Environmental and efficiency standards at a new filter plant the the Corus steelworks, Scunthorpe, have been improved by the installation of drive technology from Brevini
A new filter plant at the BOS plant on the Scunthorpe Corus steelworks is using hybrid design gearboxes combining planetary and helical gear technology to open and close the doors on the iron desulphurisation process. This new installation is being used to capture fumes created during the desulphurisation process, and has built in order to improve the plant's environmental performance.
Door drives at the plant needed to be compact yet still able to provide high torque output and low energy input, combined with strength and durability. Brevini PIV was able to deliver a solution using its Posiplan BPH shaft mounted gearbox.
Corus Scunthorpe is one of the largest steel production sites in the UK, producing plates, sections, wire rod and semi-finished steel using the BOS method. As well as reducing dust emissions, the new technology aimed to create a more pleasant working environment for employees and helped to speed up the steelmaking process. Previously the plant used two wet scrubber systems to remove the fume generated by the iron preparation and desulphurisation processes. However these were becoming outdated and inefficient, so to replace the two wet scrubber systems one new bag filter plant was commissioned.
At this plant, the desulphurisation process involves co-injecting lime and magnesium into a ladle of molten iron, the sulphur in the iron reacts to this and rises to the surface in the form of a slag. Once the injection treatment has been completed the slag is skimmed off the ladle. The desulphurised iron can then be taken into the BOS vessels to be converted into steel.
It is during the desulphurisation process that the fumes generated need to be extracted and cleaned efficiently. Doors have been designed that close to contain the fumes during the process while the extraction system draws them away. Gearboxes required to drive the doors needed to be compact in order to fit into the available space, whilst providing the strength and torque required to shut the heavy doors.
Meeting application requirements
The company commissioned to build the filter plant turned to Brevini to provide a drive solution, and Brevini was able to design a system that met all the application requirements using its Posiplan range of planetary/helical hybrid gearboxes.
“The Posiplan gearbox offers the best of both worlds, delivering higher capacities from smaller units which allows for a significant increase in capacity over a more traditional design," said Jon Snaith, Brevini UK's General Manager, Sales & Marketing. "Different sized motors are available and selected using motor performance curves to ensure maximum efficiency in realised.”
Posiplan hybrid gearboxes combine the efficiency of low weight, high reduction ratios of planetary gear stages on the input side with the higher capacity, strength and durability of bevel helical gears on the output: this, says Brevini, is ideal for medium to large-sized industrial applications. The input end employs planetary stages where higher speed and compactness are a major advantage while the output uses a helical stage as it is slower and has higher torque.
Brevini supplied four Posiplan gearboxes for the Filter Plant project, each of which has a reduction ratio 2813.5:1 and is fitted with a tiny 1.5 kW motor. This provides a huge output torque of 22,000 Nm and a low speed of 0.5 rpm. The gearboxes are shaft mounted which means they are tougher than exposed transmission alternatives such as belts, chains and pulleys: this ideal for applications that require 90deg operation or survival in harsh environments.
These gearboxes use the latest labyrinth sealing technology and high-performance bearings which extend operating life in the harshest environments.
