Energy Optimization – 4 Simple Free Steps to Save Thousands!

energy
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Before we discuss methods of saving energy, it is important to understand energy consumption and the benefits of energy saving.

Energy Consumption

Electric energy consumption is the energy demand made on existing electricity supply. Motor Driven Equipment dominate industrial electrical consumption and within this category, over 60% involves Fluid handling equipment, with pumps being the highest consumer of all.

It is common practice for engineers to overate the required energy to ensure that any given system will have enough power to operate, but as technology becomes more advanced and product efficiency increases, there are more opportunities make huge financial savings by reducing energy consumption.

Benefits of energy saving.

The obvious reason for energy savings is for financial gain, and this is arguably the most important reason for companies when investing in energy efficient products, however it is important to also highlight the environmental benefits.

In cases where pump units are continuously operating, companies save thousands of pounds annually by making simple pump or system changes.

4 Simple steps to save energy
  1. Selection should include for IE3 premium efficiency motors or Higher. Low efficiency Motor lose energy via the Pumps which basically means you are spending more than you need no wasted energy. Motor manufactures like WEG have high efficiency motors tha can go up to 97% efficiency.
     
  2. Do not throttle valves – Obtain Smaller pump units, also resulting in reduction on maintenance, and betting pumping performance.

  3. Maintain your pump units. The car analogy is use too often, but it still remains, Good tires, scheduled services and general maintenance will prolong the life of your vehicle and ensure your fuel consumption is most efficient. And when owning mechanically engineered products (such as pumps), the principle remains. Maintaining tolerance, checking levels, and servicing your pumping assets will ensure you get the most energy efficient and longest lasting unit. Which is why all water authorities and huge manufacturing companies invest in service agreements.

  4. Remove Variable Speed drives – Once frown upon, Variable speed drives have become one of the most efficient ways of reducing motor speed. However, all mechanical methods which eliminates the need for additional electrical devices are typically the preferred method for energy savings. If it is possible, it will be best to select a suitably sized pump to do the flow requirement you need.

Whether you own Pump assets, you’re an engineer involved in pumping systems, or you work within an industry that contains pumps, you would know that pump failures are major concerns, especially when they frequently fail. BEPumps has a fully trained pump system auditor, certified by the British Pump Manufacturing Association.

Common Failures

All Pumps are designed to last for the number of years specified by the manufacturer, therefore when failure occurs it is important to identify why.As this is a common problem BEP has highlighted some of the main reasons for pump failure.

Free Passage & Blockages

Arguably the single biggest reason for Pump failure is blockages. Every Pump unit has a specific free-passage (throughlet) which depicts the largest ‘solid ball’ that will pass through that particular pump unit. However, despite the free passage stated by the manufacturer, the geometry of the impeller plays a very important role to ensure that the pump unit will pass particularly difficult liquids such as sewage, slurries, and process liquids.

BEPumps generally recommends a Free passage that is between 75%-100% the diameter of the pumps discharge pipework, which is why BEP Pumps have single vain spiral Impeller to ensure the best free passage and solids handling capability despite the liquid conditions.

Velocity

Neglecting the velocity is one mistake that many engineers make. The velocity is typically calculated using the Flowrate through any given pipe (m3/sec) and divided by the diameter of that pipe (m2).

Should the velocity be too low then you would expect settlement within the pipework which will impact the performance of the pump and cause ‘off curve’ behaviour such as High temperature, Cavitation, Low bearing life, liquid recirculation, to name a few.

Alternatively, the velocity could be too high, which will impact the pipework due to high pressure, cause cavitation in the pumps impeller, increase vibration within the pump and many other performance and energy related issues.

BEPumps recommend a velocity between 0.75m/s – 1.8m/s.

Airlock and loosing Prime

Pumps cannot transfer gas (air). Therefore, there’s no surprise that a given pump will stop working when it contains air (loses its prime). Generally Submersible pumps don’t suffer from Airlock once they have been installed and commissioned, however in the case where the levels within a well drops below the volute casing, or there is a vortex within the liquid, then it is possible to entrain air which can impact the performance of the pump unit.

An improvement that can be made, is to install an air release pipe to the discharge pipe which will encourage recirculation of air and reduce the chances of air locking. Also, changing the operation levels could be a solution however, this must be done by a competent system operator who understands the control philosophy.

Maintenance & Servicing

Ensuring your assets are well maintained is important for longevity and reliability. Failure is a common issue for many pump owners who tend to run their pumps into destruction before considering a service. This can be understandable for some pump installations as they may be difficult to access, they require heavy lifting or they need expensive equipment.

Above ground pumping units are the easiest arrangements to maintain and service. By undergoing scheduled servicing, you are able to maintain good pumping performance, reliability, and significantly reduce the chances of pump failure.

For a quick troubleshoot procedure please visit www.BEPumps.co.uk to get a free PDF of typical Symptoms and Causes of Pump failure.