The Lismore City Council was having chronic problems with their digester pump choking at their South Lismore sewage treatment plant.
The sewage pump would choke on a daily basis during its job of turning over the digester, according to Mr Matt Potter and Mr Brad Hampson at the plant. They were using a Gorman-Rupp T3A3S-B self-priming pump, but the sheer number of rags made it very difficult for even this excellent solids handling sewage pump to pass all the rags, all the time.
Over the years, they tried different wear plates (even from different companies), but the best they could achieve was to limit choking to once or twice per week by installing one of Gorman-Rupp’s self-cleaning wear plates.
Lismore City Council are extremely pleased with the result. The new Gorman-Rupp system ran for 3 months without any chokes!
The Options
The council was then told of Gorman-Rupp’s new Eradicator Solids Management System and wanted to try it. The Eradicator™ system features an aggressive self-cleaning wear-plate incorporating a number of notches and grooves, as well as a patent-pending lacerating tooth that helps break up stringy materials (such as rags), scrape them off the impeller vanes and pass them through the pump – all without impacting performance or interrupting service. A special cover plate with the system also includes a patented lightweight inspection cover that can easily be removed, if necessary, to inspect sewage pump internals.
The Eradicator system is available on all Gorman-Rupp Super T Series wastewater pump models, so the range can achieve flows from 5 LPS through to 150 LPS and deliver heads to 40 metres, all while working on suction lifts to 7.6m.
The Solution
Because they are self priming pumps, these sludge pumps can be located at ground level, giving operators easy and safe access to the pumps for monitoring and/or service, unlike submersible pumps which require cranes and several operators to access. And wet well lids stay closed with self priming pumps so that operators are not exposed to falling into the wet well when anything needs to be done with the pumps. Clearance adjustments, oil changes, and general inspections only take minutes, which adds up to massive savings in time over the life of the pump.
The new system was installed into the existing Gorman-Rupp T3. The sludge pump then ran for 3 months without a single choke. In the same period, they would have expected to have between 12 and 24 chokes. Matt, Brad and their colleagues at the council were very pleased with the result.
The Pumps
The Gorman-Rupp Super T Series sewage and wastewater pumps with Eradicator™ Solids Management System are a series of self-priming centrifugal pumps designed specifically for handling municipal and industrial wastewater containing stringy, difficult to pump, solids in suspension (such as “wet wipes” , rags and feathers).