244
6 Fans and Flow Control Devices
Answer
(a) If the speed is high:
– Increased fan consumption,
– Pressure rise,
– Greater dust suspension, and
– Lack of comfort for workers due to less thermal sensation.
If the speed is low:
– Reduced turbulence and less capacity to mix and evacuate gases.
(b) In order to slow the speed down, it would be possible to:
– Split the airstream; and
– Diminish the flow of air accessing to the gallery, for example, by means of a
regulator. In order to avoid inappropriate speeds, galleries must be designed so
that they have the correct section.
6.6 Conventional Signs on the Ventilation Maps
Mining maps symbols are not standardized. The following is a suggestion of
simplified symbols for some common ventilation devices (Fig. 6.37).
4.1
Direction of flow and speed
D
Door
C
Curtain
Seal or stopping
Overcast
Undercast
Fan
Line brattice
or
Fig. 6.37 Simplified symbols used in ventilation schematics
6 Fans and Flow Control Devices
Answer
(a) If the speed is high:
– Increased fan consumption,
– Pressure rise,
– Greater dust suspension, and
– Lack of comfort for workers due to less thermal sensation.
If the speed is low:
– Reduced turbulence and less capacity to mix and evacuate gases.
(b) In order to slow the speed down, it would be possible to:
– Split the airstream; and
– Diminish the flow of air accessing to the gallery, for example, by means of a
regulator. In order to avoid inappropriate speeds, galleries must be designed so
that they have the correct section.
6.6 Conventional Signs on the Ventilation Maps
Mining maps symbols are not standardized. The following is a suggestion of
simplified symbols for some common ventilation devices (Fig. 6.37).
4.1
Direction of flow and speed
D
Door
C
Curtain
Seal or stopping
Overcast
Undercast
Fan
Line brattice
or
Fig. 6.37 Simplified symbols used in ventilation schematics