Bredel pumps save UK manufacturer £2700 per pump / per year in electricity, compared with AODD pumps – Equating to an 80% reduction in energy consumption
Today, all manufacturing and process plants see energy efficiency as a major priority on their agendas. Energy has become a board level commitment because it is driven by legislation in both the EU and the UK, and also because it’s an expensive overhead. Nearly all plants run pumps of some kind, and without the necessary energy management they can make for hefty electricity bills that can impact the bottom line and reduce competitiveness.
Knowledge is power
According to the BPMA (British Pump Manufacturers’ Association), pumps account for around 10% of the world’s electricity consumption, while an alarming two-thirds of pumps use up to 60% more power than necessary.
Correct pump selection is therefore critical in controlling energy consumption, and not just the brand, but the correct pump technology, the size of pump and drive for the application. Only this will ensure the shortest payback times and allow plants to maximise the return of their investment. Quick ROI is also a great way to ensure board level buy-in.
Look beyond the price
When considering the acquisition of a new positive displacement pump, many engineers get seduced by a cheap purchase price. However, there are far more significant savings to be made over the lifetime of a pump if factors such as energy efficiency are more carefully considered. In fact, tests and calculations have shown that Bredel heavy duty hose pumps can save up to 80% in energy costs per pump in comparison with AODD pumps.
One recent example highlights just how much can be saved by making more informed pump purchases. At a Midlands based packaging company that was an established user of AODDs (air operated double diaphragm pumps), a prospective enquiry led to a very welcome boost to the bottom line by switching to Bredel hose pumps from Watson-Marlow Fluid Technology Group.
A direct comparison was drawn between their existing AODD pump and the Bredel 50 hose pump. At 29 rpm, the flow rate at 50 Hz is 5,000 l/hr. The AODD pump air consumption at this flow rate (at 6.9 bar pressure) is equal to 35.34 CFM.
Extrapolating the mathematics further, 35.34 CFM (based on 4 CFM per kW maximum generation) is equal to 8.83 kW. Hence, with electricity costing £0.10 per kW/hr, the cost of running the AODD pump per hour is £0.88. The duty cycle of the pumps for this client’s application is 16 hours running per day, 5 days per week, 48 weeks a year – which equates to annual running costs in electricity of £3379. In reality this figure is likely to be even higher because of the air system leakage suffered by most manufacturing sites.
Using the same parameters, the Bredel 50 draws just 1.75 kW, so the running cost per hour is £0.175. Based on identical hours of operation, the annual running cost in electricity is £672, delivering an impressive saving of £2707 per year, per pump. The company has installed three Bredel hose pumps, delivering an impressive saving of £8121 per year, thereby reducing their energy consumption by 80%.
Added to this, there is a reduction in CO2 emissions of over 12500kg per year, per pump based on the 2015 DEFRA conversion ratio of 0.46219kg of CO2 per kW hour of energy used.
Factoring in the purchase price of the Bredel 50, the payback period is just 2.1 years, after which the pumps have a positive effect on the bottom line.
“For this client, the payback period was even shorter as the calculations shown do not include common issues associated with AODD pumps for this type of application – such as breakdown costs and lost production time,” says Andrew Edwards, a sector specialist at Watson-Marlow. The client also considered the reduced compressed air requirement, which resulted in less wear and tear on the compressor.
These effects were particularly common at the manufacturer in question because the product being pumped from bulk tanks to day containers is starch, which is quite abrasive and becomes even more abrasive when sheared.
Abrasives are known to wear AODD pump parts, such as expensive end caps and manifolds. Furthermore, the ball check valves of air operated double diaphragm pumps can be distorted by the wear, to the point they reach a size that they can extrude through the pump. If this occurs the result can be a contamination of the process or creating a blockage in the pipework system.
Previously, the manufacturer had to maintain the AODD pumps every 2-3 weeks, and not just to replace normal wear parts like diaphragms, but high cost components. What’s more, the failures were unpredictable, causing line stoppages, process disruption and yet more costs.
In short, industrial manufacturers can become far more energy efficient and maximise process up time by switching to Bredel pumps.
Ultimately, the example described shows that switching to Bredel pump technology can improve energy efficiency and enable plants to increase profitability and remain competitive in today’s fierce marketplace. Benefits arrive not just in the shape of energy savings, reduced carbon emissions and legislative compliance, but in demonstrable greener credentials as part of a company’s corporate responsibility initiatives.