A major producer of carbon steel, Corus Construction & Industrial at Scunthorpe is one of the company’s three integrated steelworks in the UK.  Atlas Copco’s successful relationship with the Scunthorpe steelmaking plant goes back to the British Steel days of the early eighties, with the introduction of coal injection systems for the iron making process, prior to the conversion of the iron into steel. 

Compressed air for the coal injection process

At that time, the traditional method of top charging coke into the furnaces was still employed but later process cost-efficiency studies resulted in a furnace conversion to replace the majority of the coke with granulated coal delivered via high volume, oil-free, dry compressed air, and injected at tuyre level.   

The current total of 10 Atlas Copco compressors serves the primary end of the site.  This is a result of the gradual extension of the coal injection process and the decision to replace all old reciprocating compressors, which were located at individual production plants and workshops, with a centralised system, providing oil free, clean dry compressed air. 

It began in 1984 with the installation of an Atlas Copco ZR 6 compressor and MD dryer, sited in the boiler / turbine plant, with a second ZR 6 compressor and dryer being added the following year.

As the scheme progressed, the need for a dedicated building to house additional compressors required the adaptation of a redundant oxygen generating plant to become the Central Air Compressor Station.  This location was converted in 1989 and saw the installation of two more ZR 6 compressors and dryers, together with the transfer of the two original units.  Two existing compressors, a ZR 5 and a ZR 4, which were already installed on site, but remote from the compressor station, were connected to the centralised system.  

Further developments over the years has seen two ZR 630 compressors with MD dryers installed – one unit installed remote from the compressor station – and two more ZR 6 machines.  The system also includes standby compressors for the two boiler and turbine stations on site – an Atlas Copco XAS 555 diesel and two air-cooled ZT 270 compressors.

Control and communication

Ultimately, to control the operation of all 10 central and remote compressors, an Atlas Copco ES 1000 Central Governor was introduced. This starts, loads, unloads and stops compressors to give the most efficient and cost effective operation. It also acts as a communication port to allow all compressor operating information to be displayed on the works VAX computer network, as the station is unmanned.

As Graham Blockley, Manufacturing Engineer Energy Operations, points out: “Overall, the compressed air system is a substantial installation, that has an installed capacity of 60km3/hr at 6.9bar and generates an output of over 300million m3 of compressed air per annum. For an operation on this scale, reliability of the equipment has to be assured with a planned maintenance programme. That’s why an Atlas Copco Total Responsibility Plan is a vital part of the compressed air operation.” 

The current installation is not the end of the story; Corus has announced further major investment of £130 million at Scunthorpe to strengthen its competitive position in the structural sections, rail and wire rod markets by improving operational efficiency, product range and customer service. Wherever there is a critical air requirement within this programme, Atlas Copco will be poised to provide the most energy- and cost-efficient solution.