Case Study: TASKMASTER® Alleviates Screenings Conveying Problem

The Central Valley Water Reclamation Facility, located in Salt Lake City, Utah, is a thoroughly modern 65 MGD wastewater treatment plant, which uses the Trickling Filter/Solids Contact Process. Like many other facilities across the country, Central Valley is continuously challenged to meet the expanding water treatment demands of a growing residential and industrial community.

With this growth has come a vexing problem for the plant. “We were experiencing more and more large objects coming into the headworks of our plant,” said Dan James, Maintenance Manager of Central Valley WRF. “There were huge grease balls, sticks, rocks, wood two by fours and every kind of garbage. We were constantly dealing with plugging of our conveying system that handles the screenings and major problems with our downstream equipment.”

That’s when the plant called in Franklin Miller for a solution. A heavy-duty TASKMASTER® TM1630 screenings grinder was purchased. The unit was strategically placed between the discharge of the screens and the inlet hopper of the vacuum screenings conveying system. The TASKMASTER employs a twin shaft shredding mechanism with two banks of intermeshing cutters that easily grind even large screenings solids down to a size readily handled by the system. At Central Valley, the shredded output is discharged from the TASKMASTER, transported to another level and hauled off to a landfill for disposal.

The TASKMASTER TM1630 is a heavily constructed 10HP grinder suitable for handling heavy solids accumulations. This unit employs 2-3/4″ hardened hex shafting, mechanical seals, direct inline gear drive, and special cleaning combs that assure the cutting chamber is kept clear. A model S260 Automatic Reversing Control reverses the unit in case of a jam condition.

According to Mr. James, the unit has operated perfectly to stop the plugging in the screenings conveyance piping and has been instrumental in protecting downstream equipment.

The TASKMASTER TM1600 series are powerful and versatile workhorses that can shred heavy solids in both gravity and liquid systems. The units can be installed horizontally with a stand, hopper or flange adapter, or vertically for channel or pipeline applications. Typical applications include gravity and conveyor fed sewage screenings, in-channel raw sewage, correctional institution effluent, documents, product rejects and returns, garments, filters, bottles and containers, plastics, turnings, packaging, wood, paper, and more.

The TM1600 can be supplied with high profile cutters for grabbing solids that roll on others, or with ultra-fine cutters that finely reduce wastewater solids to a size easily handled by downstream equipment. Units are available in stainless steel construction in addition to standard alloy steel and iron body construction. Available input sizes range from 16″ x 20″ (400mm x 500mm) up to 16″ x 60″ (400mm x 1500mm).

Recently, Mr. James received a call from another wastewater facility with almost the identical problem. He spoke to the engineer and highly recommended the TASKMASTER. “I told them that it does everything we need,” he concluded.

These rag-laden grease mounds would float downstream and present a menace to the entire system. That was until they installed a TASKMASTER® grinder. Purchasing the TASKMASTER TM8516, a powerful grinding unit employing counter rotating banks of intermeshing cutters, made all the difference.

The unit was installed right over the influent pipe, negating the need for a bar screen or a catch basin. When the debris entered the station, it passed directly through the grinder where it was ground up into small particles. As a bonus, the “aircraft carriers were completely destroyed and the grease was dispersed. Thereafter, it smoothly and easily passed through the pumps with no difficulties.

“We’re very pleased with the unit,” said Mr. Balcom. “It has improved system operations, cut down on maintenance and is very reliable. We maintain it according to the specs and we’ve had no trouble whatsoever.”