Characterization of wire mesh structure for coalescing oil separation

Abstract

Oil separation is commonly needed in air conditioning or refrigeration systems to reduce the oil circulation rate and keep the oil inside the compressor. For compactness, the oil separation structure integrated into the compressor is more and more popular than traditional external oil separator. This paper presents coalescence, one of the basic mechanisms of droplet separation, studied by quantitative flow visualization and measurements. The misty oil flow through separator is visualized by a high-speed camera and analyzed quantitatively. Oil droplet size and its distribution are determined by video processing. Important flow details are revealed, including oil droplet collision, oil droplet coalescence, oil film breakup and re-entrainment. Separation efficiency is determined as the ratio between drained and incoming oil mass flow rate. Pressure drop is also measured since it is a cost due to separation structures.