BigPatents India

A plurality of mixing rotors that are housed in a chamber having a cocoon-shaped cross section in a tangential non-intermeshing state, where a plurality of long wings and short wings are provided on a wing portion of the mixing rotors. The long wings and the short wings severally have a plurality of different sizes of tip clearances, a twist angle of the long wings is changed in the axis direction, and makes mixing efficiency and dispersion efficiency compatible. Further, cooling medium paths are provided severally in the chamber and the mixing rotors to suppress excessive increase of the temperature of mixing materials. According to a batch mixer using the mixing rotors, it is possible to control quality reduction of the mixing materials caused by heat generation, and to improve the productivity by increasing the number of the wings without diminishing inherent processing performance of the mixer.