Gas blanketing for storage tanks is an essential safety protection process widely applied in chemical industry, oil storage and transportation, pharmaceutical raw material storage, fine chemical and other fields. By continuously filling inert nitrogen into the top gas space of storage tanks, it isolates oxygen, water vapor and volatile flammable gas in ambient air, effectively avoiding four major hidden risks including material oxidation and deterioration, formation of flammable and explosive mixed gas, tank negative pressure collapse and overpressure gas leakage. Most conventional supporting nitrogen generation equipment suffers from common process defects such as fragmented gas supply links, no linkage feedback between front and rear processes, delayed gas supply pressure response, pipeline breakpoint pressure relief, and asynchronous operation between terminal tank pressure and main unit. The front-end nitrogen generator runs with constant gas output while the rear-end tank gas consumption fluctuates dynamically, failing to form a closed-loop linkage for the whole gas supply process. This will easily cause excessive nitrogen exhaust waste under high tank pressure, untimely nitrogen replenishment under low tank pressure, and fluctuating nitrogen purity that damages the inert blanketing atmosphere. It not only increases nitrogen gas consumption cost, but also brings potential safety hazards to tank operation. The nitrogen gas generator for gas blanketing is specially equipped with a six-seamless full closed-loop gas supply linkage process, covering raw air intake, gradient purification, nitrogen-oxygen separation, pressure stabilization buffering, terminal pressure regulation and reverse tank pressure signal feedback. It builds an integrated linkage process without breakpoints, response delay and pressure relief loss from the air inlet to the tank terminal. Customized for intermittent and dynamic variable-pressure gas consumption characteristics of tank blanketing, it enables automatic matching of main unit gas output following tank pressure and adaptive operation of the whole gas supply link, perfectly meeting unattended 24/7 nitrogen blanketing working conditions for all kinds of atmospheric pressure and low-pressure bearing storage tanks.

　　1. Atmospheric air raw material intake link: stable air source input to support overall process operation. The whole closed-loop gas supply system adopts normal-pressure ambient air as the only raw material without external liquid nitrogen gas source or additional industrial gas supply. Equipped with low-noise air intake hood and quantitative air intake regulating valve, the first standardized air intake link is formed. Different from disordered air intake and fluctuating intake flow of ordinary nitrogen generators, this link is fitted with front-end flow sensing modules to collect real-time gas load data of the whole rear gas supply link and automatically match air intake flow, keeping intake volume precisely consistent with rear nitrogen consumption. Meanwhile, a primary dust filter component is built in the air inlet to intercept dust, catkins and solid particles in ambient air and prevent impurities from entering rear pipelines to wear valves and molecular sieve media. The whole air intake link operates in fully closed negative pressure mode to avoid external air leakage and mixing inside the system. It guarantees raw air purity from the input terminal, prevents front-end air intake interference with subsequent processes, provides stable, clean and flow-matched basic air source for the whole closed-loop process, and ensures synchronous and orderly operation of all subsequent process links.

　　2. Compression and gradient air pre-purification link: preventing core medium damage and stabilizing rear separation process. Untreated atmospheric air cannot be directly used for nitrogen-oxygen separation. The second link completes dual processes including air pressurization and deep purification, acting as a key transition connecting the intake link and core nitrogen generation link. Firstly, the variable-frequency compression unit boosts normal-pressure air linearly to the standard working pressure for tank blanketing with buffered pressure rise and fall, avoiding instantaneous high-pressure air impact and pulse airflow damage to subsequent pipeline stability. Then compressed air passes through three sequential purification units including refrigerated drying link, activated carbon oil removal link and three-stage precision filtration link to form a gradient progressive purification process. The integrated purification links operate synchronously to remove liquid moisture, oil mist and fine dust impurities in compressed air sequentially, stabilizing air pressure dew point below -45℃ and controlling inlet air oil content lower than 0.01ppm. Compared with segmented independent purification equipment, the integrated serial purification link has no pipeline transfer breakpoints and no intermediate air pressure loss, improving purification efficiency by 28%. It thoroughly prevents oil and moisture from entering adsorption towers and causing molecular sieve poisoning failure, protecting the long-term stable operation of the middle core nitrogen generation link.

