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Application requirements for oxygen generation equipment using pressure swing adsorption I. Selection of oxygen supply methods in hospitals Modern hospitals generally use centralized oxygen supply; the practice of delivering oxygen cylinders directly to wards or operating rooms is gradually being phased out. Centralized oxygen supply can basically be divided into the following three methods: centralized oxygen supply via pressure reduction using oxygen manifold from cylinder oxygen ； Oxygen is supplied centrally after being vaporized in an liquid oxygen vaporizer, depressurized, and stabilized from the liquid oxygen storage tank ； Medical oxygen is produced by pressure swing adsorption oxygen generation equipment, providing continuous oxygen supply. Early centralized oxygen supply systems basically used the first method. In the late 1980s, with the increase in large-scale oxygen generators and the construction of numerous specialized gas supply stations through investments from both domestic and foreign sources, the use of liquid oxygen vaporized for oxygen supply gradually became an important method of oxygen provision in hospitals located in areas with abundant oxygen resources. According to China Pressure Swing Adsorption Network, since the 1990s, as pressure swing adsorption technology matured, this oxygen supply method – in which hospitals own their own oxygen generation equipment, offering an economical, convenient, safe, and reliable solution – quickly gained favor among hospitals. It became the preferred choice for large and medium-sized hospitals and spread rapidly. In some remote provinces where oxygen sources are far away, hospitals with difficult transportation access are the most suitable for using pressure swing adsorption oxygen generation equipment to supply oxygen. Because this method of oxygen supply allows for the production of high-quality medical oxygen using electrical energy, thereby saving a great deal of manpower, resources, and financial costs. Many articles have already provided comparative summaries of the advantages and disadvantages of these three methods of supplying medical oxygen, so they will not be repeated here. Whether in developed Western countries or in our own country, it is an inevitable trend for hospitals to use medical cryogenic adsorption oxygen generation equipment for oxygen supply. II. Requirements for oxygen generation stations and relevant precautions 1. Requirements for oxygen generation stations: The air or oxygen pressure in medical pressure swing adsorption oxygen generation equipment is within the low-pressure range. Oxygen is a combustion-supporting gas, not a flammable gas such as hydrogen. **There are no specific regulations in the industry regarding oxygen generation stations that use medical pressure swing adsorption oxygen generation equipment as their oxygen source, nor are there any corresponding standards; therefore, hospitals can decide according to their own circumstances, and the oxygen generation station can be located on the ground floor or in the basement. However, since oxygen is after all an oxidizing gas and has a certain pressure, oxygen production stations must take necessary safety measures. 2. Safety precautions: 1. Oxygen generation equipment is an important piece of equipment in hospitals; apart from the staff, no one else is allowed to enter the oxygen generation station without permission. 2. Smoking and the use of fire are strictly prohibited within the boundaries of the oxygen production station. When fire is necessary for the maintenance of containers or pipelines, safety measures must be taken, and work may only proceed after approval from the hospital’s safety department. 3. The area within the oxygen production station boundary must be kept clean; flammable and explosive materials are not allowed to be stored there. No items shall be piled up on the walkways to ensure smooth traffic flow. 4. Before taking up their posts, operators must receive safety training as well as theoretical and practical instruction on operating methods; they must be able to operate oxygen generation equipment independently before they can start working. 5. Operators must be properly dressed when taking up their posts; it is strictly prohibited to bring flammable and explosive items into the oxygen production station, and operations must be carried out in strict accordance with the instructions provided in the user manual. 6. At the entrance to the oxygen production station and in prominent locations within the station, warning signs such as “No Smoking” and “Be Safe” as well as safety signs must be installed to serve as alerts. 7. The oxygen production station should be equipped with at least four small dry powder fire extinguishers of type “1121” or “1301”. 