As part of an ongoing initiative to improve efficiency and reduce maintenance costs, Severn Trent Water has installed two high performance Mutrators from NOV Mono at its Burnhill Green sewage treatment works in Staffordshire.
Mono Mutrators are packaged pumping systems that combine a Mono macerator and Mono progressing cavity pump to macerate any solids within a flow and protect the pump from blockages. They were specified by Severn Trent Water to replace its existing CMD40 Mutrators, which had continued to perform efficiently for nearly thirty years, and now needed replacing. The new equipment has been installed for the transfer of raw sewage at a capacity of 13m3/h to a high level Rotating Biological Contactor (RBC).
Neil Horton, Project Engineer for Adroit Construction Services, the framework contractor on the project, commented: "We were very happy with the performance of the existing units at Burnhill Green and therefore wanted a ‘like for like’ replacement.
"Mono’s service was excellent. We simply informed Mono of the model number of the existing Mutrators and they quickly supplied us with the latest design. The new Mono Mutrators are not only saving us energy but also reducing our maintenance costs."
By combining a Mono progressing cavity pump, together with a tri-hammer macerator fitted in the suction line, the Mono Mutrator is able to lift the raw sewage from the collection sump into the cutting chamber to finely macerate any solids prior to entry into the pump. Blockages are therefore eliminated and when the pumping cycle ends, large unmacerated solids fall back into the sump, clearing the suction pipe for the next duty run.
The Mono Mutrator is available in various design options to suit different wastewater handling applications and can be installed either vertically or horizontally to give the lowest possible design/construction costs. It has a number of drive options for optimum pump speed and reduced power consumption, and is also able to pump long distances and high heads.
The positive displacement action of the Mono pump offers the benefits of smooth and controlled transfer of the sewage through small bore pipes into the main sewage system for further treatment. Being a positive displacement pump, head is independent of speed. This, combined with correct pump selection, leads to low wear rates, minimal spares usage, lower running costs and less downtime, minimising least whole life costs. On many high head pumping duties, Mono Mutrators can consume less than 50% of the energy of conventional sewage pumps.