OLKO-Maschinentechnik GmbH has ordered the electrical equipment for two Blair Multi-Rope machines (BMR) from Siemens. The hoisting winders are being used in the Woodsmith mine run by Sirius Minerals, a world leading producer of polyhalite, a unique multi-nutrient fertiliser in North Yorkshire, UK.
One hoist will work as a so-called production winder for material hoisting, one as a service winder for personal transport, with a hoisting capacity of 35 t payload. The polyhalite is hosted from approximately 1,450 m below sea level to the surface at a hoisting speed of 18 m per second (m/s). The delivery includes a medium-voltage synchronous motor with an output of 9.3 MW and a torque of 1,550 kilonewton metres (kNm) for each machine which are powered directly from a medium-voltage Sinamics SM150 (PWM) frequency converter.
Both winders are fitted with a COBRA01 multi-channel brake system which is a joint development between OLKO and Siemens. The digital speed control and supervision unit, which was developed by Siemens, meets the Safety Integral Level 3 standard (SIL 3, corresponds to IEC 61508) as well as the German TAS standard which applies to shaft hoisting systems. Siemens is therefore the first company in the world to integrate the highest safety standard in a mine hoist. The delivery also includes complete commissioning as well as annual inspection, maintenance and servicing.
From 2021, the Woodsmith mine will be the world’s largest polyhalite producer, a material which is used to produce fertilisers. This is hoisted via two mine shafts and conveyed out of the national park to Seesside via a 37 km bconveyor belt system in an underground tunnel. The majority of the polyhalite is exported once it has been pelletised.
OLKO-Maschinentechnik GmbH, part of Thyssen Schachtbau holdings, received the order to supply two mine hoists for the extraction of the world’s largest polyhalite deposit. Siemens supplied the electrical equipment consisting of medium-voltage synchronous motors which are powered by medium-voltage Sinamics SM 150 frequency converters. The COBRA01 multi-channel brake system provides a soft braking, comparable to a cars ABS system, but operating with four independent hydraulic braking channels. The production hoists is one of the largest in the world. The drum diameter, including the disk brakes, is 6.8 m. The motor has an output of 9.3 MW.