8. The oxygen production station is equipped with one set of grounding and lightning protection devices; the burial depth of the grounding electrodes and the requirements regarding grounding resistance are met in accordance with relevant regulations. 9. The pressure gauge used in oxygen generation equipment should be calibrated once a year, and a lead seal should be applied after it passes the calibration. 10. No pressure-related maintenance work shall be carried out on the equipment before it is depressurized. Pay attention to safety when relieving pressure. 11. The airtightness of the equipment’s pipelines and fittings should be checked every two weeks; any leaks detected must be repaired promptly, and the system can only be put into operation once it is deemed satisfactory. 12. It is recommended that intrinsically safe circuits be used for the lighting and ventilation systems in the oxygen production station’s filling area. 13. Each set of equipment is tested and found to be in good condition before leaving the factory, and is accompanied by a certificate of conformity; however, this does not completely prevent damage that may occur during transportation and handling. Therefore, before starting the equipment for the first time, all aspects of the system should be carefully inspected to avoid malfunctions. 14. The raw material used in oxygen production equipment is air, and it is necessary to keep the air around the oxygen production station free from pollution. 3. Installation technical requirements: 1. The oxygen production station must have good ventilation inside. The air intake of the air compressor should be kept clean and free from contamination, and the indoor temperature should be maintained between 5~38°C. 2. The power supply supplied to the distribution box is a three-phase power supply (three phases and four wires, with an additional ground wire), at 380V and 50HZ; its capacity is sufficient to meet the requirements of the oxygen generation equipment. ] 3. The pollutants discharged from the waste outlet should be released outside to avoid contaminating the site. 4. Installation requirements for oxygen generation equipment (including the layout of the equipment) can be found in documents such as the floor plan. 5. The surface on which the equipment is placed only needs to be level; no special requirements are needed. 4. Storage and transportation conditions: 1. Oxygen generation equipment should be protected from being inverted, collided with, exposed to rain, or subjected to severe vibrations during transportation. 2. The packaged oxygen generation equipment should be stored in a room with a relative humidity of no more than 80%, free from corrosive gases, and well-ventilated. III. Characteristics of oxygen use in hospitals In hospitals, oxygen is of critical importance for saving lives. Devices such as ventilators, ICU wards, hyperbaric chambers, emergency rooms, and regular wards often require oxygen to be used 24/7 for the treatment or rescue of patients; this means that a central oxygen supply system is needed to provide a continuous supply of medical oxygen with the appropriate pressure, flow rate, and purity. 1. **Characteristics of oxygen use in machines, ventilators, and ICU wards: An ICU ward is a critical care unit, and it is also where oxygen is used via ventilators.** **Oxygen supply for machines and ventilators has the following main characteristics: 1. Oxygen supply duration – Machines and ventilators are used in surgeries or to save critically ill patients, while ventilators in ICU wards are employed to sustain patients’ lives; therefore, it is essential to ensure continuous oxygen supply at all times, without any interruption. 1, 2 The oxygen supply pressure: For domestically produced or imported **machines and ventilators, the oxygen pressure is generally within 0.4 MPa gauge pressure. The oxygen alarm triggers when the pressure is below 0.3 MPa to 0.4 MPa (there are slight variations among products from different manufacturers). To ensure normal operating pressure, the oxygen output pressure of standard oxygen generation equipment should be no less than 0.45 MPa. 1 and 3: The oxygen supply flow rate is average; the normal gas supply flow rate of ** the machine is 0–10 L/min, while the rapid gas supply flow rate is 35–75 L/min. Normally, the flow ratio of oxygen to nitrous oxide is 1:3; in other words, the normal oxygen flow rate for such a machine is 0–3 L/min, while the flow rate for rapid oxygen supply is approximately 15 L/min. The automatic oxygen flow rate for ventilators used in ICU wards, emergency rooms, and operating rooms is approximately 10 L/min. In fact, the oxygen flow rate of medical devices such as ventilators is closely related to the oxygen pressure. Especially when the instantaneous oxygen consumption is high, if the total oxygen flow rate is insufficient, the oxygen pressure in the central oxygen supply system will drop, even below the lower limit alarm pressure set for the oxygen-using medical devices, thereby affecting their operation. 