High energy prices pose an unprecedented profit-robbing threat to every manufacturing operation, large or small. Left unmanaged and unchecked, rising energy expenditures can erode a company's stability, performance, productivity and, ultimately, its competitiveness and viability. Confronted by these rising energy costs, manufacturing operations around the globe are implementing energy-management processes and procedures.
To address energy consumption, many areas worldwide are developing new climate and energy policies that have been designed to create behaviors to moderate energy usage. As an example, in March 2007, the European Union's Heads of State Government announced a series of demanding climate and energy consumption targets that must be met by 2020. These are:
- A reduction in EU greenhouse gas emissions of at least 20 percent below 1990 levels
- Requiring 20 percent of EU energy consumption to come from renewable resources
- A 20 percent reduction in primary energy use compared with projected levels, to be achieved by improving energy efficiency
The European Parliament and Council approved this "climate and energy package" in December 2008, and it became EU law in June 2009.
Similarly, 2005's wide-ranging Energy Policy Act in the United States elevated the profile and increased discussion of energy use and conservation in the country. Since the inception of EPAct, there have already been enviable gains in energy conservation in the industrial sector thanks to a series of energy-efficiency assessments that were conducted at more than 400 of the nation's largest manufacturing plants.
These assessments showed that it is possible for the industrial sector to improve its "energy intensity" by 25 percent by the end of 2017, or an average of 2.5 percent per year leading up to that deadline. The key to meeting this goal is instituting a "systems approach" to energy efficiency and conservation in manufacturing plants, i.e., turning the focus away from individual components and, instead, analyzing both the supply and demand sides of the system as a whole.
However, while it is easy to establish thresholds for energy consumption, identifying and implementing the most efficient means to meet those thresholds can be more problematic. Using the industrial sector as an example, since pumps account for anywhere between 27 and 33 percent of total electricity used in this sector globally, improvements in pump-system performance can play an important role in minimizing energy costs.
At their most basic, poor design and improper system operation are the root causes of inefficient pumping systems. As rotating equipment, pumps are subject to wear, erosion, cavitation and leakage. These problems can be exacerbated through improper pump selection and operation. If they are not selected or operated properly, pumps can waste enormous amounts of energy, as well as require considerable maintenance.
This pump-selection process can be complicated by the fact that many different types of pumps can be applicable in a single operation. When making the final choice in pump type, the list of crucial factors that need to be taken into account can be daunting: required flow rate, differential pressure, temperature, viscosity, shear sensitivity, corrosiveness of the liquid handled, etc.
Facility managers tend to choose oversized pumps. While installing an oversized pump ensures that the system needs will be met under all operating conditions, the added energy cost inherent in operating oversized equipment is generally ignored.
As manufacturers work to align their energy-efficiency initiatives with their business goals, pump system improvements will play an increasingly important role in this effort. Since no "one pump fits all" solution exists, particular attention to proper pump selection will become increasingly more important in the effort to select the right pump that not only will deliver productivity gains, but will work equally as well at controlling energy consumption.
By virtue of their inherent energy- and mechanically efficient designs, positive displacement sliding vane pump technologies can offer options for energy-saving initiatives.
Sliding vane pumps are among the most energy efficient PD pump technologies. Significant design advancements have given sliding vane technology an advantage over gear pumps, specifically with regard to optimized performance, low-shear capability, lowest life cycle cost and best energy efficiency. The sliding vane pump has a self-adjusting vane-design feature that eliminates energy-robbing slip and promotes high volumetric efficiency even after substantial time in service.
This design makes sliding vane pumps more efficient and desirable for use than gear pumps. Gear pumps use the meshing of gears to pump fluid by displacement. This style of operation wears down a gear pump since the pump's gears mesh together to move fluid. This constant wear increases the internal clearances between the gear teeth, in the process reducing flow capacity and volumetric consistency while increasing the possibility that "slip" will occur. All of these operational deficiencies result in not only decreased pump performance and increased maintenance occurrences, but also in wasted energy use, which can increase costs.