Turbo-blowers and their control systems are a crucial part of the steel-making process, and Sensonics were delighted to be involved in a major project involving the relighting of the blast furnace at the SSI steelworks in Redcar, on Teesside.
Originally a British Steel facility and formerly owned by TATA, CORUS, the site, which is the second-largest blast furnace in Europe, was acquired by SSI (Sahaviriya Steel Industries) in 2011. The Cordell Group, a Teesside-based engineering contractor providing engineering services to the local steel industry for many years, was appointed by SSI to carry out a major upgrade of the Turbo-blowers control systems in 2011 including Sensonics equipment, some of which was originally installed in 1997.
The Turbo-blowers consist of a pair of axial flow compressors which are driven by fully condensing 54Mw steam turbines with a normal operating range of 4200Nm/min at minimum blade angle, up to a maximum of 9350Nm/min at 6.2 Bar G. Each turbo blower is capable of supplying the total air demand of the blast furnace, with only one machine in continuous operation while the other is on cold standby. The output air flow of the compressor is controlled by means of variable pitch stator blades with the machine running at constant speed, while the up / down of the blower is controlled local to the machine. During the starting and stopping phase of each blower, monitoring is performed by a local turbine panel adjacent to each machine. When the machine is up to speed, control of the unit is performed by the turbo-blower control panel located in a central control room.
Sensonics’ new system comprised a total of 15 sets of Senturion proximity probes monitoring a range of functions on each turbo blower, including relative shaft vibration, rotational speed and thrust positions. The protection system comprised a 19” rack-mounted Sentry G3 system retrofitted into the existing floor standing panel, along with 16 channels of relative shaft vibration monitoring. The 14-channel Sentry G3 protection equipment provides a high-integrity protection configuration with two out of three voted speed and two out of three voted thrust position on both the turbo blowers.
Commenting on the new system, Graham Blackburn, the Control & Instrumentation Engineer for Power & Energy at SSI Redcar says: “The need for careful monitoring of the condition of these machines when running is crucial and we have relied upon Sensonics equipment for the speed monitoring (3,540 RPM) and for axial displacement, for many years. Although the original Sensonics equipment was still serviceable, we decided to upgrade to the new Sentry G3 modules in 2011. The other Sensonics equipment installed earlier monitoring the ‘X’ and ‘Y’ vibration on the four bearings is also serviceable and providing the plant condition detail we need with peace of mind. Having seen the new Sentry G3 modules we are now planning to incorporate these during planned outages within the next two years on the four turbine alternators where we have also previously relied on Sensonics for our plant condition monitoring.”
The successful upgrading of condition monitoring equipment at the SSI Steelworks in Redcar is an example of Sensonics’ position as a supplier of turbine supervisory and high-integrity protection equipment to industry. They supply a full range of sensors and API 670-compliant measuring and protection equipment, and also design through to installation and commissioning. For further details visit www.sensonics.co.uk.