Maximising motors for energy efficiencyHigh efficiency motors can bring significant savings but if budgets won't stretch to motor replacement, energy efficient bearings offer a powerful cost-saving alternative, says Phil Burge.
In the current economic climate, the pressure to maintain a healthy operating margin is great but attempting to protect this margin by increasing prices is risky. An alternative option is to look at your current practices and identify potential changes that could help to reduce your costs. The problem here is that it is sometimes difficult to see how any cost reduction can be achieved, particularly when many raw material prices are running high and the demands of increasing environmental legislation continually add to the cost base. However, there are options that can help you cut a major cost in any plant, and that cost is, of course, energy.
The majority of commentators estimate that factory energy expenditure accounts for at least 50% of the total running costs. Correspondingly, any savings made here can make a marked effect on the balance sheet.
One strong option that can have a positive, long-term effect on the business is to replace older motors with modern, high efficiency equivalents. However, this is not always feasible; when budgets are tight, even proven, long-term cost-saving options such as the installation of energy efficient motors may be tricky and cash flow problems may rule out the possibility altogether. So, if we have had to rule out motor replacement, how do we effect an energy saving?
Switching components offers a more affordable option and a powerful one, too. Energy efficient bearings can make a massive contribution to profitability, cutting energy wastage by up to 50% and also extending the lifespan of your existing motors.
Today's leading energy efficient bearings enable components to rotate more easily with minimum friction and heat, dramatically reducing wear and enhancing performance. For example, E2, a range of energy efficient deep groove ball bearings from SKF, features a host of technical innovations that reduce friction. The internal geometry of the bearings has been optimised via the use of advanced modelling tools, which, in tandem with a new, fit-for-purpose polymer bearing cage, has brought a marked improvement in operating efficiency.
The very best of today's energy efficient bearings offer the potential to minimise frictional losses to such a degree that operating temperatures can be lowered by as much as 30°C, resulting in an improved lubricant viscosity that extends the operating life of moving parts. In addition, these innovative energy efficient bearings can last twice as long as their conventional alternatives, cutting the cost of purchasing as well as running the equipment at your plant. Such developments as these have proved that energy efficiency can be achieved even without the expense of replacing plant motors, boosting performance and productivity to the benefit of operators while also satisfying environmental pressures to consume less energy.
Another positive point to bear in mind is that replacing your existing bearings with energy efficient alternatives does not require additional downtime; they can be exchanged during routine maintenance. For example, SKF E2 deep groove ball bearings are dimensionally interchangeable with standard equivalents and available in a range of sizes, enabling the change to be made during planned downtime.
Without generating the considerable cost of replacing motors, energy efficient bearings can make a difference in all applications, and where energy savings are concerned, it's not only a one-off benefit; any saving you make is being made day-by day and year on year. To give an example of how this might be calculated in practice, take a typical electric motor, which can generally be fitted with energy efficient bearings in sizes of up to 37kW. If the best of the current crop of E2 bearings are used in a single 37kW motor, running continuously at 3,000rpm, that will make an energy saving of 270kW per year, and keep more than 150kg of CO2 out of the atmosphere. The benefits are even greater on a larger scale: SKF helped a leading consumer healthcare company to reduce frictional losses by 46% by providing energy efficiency deep groove ball bearings in cold water pump motors (22kW) running at speeds of 2,990 rpm. Ultimately, this translated to energy savings of 4,583kWh per year per motor.
Energy is becoming an increasingly precious commodity, both financially and environmentally, and reducing consumption by plant and machinery across all sectors brings benefits to everyone. The development of energy-saving technologies is, thankfully, a growth area and the recent innovations in energy efficient bearings represent not only a positive step in the right direction but also a significant opportunity for companies throughout industry to minimise the environmental impact of their operations and cut energy costs.
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