Method of calculating the drive power of a drum-type feed mixer

The paper describes the design and principle of operation of a drum-type feed mixer. The required mixing quality of the feed ingredients is achieved by repetitive pouring the mixture, lifted by ribs installed inside the drum cavity during its rotation. At the same time, since the drum is installed inclined, the movement of the mixture settles in a spiral, the pitch of which is higher the greater the angle of inclination of the drum. A technique has been developed on the basis of which and with the Mathcad mathematical package there was given an example of calculating the torque and power on the mixer drive shaft for lifting the mixture with ribs. The following initial parameters were taken: the inner radius of the drum is 0.10 m; the length is 1.00 m; the rib height is 0.04 m; the angular velocity is 5 rad/s; the natural slope angle of the mixture is 25.000 °, the density of the mixture is 1000 kg/m3. In accordance with the design scheme, the volume of the mixture located on the rib was determined at different positions of the rib within the rotation range of the drum from 0.000 to 150.000 °, taking into account the density of the weight and the moment of resistance created by this weight. Calculations of the RMS power required to rotate a drum with a given number of ribs and its length, depending on the angle of rotation, have been performed. This made it possible to calculate the required power of the drum drive motor, taking into account its efficiency. Depending on the parameters of the mixer selected as a sample for calculation, the power consumption is 0.589 W. Using the methodology and calculation program tested on this sample, it is not difficult to determine the power consumption for other mixer parameters. For example, for a mixer with an internal drum radius of 0.50 m and a length of 2.00 m, the program outputs a power consumption of 64 W.