In Winfield, Kansas they know a thing or two about energy. Since 1904, it has been a Pubic Power Community. Its residents are stockholders, with profits going to support vital city services such as police, fire, streets, and parks.
At the local wastewater facility, Clint Gregor also knows a thing or two about the treatment plant. He’s worked there since it was commissioned in 1996.
“We’re a top three power user here,” says Clint. “Energy takes up thirty percent of our budget, and in today’s world, we have to look at power consumption more than ever”.
While energy costs are firmly in the industry spotlight, Clint’s driving factor for continuous improvement at Winfield is total cost of ownership. Return on investment has been in focus of late over due to the prohibitive costs of maintaining some of their mixers.
The 1.5MGD plant serves a population of 12,000. A 7.5HP direct drive mixer in a 26-feet deep tank continued to have issues, causing unwanted downtime. Repair bills were somewhat of a shock.
“Being quoted around $8,000 to repair a mixer that cost $10,000 gets your attention,” added Clint. “We did everything we could to keep it going, but eventually it was all chewed up beyond repair. The costs of having the copper rewound on a direct drive mixer or replacing an impeller seem sky-high, with it seems everything geared to make the mixer almost a throwaway piece of equipment. This can’t be right. The work couldn’t be undertaken by a local repair shop, which adds to our costs, and then we were given lead times of anything between 18 and 20 weeks, which is totally unacceptable”.
Keen to find an alternative mixer that would not only give the best value in total cost of ownership, but also be energy efficient, Clint found help from local supplier, Fluid Equipment, for whom Jeff Ubben recommended a Landia mixer that he said would give a good 20-plus years of reliable service.
‘Not all mixers are the same’
“It was a very different, but far better construction compared to what we had”, continued Clint. “The mixer that failed also had a 16-pole motor, but the new one from Landia was just a 4-pole, which would be much better for controlling speeds. These were just the first signs, that despite what some people say in the industry, not all mixers are the same”.
Although it has a much lower rpm and considerably less horse power than the previous mixer, Clint reports that the Landia mixer provides just as good mixing, if not better. Additionally, the existing guide rail could be utilized, so installation was also easy and extremely cost-effective.
“Direct drive mixers have their place” commented Clint,” but with such a high content of internal copper for the size of the stator, this had also become a factor in their excessive weight for servicing. The Landia propellers are sturdier and therefore heavier, but overall, without all that copper, the Landia mixer is far lighter and easy to service, with a motor that is almost half the size of the failed unit”.
The City of Winfield was established in 1870 by the American military commander and political candidate, Winfield Scott (1786-1866). Known as ‘Old Fuss and Feathers’ for his insistence on proper military etiquette, he was also called ‘the Grand Old Man of the Army’ for his many years of service. That adherence to high standards and commitment to the job certainly seems to prevail in modern day Winfield. Clint and his team work tirelessly to meet ever stricter permit requirements (prescribed by the Environmental Protection Agency and the Kansas Department of Health and Environment) to protect the Walnut River, which was declared an outstanding national resource water in the late 1990's.
‘This mixer will soon pay for itself’
One year on, and persistence in best practice is paying off for Winfield with the Landia mixer using half the energy of its predecessor.
“I’ll say it again” concluded Clint, “total cost of ownership is best. This mixer will soon pay for itself. We also know that because of the way it is designed and the way the company behind it operates, we won’t be held to ransom for heavy repair bills and very expensive replacement parts. The amp draw is less than half of the old direct drive mixer, so we were confident of making significant energy savings, just as we are in its longevity – so much so, that in our adjacent tank we have another mixer that is coming to the end of its days – and when it needs to go, we’ll be replacing it with a Landia mixer”.