Dust Control Handbook for Industrial Minerals Mining and Processing

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filtering system to eliminate the possibility of sediment and debris clogging the water sprays.Most spraying companies offer filtering systems for this purpose.An effective method of supplying water to the system is to use a self-contained water deliverysystem specifically designed for the application. Such a system includes a water pump selectedto provide water at the specific flow and pressure required for the application. Also included area manual inlet valve, an inlet strainer, a flow switch to prevent the pump from operating withoutany water supply, pressure indicators, a bypass circuit to allow manual adjustment of water flow,a manual outlet valve, and a manual or timer-based control panel. A typical water deliverysystem is illustrated in Figure 2.13.Water supply systems can be as simple as one which delivers a fixed water flow rate or onewhich can adjust the water flow rate in reaction to the needs of an application. Today'selectronic technology offers the ability to sense factors such as the dust loading andautomatically adjust the liquid flow rate and pressure to optimize the dust control systemperformance.Figure 2.13. Typical self-contained water delivery system [SSCO 2006].In applications where water quality is poor and where the water contains excessive amounts ofparticulate, such as water drawn from settling ponds, additional filtration should be provided. Inthese cases, it is recommended that a duplex basket strainer be used prior to the water deliverysystem inlet. These units provide two basket strainers and a manual valve, which allows theoperator to switch from one strainer to the other to allow the inactive strainer to be removed andcleaned. The strainer mesh should be selected based on the particulate size present in the watersupply. The function of the strainer is to stop particles that could ultimately clog the spraynozzle orifice. For this reason the strainer mesh should be such that it will stop solid particlesthat are larger diameter than the orifice of the spray nozzles in the system. A typical duplexbasket strainer is shown in Figure 2.14.Wet Spray Systems 71
Nozzle MaintenanceFigure 2.14. Typical duplex basket strainer [SSCO Catalog 70].Nozzles require maintenance, regular inspection, cleaning, and even replacement to preservefinal production quality and to maintain production processes on a cost-efficient basis. The typeand frequency of the maintenance schedule depends on the particular application. In someoperations, nozzles can spray usefully after hundreds of hours of operation, while in others,nozzles require daily attention. Most nozzle applications fall between these extremes. At aminimum, nozzles should be visually surveyed for damage on a regular basis. Additionalmaintenance will depend on application specifications, the water quality used, and nozzlematerial.Erosion and WearThe gradual removal of material from the surfaces of the nozzle orifice and internal flowpassages causes them to become larger and/or distorted (Figure 2.15), which can affect flow,pressure, and spray pattern.CorrosionFigure 2.15. Nozzle erosion—new versus used [Schick 2006].The chemical action of sprayed material or the environment causes corrosion breakdown of thenozzle material (Figure 2.16).72 Wet Spray Systems
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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
Page 50 and 51: A major disadvantage of the high-ve
Page 52 and 53: A common misconception when designi
Page 54 and 55: Avoiding Mitered Elbows Greater Tha
Page 56 and 57: Figure 1.13. Depiction of the horiz
Page 58 and 59: Figure 1.14. Typical design of grav
Page 60 and 61: Baghouse CollectorsBaghouse dust co
Page 62 and 63: Table 1.2. Emission factors for cru
Page 64 and 65: Figure 1.17. Typical design of a me
Page 66 and 67: Reverse Jet (Pulse Jet) CollectorsR
Page 68 and 69: Figure 1.20. Cartridge collector wi
Page 70 and 71: Wet scrubbers are particularly adva
Page 72 and 73: Electrostatic precipitators normall
Page 74 and 75: may be related to specific applicat
Page 76 and 77: times. When considering the depth o
Page 78 and 79: Figure 1.25. Demonstration of how a
Page 80 and 81: Figure 1.26. A typical fan performa
Page 82 and 83: Fan TypesThere are two basic types
Page 84 and 85: Figure 1.30. Typical centrifugal fa
Page 86 and 87: Figure 1.32. Typical roof ventilato
Page 89 and 90: DUST CONTROL HANDBOOK FOR INDUSTRIA
Page 91 and 92: The vast majority of dust particles
Page 93 and 94: Table 2.1. Particle/droplet size in
Page 95 and 96: Air Atomizing NozzlesAir atomizing
Page 97 and 98: Hydraulic Flat Fan NozzlesFigure 2.
