Pelletized lime no match for Smart Elbow® deflection elbow

June 16, 2015 by Miaja Cornelius

As the primary wastewater treatment facility for the city of Alexandria and Fairfax County, Va., the Alexandria Sanitation Authority’s sewage plant operates around the clock — with a daily volume that can exceed 80 million gallons. For pH control, the facility uses more than 500,000 pounds of pelletized lime each month, conveyed from trucks delivering the material to 70-foot silos via a pair of four-inch lines.

A key component in the wastewater treatment process, pelletized lime is a powdery, abrasive material. The plant was plagued by leaks in the lime conveying system, its traditional long-sweep elbows rapidly wearing down from the inside out.The never-ending cycle of repair and replace began within six months of elbow installation.

Even after upgrading the plant’s elbows, lead mechanic Bob Devereaux noted the plant was still “losing an elbow every nine months.” When the elbows would fail, the powdery, dusty lime created a host of problems: downtime, additional maintenance and cleaning costs, and the risk of respiratory problems for anyone exposed.

When a postcard from Hammertek offering a free trial was passed on to Devereux by Plant Process Manager Tom Tyler, he decided to put the Smart Elbow deflection elbows to the test. Alexandria Sanitation Authority began replacing sweeps in the lime conveying system with 4″ Hammerloy™ Smart Elbow models. Over three months, five Smart Elbow products were deployed.

Smart Elbow designs rely on deflection, not impact, to change flow direction, thereby eliminating the impact-related problems associated with virtually every other conveying elbow design. At system start-up, a gently rotating ball of suspended material forms in the vertex chamber of the Smart Elbow deflection elbow. As the main flow of material passes this ball, it is deflected through the desired change of direction without impact, friction or wear to the elbow’s interior surfaces.

Close examination of the Smart Elbow products after two years of service revealed zero wear, and the Authority has continued replacing its old-style sweeps with Smart Elbow models. According to Devereaux, switching to Smart Elbow deflection elbows has been a wise investment. When the Authority expanded operations, an additional 14 Smart Elbow products were specified as part of that project.

Click here to read the full case study, and see for yourself how much time — and money — Hammertek’s Smart Elbow deflection elbow could mean for your operation.