Pumping processes are used in various industrial activities, such as de-watering, pumping of condensate, chemical dosing or hot water circulation. A common use of pumping in the manufacturing and services sector is the circulation of liquids like fuel, water, chemicals, oil, petroleum, sludge, slurry or reactants.
Throttle controls are typically used on fixed-speed pump systems to vary the flow rate to match other system inputs. However, this can consume energy both through the operation of the throttling valve and through loss of pump efficiency when it is not used at its most efficient operating point.
With a variable speed drive, the speed of the pump and the pumping rate can more closely match the flow rate of the system as it varies over time. This reduces or eliminates energy losses associated with throttling and more closely maintains the best efficiency point for the pump.
Sectors and common applications
- Electricity generation – pumping of coolant, condensate extraction pumps and boiler feeds
- Mining – mine dewatering, slurry and wastewater extraction, flocculant dosing or provision of fire-fighting water
- Manufacturing – boiler feed, hot water circulation, mixer pumping, condensate and dosing, as well as transfer systems and others
- Oil and gas – product circulation and offloading systems on oil tankers and offshore platforms, dewatering and coolant transport
- The estimated energy savings in 2014 across sectors was 60 PJ.
|1. Energy saving potential|
|1.1 Level of energy efficiency||15/15|
|1.2 Market prospect||2/10|
|1.3 Energy saving potential||9/10|
|2. Technical practicality|
|2.1 Innovative or advanced nature||15/25|
|3. Economic characteristics|
|3.1 Investment per unit energy||8/10|
|3.2 Payback period||10/10|
|3.3 % of Industry $ gross added value||5/5|
|4. Social characteristics||3/5|
Fortescue Metals Group Ltd reviewed de-watering bores on site, finding that many of the standard pumps are throttled to reduce flow to a sustainable level. Detailed analysis showed that highly throttled pumps consume significantly more diesel per mL of water pumped than non- or low-throttled pumps. A rateable store of spare pumps of varying sizes was implemented, and heavily throttled pumps in the field were replaced with better matched pumps and generators. Pumps have been progressively swapped to more appropriate sized equipment at each mine.
Other companies that have identified optimisation of pump throttling as a source of energy savings:
- Cristal Australia Pty Ltd
- Great Energy Alliance Corporation
- James Hardie Austgroup Pty
- Newgen Power Kwinana Pty Ltd
- NSW Sugar Milling Co-operative Ltd
For more information, see: