Wisconsin Wastewater Operators
Association
Maximizing Lift Station Efficiency
February 13 , 2014
Water & Wastewater Control Solutions
Pump Efficiency
Increasing Pump Station Efficiency
Pump Efficiency
• Major Components of Pump Efficiency
• Motor Efficiency
• Impeller Types
• Pump Selection
• Maintaining Pump Efficiency
Orange = Hydraulic Eff.
Motor Eff. + Hydraulic Eff. = “Wire to Water” Eff.
Increasing Pump Station Efficiency
Pump Efficiency
• Motor Efficiency
• Traditional Dry Pit Motors
• Standard Eff.
• High Eff. ~ +1.3%
• Premium Eff. ~ +2.3%
• Ultra Eff.
Premium
High
Standard
Increasing Pump Station Efficiency
Pump Efficiency
• Motor Efficiency
• Submersible Motors (Wet & Dry Pit)
• 3-7% Lower (hp)
• Cooling
Increasing Pump Station Efficiency
Pump Efficiency
• Impeller Design – Hydraulic Eff.
• Multi-vane (clean water or small solids)
• 2-vane
• 1-vane
• Vortex (a.k.a. recessed impeller)
Increasing Pump Station Efficiency
Pump Efficiency
Tradeoff between Efficiency and Solids Handling
Increasing Pump Station Efficiency
Pump Efficiency
• Pump Selection
• B.E.P. – Best Efficiency Point
• VFD Operation?
• System Curve Awareness
• Flow Pacing Efficiency Awareness
Better Pick?
Example 1
Example 2
VFD curves
Example 1
70% Eff.
200 gpm
60% Eff.
-10% Eff. Loss
VFD curves – Better Pick?
Example 2
68% Eff.
200 gpm
68% Eff.
No Efficiency Loss!
Increasing Pump Station Efficiency
Pump Efficiency
• Maintaining Pump Efficiency
• Wear Rings, Wear Rings, Wear Rings!
• Impeller and Volute
• Fingernail Clearance (2/100”)
• Average 5 year life
Worn Front head – No Wear Ring
Increasing Pump Station Efficiency
How can I improve my station’s efficiency?
SUMMARY
• Verify pumps are operating within their design
curves
• Maintain pumps, bearings, wear rings, seals
• Explore solid state starter or variable frequency
drive operation for station.
• Upgrade control system to keep pumps from
starting and stopping excessively and pumps
running within design curves.
• Replace/maintain suction/discharge valves to
eliminate excess pressure on system.
Water & Wastewater Control Solutions
Where does the clogging
begin?
• Sewage containing
excessive fibrous
material, long
strands of debris,
hair, clogging
typically initiates at
the leading edges of
a impeller
Fairbanks Morse Bladeless Solids
Handling Trash Pump
Chopper/Cutter Pumps
• Chopping and pumping of lift station debris
Chopper Pumps
Chopper Pumps
– Unique Hardened Steel Knife System
– The externally-mounted knife system performs the chopping before
the solids enter the impeller area.
– The complete knife system or individual knives are easily serviced
using only an Allen wrench
– The open impeller is designed for pumping the solids
– This is the design of a true chopper pump
Thank You
Questions?
Rick Bartelt
L.W. Allen Inc.
4633 Tompkins Drive
Madison, WI 53716
608.222.8622
[email protected]