Page 99: for dust knockdown or suppression,
Page 103 and 104: Accidental DamageInadvertent harm t
Page 105 and 106: NDT Educational Resource Center, Io
Page 107 and 108: 78 Wet Spray SystemsDUST CONTROL HA
Page 109 and 110: contains a piston which delivers ha
Page 111 and 112: produce an increase in the penetrat
Page 113 and 114: Dry DrillingDry drilling is accompl
Page 115 and 116: Circular ShroudIn contrast to the u
Page 117 and 118: The collector airflow has a more su
Page 119 and 120: Air-Blocking ShelfThe air-blocking
Page 121 and 122: dust emissions from mast lowering,
Page 123 and 124: This simple procedure of creating a
Page 125 and 126: Figure 3.15. Air ring seal used to
Page 127 and 128: Figure 3.17. Illustrations showing
Page 129 and 130: unsubstantiated due to the inconsis
Page 131 and 132: safety considerations may preclude
Page 133 and 134: Figure 3.22. A filtration unit, loc
Page 135 and 136: Miller S, Emerick JC, Vogely WA [19
Page 137 and 138: USBM [1995]. The reduction of airbo
Page 139 and 140: 110 Drilling and BlastingDUST CONTR
Page 141 and 142: Wet Control MethodsPREVENTION AND S
Page 143 and 144: Figure 4.2. Examples of compressive
Page 145 and 146: Figure 4.5. Illustration of a dry (
Page 147 and 148: Figure 4.6. Illustration of a dry (
Page 149 and 150: 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
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Figure 5.25. Venturi eductor utiliz
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CHAPTER 6: BAGGINGThis chapter disc
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caused during manufacturing, includ
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Overall PerforationsThe use of over
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Figure 6.5. Open-top bag being load
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Bagging operators should be aware t
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Figure 6.8. Exhaust hood to capture
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In the original design, a single no
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The OASIS is a relatively simple de
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Figure 6.13. Bag storage shelves sh
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Figure 6.14. Bag and belt cleaner d
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other industrial application using
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The robotic arm automatic palletize
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For many years, this plastic wrappi
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warehouse location until a later ti
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used successfully to perform this c
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CHAPTER 7: BULK LOADINGDuring the b
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Figure 7.2. Loading spout discharge
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Cascading Loading SpoutFigure 7.5 i
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a seal at the entry and exit points
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REFERENCESBiere G, Swinderman RT, M
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200 Bulk LoadingDUST CONTROL HANDBO
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many years, as well as some new and
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Figure 8.2. Air spray manifold desi
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Figure 8.3. Test subject wearing po
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Spills of product material are a co
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epetitive dust leaks should not sim
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Effective Upward Airflow PatternThe
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Figure 8.8. Open-structure design c
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manually removing the bags and plac
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Figure 8.12. Increase in worker’s
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In other cases, an operation may wa
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Cecala AB, O'Brien AD, Pollock DE,
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224 Controls for Secondary SourcesD
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where C o = outside respirable dust
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minimal improvement in the cab's ai
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RECOMMENDATIONS FOR FILTRATION/PRES
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Effective FiltrationFigure 9.4. Res
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average decay times were between 16
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Figure 9.6. Filtration unit showing
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This table highlights a number of c
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NIOSH [2001b]. Technology news 486:
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upon the wind velocity (or disturba
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Maximum size is the largest particl
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Figure 10.4. Use of end-dumping wit
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conditions. Performance of each of
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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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