Concret mixer is a machine that mixes cement, sand aggregate and water and mixes it into concrete mixture. It is mainly composed of mixing drum, feeding and unloading mechanism, water supply system, prime mover, transmission mechanism, frame and supporting device. According to the nature of work, it is divided into batch (batch) and continuous; according to the mixing principle, it is divided into self-dropping and forced; it is divided into fixed and mobile according to the installation method; it is divided into tipping and non-tilting according to the discharge method; According to the structure of the mixing drum, it is divided into pear type, drum type, double cone, disc vertical shaft type and round groove horizontal shaft type.
Self-dropping mixers have a long history. As early as the early 20th century, drum-type concrete mixers driven by steam engines have begun to appear. After the 1950s, double-cone mixers with reverse discharge and tilting discharge, and split-cylinder mixers were successively introduced and developed. Radially arranged mixing blades are arranged on the inner wall of the mixing cylinder of the self-falling concrete mixer. During work, the mixing drum rotates around its horizontal axis. After adding the materials in the mixing drum, it is lifted to a certain height by the blades and then falls by its own weight. This repetitive movement achieves the effect of uniform stirring. The structure of the self-falling concrete mixer is simple, and generally it is mainly mixing plastic concrete.
After the rise of forced mixers in the early 1950s, they have been rapidly developed and promoted. The first to appear was a disc vertical shaft forced concrete mixer. This type of mixer is divided into two types: turbo and planetary. After the 1870s, with the application of lightweight aggregates, circular groove horizontal shaft type forced mixers appeared. It is divided into two types: single horizontal shaft type and double horizontal shaft type. . The stirring blade has a low linear speed, good abrasion resistance and low energy consumption, and develops rapidly. The rotary arm arm in the mixing drum of the forced concrete mixer is equipped with stirring blades. The materials in the mixing drum are added, and under the strong stirring of the stirring blades, a cross-flow is formed. This mixing method is far more powerful than the self-falling mixing method, and is mainly suitable for mixing dry hard concrete.
The continuous concrete mixer is equipped with spiral-shaped stirring blades, and various materials are continuously weighed according to the mixing ratio and sent into the mixer. The stirred concrete is continuously discharged from the discharge end. This type of mixer has short stirring time, high productivity and attractive development.