Design And Analysis Of Venturi Vacuum Regeneration System For PSA Oxygen Generator S. Selvakumar Department of Mechanical Engineering Vel Tech Rangarajan Dr. Sagunthala R&D Institute of Science and Technology Avadi, Chennai - 600 062. selvaskms@gmail.com P. Anand Department of Mechanical Engineering Vel Tech Rangarajan Dr. Sagunthala R&D Institute of Science and Technology Avadi, Chennai - 600 062. dranand@veltech.edu.in Abstract— Oxygen is the third most widely used gas in medical and industrial fields. Oxygen cylinders are heavy and prone to number of hazards and liquid oxygen is too heavy and requires special handling and storage. Portable high-pressure D-type oxygen cylinders can only last up to 3 hrs. The availability of oxygen cylinders in remote villages and hill stations is very poor. Because of this the cost associated with the oxygen procurement is very high. So, the demand for onsite and portable oxygen generation is increased in the recent years. Most of the current onsite and portable oxygen generation systems are working on the pressure swing adsorption principle (PSA) only. The selective adsorption of nitrogen in the regenerable adsorbent produces high purity oxygen, to remove the adsorbed nitrogen from the adsorbent a portion of pure oxygen is given back as a purge flow by venting in to atmosphere. The purge flow is a complete loss. This project aims to develop a compact vacuum regeneration system with zero purge flow in order to eliminate the above-mentioned problem without compromising the oxygen purity. Studies of different kind of available vacuum systems are studied. One such design is a Venturi vacuum nozzle. It is modeled with the help of Solidworks and simulated in FEA and CFD software. Keywords— PSA, Oxygen generation, Vacuum, Venturi, Regeneration, Adsorption. I. INTRODUCTION A. Pressure Swing Adsorption PSA processes are generally used for gas drying and in bulk gas separation. In PSA process the adsorption is carried out at higher pressure and the desorption is carried out at atmospheric pressure or pressure lower than that of adsorption. In most of the PSA process a portion of purified fluid stream is sent back to remove the adsorbed molecules. B. Problem Definition PSA The Current PSA oxygen separation process uses about 50 to 60% of oxygen as a purge flow for regenerating the desiccant. For a 10 LPM of oxygen outlet, the oxygen generator needs to be designed to produce oxygen flow of 16 LPM. So, the inlet air requirement for the oxygen production also increases proportionally. High inlet air flow requirement needs high capacity of filtering and moisture removal components. So, the material cost associated with all auxiliary components like, Air compressor, Desiccant quantity, adsorber column size and pipe sizes are increase which makes PSA system bulky. To overcome the current problem a new regeneration concept, need to be developed with low to zero purge flow. C. Objective of the Project To design and develop a new regeneration / desorption system for PSA type oxygen generator to remove the adsorbed nitrogen from the desiccant. The design should have the following objectives, • Low / zero purge purge flow requirement • Low running cost • Low / zero power consumption • Should not affect the oxygen purity • Should not affect the desiccant life • Should be smaller in size II. PSA OXYGEN GENERATOR The following is the principle of operation for PSA oxygen generator. 1.Compression, drying and filtering of input air: The atmospheric air is compressed by an air compressor and before entering in to the adsorber column air is dried (removing water vapor) and filtered. 2. Nitrogen adsorption: PSA units have twin adsorber column which are filled with Zeolite Molecular Sieve (ZMS). Dry air flows through the adsorber column at high pressure, Zeolite bed adsorbs the nitrogen, while oxygen passes through to the oxygen buffer tank. The adsorption process is interrupted to avoid nitrogen saturation in the ZMS by diverting the input air to the second adsorber column, which at this point starts adsorption phase. During this time, the second adsorber column (right) is cleaned by allowing a portion. IMAGE I PSA OXYGEN GENERATOR LAYOUT