Since the 1960s, wet spraying technology has been gradually implemented in western developed countries, and various wet shotcrete machine have also been developed. The so-called wet spraying, the basic principle of which is to add the finished concrete mixed with water to the wet shotcrete machine, Transported to the nozzle, mixed with accelerating coagulant and sprayed to the construction surface. In China, dry shotcrete machine are still the main spraying equipment for various reasons. However, with the enhancement of people's awareness of environmental protection and the improvement of the quality of shotcrete, more and more wet concrete shotcrete machines have been used. In some large-scale water conservancy projects for international tenders, such as the Ertan Hydropower Station, the Xiaolangdi Project on the Yellow River, and the Three Gorges Project, wet concrete shotcrete machine are used. The various wet shotcrete machine currently used in China are mostly equipment imported from abroad. In recent years, some domestic units have also begun to develop several concrete wet shotcrete machine.
The domestic SPZ-6 wet shotcrete machine is a one-air-supplied rotor type wet concrete jetting machine successfully developed by Beijing General Research Institute of Mining and Metallurgy. Its working principle is similar to Ruitu Aliwa 280 model, and its rotor is driven by a motor through a reducer to rotate. The machine has low equipment investment, high productivity, light gravity and good maneuverability.
The SPZ-6 wet shotcrete machine has carried out industrial experiments at the Beijing Urban Construction Daliushu site and Gansu Jinchuan Nonferrous Metals Company, and achieved excellent results. It passed the technical appraisal of China Nonferrous Metals Industry Corporation in December 1996. Obtained the national patent in August 1998.
TK-961 wet shotcrete machine is a rotor piston wet spraying machine developed by the Southwest Branch of the Academy of Railway Sciences in recent years. The machine uses a set of pistons to push the mixed material to the mixing chamber at the top of the machine. After being mixed with air, it is transported to the nozzle through a hose, and the accelerator is added to the nozzle and sprayed out. The main advantage of this machine is that there is no residual air emission and the feeding continuity is good. According to reports, it has been applied in Baocheng branch line, Yuchang expressway and other projects. And won the national patent.
