Micromist Spray Ultrasonic Atomizing Nozzle

Jan 09, 2025

Brief Introduction

The focused ultrasonic atomizer nozzle of the line spray type is combined with low-pressure air/gas to produce a soft, highly focused small droplet beam. The isolated hypotube delivers the liquid to the atomization surface of the nozzle, while the air/gas delivered through the nozzle hole at a fixed low pressure shapes the atomized droplets into a very precise target jet with a diameter of only 0.020 inches (0.5 millimeters).

Principle

Ultrasonic nozzles convert high-frequency sound waves into mechanical energy through piezoelectric transducers, and then convert the mechanical energy into liquid. This longitudinal upward and downward vibration generates standing waves in the liquid film at the tip of the ultrasonic nozzle, where the amplitude of these waves can be controlled by a power generator. These stationary liquid waves can extend upwards from the top of the ultrasonic nozzle, and when the droplets leave the atomizing surface of the nozzle, they are decomposed into a uniform fine mist of micrometer sized droplets.

Unlike pressure nozzles, ultrasonic nozzles do not use high pressure to force liquid through a small hole to produce spray. The liquid enters through a relatively large nozzle center without pressure and is atomized by ultrasonic vibration inside the nozzle.

Each ultrasonic nozzle operates at a specific resonant frequency, which determines the median size of the droplet. The difference in droplet size is very small, and its distribution can be accurately predicted within a certain range through mathematical calculations. For example, a 120 kHz nozzle produces a median droplet size of 18 microns when spraying water. The higher the frequency, the smaller the decrease in median value.