Shot Blasting Machine is used as a mechanical method for the surface treatment by using an abrasive with the help of a centrifugal wheel at high speed to obtain excellent surface and remove impurities for secondary operations.
Shot blasting is done in two ways:- Wheel blasting: It is a common and economical method. In this process, the electric motor energy is converted into kinetic energy by rotating a turbine wheel. This is mostly used for treating heavy equipment. The turbine wheel works here as a centrifugal pump and it delivers the abrasive by centrifugal force on the surface.
- Air blasting: In this method compressed is used and sprayed out through nozzles on the surface. This is mostly used for smaller equipment. Air blasting is comparatively expensive due to the use of steel frames and weldments.
After the process of shot blasting, shots are removed by the air washing process.
The shot blasting machine works on the projectile motion of an abrasive on the metal surface to get a better surface finish. So, this mechanical method depends on the abrasive. For this, mostly metal abrasive should be used.
Metal abrasives can provide the following benefits
- They can increase productivity by reducing maintenance costs.
- Waste generation can be reduced to get better quality of work.
- They cause less environmental pollution and also there is no risk to the operator’s health by using metal abrasive.
- Blast wheel: The efficiency of the shot blasting machine depends on the quality of wheels used. So one used to use a better quality of the wheel.
- Cabinet: Cabinet consists of dust and abrasive. The shot blasting cabinet is made up of steel material to secure strength. A dust collector is mounted on the machine to prevent dust from entering the shop environment.
- Work handling mechanism: The handling of parts depends on the quantity of the parts. Tumblast Shot Blasting Machines are used for large quantities and spinner hangers are used for heavier parts.
- Elevator: After the metallic shots hit the surface they fall into the hopper under the machine from which the elevator carries them to the separator at the upper part of the machine.
- Separator: The separator, separates contaminates, and the cleaned abrasive is fed into the shot turbine.
- Dust collector: A dust collector system is used to release clean air. A properly designed and sized dust collector is preferred for shot blasting machines.
- Control and instrumentation: The starting and stopping of all operations depend on the controls and instrumentation features of the shot blasting machines.
The shot blasting machine is mostly used in chemical industries, petroleum industries, Aerospace, Automobile industry, Heavy engineering industry, Railways, Defence.
Shot blasting is used for the following main purposes:- It provides a better texture to enhance paint adhesion.
- It increases the coating life of a machine by reducing its maintenance cost.
- For cleaning and preparing the surface before painting, coating, metalworking.
- It also used for making non-slipping surfaces and providing surface homogenization.
- Shot blasting is done after heat treatment and also for mechanic descaling.
