CONTROL OF MEAN DROPLET DIAMETER ISSUED FROM Y-JET-TYPE AIRBLAST ATOMIZER BY USING FLUID AMPLIFIER

Abstract

A new type of atomizer has been developed to control mean droplet diameter over a wide range of liquid flow rates; this newly developed atomizer of Y-jet type employs a fluid amplifier to control the liquid flow rate. The liquid flowing into the atomizer is distributed by a fluid amplifier into two ports with different inner diameters. During the present experiments, the liquid flow rate was varied over a turndown ratio of 7, while the air flow rate was kept constant. Generally, the mean droplet diameter is greatly influenced by the atomizing air velocity, and the mean diameter decreases steadily as the atomizing air velocity increases. In the proposed method, to keep the mean diameter constant, the liquid flowing into smaller ports where high-speed air passes is greatly increased with total liquid flow rate. On the other hand, liquid flowing into larger ports, where low-speed air passes through, is gradually increased. Consequently, the mean droplet diameter changes only 10 μm for the optimum design over the turndown ration of 7, whereas the mean diameter changes 30 μm without the fluid amplifier.