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The shape of particles affects how
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EXHAUST SYSTEMS DESIGNAll exhaust s
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stripping, which allows workers to
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When using the air quantities in Ta
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X = distance in feet from the face
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Checklist for Hood EffectivenessThe
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A major disadvantage of the high-ve
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A common misconception when designi
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Avoiding Mitered Elbows Greater Tha
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Figure 1.13. Depiction of the horiz
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Figure 1.14. Typical design of grav
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Baghouse CollectorsBaghouse dust co
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Table 1.2. Emission factors for cru
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Figure 1.17. Typical design of a me
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Reverse Jet (Pulse Jet) CollectorsR
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Figure 1.20. Cartridge collector wi
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Wet scrubbers are particularly adva
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Electrostatic precipitators normall
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may be related to specific applicat
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times. When considering the depth o
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Figure 1.25. Demonstration of how a
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Figure 1.26. A typical fan performa
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Fan TypesThere are two basic types
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Figure 1.30. Typical centrifugal fa
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Figure 1.32. Typical roof ventilato
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The vast majority of dust particles
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Table 2.1. Particle/droplet size in
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Air Atomizing NozzlesAir atomizing
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Hydraulic Flat Fan NozzlesFigure 2.
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for dust knockdown or suppression,
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Nozzle MaintenanceFigure 2.14. Typi
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Accidental DamageInadvertent harm t
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NDT Educational Resource Center, Io
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78 Wet Spray SystemsDUST CONTROL HA
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contains a piston which delivers ha
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produce an increase in the penetrat
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Dry DrillingDry drilling is accompl
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Circular ShroudIn contrast to the u
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The collector airflow has a more su
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Air-Blocking ShelfThe air-blocking
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dust emissions from mast lowering,
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This simple procedure of creating a
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Figure 3.15. Air ring seal used to
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Figure 3.17. Illustrations showing
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unsubstantiated due to the inconsis
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safety considerations may preclude
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Figure 3.22. A filtration unit, loc
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Miller S, Emerick JC, Vogely WA [19
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USBM [1995]. The reduction of airbo
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110 Drilling and BlastingDUST CONTR
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Wet Control MethodsPREVENTION AND S
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Figure 4.2. Examples of compressive
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Figure 4.5. Illustration of a dry (
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Figure 4.6. Illustration of a dry (
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Wet dust control methods for crushi
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Work Practices to Minimize Dust Exp
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Some specialty grinding operations
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should be frequently inspected for
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Open screen decks slowly to allow i
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CHAPTER 5: CONVEYING AND TRANSPORTT
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Figure 5.3. Basic depiction of mate
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that the material falls before land
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Figure 5.10. Skirtboard used within
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CarrybackMaterial that sticks or cl
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CONVEYOR DESIGN AND MAINTENANCE ISS
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Figure 5.15. Conveyor transfer encl
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High-volume, high-pressure sprays s
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Figure 5.19. Depiction of a bucket
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Figure 5.21. Depiction of two types
Page 182 and 183: Figure 5.25. Venturi eductor utiliz
Page 184 and 185: DUST CONTROL HANDBOOK FOR INDUSTRIA
Page 186 and 187: CHAPTER 6: BAGGINGThis chapter disc
Page 188 and 189: caused during manufacturing, includ
Page 190 and 191: Overall PerforationsThe use of over
Page 192 and 193: Figure 6.5. Open-top bag being load
Page 194 and 195: Bagging operators should be aware t
Page 196 and 197: Figure 6.8. Exhaust hood to capture
Page 198 and 199: In the original design, a single no
Page 200 and 201: The OASIS is a relatively simple de
Page 202 and 203: Figure 6.13. Bag storage shelves sh
Page 204 and 205: Figure 6.14. Bag and belt cleaner d
Page 206 and 207: other industrial application using
Page 208 and 209: The robotic arm automatic palletize
Page 210 and 211: For many years, this plastic wrappi
Page 212 and 213: warehouse location until a later ti
Page 214 and 215: used successfully to perform this c
Page 218 and 219: CHAPTER 7: BULK LOADINGDuring the b
Page 220 and 221: Figure 7.2. Loading spout discharge
Page 222 and 223: Cascading Loading SpoutFigure 7.5 i
Page 224 and 225: a seal at the entry and exit points
Page 226: REFERENCESBiere G, Swinderman RT, M
Page 229 and 230: 200 Bulk LoadingDUST CONTROL HANDBO
Page 231: many years, as well as some new and
Page 235 and 236: Figure 8.3. Test subject wearing po
Page 237 and 238: Spills of product material are a co
Page 239 and 240: epetitive dust leaks should not sim
Page 241 and 242: Effective Upward Airflow PatternThe
Page 243 and 244: Figure 8.8. Open-structure design c
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Page 247 and 248: Figure 8.12. Increase in worker’s
Page 249 and 250: In other cases, an operation may wa
Page 251 and 252: Cecala AB, O'Brien AD, Pollock DE,
Page 253 and 254: 224 Controls for Secondary SourcesD
Page 255 and 256: where C o = outside respirable dust
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Page 259 and 260: RECOMMENDATIONS FOR FILTRATION/PRES
Page 261 and 262: Effective FiltrationFigure 9.4. Res
Page 263 and 264: average decay times were between 16
Page 265 and 266: Figure 9.6. Filtration unit showing
Page 267 and 268: This table highlights a number of c
Page 269 and 270: NIOSH [2001b]. Technology news 486:
Page 273 and 274: upon the wind velocity (or disturba
Page 275 and 276: Maximum size is the largest particl
Page 277 and 278: Figure 10.4. Use of end-dumping wit
Page 279 and 280: conditions. Performance of each of
Page 281 and 282: A water truck, used to apply water
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Surfactants work by reducing the su
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which differed for the various site
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Figure 10.9. Self-tarping dump truc
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percent [Fryrear and Skidmore 1985]
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Figure 10.12. The armoring process
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A current method of stockpile forma
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Figure 10.15. Demonstration of how
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Chekan GJ, Cecala AB, Colinet JF [2
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Midwest Research Institute [1981].
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GLOSSARYAbrader. An implement used
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Carryback. Material that sticks or
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End-dumping. A process of spreading
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Open structure building design. A p
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Table bushing. A bushing used to se
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Delivering on the Nation’s promis
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