Origin and development of concrete batching plant

Concrete was first invented by the British, so people infer that the concrete mixer was also invented by the British.

Concrete mixer appeared in the form of self falling mixing. With the increasing requirements for concrete, there is a forced mixer. Forced mixer can be divided into vertical shaft type and horizontal shaft type. There are almost two kinds of mixers in China.

The self falling mixer can be traced back to the early 20th century. At the beginning of the 20th century, drum concrete mixer driven by steam engine began to appear. In the next 50 years, the double cone mixer of reverse discharge type and tilting discharge type and split drum mixer came out and developed one after another.

As the self falling concrete mixer is mainly to mix plastic concrete, so the forced mixer began to rise. Since the rise in the early 1950s, the forced mixer has been rapidly developed and promoted. The first is the disc vertical shaft type forced concrete mixer. This kind of mixer is divided into two types: propeller type and planetary type.

After the 1970s, with the application of lightweight aggregate, the horizontal shaft forced mixer with round trough appeared, also known as horizontal shaft mixer. It is divided into single horizontal shaft type and double horizontal shaft type, and has the characteristics of self falling and forced mixing. It is a new type of mixer developed in the 1970s. It can be divided into single shaft type and double shaft type. This type of mixer has the functions of self falling and forced mixing. The linear speed of mixing blade is smaller than that of vortex slurry type, so the wear resistance is higher than that of vortex slurry type. The single horizontal shaft mixer is made in Germany, which has the advantages of compact structure, low power consumption, good wear resistance of blade liner, full load start-up and the ability of mixing lightweight concrete. China has also introduced a prototype to the company. Double horizontal shaft mixer is a new type of machine developed with the improvement of concrete construction technology. Foreign countries began to appear in the United States and Germany in the late 1940s, but because of the immature shaft end sealing technology, its development is basically at a standstill.

Until the early 1970s, due to the breakthrough of this technology, the double horizontal shaft mixer was re developed in many countries, and now has formed a series of products. It was successfully developed in our country in the early 1980s, but it has developed rapidly. In terms of product specifications and product quantity, it has far exceeded other models. Mixing mechanism is the core part of double horizontal shaft mixer. The quality of concrete mixing, productivity and maintenance cost are related to it. The mixing mechanism is composed of a double circular groove type companion cylinder arranged horizontally, two mixing shafts rotating in opposite directions and mixing blades installed on it. When the mixing shaft rotates, on the one hand, the blades drive the mixed material to make circular motion in the two mixing cylinders and roll up and down. At the same time, the mixed material exchanges in the common area between the two shafts where the mixing blades meet or overlap; On the other hand, it pushes the mixture along the direction of the mixing shaft and continuously moves from the rotating plane to another rotating plane. Compared with the self falling concrete mixer, this mixing method is more powerful and is mainly suitable for mixing dry and hard concrete.

Then the continuous concrete mixer appeared. Its working principle: it is equipped with spiral mixing blades, various materials are continuously weighed according to the mix proportion and then sent into the mixer, and the mixed concrete is continuously discharged from the discharge end. Advantages of continuous concrete mixer: short mixing time, high productivity.

With the development of concrete materials and construction technology, there are many new structure concrete mixers, such as steam heated mixer, supercritical speed mixer, sonic mixer, swing disc mixer without mixing blade and secondary mixing concrete mixer.