by Matt Migliore
|ITT Monitoring & Control’s PumpSmart variable-speed drive system features a sensorless flow measurement function that is designed to calculate the flow of a centrifugal pump within +/- 5 percent of the pump’s rated flow without the need for any external instrumentation.|
In an effort to meet the demand for solutions that control the lifecycle costs associated with pumps, manufacturers are developing new technologies designed to limit system maintenance and energy consumption. According to Dan Kernan, product manager for the Monitoring & Control division of ITT Corporation (www.ittmc.com), approximately 85-90 percent of the total cost of operating a pump can be attributed to ongoing maintenance and operating inefficiency. “The bulk of the cost is outside the flanges, so we’re focused on helping customers to optimize their systems and be more predictive in terms of condition monitoring,” he says.
As such, Kernan advises end-users to resist the temptation to base pump purchases on a “low-cost impulse.” Rather, he says it is important to consider the long-term costs associated with operating the pump under consideration.
In an effort to help its customers better understand the lifecycle costs of pumping applications, Kernan says ITT Monitoring & Control employs a systems-based approach. Instead of just quoting a pump, Kernan says ITT considers the overall system and how it can be tailored to reduce ongoing maintenance and energy costs over the life of the pump.
Kernan says the most common problem he sees when it comes to inefficient pumping systems is oversized pumps and throttling valves. “I can’t emphasize enough how important it is to try to right-size the pump for the system,” says Kernan, noting that an overly large pump wastes energy and affects other pieces of process equipment, including valves, pipes, etc. “So the more you can do to reduce the energy that is coming out of the pump, the better off you’ll be,” he says.
To determine if the pump is too large for the job, Kernan recommends that all users perform a valve survey. If the valves are less than 50 percent closed, this would indicate the pump is too large for the job, and thus is using too much pressure and wasting energy. When faced with such a scenario, Kernan says the user has several options: trim the pump impeller; replace the pump with a smaller unit; or implement a variable-frequency drive (VFD).
Another best practice Kernan recommends for pump users is implementing a pump protection program. He says, while dry-run protection is commonplace when it comes to sealless magnetic-driven pumps, similar protection programs should also be employed for other pump types. In addition to dry-run conditions, Kernan says pump users should also aim to protect their pumps against a shutoff condition (i.e., blockage in the discharge of the pump), which can result in heating of the process fluid and may lead to a catastrophic failure of the pump casing. “Implementing a pump protection system, I think is just as critical as right-sizing the pump to the application,” says Kernan.
Going forward, Kernan says he expects to see rapid adoption of predictive diagnostics for both maintenance and operation of the pump. He says items such as vibration, temperature, oil quality, performance, and pumping efficiency figure to benefit from predictive diagnostics.
Currently, ITT Monitoring & Control is offering embedded intelligence as part of it PumpSmart VFD system. The PumpSmart solution uses sensorless data derived from the VFD, such as speed and torque, to provide users with real-time feedback on pump performance. Kernan believes technologies of this sort are a harbinger of technological evolution in the pump space. “Before you see the next breakthrough in pump design, you’re going to see the next breakthrough in pump maintenance and energy efficiency,” says Kernan, who believes predictive diagnostics and VFD technology will ultimately enable more efficient pumping systems.
Matt Migliore is the editor or Flow Control magazine. He can be reached at Matt@GrandViewMedia.com.