Quarry water level control:
Company Name:AfriSam
Presenter:Edwin Swanepoel
Institute of Quarrying Annual ConferenceDate: 10 April 2014
Quarry water level control: (Olifantsfontein pumping system) Edwin Swanepoel10 April 2014 3
Introduction Introduction (Olifantsfontein pumping system)
Sudden increase of water flowing into quarry experienced Existing pumping system capacity not adequate Could eventually have a negative influence on mining plan
Contents of presentation Determining water Influx and required pump capacity Dispersing large amounts of water into the environment Selecting the best pump for the application
o System resistance curve vs. Pump performance curveso Actual vs. Required flow rateo Testing installed system performance and identifying problems
Quarry water level control: (Olifantsfontein pumping system) Edwin Swanepoel10 April 2014 4
Determining water Influx and required pump capacity
Why determine influx? Sustainability
Where does it come from?
Quarry water level control: (Olifantsfontein pumping system) Edwin Swanepoel10 April 2014 7
Determining water Influx and required pump rate Calculate Influx
Water level rise X Surface Area
Divide by total time
Quarry water level control: (Olifantsfontein pumping system) Edwin Swanepoel10 April 2014 8
Determining water Influx and required pump rate Quarry water level change as a function of time
Old fashioned Total station measurement Many other ways to measure if you apply your mind...
Quarry water level control: (Olifantsfontein pumping system) Edwin Swanepoel10 April 2014 9
Determining water Influx and required pump rate Quarry surface area measurement/Calculation
Old Fashioned way Draw water line on existing quarry map and calculate
Quarry water level control: (Olifantsfontein pumping system) Edwin Swanepoel10 April 2014 10
Determining water Influx and required pump rate Important points to consider while conducting
measurements Rain
o Heavy rain will influence measurements.
Current pumping system performanceo Make sure of total volume dispersed during
measuring period.
Quarry water level control: (Olifantsfontein pumping system) Edwin Swanepoel10 April 2014 11
Dispersing large amounts of water into the environment What does the law say
Every person in control of a mine or activity must take reasonable measures to-o Prevent water containing waste or any substance which
causes or is likely to cause pollution of a water resource from entering any water resource, either by natural flow or by seepage, and must retain or collect such substance or water containing waste for use, re-use, evaporation or for purification and disposal in terms of the Act;
o Minimise water flow of any substance or floodwater into mine workings, opencast workings, etc.
However, water may be discharged provided quality of this water is maintained or improved relative to that of the receiving stream(s)
Quarry water level control: (Olifantsfontein pumping system) Edwin Swanepoel10 April 2014 12
Water quality
Measurements of water quality at various points Better than upstream quality – OK TO DISPERSE Worst than upstream quality – Treatment needed
Continuous measurements must be taken to ensure water quality stays within guideline ranges
Quarry water level control: (Olifantsfontein pumping system) Edwin Swanepoel10 April 2014 13
System resistance Calculation
Quarry water level control: (Olifantsfontein pumping system) Edwin Swanepoel10 April 2014 14
Static Head The static/geodetic head of the system is the difference
between the suction and discharge altitudes (Water level!!!)
Quarry water level control: (Olifantsfontein pumping system) Edwin Swanepoel10 April 2014 15
Pipe Size Discharge: Capital Cost vs. Running cost
1.8m/s > V < 2.5m/s Discharge pipes. Friction Head Proportional to V2 (Haaland)
Suction: To reduce cavitation V < 1m/s (NPSHavailable vs. NPSHrequired)
Quarry water level control: (Olifantsfontein pumping system) Edwin Swanepoel10 April 2014 16
Selecting the best pump for the application
Actual vs. Required flow rate
0 40 80 120
160
200
240
280
320
360
400
440
480
520
560
600
640
680
72030
38
46
54
62
70
78
86
94
System Resistance curves vs. Pump Curve
Flow rate (m3/hr)
Tota
l Hea
d (m
)
Actual Flow rate = 692m3/hrRequired Flow rate = 600m3/hr
Actual vs. Required flow rate
0 40 80 120
160
200
240
280
320
360
400
440
480
520
560
600
640
680
72030
38
46
54
62
70
78
86
94
System Resistance curves vs. Pump Curve
Flow rate (m3/hr)
Tota
l Hea
d (m
)
Determine Pump Head at required flow rate
Actual vs. Required flow rate
0 40 80 120
160
200
240
280
320
360
400
440
480
520
560
600
640
680
72030
38
46
54
62
70
78
86
94
System Resistance curves vs. Pump Curve
Flow rate (m3/hr)
Tota
l Hea
d (m
) (Increase Resistance Head)Install regulating valve & Set at predetermined pressure.
Quarry water level control: (Olifantsfontein pumping system) Edwin Swanepoel10 April 2014 20
Monitoring Installed system Remember pump can only perform on Pump curve:
Sudden change in either flow rate or discharge pressure:o Check for leakso Check pump impellor
However, if both the pressure and Flow rate changeso Compare new Duty point with pump curve:
o If it falls on pump curve but:o Pressure ↑ and Flow rate ↓ or vice versa:
Pump √ Change in static head Restriction in pipeline