Newtech (Hangzhou) Energy Technology Co., Ltd

 

PSA oxygen generation plant is an advanced oxygen production equipment based on molecular sieve technology. Its main principle is to use the physical adsorption and desorption characteristics of molecular sieves. Under pressurized conditions, molecular sieves selectively adsorb nitrogen in the air, so that the unadsorbed oxygen can be concentrated. After further purification, these concentrated high-purity oxygen is released and provided for patients to breathe. When the system is depressurized, the molecular sieve releases the previously adsorbed nitrogen and discharges it back into the atmosphere. This process is carried out alternately between two adsorption towers. Through periodic pressurization and decompression cycles, high-concentration oxygen is continuously and stably produced to ensure continuous oxygen supply.

 

 

 

Pressure swing adsorption (PSA) is based on the different adsorption of oxygen and nitrogen by molecular sieves, which separates oxygen and nitrogen in the air to produce oxygen. Oxygen production can be completed at normal temperature and low pressure conditions, with low cost, simple operation and fast oxygen production. It quickly replaced bottled liquid oxygen and became the mainstream equipment for oxygen supply in hospitals with its safety, economy and convenience. PSA technology has been put into use in the United States and Germany since the 1970s. Most PSA oxygen generators are composed of air compression system, cold drying system, oxygen production system and control system. Its basic working process is as follows: the air compressor presses the air into the air storage tank, which is dried by the cold dryer. The compressed and dried air enters the oxygen production system. The oxygen production system uses the molecular sieve to change the adsorption capacity of oxygen and nitrogen under high and low pressures to separate the oxygen and nitrogen in the air. During the circulation of the adsorption tower, when the oxygen concentration reaches more than 90%, the booster pump automatically starts to press the oxygen into the storage tank, and then oxygen can be supplied to the oxygen-using equipment.

 

 

Air compression system

The function of the air compression system is to inhale and filter the air, compress and store it, and provide clean air and partial pressure for the oxygen production system. The general structure consists of an air filter, an air compressor and an air storage tank. The inhaled air is generally filtered through multiple stages before being pressurized by the air compressor. The pressurized air enters the air storage tank. In this part, due to the large amount of inhaled air, the filter part is easily filled with impurities in the air, causing blockage, resulting in failure of the air intake part, and thus the whole machine does not work. In actual application, the filter part is often not maintained and cleaned in time, resulting in shutdown. In addition, since the air compressor works for a long time, its maintenance is also very important. The lubricating oil should be replaced frequently to prevent the machine head from being damaged due to severe friction.

 

Cold drying system

The key part of the PSA oxygen generation plant is the molecular sieve, and the molecular sieve has high requirements for the humidity of the air. If the humidity is too high, the molecular sieve will absorb too much moisture in the air, and its separation and adsorption of oxygen and nitrogen will quickly fail. Therefore, the cold drying system is also an indispensable and important part of the oxygen generator. The cold drying system cools and condenses the moisture in the compressed air, and then discharges it. The compressed air after cold drying enters the oxygen production part. At present, the cold drying part of the mainstream oxygen generator is cooled by refrigerant. Through the heat exchanger and evaporator, the moisture in the compressed air is condensed and discharged. The humid compressed air first enters the heat exchanger for preliminary cooling, and then passes through the evaporator. The refrigerant evaporates and further absorbs the heat in the air. The compressed air is cooled again, and the moisture and oil in it are condensed. The cooled compressed air passes through the water separator to separate the condensed moisture and oil from the air. The compressed air after cold drying flows through the heat exchanger to cool the compressed air input by the air compressor system and outputs it to the oxygen production system.

 

Oxygen production system

The oxygen production system is the core part of the oxygen generator. It is in this part that the air can be converted into oxygen with a purity of more than 90% and provided to the patient. Its main part is the adsorption tower, in addition to the pressure pump, oxygen buffer tank and some multi-way rotary distribution valves and other accessories. Most oxygen generators are equipped with two adsorption towers that work in a cycle. The compressed air sent by the cold drying system flows through the adsorption tower, which adsorbs nitrogen, so the output becomes high-purity oxygen. After being pressurized by a booster pump, oxygen can be directly supplied to the patient through an oxygen buffer tank. At present, the molecular sieves of most oxygen generators use zeolite molecular sieves that can preferentially adsorb nitrogen. In addition, the adsorption tower is also equipped with a desiccant that further dehumidifies and removes carbon dioxide. The cold-dried air enters the adsorption tower, and the nitrogen, carbon dioxide and very little water vapor in the air are adsorbed by the adsorption tower. The remaining oxygen is directly discharged. After decompression, the molecular sieve's adsorption capacity for nitrogen is reduced, and the adsorbed nitrogen is discharged. The molecular sieve after nitrogen discharge can adsorb nitrogen again after pressurization.

