Four new shafts are being sunk by specialist shaft sinking contractor DMC Mining (UK) Ltd comprising two main shafts each extending over 1500m deep and two further shafts up to 450m deep for the Materials Transport System (MTS) tunnel.
This tunnel is being driven by three separate Strabag TBMs and is designed to deliver the polyhalite product underground, direct to a materials handling facility being purpose built at Wilton before despatching from the old Redcar Bulk Handling Terminal on the River Tees.
STS have already supplied the ventilation ducting for both MTS shafts being sunk using Galloway rigs and STV are supplying ducting for the shaft boring road headers (SBR) on both main shafts and 1.6m diameter flat lay ducting designed to be cassette packed for the TBMs in the MTS tunnel.
CFT are supplying the complete temporary shaft sinking ventilation packages comprising Korfmann fans, WAT cooling systems and DFT dust collection systems. The packages are containerised and include comprehensive sound attenuation measures and state-of-the-art E-Houses with all switchgear and control and moniotoring systems. Korfmann Luftechnik, WAT Wärme-Austausch Technik and DFT Deichmann Filter Technik are all sister companies of CFT within the CFH Group.
Each of the two main shafts required:
- A supply air fan station capable of delivering 29.2 m³/s of fresh air at 8700 Pa total static pressure plus pressure losses for inlet and discharge silencers, baffles and screens, gas heating system and cooling system.
- An exhausting air fan station capable of removing 46.2 m³/s of exhaust air at 1250 Pa total static pressure plus pressure losses for inlet and discharge silencers, baffles and screens.
- Two air-cooled chiller units each rated 1000 kW capacity to chill and supply 85 m³/h of water with from 12°C to 1°C to the air coolers.
- Two air coolers each rated 1000 kW cooling capacity to cool an air flow of 32.3 m³/s from 22.7°C WB inlet temperature to 3°C.
- An E-House including a transformer to convert from 11 kV to 400 V, electrical distribution equipment and PLC and VFD control panels for both the fan stations PLC controls and switchgear for the cooling system.
- A Stench Gas Alarm System to warn mining personnel in case of an emergency in a noisy environment.
- A dust collector type KJF 1500/18-54 with 54 compact polyester felt filter elements with a total surface area of 205 m² capable of handling 23,785 m³/h of dust laden air.
- A dust collection fan located on the clean gas side rated at 23,785 m³/h flow and 3,800 Pa pressure drop directly driven by a 45.0 kW motor.
Further considerations included; vibration and temperature monitoring of the fans and variable speed controllers, a separate air-conditioning system for the E-House with temperature monitoring, noise dampening to minimise environmental impact.
The MTS shaft packages are similar but have no cooling or dust collection systems.