1. Metso - Slurry Pumping

2. The industrial pump family
Pumps
Centrifugal pumps
Displacement pumps
Slurry pump Water pump Piston pump Membrane pump Gear pump Peristaltic pump
(Hose pump)
“A pump is a machine that conveys energy to a liquid”
Slurry Pumping Basic Training Course

3. Slurry pump functions Displacement pumps
“High pressures and moderate flows”
Slurry Pumping Basic Training Course

4. Slurry pump functions Centrifugal pumps
“Variable pressure and flow”
Slurry Pumping Basic Training Course

5. Mechanics of slurry pumps Basic designs
Horizontal
Vertical - sump
Vertical - tank
Impeller
Pump housing
Shaft seal
Bearing
Drive system
No Shaft Seal !
Slurry Pumping Basic Training Course

6. Mechanics of slurry pumps The impellerVT VN VR
“Conveying energy from the pump shaft to the liquid and accelerates it”
Slurry Pumping Basic Training Course

7. Semi Open Impeller (O)
Not so sensitive against blockage by BIG particles and air.
Can be a good selection when pumping very thick slurry, frothy slurry (air).
Lower efficiency relative to Closed impeller
Normally used in vertical sump and tank pumps
Slurry Pumping Basic Training Course

8. Closed Impeller (C) Better efficiency
More sensitive to blocking by big particle and air
Small impellers are even more sensitive to blocking
Always use Closed impellers for pumping dense and abrasive slurries
Slurry Pumping Basic Training Course

9. Closed Impeller (C) ~ High efficiency impeller, “Low” wear
Slurry Pumping Basic Training Course

10. Vortex Impeller Also called Induced Flow
Prevents blocking when pumping larger particles, fibers and “sticky material”
More gentle pumping if particles are easily damaged (carbon particles)
Relatively low efficiency
Slurry Pumping Basic Training Course

11. Number of Vanes (for Slurry Pumps)
More vanes give higher efficiency………….
In practice max. 5 otherwise risk of blocking! !
Slurry Pumping Basic Training Course

12. Impeller Width Greater width gives a higher flow at fixed speed
When pumping Bigger particles (Ex. Dredge applications)
Slurry Pumping Basic Training Course

13. Impeller Diameter
Larger impeller diameter gives lower RPM. But lower efficiency. Good for high-wear applications.
Smaller impeller diameter and higher RPM gives better efficiency but greater wear. Good for pumping water and low wear slurries.
Slurry Pumping Basic Training Course

14. Mechanics of slurry pumps Pump housing
“Converts kinetic energy to hydraulic pressure”
Whole pump housing
Split pump housing
Slurry Pumping Basic Training Course

15. Mechanics of slurry pumps Shaft seals
Flushed Dynamic Mechanical
(Expeller)
Slurry Pumping Basic Training Course

16. Mechanics of slurry pumps Flushed seal – high flow function
Sealing water pressure should be minimum 0,5-1 bar above discharge pressure !
Slurry Pumping Basic Training Course

17. Mechanics of slurry pumps Flushed seal – high flow function
Slurry Pumping Basic Training Course

18. Mechanics of slurry pumps Flushed seal – low flow function
Slurry Pumping Basic Training Course

19. Mechanics of slurry pumps Flushed seal – low flow function
Slurry Pumping Basic Training Course

20. Mechanics of slurry pumps Dynamic seal (Expeller) – function
Slurry Pumping Basic Training Course

21. Mechanics of slurry pumps Dynamic seal (Expeller) – function
Slurry Pumping Basic Training Course

22. Mechanics of slurry pumps Mechanical seal – function
Slurry Pumping Basic Training Course

23. Mechanics of slurry pumps Mechanical seal – function
Slurry Pumping Basic Training Course

24. Performance of slurry pumps Pump curve
Slurry Pumping Basic Training Course

25. Performance of slurry pumps Pump curve with power consumption
Slurry Pumping Basic Training Course

26. Performance of slurry pumps Pump curves at different RPM – constant flow
Slurry Pumping Basic Training Course

27. Performance of slurry pumps Pump curves at different RPM – constant pressure head
Slurry Pumping Basic Training Course

