Dust Collection for Thermal Spray Processes

Introduction to Dust and Emission Control for Thermal Spray Processes

Thermal spray processes are widely used across numerous industries, including automotive, aerospace, marine, oil & gas, industrial equipment and consumer products. This flexible and adaptable technology is used to coat solid surfaces using metals, alloys, plastics, ceramics and composite materials. When spraying metals, it may also be called metalizing, flame spraying, metal spraying or hardfacing.

Thermal spraying is favored for many coating applications that require an even deposition over a large area at a high deposition rate. Compared to other processes such as electroplating or physical or chemical vapor deposition, thermal spray processes generally provide a more even application of thick coatings at a higher rate of deposition, leading to higher quality coatings and faster production. Thermal spray coatings can be designed to add desirable characteristics to the surface, such as resistance to corrosion or wear, chemical resistance, electrical conductivity or insulation, or different friction properties. Thermal spraying is also used to build up worn parts (hardfacing).

Thermal spray processes produce large volumes of dust and fumes made up of very fine particulates of the feedstock material along with trace gases from the heating process itself. The intense heat used in thermal spraying processes atomizes the feedstock material, generating very tiny particulates. A portion of these particulates become airborne, much like the fine airborne mist generated by spray painting or other aerosol sprays. This excess dust—known as “overspray”—causes health, safety and maintenance problems in a thermal spray operation. Controlling dust and emissions is necessary to protect the health of workers, prevent re-entrainment of particulates onto the coated surface, and prevent combustible dust explosions.