Introduction
Against the background of the increasing global demand for energy and materials, the importance of air separation units as key gas separation equipment is becoming increasingly prominent. The efficient operation of air separation units can not only improve production efficiency and reduce operating costs, but also ensure the safety of the production process. However, the installation of air separation units is a complex and meticulous process, which requires comprehensive consideration of multiple factors such as geological conditions, equipment quality, construction specifications and operational safety. Any negligence of a small detail may lead to a decline in equipment performance or even a safety accident. Therefore, in-depth research and discussion on the layout and installation precautions of air separation units will not only help improve the operating quality and safety of the unit, but also provide strong support for the sustainable development of the enterprise.
Overview of air separation units
Air separation units, which are widely used in the industrial field, mainly have the function of separating oxygen, nitrogen and other inert gases in the air. Such units are generally composed of several key components such as compressors, precooling systems, purification systems, expanders, heat exchangers, distillation towers and storage tanks. The compressor in the air separation unit, as its key component, is responsible for raising the gas to a suitable pressure to facilitate subsequent separation operations. The compressed air cooled by the pre-cooling system is designed to remove moisture and carbon dioxide inside it to prevent impurities from crystallizing under low temperature conditions, thereby ensuring that the separation efficiency is not disturbed. The purification system mainly removes tiny particles and harmful gases in the air through physical adsorption or chemical reaction to ensure that the gas entering the distillation tower is pure. The expander in the device plays a vital role. It expands high-pressure air to low pressure, causing a sudden drop in temperature, thereby creating indispensable environmental conditions for the condensation and separation process. Inside the recovery unit, the heat exchanger is responsible for capturing and utilizing cold energy to optimize energy utilization efficiency and significantly reduce energy consumption.
Layout principles of air separation units
Environmental factors
When arranging an air separation unit, it is necessary to deeply study its surrounding environmental factors to ensure its smooth operation and long-term stability. The operating status of the device is significantly affected by factors such as air temperature, humidity, dust content, and harmful gas concentration. When selecting the installation site of the device, climate factors should be the primary consideration. In a high-temperature environment, the operation of the compressor often leads to an increase in its energy consumption, which in turn has a negative impact on the overall efficiency of the system; in a low-temperature environment, the startup and operation of some equipment will encounter challenges, so additional insulation strategies must be implemented to ensure its smooth operation; in an environment with high humidity, the moisture content in the air increases, which increases the load on the precooling and purification system, thereby affecting the long-term operation performance of the equipment. Harmful gas concentration and air dust content are both key evaluation indicators. In an environment with high air dust content, the equipment wears faster and its service life is shortened accordingly, especially for key components such as compressors, pipes and filters. In order to ensure that the device is arranged in an area with good air quality, if it encounters an unavoidable high-dust environment, it is necessary to configure high-efficiency filtering equipment at the air inlet, and perform cleaning and maintenance operations regularly, and strictly control harmful gases such as hydrogen sulfide and chlorine to avoid them from causing harm to equipment and operators.
Safety distance and isolation requirements
The layout of the air separation unit must strictly implement safety regulations to ensure the safety of the operator and the surrounding environment. In particular, the high-pressure and low-temperature components in the unit have more stringent safety standards. Equipment such as high-pressure compressors and storage tanks must be placed away from crowded areas and flammable and explosive materials to reduce the risk of accidents caused by high-pressure gas leakage. These equipment must be equipped with complete explosion-proof facilities, such as leak detection systems and emergency pressure relief systems, so that they can respond quickly in emergency situations. Cryogenic equipment such as expanders, heat exchangers and storage tanks also require special attention. They will produce low-temperature gases and liquids during operation. If they leak, the air may condense into frost quickly, increasing safety risks. These cryogenic equipment should be installed in well-ventilated places, and appropriate insulation and anti-condensation measures should be taken, such as installing insulation materials around the equipment to reduce heat exchange and prevent condensation, setting up safety fences and warning signs to remind people to keep their distance and prevent frostbite and other accidents.
