A fan upgrade by Siemens at Hanson Cement’s highly productive Purfleet plant has resulted in energy savings of more than 36% being made, with payback on the investment anticipated to be well under two years.
Hanson Cement’s Purfleet Works is situated next to the River Thames in Essex and is capable of producing around one million tpy of Regen – a cement replacement in ready-mixed and pre-cast concrete which is manufactured from ground granulated blast-furnace slag. The works consist of two closed circuit ball mills and a Loesche vertical grinding mill. It was Mill 3 that Hanson required an upgrade to, as the existing mill fan was fixed-speed, using a 1 MW 11kV slip-ring machine running at around 980 kW. The airflow was continuously at full speed and was controlled by a damper. The fan design airflow was 350 000m3/hr; but the system was damped to the operational requirement of approx 241 000m3/hr.
The Siemens Total Engineered Solution centred around the integrated drive systems (IDS) concept, which ensures that all products within the drive system are as integrated as possible, supported by Siemens both in specification and throughout their lifecycle. By optimising the drive system to the highest degree of performance, and by acquiring data through monitoring that system, the best operational performance can be achieved.
For mill 3, this meant replacing the fixed speed fan with a 1000 kW Sinamics Perfect Harmony 11000/4160 V medium voltage (MV) converter, installed and commissioned to link with existing Siemens process control systems at the plant. A new Siemens MV 1000 kW, 4160 V, 6-pole motor was also installed along with new motor cable and a modified motor base (the bed plate was raised by 60mm). Siemens was able to provide the full turn-key solution.
Every element of the Sinamics Perfect Harmony cell-based drive range is engineered to maximise productivity and protect a customer‘s process in a way that other drives are unable to do. Its modularity allows for a scaleable solution achieving near-100 per cent reliability and 99 per cent availability, two key factors for a busy plant like Purfleet.
Benefits of the upgrade included:
- greater productivity through optimised speed and process performance
- improved flexibility, with faster run-up/run-down times
- standardisation, reduced size and line attendance
- increased amount of pre-emptive maintenance information
- a significantly reduced total cost of ownership over the product’s lifecycle.
The annual savings to Hanson from the upgrade have been estimated at £175 000-£200 000.
Being able to address a reduction in energy usage and increase plant availability have become key targets for industrial companies. Hanson Cement has been able to reduce its carbon footprint at Purfleet by 1487 t since the new system was installed eight months ago and is continuing to make further savings.
Adapted from press release by Joseph Green
Read the article online at: https://www.worldcement.com/europe-cis/20102015/siemens-fan-upgrade-hanson-purfleet-807/