The two adsorption towers alternately repeat the process of pressurizing nitrogen absorption/decompressing nitrogen discharge, and the required oxygen is continuously produced.

 

Control System

The control system mainly controls the working sequence of each component. According to the working pressure threshold of each component, it controls the working procedures of the air compressor, booster pump, cold dryer and other components. In addition, it also provides I/O control of the user interface, alarm and error information, etc. It is a general electrical part and is no different from other electrical appliances.

 

 

(1) Electronic Manufacturing

In the field of electronic manufacturing, especially in the semiconductor production process, PSA (Pressure Swing Adsorption) oxygen generators play a vital role. Semiconductor production involves multiple key process steps, which have strict requirements for high-purity oxygen. For example, in the oxidation process, a uniform thin oxide layer needs to be formed on the surface of the silicon wafer, which directly affects the performance and reliability of the device. The cleaning step uses high-purity oxygen to remove organic matter and particles on the surface of the silicon wafer to ensure the cleanliness of the device and avoid defects in subsequent processes. Processing processes such as chemical vapor deposition (CVD) and physical vapor deposition (PVD) of electronic components also require a stable and high-purity oxygen supply. PSA oxygen generators can continuously provide these needs and ensure precise atmosphere control during the process, thereby improving product consistency and quality. In addition, the high efficiency and economy of PSA oxygen generators make them an ideal choice for semiconductor manufacturing plants. The internally established oxygen production system reduces dependence on external supply, reduces logistics costs and supply chain risks, and can flexibly adjust oxygen production to cope with production fluctuations and meet the needs of large-scale production.

 

(2) Food and Beverage Industry

In the food and beverage industry, PSA (Pressure Swing Adsorption) oxygen generators are widely used in the food preservation process. Their main function is to provide high-concentration oxygen to extend the shelf life of food. In modern food packaging technology, the use of high-purity oxygen for packaging can effectively inhibit the growth of anaerobic bacteria and slow down the oxidation process of food, thereby maintaining the freshness and nutritional value of food. For example, the shelf life of perishable foods such as fresh meat, fruits, vegetables and dairy products can be significantly extended after being treated with high-concentration oxygen. In addition, the use of PSA oxygen generators can ensure the stability of oxygen purity and concentration during the packaging process, thereby avoiding the problem of oxygen concentration fluctuations that may exist in traditional methods and further improving the safety and quality of food. On the food and beverage production line, PSA oxygen generators not only improve the shelf life of products, but also help companies improve production efficiency and reduce losses and costs. At the same time, high-concentration oxygen packaging technology also improves the market competitiveness of products and meets consumers' demand for high-quality food.

 

(3) Submarines and diving equipment

In submarines and diving equipment, the application of PSA (Pressure Swing Adsorption) oxygen generators is crucial, mainly to ensure that crew members and divers have sufficient oxygen supply in a closed environment. In submarines, one of the biggest challenges facing crew members is maintaining adequate oxygen levels due to long-term diving and underwater operations. Traditional oxygen supply methods usually rely on storing large amounts of compressed oxygen, which not only takes up valuable space but also poses certain safety risks.

 

PSA oxygen generators extract oxygen from the surrounding air to provide a continuous, stable and efficient way to generate oxygen, significantly improving the submarine's autonomous combat capability and safety. For diving equipment, especially in long-term underwater operations and deep-sea exploration, PSA oxygen generators also play a key role. When divers work in a closed diving bell or diving suit, traditional oxygen cylinders will limit their working time due to oxygen depletion, while PSA oxygen generators can generate oxygen in real time, ensuring that divers have a continuous oxygen supply throughout the mission, greatly extending the underwater operation time and improving work efficiency and safety. In addition, the portability and high efficiency of PSA oxygen concentrators make them an important part of modern diving equipment. They are widely used in military diving, deep-sea exploration, marine engineering and other fields, promoting the development and application of diving technology. Therefore, the application of PSA oxygen concentrators in submarines and diving equipment not only solves the problem of oxygen supply, but also improves the safety and efficiency of overall operation, becoming an indispensable technical equipment in these fields.

 

 

 

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