1997 Volume 76 Issue 4 Pages 305-312
In order to clarify the influence of outlet hole of a mixing chamber on the atomization by the internal mixing twin-fluid atomizer, visualization of the flow pattern within the mixing chamber and measurement of the Sauter mean diameter were made under the condition of various outlet hole diameters, ratios of outlet hole length and diameter, positions of the outlet hole and numbers of the outlet holes. The changes of the outlet hole have an effect on the flow pattern within the mixing chamber and the Sauter mean diameter especially at the low atomizing air/water mass ratio. Since the water is mixed with the atomizing air in the mixing chamber well by using an eccentric outlet hole, the atomizer with an eccentric outlet hole produces smaller Sauter mean diameter than that of the atomizer with a center outlet hole. The ratio of outlet hole length and diameter influences the Sauter mean diameter. When the water injected into the outlet hole as a column state, the ratio of outlet hole length and diameter is required to be longer than 2 for efficient atomization.