Atlas supplies air pressure for Brazil Metro
Atlas Copco air compressor technology is being used on the extension of the S?o Paulo Metro in Brazil to provide air pressure within the tunnel and to help move the tunnelling shield. This saves costs for the contractor.
Atlas Copco air compressor technology is being used on the extension of the São Paulo Metro in Brazil to provide air pressure within the tunnel and to help move the tunnelling shield. This saves costs for the contractor.
The Atlas Copco compressors are located in a room at the top of the shaft from which the German-built tunnel boring machine is based, 30m below ground level, and consists of two stationary compressors and two portable compressors, with the latter taking over from the fixed installation at the periods of the city's peak electricity demand, when power supplies are substantially more expensive.
In addition to providing a constant and reliable supply of compressed air technology underground, therefore, the Atlas Copco installation is also helping the consortium building the Metro extension to be more cost effective.
German tunnelling machine specialist Herrenknecht has supplied the Earth Pressure Balance (EPB) tunnelling shield, a machine that is ideal for the mix of cohesive and non-cohesive soil with high clay or silt content and low water permeability that is found in this western area of São Paulo.
For the primary supply, Atlas Copco has installed at the top of the Faria Lima access shaft two GA160 stationary oil-injected screw compressors, each producing air at 160 psi, or 11 bar.
These are working in conjunction with three FD 450 refrigerant dryers that treat the air to remove any moisture and dirt particles, delivering clean, dry air to the tunnelling face and the machine operators.
The system also includes two air receivers, each of 6m³ capacity.