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<<< Back to Dust Control Handbook for Minerals Processing Printing Instructions Chapter 5: Specific Illustrations For problems with accessibility in using figures and illustrations in this document, please contact the Directorate of Technical Support and Emergency Management at (202) 693-2300. Wet: Truck or Loader to Crusher Note 1: Dust suppression system should be activated only during dumping cycle. Note 2: Airborne dust capture system should also be activated during dumping cycle and may be kept on beyond the dumping cycle until adequate control of dust is achieved. Dry: Truck or Loader to Crusher QE =  33.3 × ( 600 T ) G     QE = Exhaust air volume, CFM T = Weight of material dumped, TPM, tons per minute G = Bulk density of material, pounds/Ft3   Note: The open area at the face of the enclosure should be kept to a minimum. Wet: Railroad Rotary Dump to Receiving Hopper Note 1: Dust suppression system should be activated only during dumping cycle. Note 2: Airborne dust capture system should be activated during dumping cycle and may be kept on beyond the dumping cycle until adequate control of dust is achieved. Dry: Railroad Rotary Dump to Receiving Hopper QE =  33.3 × ( 600 T ) G     QE = Exhaust air volume, CFM T = Weight of material dumped, TPM, tons per minute G = Bulk density of material, pounds/Ft3 Wet: Railroad Dump to Conveyor Dry: Railroad Dump to Conveyor     _____ QE1 =  10 AU1  √  R1S12 D _____ QE2 =  10 AU2  √  R2S22 D QE1, QE2 = Exhaust air volume, CFM AU1, AU2 = Enclosure open area at upstream, FT2 R1, R2 = Rate of material flow, TPM S1, S2 = Height of fall, FT D = Average material size, FT Note 1: QE1 and QE2 should be calculated by using appropriate values of AU , R, and S. Note 2: This equation should be applied where D is greater that 1/8 in. Wet: Feeder to: Hammermill Crusher   Cone Crusher Impactor Dry: Feeder to:   Hammermill Crusher   Cone Crusher Impactor _____ QE = 10 × AU × √  RS2 D   QE = Exhaust air volume, CFM AU = Enclosure open area at upstream, FT2 R = Rate of material flow, TPH S = Height of fall, FT D = Average material size, FT   Note: This equation should be applied where D is greater than 1/8 in. Wet:   Feeder to: Bucket Elevator   Belt Conveyor Storage Hopper Dry:   Feeder to: Bucket Elevator   Belt Conveyor Storage Hopper S = S1 +  S2 2 _____ QE = 10 × AU × √  RS2 D   QE = Exhaust air volume, CFM AU = Enclosure open area at upstream, FT2 R = Rate of material flow, TPH S = Height of fall, FT D = Average material size, FT   Note: This equation should be applied where D is greater than 1/8 in. Wet: Feeder to: Screen or Mill                                           *Not Recommended* Dry: Feeder to:   Rotating Screen   Vibrating Screen Ball/Rod Mill _____ QE = 10 × AU × √  RS2 D   QE = Exhaust air volume, CFM AU = Enclosure open area at upstream, FT2 R = Rate of material flow, TPH S = Height of fall, FT D = Average material size, FT   Note: This equation should be applied where D is greater than 1/8 in. Wet: Conveyor to:     Cone Crusher   Roll Crusher     Hammermill Crusher Impactor Note: Excessive moisture may cause crusher jamming. Dry: Conveyor to:     Cone Crusher   Roll Crusher     Hammermill Crusher Impactor   _____ QE = 10 × AU × √  RS2 D   QE = Exhaust air volume, CFM AU = Enclosure open area at upstream, FT2 R = Rate of material flow, TPH S = Height of fall, FT D = Average material size, FT   Note: This equation should be applied where D is greater than 1/8 in. Wet: Conveyor to: Bucket Elevator   Belt Conveyor Storage Hopper Dry: Conveyor to: Bucket Elevator   Belt Conveyor Storage Hopper S = S1 +  S2 2 _____ QE = 10 × AU × √  RS2 D   QE = Exhaust air volume, CFM AU = Enclosure open area at upstream, FT2 R = Rate of material flow, TPH S = Height of fall, FT D = Average material size, FT   Note: This equation should be applied where D is greater than 1/8 in. Wet: Conveyor to: Screen or Mill                                          *Not Recommended* Dry: Conveyor to: Revolving Screen   Vibrating Screen Ball Mill   _____ QE = 10 × AU × √  RS2 D   QE = Exhaust air volume, CFM AU = Enclosure open area at upstream, FT2 R = Rate of material flow, TPH S = Height of fall, FT D = Average material size, FT   Note: This equation should be applied where D is greater than 1/8 in. Wet: From: Jaw Crusher From: Roll Crusher From: Impactor To: Belt Conveyor Note: Excessive moisture may cause crusher jamming. Dry: