Chapter 5 - Specific Illustrations

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Safety and Health Topics > Mineral Processing Dust Control > Dust Control Handbook > Ch. 5 - Specific Illustrations

Chapter 5

Specific Illustrations

Wet:

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 until adequate control of dust is achieved.

Dry:

Q_E =	33.3 ×	(	600 T	)
			G

Q_E

= Exhaust air volume, CFM

= Weight of material dumped, TPM, tons per minute

= 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 Recieving 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 until adequate control of dust is achieved.

Dry:

Q_E =	33.3 ×	(	600 T	)
			G

Q_E

= Exhaust air volume, CFM

= Weight of material dumped, TPM, tons per minute

= Bulk density of material, pounds/Ft³

Wet:

Dry:

		_____
Q_E₁ = 10 A_U₁	Ö	R₁S₁² D

		_____
Q_E₂ = 10 A_U₂	Ö	R₂S₂² D

Q_E₁, Q_E₂

= Exhaust air volume, CFM

A_U₁, A_U₂

= Enclosure open area at upstream, FT²

R₁, R₂

= Rate of material flow, TPM

S₁, S₂

= Height of fall, FT

= Average material size, FT

Note 1: Q_E₁ and Q_E₂ should be calculated by using appropriate values of A_U , R, and S.

Note 2: This equation should be applied where D is greater that 1/8 in.

Wet:

Dry:

		_____
Q_E = 10 × A_U ×	Ö	RS² D

Q_E

= Exhaust air volume, CFM

A_U

= Enclosure open area at upstream, FT²

= Rate of material flow, TPH

= Height of fall, FT

= 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:



S = S₁ + S₂
2

_____

Q_E = 10 × A_U× Ö RS²
D

Q_E = Exhaust air volume, CFM

A_U = 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    *Not Recommended*

Dry:

                 Rotating Screen
Vibrating Screen           Ball/Rod Mill

_____

Q_E = 10 × A_U× Ö RS²
D

Q_E = Exhaust air volume, CFM

A_U = 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:


_____

Q_E = 10 × A_U× Ö RS²
D

Q_E = Exhaust air volume, CFM

A_U = 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:



S = S₁ + S₂
2

_____

Q_E = 10 × A_U× Ö RS²
D

Q_E = Exhaust air volume, CFM

A_U = 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 *Not Recommended*

Dry:
                       Revolving Screen
Vibrating Screen             Ball Mill

_____

Q_E = 10 × A_U× Ö RS²
D

Q_E = Exhaust air volume, CFM

A_U = 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:

_____

Q_E = 10 × A_U× Ö RS²
D

Q_E = Exhaust air volume, CFM

A_U = 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:

_____

Q_E = 10 × A_U× Ö RS²
D

Q_E = Exhaust air volume, CFM

A_U = 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:

_____

Q_E = 10 × A_U× Ö RS²
D

Q_E = Exhaust air volume, CFM

A_U = 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: "A_U" depends upon tightness of enclosure at the screen

Wet:
Screen to:                            Elevators
Conveyors Hoppers

Note: Excessive moisture may cause crusher jamming

Dry:

                Hoppers

S = S₁ + S₂
2

_____

Q_E = 10 × A_U× Ö RS²
D

Q_E = Exhaust air volume, CFM

A_U = 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: "A_U" depends upon tightness of enclosure at the screen

Wet:
Screen to:          Conveyors
                                          Hoppers

Dry:

                Hoppers

S = S₁ + S₂
2

_____

Q_E = 10 × A_U× Ö RS²
D

Q_E = Exhaust air volume, CFM

A_U = 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: "A_U" depends upon tightness of enclosure at the screen

Wet:
Ball/Rod Mill to: Feeder or Screen - Not Recommended *Not Recommended*

Dry:
                       Vibrating Feeder
                Vibrating Screen

Q_E = 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:



S = S₁ + S₂
2

_____

Q_E = 10 × A_U× Ö RS²
D

Q_E = Exhaust air volume, CFM

A_U = 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:


Revolving Screen                 Vibrating Screen

_____

Q_E = 10 × A_U× Ö RS²
D

Q_E = Exhaust air volume, CFM

A_U = 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 Conveyors    Storage Bin/Hopper

Note: Wet systems are not recommended for powdery material

Dry:


S = S₁ + S₂
2

_____

Q_E = 10 × A_U× Ö RS²
D

Q_E = Exhaust air volume, CFM

A_U = 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:


S = S₁ + S₂
2

_____

Q_E = 10 × A_U× Ö RS²
D

Q_E = Exhaust air volume, CFM

A_U = 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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