SITUATION...
As the city's primary sewage treatment facility, this plant treats an average of 40 to 45 million gallons a day. At peak, the volume can exceed 80 million gallons a day, as the plant operates 24 hours a day, seven days a week. In addition to Alexandria, the plant also serves Fairfax County and parts of the city of Arlington, Virginia. The operation uses about 500,000 pounds of pelletized lime per month for odor and pH control. This powdery mix is pneumatically conveyed from trucks to 70' silos through twin four-inch lines.
THE "GLITCH"...
Initially fitted with 4" sweep elbows, the lime conveying system started experiencing leaks in the sweeps after about six months of operations. The sweep elbows were swapped for sweeps fitted with wearbacks. Those lasted a bit longer. "Then we were probably losing an elbow every nine months," according to Bob Devereaux, Lead Mechanic. The dust was a problem -- and so was the downtime. Plant Process Manager Tom Tyler sent Devereaux a postcard featuring a different kind of elbow offering a free trial. He checked out the Web site and then contacted HammerTek for the name of a local rep.
THE SMART SOLUTION...
In April 1998, Alexandria Sanitation Authority began replacing sweeps in the lime lines with 4" HammerLoy Smart Elbows. By June 2000, there were five Smart Elbows in service. According to Devereaux, two years later they pulled a couple Smart Elbows and inspected them for wear -- and there wasn't any they could see. Since 1998, the hammerTek Smart Elbows have steadily replaced sweeps and consistently resisted any hint of wear. According to Devereaux, the switch to the Smart Elbow has more than paid for itself. In fact, 14 more Smart Elbows had been specified for a plant expansion.
