The plant, which serves the Dayton area, also faced hefty downtime expenses if it stayed shut down too long, Plant Manager Dave Martin said.
Powdered limestone must be injected into the plant’s three incinerators to meet EPA air pollution control standards for sulfur dioxide emissions. The pneumatic conveying system used in this process contained long-radius sweep elbows. But these elbows proved unable to withstand the lime’s abrasive action.
At the pressure required to move 18,000 pounds of powdered limestone 24 hours a day, 363 days a year, even a pinhole-sized leak in a sweep elbow creates a tremendous cloud of dust and presents a considerable mess to clean up, Martin said.
But that’s just what was happening, every three months or so, necessitating a system shutdown for repair and cleanup.
To make matters worse, if the lime injection system stays out of operation for more than a few hours, the EPA requires the plant to shut the incinerators down completely – resulting in a downtime expense of approximately $40,000 per day.
Martin thought he had found a possible solution when he discovered HammerTek’s Smart Elbow deflection elbow at a trade show a few years ago. It was there that he learned that the Smart Elbow deflection elbow is designed to allow changes in direction in pneumatic and slurry conveying systems without the excessive wear, plugging and product degradation problems associated with virtually all other elbow types.
The secret to the Smart Elbow units success is the patented vortex chamber at the back of the elbow. At a point where traditional elbows fail, the Smart Elbow design creates a rotating ball of suspended material that helps redirect the entire product without friction, impact or wear. Smart Elbow deflection elbows are also easier to install.
Years later and with zero surprise dust clouds, that first Smart Elbow model is still in operation, and the plant has added more.
“Since installation of the Smart Elbow products, we have saved on maintenance costs, decreased our downtime, and increased system reliability,” Martin said, adding, “We don’t have to cut and weld like we did with the sweep elbows — they just bolt right in.”
North Incinerator is now installing Smart Elbow models in a new, higher-capacity lime injection system, and they are the elbow of choice for a future fly ash handling system which is currently in its final planning stages.
To read the full case study, please visit the HammerTek website.