Dust Control Handbook for Industrial Minerals Mining and Processing

Hydraulically atomizing nozzles force liquid through a fixed orifice at high pressures to achieveatomization into droplets. The orifice geometry produces various spray patterns and dropletsizes.Hydraulic Full Cone NozzlesHydraulic full cone nozzles produce a solid cone-shaped spray pattern with a round impact areathat provides high velocity over a distance (Figure 2.6). They produce medium to large dropletsizes over a wide range of pressures and flows. They are normally used when the sprays need tobe located further away from the dust source [Bartell and Jett 2005].Hydraulic Hollow Cone NozzlesFigure 2.6. Typical full cone nozzle and spray pattern.Hydraulic hollow cone nozzles produce a circular ring spray pattern and typically producesmaller drops than other hydraulic nozzle types of the same flow rate (Figure 2.7). They alsohave larger orifices which results in reduced nozzle clogging. Hollow cone nozzles are normallyuseful for operations where airborne dust is widely dispersed and are available in two differentdesigns: whirl chamber and spiral sprays. In most whirl chambers, the spray pattern is at a rightangle to the liquid inlet; however, in-line designs are also available. Both produce a moreuniform pattern with smaller droplets (Figure 2.7). Spiral sprays are used when greater waterflow is needed, resulting in less clogging due to the large orifices. There is also less patternuniformity and larger droplets are created (Figure 2.8) [Bartell and Jett 2005].Figure 2.7. Typical hollow cone whirl chamber nozzle andspray pattern. Right angle design shown.Wet Spray Systems 67