Nusselt’s correlations in agitated tanks using the spiral coil with Rushton turbine and PBT 45° impeller: comparison with tanks containing vertical tube baffles - Rosa, Vitor da Silva; Taqueda, Maria Elena Santos; Paiva, José Luís de; Moraes, Marlene Silva de; Moraes Júnior, Deovaldo (Applied Thermal Engineering, 2017)