Micro bubbles are widely used in many cases such as agriculture, fishery, skin care, prevention of water pollution. A high pressure compressor which is one of part of a micro bubble generating system is needed to generate these micro bubbles. The purpose of this research is the development of a high pressure compressor which is achieve following conditions; discharge flow 0.6ℓ/min, maximum air flow 2ℓ/min, discharge pressure 5bar. To achieve these conditions, we optimized the geometry of cylinder and piston, clearance volume, compression ratio, power of operating motor experimentally. Moreover, we minimized the compressor which is the biggest part of a micro bubble generating system so that we could minimized the size of entire system.

Experimental measurements of flame shape and heat transfer characteristics were performed for impinged inverse diffusion flame(IDF) using propane as a fuel. The purpose of this study is to identify the favorable co-axial inverse diffusion flame structure for impingement heating. The flame consisted of an entrainment zone and mixing and combustion zone. The heat flux which represents heat transfer rate is measured by using a heat flux sensor that is located at the center of the impingement plate. The inverse diffusion flame structure has been classified into six modes. In these modes, several favorable flames for impingement heating were identified. In this study, the parameters are overall equivalent ratio(Φ), nozzle to impingement plate distance(h/d), vertical distance from the stagnation point and Reynolds number(Re) of combustion air.