In the absence of an interaction , central bars might be the most effective mechanism for radial motions of gas in barred spiral galaxies , which represent two-thirds of disc galaxies . The dynamical effects induced by bars in the first few kpc of discs might play an important role in the disc profiles in this region . In this work , a chemical evolution model with radial gas flows is proposed in order to mimic the effects of the Milky Way bar in the bulge and inner disc . The model is an update of a chemical evolution model with the inclusion of radial gas flows in the disc and bulge . The exchange of gas between the cylindrical concentric regions that form the Galaxy is modelled considering the flows of gas from and to the adjacent cylindrical regions . The most recent data for the bulge metallicity distribution are reproduced by means of a single and longer bulge collapse time-scale ( 2 Gyr ) than other chemical evolution models predict . The model is able to reproduce the peak in the present star formation rate at 4 kpc and the formation of the molecular gas ring . The model with a bar predicts a flattening of the oxygen radial gradient of the disc . Additionally , models with radial gas flows predict a higher star formation rate during the formation of the bulge . This is in agreement with the most recent observations of the star formation rate at the centre of massive barred spiral galaxies .