Study of the gas-droplet outflow from a microchannel nozzle device

High-speed shadow imaging of a gas-droplet flow from a microchannel nozzle device was performed by varying the liquid flow rate from 1 to 50 ml/min and the gas pressure drop from 0.5 to 8 bar. For this purpose, an optical system with a stereomicroscope was assembled to ensure a large depth of field and relatively high resolution. The outflow was studied for two types of nozzles: a three-nozzle device with an internal channel diameter of 200 µm and a custom-made nozzle with a microchannel silicon membrane of 243 µm thickness and a microchannel size of 10×10 µm. Spray angles for a single nozzle and an angle averaged over three nozzles were determined. Dependences of the angles on liquid flow rate for each pressure drop and dependences on pressure drop with varying liquid flow rate were obtained. It is shown that a uniform gas-droplet flow can be organized at the nozzle edge with small droplets using a microchannel membrane.