Effect of the Air Flow Angle on a Microbubble Generator with a Spherical Body

Abstract

This research has been carried out on the characteristics of a microbubble generator in a spherical body. It aims to study the influence of the air flow angle on generated bubble characteristics. A water loop system consisting of a water reservoir, an observation box, a pump, water and air flow meters, valves and a test section is used. The test section is a microbubble generator in the shape of a spherical body. Three types of microbubble generator with various air flow angles have been used as a test section at various water flowrates, air flowrates and height of water in reservoir. The tested parameter significantly influences the number and the size of the bubbles. Increasing the air flowrate increases the size of the bubbles, while increasing the water flowrate increases the number of microbubbles. The effect of the air flow angle in the microbubble generator is significant. A Microbubble generator with a 45° air flow angle produces a larger size of bubbles compared to a direct (0° air flow angle) microbubble generator. A microbubble generator with a 90° air flow angle could not suck up the air more than 0.1 lpm, so it is inefficient to produce bubble. From this study it is concluded that a microbubble generator is capable of producing microbubbles and the number and the size of bubbles is affected by the air flow angle.