International Specialty Products Chemicals Inc. (ISP) serves the pharmaceutical, beverage and personal care industries as the single largest privately-owned specialty chemicals manufacturer in the US. The ISP Calvert City facility in Kentucky, built in 1956, is the largest of the company's seven American manufacturing plants, with over 500 employees producing 325 different chemicals.
Monitoring failure
In order to reduce productivity losses caused by process equipment failure, the plant has tried a number of monitoring technologies for its pumping systems. Temperature sensors were installed at the bearings and in the casing of the magnetic drive pumps. Flow switches were installed in an attempt to stop dry running or no flow conditions.
“Both devices proved unreliable in preventing premature failure due to the lack of response under low load conditions,” according to reliability engineer Ken Myers.
Another technology sometimes used is current monitoring, but this often fails to detect under load conditions on AC induction motors. Motor current barely changes until the motor load reaches or exceeds 65 to 70% of its rated power, and even after this point it is non-linear. This makes it difficult to establish protection for the pump.
Maintenance failures
In 2000, ISP's local pump supplier, BRI Inc., introduced ISP to the Emotron M20 shaft power monitor. “Initially our main goal was to protect our magnetic drive pumps from dry run conditions that proved detrimental to the pump operation,” says Ken Myers. “Prior to installing the Emotron M20 monitors, we had three particular pumps involved in significant issues that averaged greater than $90,000 per year in maintenance and downtime costs. After the monitors were installed, the average costs for the next years dropped to zero.”
Installation
The Emotron M20 monitor has a shaft power calculation technique that immediately detects pump load changes due to dry running or other abnormal process conditions, across the whole motor load range. This gives reliable monitoring with direct correlation to the pump curve. Since the Emotron M20 uses the drive motor as a sensor, there is no need for costly and service-demanding external sensors or extra cabling. The result is reduced installation and maintenance costs, as well as increased reliability. An auto-set feature allows four protection set points to be established in three seconds with the push of a single button.
Investment return
When assessing reliability solutions, ISP looks for investments with a short payback period. “We saw an immediate return on investment with the Emotron M20 solution,” states Ken Myers. “From our experience, we expect to see the investment pay for itself in just one week in most cases.” The plant actively continues to pursue new applications for the shaft power monitor on its process pumps. This is done with regard to monitoring reliability, range of capability, ease of installation, and user-friendly set-up.
“Some other equipment problems we encountered came to our attention, such as overload protection, underload situations, troubleshooting, efficiency verification, and failure mode identification,” says Ken Myers. “This led us to install Emotron M20 units on other applications, such as positive displacement pumps, transfer elevators and conveyors, and product blenders.”