Precautions for the installation of air separation units
Preparation and inspection before installation
In the installation process of air separation units, preparatory work and detailed inspection work constitute the key steps to ensure a smooth installation process. Such preparatory measures not only cover the assessment of site conditions, but also involve professional training of the equipment itself and the installation team. The thoroughness of site assessment and preparation are also crucial, covering geological surveys, site layout planning, and obtaining construction permits. The geological survey aims to confirm the firmness and load capacity of the foundation. For sites with poor geological conditions, reinforcement measures such as piling or replacement filling must be implemented. The assessment of the drainage conditions of the site is also indispensable to avoid water accumulation during the rainy season or other severe weather conditions that affect the installation and operation of the equipment. The site layout planning needs to reasonably arrange the placement of the air separation unit to ensure that there is sufficient operation and maintenance space between the equipment, away from flammable and explosive substances and strong vibration sources, reduce safety hazards, and consider the air intake and exhaust directions of the device to ensure unobstructed air circulation and improve the efficiency of the device. In addition, obtaining a construction permit ensures the legality of the construction and reduces possible subsequent legal risks, including the permits of the environmental protection department, safety supervision department and fire department, ensuring that all necessary approval procedures are complete. Equipment inspection and acceptance should not be ignored, including factory inspection, transportation and storage, and on-site inspection. Factory inspection ensures that the quality and performance of the equipment meet the design standards, involving appearance, function and pressure tests to confirm that the equipment is not damaged during transportation. During transportation and storage, protective measures must be taken to prevent damage to ensure the safety of equipment transportation and store it in a dry, ventilated and fireproof environment. Regular maintenance and inspection ensure that the equipment is in the best condition before installation. On-site inspection is a checkpoint when the equipment arrives, including appearance inspection, parts inventory and function testing to ensure that the equipment meets the installation requirements. If the equipment is found to be damaged or missing, the manufacturer should be contacted immediately for replacement or supplementation to ensure the integrity and availability of the equipment. Technical and safety training constitutes another key link in the installation preparation work, including technical operation training, safety knowledge education and the formulation and drill of emergency plans. Technical training ensures that operators and technicians fully understand the equipment structure, performance and operation methods. The content covers installation steps, commissioning technology and maintenance knowledge to improve installation and operation efficiency. Safety training ensures that all personnel involved in installation and operation have the necessary safety awareness and operation skills. The training content includes high-altitude operations, electrical safety, fire and explosion prevention, hazardous materials handling, etc., to reduce the occurrence of safety accidents. The formulation and drill of emergency plans are an important part of safety preparation work, including response measures for common accidents such as equipment failure, gas source leakage, fire and explosion, as well as emergency contact and evacuation plans, to ensure that effective measures can be taken quickly in the event of an accident to protect the life safety of personnel and the integrity of equipment.
Key points of equipment foundation construction
The installation of air separation units is crucial to the equipment foundation, which is directly related to the stability of the unit and the expected service life. In all aspects of foundation construction, it is necessary to abide by the established specifications and standards to ensure the quality of its construction and the safety and reliability of the construction process. Before construction, a detailed load estimate must be made to ensure that the foundation has the performance required to fully bear the equipment. The equipment load calculation must not only consider its static weight, but also pay attention to the dynamic load when the equipment is in operation. This is a key measure to prevent the foundation from settling or cracking during the operation of the equipment. In the foundation construction process, material selection is a crucial link. Among them, the selection of high-quality foundation materials such as steel bars and concrete plays a decisive role in ensuring the durability and stability of the foundation. The material review of the concrete to be poured is carried out to ensure the quality of the foundation construction and strictly prevent quality risks caused by the use of non-standard materials. In the foundation construction process, the accurate execution of the design drawings is crucial. The drawings must record the specific location, scale, elevation and other relevant data of the foundation in detail so that the construction personnel can follow the design specifications for construction to avoid potential deviations and errors. In the initial stage of concrete pouring, its composition ratio and pouring rate must be strictly controlled to maintain its structural density and mechanical properties. After the pouring operation is completed, thorough maintenance measures must be implemented to ensure that the concrete is fully hardened and reaches the predetermined design strength standard. After the foundation construction is successfully completed, the foundation must be fully inspected, covering aspects such as flatness, elevation and bearing capacity to ensure that it meets the standard requirements for installation. When the foundation inspection fails to meet the standards, repair and adjustment measures must be implemented immediately to prevent adverse effects on subsequent equipment installation operations. Before carrying out foundation construction, environmental preparation is crucial. The surrounding environment must be thoroughly cleaned to keep the foundation area clean and free of obstacles to facilitate the smooth installation and maintenance of subsequent equipment.
