What is a compulsory concrete mixer

A compulsory concrete mixer is named in comparison with a self-falling concrete mixer. Concrete mixers can be divided by varied standards, and these two are by the mixing principle.

The forced concrete mixer consists of a mixing drum, which is equipped with a mixing shaft. A side arm is equipped at both ends of the mixing drum to clean the end wall. A set of spiral mixing arms are installed at each side of the midpoint of the mixing shaft between the two arms. The two groups of mixing arms are arranged from the end arm to the middle arm in the axial arrangement, and the arrangement in the rotation direction is self-contained. From the end arm to the middle arm, the top of each stirring arm is fixed with stirring blades, and the two arms lag behind the end arm of the same side in the rotation direction.

The compulsory concrete mixer has a long history. The first type was the disc vertical axis forced concrete mixer which can be divided into two types: turboprop type and planetary type. After the 1970s, with the application of light aggregate, the circular trough horizontal axis forced mixer appeared. This is divided into single horizontal axis and double horizontal axis, and has the characteristics of self-falling and forced mixing. Its mixing blades have the advantages of small linear speed, good wear resistance and less energy consumption, and rapid development. A mixing blade is installed on the rotating shaft boom of the mixing barrel of the forced concrete mixer, and the material in the mixing barrel is added to form a cross-flow under the strong agitation of the mixing blade. This kind of mixing method is much stronger than the self-falling mixing method, and is mainly suitable for mixing dry and hard concrete.