industry
TETRA in the tropics O
It’s not only in Europe and Asia that TETRA has taken root. Richard Lambley visited a steelworks in Brazil to learn how a private network is meeting its complex radio needs
Above: steel coil at the Tubarão plant of ArcelorMittal in Brazil
ne of the first major industrial plants in the world to have chosen a TETRA radio system for its on-site communications is large steelworks in Brazil, the
Tubarão plant of ArcelorMittal. Located on the Atlantic coast some 430km from Rio de
Janeiro, the plant converts ores arriving from the Brazilian hinterland into iron and steel. It exports carbon steel coils and slabs by sea, for further processing by customers such as rolling mills. And it does all this on a spectacular scale, through a
complex system of integrated processes, some involving temperatures up to 1600°C, molten metal and high pressures. With its blast furnaces, continuous casting machines and hot strip mill, it produces 7½ million tonnes of steel annually, on a site measuring some 7km long and 4km across. Tese processes continue 24 hours a day, every day of the year. “It’s said that in the company there’s no holidays”, jokes one of the radiocommunications team. For the safe working of the plant, reliable communications
are vital – so essential that for even the most urgent maintenance work on the radio system, operations cannot be interrupted for longer than one or two minutes. Even then, special contingency plans must be prepared. “For some operations, it’s very important to count on that
system”, said José Martins, automation engineering manager for ArcelorMittal. “Otherwise we could have a lot more risk and accidents in our operations.” Alongside the main steel production processes are a variety
of supporting industrial plants and activities. For example, the coke needed to make steel is produced by huge ovens which
10
cook the incoming coal, at the same time generating coal gas as fuel for the site’s 216-megawatt electricity generating station. Tere’s a pelletizing plant, a refinery for coal by-products and a cement plant with a capacity of one million tonnes per year. An extensive road network, including a dual three-lane
main highway, connects all these facilities within the huge site (rule of the road is that you must give way to industrial vehicles) and it is criss-crossed by railway tracks.
Time for change Until two years ago, the Tubarão plant relied for its radio communications on an EDACS analogue system from Ericsson, implemented in 1996. But change became unavoidable, partly because it was becoming impossible to buy replacement parts. “We had many terminals out of operation because of damage”, said Antônio Gagno, automation specialist at the plant. “Repair was not viable.” But in any case, performance of the analogue network – a
20-channel system with 1900 mobile terminals – no longer met the plant’s developing requirements. Radio coverage from its single base station was unsatisfactory because of shadowing by buildings, by the lush tropical tree cover on some parts of the site, and by ferromagnetic structures such as the large gas- holder and the coke ovens. On top of all that, new frequency plans imposed by the
Brazilian telecoms regulator Anatel were shortly to make a switch to digital radio mandatory. “So we made a start, analysing the opportunities”, Mr Gagno continued. “And we established our objectives: a
TE TRA TODAY Issue 6 2012
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40