Equipment installation and connection
The equipment installation and connection of the air separation unit is the core part of the entire installation process and must be carried out in strict accordance with the design requirements and operating procedures. The installation of the equipment first requires the positioning and adjustment of the equipment to ensure that the installation position and direction of the equipment meet the design requirements. During the installation process, accurate measuring tools such as level meters, laser rangefinders, etc. should be used to ensure the installation accuracy of the equipment. The fixing of the equipment is a key step in the installation. High-strength anchor bolts and fixings must be used to ensure that the equipment will not shake or move during operation. The selection of fixings should take into account the weight of the equipment and the operating environment to ensure that the material and specifications of the fixings meet the requirements. After the installation is completed, the equipment should be initially debugged to check the installation of the equipment and ensure that all parts are firmly connected and leak-free. During the equipment installation process, the pipeline connection link is crucial, and its connection form and materials must meet the established design specifications. Before the pipeline connection operation is implemented, the pipeline must be thoroughly cleaned and carefully inspected to ensure that there is no debris inside the pipeline and no damage. During the construction stage of the pipeline system, appropriate connection components such as flanges and bolts must be selected to ensure the sealing performance and stability of the pipeline connection. After completing the pipeline connection process, the pressure detection procedure must be implemented to verify the airtightness and firmness of the pipeline, thereby ensuring that the pipeline is leak-free and damaged.
During the equipment installation process, the electrical connection link plays a key role. The correct and safe connection of its lines is an indispensable guarantee. Before implementing the electrical connection, the lines must be thoroughly inspected and verified to eliminate the risk of damage and short circuit. In the connection operation of the electrical line, materials with fireproof and explosion-proof properties must be selected to ensure the safety and stability of the line. After the electrical system is properly connected, the insulation detection and grounding detection procedures must be performed to ensure its safety and stability.
Degreasing construction
In the key steps of air separation unit installation, degreasing plays a decisive role, ensuring the complete removal of grease inside the equipment, ensuring the efficient operation of the equipment in a pure environment, and avoiding corrosion and safety threats caused by oil pollution. The oil content of the organic solvent used must be strictly controlled. Only solvents with an oil content of no more than 50 mg/L can be used for fine degreasing, while solvents with an oil content of 50~350 mg/L can only be used for rough degreasing. Any solvent with an oil content of more than 350 mg/L is not advisable. Degreasing operations should be carried out after the pressure test is completed and the equipment components are normal to prevent leakage problems caused by improper early treatment. In the face of equipment with complex structures or dead corners, special measures need to be taken, such as disassembly or use of professional tools, to ensure that the degreasing agent can evenly cover all surfaces and thoroughly remove deep oil stains. It is particularly important to emphasize that when using highly toxic degreasing agents such as dichloroethane, trichloroethylene or tetrachloroethylene, it is necessary to ensure that there is no moisture in the equipment and avoid contact with water before and after degreasing and before the solvent is completely volatilized, because these solvents may decompose when exposed to moisture under ultraviolet light or heating, producing toxic phosgene and corrosive hydrochloric acid fumes, which not only damage the equipment, but also may cause safety hazards, such as increased pressure in the equipment or pipeline, and may even cause cracking or explosion. Degreasing operations should be carried out outdoors or in well-ventilated rooms, and protective facilities such as wind and sand, rain, snow and sunlight should be set up to ensure the safety of operators.
Conclusion
In summary, as an indispensable key equipment in modern industry and medical fields, the efficient and stable operation of air separation units is directly related to production efficiency and safety. The research in this paper not only provides practical operation guidelines for engineers and technicians in related fields, but also provides strong support for the sustainable development of enterprises. It is hoped that the discussion in this article will further promote the application and development of air separation unit technology and contribute to the progress of the industrial and medical fields. In the future, with the continuous advancement of technology and the increase in application needs, the installation and layout of air separation units will face more new challenges and opportunities. We look forward to constantly summarizing experience in practice, optimizing the installation process, improving the performance and safety of the unit, and injecting new impetus into the sustainable development of the industry.
