The working principle of shot blasting machine

Shot blasting machine is a shot blasting surface treatment method that has been applied in developed countries in Europe and America. The world's first shot blasting equipment was born 100 years ago, and it started to have applications in various metal or non-metal surfaces to remove impurities, oxide scale, and increase roughness.

After a hundred years of development, the shot blasting process and equipment have become quite mature, and its application has not only been in various heavy industry factories. With the birth of the world’s horizontal mobile shot blasting equipment in the United States, BLASTRAC, its application fields have rapidly expanded to concrete surface coating treatment and ship deck metal surface treatment, and directly lead the industry’s standard formulation and industry Specification of construction method.

With the continuous improvement of Baretech shot blasting equipment and mature technology, shot blasting technology and equipment have entered the fields of road maintenance, bridge construction and airport maintenance in developed countries in Europe and America.

However, China's application in this area is still very few, only a few projects have used shot blasting processing technology, and there is still a blank in the waterproof coating of highways, municipal roads and concrete bridges.

1. Shot blasting process and working principle of shot blasting equipment

Shot blasting means that the shot material (steel shot or sand) is projected onto the working surface at a high speed and at a certain angle by a mechanical method, so that the shot material impacts the working surface, and then is cleaned by the airflow of the matching vacuum cleaner inside the machine , The technology to recover the pellets and the cleaned impurities separately, and make the pellets reusable. The shot blasting machine is equipped with a dust collector, which can achieve dust-free and pollution-free construction, which not only improves efficiency, but also protects the environment. Shot blasting machines can be divided into three types according to their walking modes: hand-push type, vehicle-mounted type and self-propelled type.

During the operation of the shot blasting machine, by controlling and selecting the particle size and shape of the shot material, and adjusting and setting the walking speed of the machine, the shot flow rate of the shot material is controlled to have different shot strengths and different surface treatment effects.

2. Control the quality of surface shot blasting

The shot blasting process and shot blasting equipment use three parameters to control the surface condition after treatment according to the different surfaces to be treated. Choose the size and shape of the pellets; the walking speed of the equipment; the flow rate of the pellets. The above three parameters cooperate with each other to have different treatment effects and ensure the ideal roughness of the surface after shot blasting.

For example: using S330 steel shot, flow rate 10A, processing C50 concrete surface, the roughness can reach 90; processing the asphalt surface can remove the oily layer while reaching the roughness 80; when processing the steel plate, it can reach the cleanliness standard of SA3.

Roller-type shot blasting machine: It uses high-speed impellers to throw projectiles toward castings and forgings that are constantly turned over by the roller to remove oxide scale, so that the surface of the workpiece can be uniformly cleaned, showing the original metal color.

Crawler shot blasting machine: the workpiece is loaded by high-strength wear-resistant rubber track or manganese steel track, and the high-speed projectile is thrown on the track by the shot blasting device to achieve the purpose of cleaning.

Rotary shot blasting machine: The surface of the workpiece is hit by a uniform steel shot through the frequency conversion shot blasting machine, and the coverage rate of the surface steel shot reaches more than 98% to achieve the strengthening effect.

Hanging chain stepping shot blasting machine: adopts multi-station fixed-point projection cleaning method to remove the sticky sand and oxide scale on the surface of the casting, so that the casting reproduces the metal color.