28. Performance of slurry pumps System curve/Operational point with fixed pipe dimension. Fixed Pump speed.
Slurry Pumping Basic Training Course

29. Performance of slurry pumps System curve/Operational point with different pipe dimensions. Fixed pump speed.
Slurry Pumping Basic Training Course

30. Performance of slurry pumps System application
Performance of slurry pumps System application. Variable Pipe System and Speed
Slurry Pumping Basic Training Course

31. Performance of slurry pumps Best efficiency
Pump curves at different RPM
For all centrifugal pump designs, there are:
ONE rpm
ONE pressure head
ONE volume flow
At which the efficiency is Maximum.
“The further we work from this area – the lower the efficiency”
Slurry Pumping Basic Training Course

32. Performance of slurry pumps Best Efficiency Point (BEP) or Best Eff
Performance of slurry pumps Best Efficiency Point (BEP) or Best Eff. Line (BEL)
Wear is minimized
Axial and radial shaft forces are next to nothing
Electric power consumption is optimal
Pump’s service life increases
“If the operational point on the system curve lies within the area of the best efficiency, then we are working at the pump system’s best working point”
Slurry Pumping Basic Training Course

33. Radial Forces = Shaft Deflection and B.E.P
Slurry Pumping Basic Training Course

34. Total Dynamic Head (TDH)
Total static head = H2-H1
Slurry Pumping Basic Training Course

35. Wear in slurry pumps Wear on impeller and housing
(Crushing and pulverisation)
Impact and sliding
Impact and sliding
Slurry Pumping Basic Training Course

36. Wear in slurry pumps General about wear
Wear caused by
Compression
Impact
(high speed)
Impact
(low speed)
Sliding
METAL
POLYMER
Manganese steel
Rubber
Protected by
Ni-hard
Polyurethane
Chrome steel
Ceramics
“All machines in contact with ores or free minerals are subject to wear when movement energy, solids, and machine parts meet in the process. Slurry pumps are no exception to this!”
Slurry Pumping Basic Training Course

37. Wear in slurry pumps Wear materials - limitations
For rubber
Particle size ( >5 mm)
Sharp slurry (cutting damage)
Hydrocarbons (diesel, pine oil, etc.)
Temperature
Peripheral speed pump impeller
(max 27 m/s)
Inlet speed
For metals
Acids
Salts
Peripheral speed pump impeller (max 45 m/s)
Inlet speed
Slurry Pumping Basic Training Course

38. Slurry pumps, supplies General
“90% of all problems with slurry pumps are associated with the pump inlet (suction side)!”
Slurry Pumping Basic Training Course

39. Slurry pumps, supplies Pump Sump
Good
Not so good
A good supply must …
Feed slurry and not air
Accept normal variations in flow
Not accept sedimentation
Stand free from the pump
Slurry Pumping Basic Training Course

40. Slurry pumps, supplies Effects due to Cavitation
Lost efficiency
Noise and vibrations
Increased wear on seals, wear parts, bearings, base etc…
Mechanical damage on pump !
A pump is cavitating easier when high altitude (like Iran mine sites)
The high altitude should always be calculated with, when sizing a pump and motor !
Slurry Pumping Basic Training Course

41. Slurry pumps, supplies Cavitation
Atmospheric pressure can affect the temperature that a liquid boils at.
At 2800 m.asl liquid boils at 92ºC
95ºC
1000m
100ºC
Slurry Pumping Basic Training Course

42. Slurry pumps, supplies Cavitation
If a slurry pump is to function properly, the inlet pressure must be sufficient.
If the inlet pressure drops below the vapour pressure inside the impeller (due to blockage, restrictions, etc.) vapour bubbles will be formed!
Extremely high pressure waves are created when the bubbles collapse (implode). This is called cavitation and can damage the pump!!
Slurry Pumping Basic Training Course