Twin-shaft batch mixer

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The twin-shaft batch mixer is a mixer that mixes two or more raw materials . It is characterized by two horizontal shafts , each equipped with mixing tools and rotating against each other. The bottom of the vessel is designed as a double curve corresponding to the two mixing circles. In the longitudinal center of the bottom of the emptying opening, as according to the manufacturer is rotary slide valve or as a hinged door is formed. The mixing tools are ideally designed so that there is a circular movement of the material to be mixed in the trough and at the same time a helical movement along each mixing shaft . This causes a targeted three-dimensional material exchange in the entire mixing space. However, depending on the manufacturer, there are also other forms of movement. A change in the speed of the mixing tools is easily possible with the appropriate control technology in order to achieve reliably repeatable mixing results even with special requirements ( SVB , UHPC etc.).

In addition, the two mixing circles overlap in the middle of the mixing trough in order to additionally intensify the turbulence of the relative movements of the mix. A degree of homogeneity of 95% with a mixing time of just 30 seconds is reliably achieved by twin-shaft batch mixers from leading manufacturers, even with large batch sizes . However, the mixing time depends on the recipe and can therefore vary. The twin-shaft batch mixers have therefore established themselves as the predominant machine type today in high-performance concrete plants and also in asphalt mixing plants in Europe and Asia in general.