XRipper XRC186-520QD SIK: Reduction of twin shaft grinder maintenance costs

Case Study - Scottish Water Services (Grampian)

Scottish Water Services (Grampian) have a 28 year contract to design, build, operate and maintain a number of wastewater treatment sites in the North East of Scotland. The Nigg waste water treatment site in Aberdeen, serves a population equivalent of 250,000 people.

Scottish Water Services (Grampian) installed twin shaft grinders at the inlet works of the Nigg site a number of years ago, in order to protect downstream pumping equipment and to improve the efficiency of the screening. Whilst they were happy with the general function of the grinders, the ongoing cost of ownership was a growing concern. These grinders did not allow for easy maintenance and could not be serviced by their own engineers, resulting in frequent overhauls carried out off-site and creating expensive and time-consuming repairs.

With a large number of Vogelsang rotary lobe pumps already installed on the Nigg site, Scottish Water Services (Grampian) engineers were familiar with the easy to service nature of Vogelsang products. When the XRipper concept was presented to the customer, they were keen to install the XRC186-520QD SIK on a comparitive trial. Unlike other twin shaft grinders, the Vogelsang XRipper’s rotors are machined from a monolithic block of hardened steel, which allows them to be changed in minutes. The robust design and the powerful drive at low speed helps the unit produce more torque, providing a better cutting performance whilst consum less power. After 12 months of operation, the Vogelsang XRipper has already demonstrated a 60 % maintenance cost reduction against the previously installed units.