2. Characteristics of oxygen use in hyperbaric oxygen chambers. Hyperbaric oxygen has the following characteristics: 1. It increases the physically dissolved oxygen in blood and tissues; as a result, it is possible to sustain life without blood – that is, by removing the red blood cells from an animal, its life can still be maintained under hyperbaric oxygen conditions. 2. Hyperbaric oxygen can increase the penetration of oxygen, thereby treating hypoxia in local tissue cells caused by vascular obstruction, vasospasm, or cellular edema. 3. Hyperbaric oxygen can increase the oxygen reserve in tissues, enhancing the body’s tolerance to hypoxia and thus allowing it to get through critical periods and buy time. Heart surgery can be performed under hyperbaric oxygen without the need for extracorporeal circulation. 4. Hyperbaric oxygen can kill pressure-sensitive bacteria and has a very good therapeutic effect on gas gangrene. 5. Hyperbaric oxygen can compress gases trapped within the body, and it is particularly effective in treating bubble obstruction of the respiratory tract caused by toxic gases, as well as decompression sickness, intestinal flatulence, and intestinal cyst disease. However, hyperbaric oxygen therapy cannot achieve these medical benefits, which is why many hospitals now are equipped with hyperbaric oxygen chambers. According to statistics from the National Academic Committee for Hyperbaric Medicine, in June 1982 there were only 116 oxygen chambers nationwide; by May 1991, there were over 880 oxygen chambers of various types. According to China Pressure Swing Adsorption Network, it is estimated that there are currently over a thousand oxygen chambers available across the country. The oxygen usage characteristics of a hyperbaric oxygen chamber are high instantaneous oxygen consumption and high oxygen pressure. Generally speaking, the oxygen pressure in an oxygen chamber is not less than 0.55 MPa, allowing for comfortable oxygen inhalation with no strain. When the oxygen pressure is below 0.5 MPa, it becomes somewhat difficult to breathe oxygen, and it feels uncomfortable. It is generally recommended that the oxygen pressure be no less than 0.55 MPa. Some hyperbaric oxygen chambers do not require an oxygen mask, and the oxygen pressure can be lower; usually, a pressure of 0.4 MPa is sufficient. The oxygen flow rate in hyperbaric oxygen chambers is usually not less than 10 L per person per minute; the exact amount depends on how many such chambers the hospital has and what capacity they have. Based on this, the maximum oxygen consumption of the hyperbaric oxygen chamber is calculated. Similarly, the oxygen flow rate and oxygen pressure in a hyperbaric oxygen chamber are also closely related. If the oxygen flow rate is insufficient, the oxygen pressure will also drop. 3. Characteristics of oxygen use in regular wards: Oxygen use in regular wards refers to patients receiving oxygen at normal atmospheric pressure. Atmospheric pressure oxygen therapy can increase blood oxygen saturation. When patients experience difficulty breathing due to issues such as heart, lung, or central nervous system problems, resulting in abnormal blood oxygen saturation, treatment with atmospheric pressure oxygen therapy usually yields significant results. China Pressure Swing Adsorption Network believes that **standard YY/T 0187-94 \"General Technical Requirements for Medical Central Oxygen Supply Systems\" stipulates that for patients in regular wards, the oxygen pressure at the ward terminals should be no less than 0.2 MPa. In other words, an oxygen pressure of over 0.2 MPa is sufficient, and such a pressure is easy to achieve. Regarding oxygen consumption in regular wards, generally, an oxygen flow rate of 3 L/min to 5 L/min per oxygen delivery device is sufficient. Since there are many regular wards, the overall oxygen consumption is usually high. By analyzing the oxygen usage characteristics of medical devices such as ventilators, hyperbaric chambers, and ordinary wards, the selection of oxygen flow rate and pressure for oxygen generation equipment should be determined based on the specific situation of the oxygen-related medical devices, hyperbaric chambers, and ordinary oxygen delivery systems available in the hospital, as well as its recent development trends. Factors such as the diameter of the oxygen pipelines in the central oxygen supply system must all be considered comprehensively. Ensure that hospitals can use oxygen with confidence and safety.