From: Jaw Crusher From: Roll Crusher From: Impactor To: Belt Conveyor   _____ QE = 10 × AU × √  RS2 D   QE = Exhaust air volume, CFM AU = Enclosure open area at upstream, FT2 R = Rate of material flow, TPH S = Height of fall, FT D = Average material size, FT   Note: This equation should be applied where D is greater than 1/8 in. Wet: From: Cone Crusher From: Hammermill Crusher From: Gyratory Crusher To: Belt Conveyor Note: Excessive moisture may cause crusher jamming. Dry: From: Cone Crusher From: Hammermill Crusher From: Gyratory Crusher To: Belt Conveyor   _____ QE = 10 × AU × √  RS2 D   QE = Exhaust air volume, CFM AU = Enclosure open area at upstream, FT2 R = Rate of material flow, TPH S = Height of fall, FT D = Average material size, FT   Note: This equation should be applied where D is greater than 1/8 in. Wet:  Screen to: Crushers   Impactors       Conveyors Note: Excessive moisture may cause crusher jamming. Dry:             Screen to:     Crushers   Impactors       Conveyors _____ QE = 10 × AU × √  RS2 D   QE = Exhaust air volume, CFM AU = Enclosure open area at upstream, FT2 R = Rate of material flow, TPH S = Height of fall, FT D = Average material size, FT   Note: This equation should be applied where D is greater than 1/8 in. Note: "AU" depends upon tightness of enclosure at the screen. Wet:     Screen to: Elevators   Conveyors Hoppers Note: Excessive moisture may cause crusher jamming. Dry:  Screen to: Elevators   Conveyors Hoppers S = S1 +  S2 2 _____ QE = 10 × AU × √  RS2 D   QE = Exhaust air volume, CFM AU = Enclosure open area at upstream, FT2 R = Rate of material flow, TPH S = Height of fall, FT D = Average material size, FT   Note: This equation should be applied where D is greater than 1/8 in. Note: "AU" depends upon tightness of enclosure at the screen. Wet: Screen to:   Conveyors     Hoppers Dry: Screen to:   Conveyors   Hoppers S = S1 +  S2 2 _____ QE = 10 × AU × √  RS2 D   QE = Exhaust air volume, CFM AU = Enclosure open area at upstream, FT2 R = Rate of material flow, TPH S = Height of fall, FT D = Average material size, FT   Note: This equation should be applied where D is greater than 1/8 in. Note: "AU" depends upon tightness of enclosure at the screen. Wet: Ball/Rod Mill to: Feeder or Screen                                                     *Not Recommended* Dry: Ball/Rod Mill to:   Vibrating Feeder     Vibrating Screen QE =  200 CFM per square foot of open area Note: Avoid excessive air velocities at the face of the hood to prevent reentrainment of finely ground material. Wet: Ball/Rod Mill to: Bucket Elevator   Belt Conveyor Storage Bin Hopper Note: Moisture my cause sticking of Material in chutes. Dry: Ball/Rod Mill to:   Bucket Elevator   Belt Conveyor Storage Bin Hopper S = S1 +  S2 2 _____ QE = 10 × AU × √  RS2 D   QE = Exhaust air volume, CFM AU = Enclosure open area at upstream, FT2 R = Rate of material flow, TPH S = Height of fall, FT D = Average material size, FT   Note: Avoid excessive air velocities at the face of the hood to prevent          reentrainment of finely ground material. Wet: Elevator to:   Belt Conveyor Note: Wet systems are not recommended for fine powdery material. Elevator to: Screens         *Not Recommended* Dry: Elevator to:     Belt Conveyor   Revolving Screen Vibrating Screen   _____ QE = 10 × AU × √  RS2 D   QE = Exhaust air volume, CFM AU = Enclosure open area at upstream, FT2 R = Rate of material flow, TPH S = Height of fall, FT D = Average material size, FT   Note: This equation should be applied where D is greater than 1/8 in. Wet: Elevator to:     Screw Conveyor Storage Bin/Hopper Note: Wet systems are not recommended for fine powdery material. Dry: Elevator to:       Screw Conveyor Storage Bin/Hopper S = S1 +  S2 2 _____ QE = 10 × AU × √  RS2 D   QE = Exhaust air volume, CFM AU = Enclosure open area at upstream, FT2 R = Rate of material flow, TPH S = Height of fall, FT D = Average material size, FT   Note: This equation should be applied where D is greater than 1/8 in. Wet: Hopper to:   Vibrating Feeder   Belt Conveyor Bucket Elevator Dry: Hopper to:     Vibrating Feeder   Belt Conveyor Bucket Elevator S = S1 +  S2 2 _____ QE = 10 × AU × √  RS2 D   QE = Exhaust air volume, CFM AU = Enclosure open area at upstream, FT2 R = Rate of material flow, TPH S = Height of fall, FT D = Average material size, FT   Note: This equation should be applied where D is greater than 1/8 in.

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