The working principle of shot blasting machine

With the continuous improvement of the shot blasting equipment and the maturity of the technology, the shot blasting process and equipment have entered the fields of highway maintenance, bridge construction and airport maintenance in developed countries in Europe and America. While its application in these fields is still very narrow in China, where the shot blasting process is used only in a few projects, and there is still a gap in the waterproof coating of highways, municipal roads and concrete bridges. I hope that this article can introduce this new shot blasting process to our friends specializing in the maintenance of highway and bridge construction, and hope that this new process and technology will be promoted.

Shot blasting has been applied as a surface treatment method in developed countries in Europe and America. The first shot blasting equipment was born 100 years ago in the world. It began to remove impurities, oxide skin and increase roughness on the surface of various metal or non-metal materials. After a hundred years of development, the shot blasting process and equipment have been quite mature, and its application has not only been in the factories of various heavy industries. With the birth of the world's first horizontal mobile shot blasting machine in BLASTRAC, its application field rapidly expanded to concrete surface coating and metal surface treatment of ship deck, and directly guided the industry's standards setting and standards of construction methods in the industry.
 
Working principle of shot blasting process and shot blasting equipment
Shot blasting is a technology of mechanically propelling the blasting material, steel shots or grits, onto a surface at a high speed and a certain angle, letting abrasive material forcibly blast against the surface, and then cleaning the inside of the machine through the airflow of the equipped dust collector, finally recycling separately the blasting material and cleaned impurities, which makes the shot blasting material recyclable. The shot blasting machine is equipped with a dust collector, which leads to dust-free and pollution-free construction, not only improving efficiency but also protecting the environment. The shot blasting machine can be divided into three types according to its moving form: hand-propelled, vehicle-mounted and self-propelled.

When the shot blasting machine operates, by controlling and selecting the particle size and shape of the shots, adjusting and setting the moving speed of the machine, the projectile flow rate of the shots is controlled to obtain different projection strengths and different effects of surface treatment.

Quality control of the surface shot blasting
The shot blasting process and the shot blasting equipment control the treated surface condition by three parameters depending on the surface to be treated, that is, the size and shape of the shots, the moving speed of the equipment and the flow rate of the shots. The above three parameters coordinate with each other to obtain different treatment effects, and to ensure the ideal roughness of the surface after shot blasting.

For example, if you use S330 steel shot at flow rate of 10A to treat C50 concrete surface, the roughness of the surface after shot blasting will reach 90, or to treat asphalt surface, the oil layer will be removed and the roughness will reach 80, or to treat steel plate, it will reach the cleanliness standard of SA3.