　　3. Dual-tower PSA alternating nitrogen-oxygen separation core link: uninterrupted continuous gas production to meet 24/7 tank blanketing demand. As the core hub of the whole technological process, the dual-tower pressure swing adsorption separation link directly determines nitrogen purity and gas supply continuity, fully adapting to year-round uninterrupted inert protection demand of storage tanks. Two adsorption towers work alternately in four strict cyclic processes: pressure adsorption, pressure equalization energy storage, pressure relief desorption and countercurrent purging. The PLC electronic control system controls solenoid valve switching sequence within milliseconds for seamless tower switching without gas production interruption or gas supply pressure breakpoint. Customized for special tank blanketing working conditions, this link locks stable nitrogen purity ranging from 99.5% to 99.9%, meeting basic inert protection requirements of explosion prevention and oxidation resistance for storage tanks while avoiding invalid energy waste caused by ultra-high purity nitrogen. In addition, the optimized tower pressure equalization recovery link recycles residual pressure energy during pressure relief process, reducing overall energy consumption of the gas supply system. It achieves a comprehensive power saving rate of 22% compared with ordinary nitrogen generation links without energy recovery, ensuring uninterrupted gas production and lower overall operation power consumption.

　　4. Nitrogen pressure stabilization and buffer energy storage link: eliminating airflow pulse and balancing pressure difference between front and rear links. Nitrogen produced by the main unit carries tiny airflow pulse and pressure fluctuation, which will cause frequent small oscillation of tank internal pressure and disturb blanketing pressure balance if directly delivered to storage tanks. The fourth buffer energy storage link is equipped with a large-capacity nitrogen buffer tank to receive nitrogen from the front separation link, store redundant nitrogen and eliminate airflow pulse fluctuation. It balances the pressure difference between front-end gas production and rear-end dynamic gas consumption. The system automatically stores surplus nitrogen during off-peak gas consumption and releases reserved nitrogen rapidly to fill gas supply gap during peak gas demand and rapid tank pressure replenishment. This link effectively isolates gas production fluctuation of the front main unit and gas consumption fluctuation of rear storage tanks, avoiding mutual pressure interference between front and rear processes and ensuring constant and stable nitrogen pressure delivered to terminal tanks.

　　5. Terminal nitrogen blanketing precision pressure regulation delivery link: matching tank micro-pressure standard and controlling tank top gas pressure accurately. Tank blanketing requires extremely strict pressure control, with standard working micro positive pressure maintained at only 50-200mbar. Excessively high pressure will lead to direct nitrogen exhaust and gas waste, while excessively low pressure will cause reverse air penetration and complete blanketing failure. The fifth terminal dedicated pressure regulation delivery link is equipped with special micro-pressure regulating valves, high-precision pressure transmitters and current-limiting pressure stabilization components for tank blanketing, reducing high-pressure pipeline nitrogen to match micro-positive pressure requirements of storage tanks accurately. It regulates real-time nitrogen outlet flow and pressure, controlling nitrogen pressure error delivered into tanks within ±2mbar. Meanwhile, a one-way check pipeline link is equipped to completely prevent reverse flow of volatile materials and mixed gas inside storage tanks back to the nitrogen generator main unit, protecting the whole nitrogen generation system reversely and avoiding internal pipeline and valve corrosion caused by tank exhaust gas.

　　6. Tank pressure reverse signal feedback closed-loop link: realizing full-link intelligent linkage and on-demand gas production automatically. Different from open-loop unidirectional gas supply systems without reverse feedback on the market, thisnitrogen gas generator for gas blanketing adopts an exclusive rear-end tank pressure reverse feedback intelligent link to realize full-process closed-loop automatic control. Pressure sensors installed inside terminal tanks collect real-time top gas pressure data and transmit signals back to the front main control system in real time, building a bidirectional signal feedback loop from storage tank to nitrogen generator main unit. When tank liquid level drops during material discharging and tank pressure decreases, the feedback link sends gas replenishment instructions automatically, and the main unit improves gas output flow rapidly to restore standard tank pressure. When tank liquid level rises during material feeding and tank pressure exceeds threshold, the feedback link commands the main unit to reduce operating load and enter low-power standby mode to stop redundant nitrogen production. The whole gas supply link operates bidirectionally with automatic gas output adjustment following real-time tank pressure changes, eliminating invalid gas production and nitrogen exhaust waste completely and realizing unattended adaptive on-demand gas supply.

　　Comprehensive advantages of integrated closed-loop links: Traditional nitrogen generation equipment for tank blanketing adopts open-loop unidirectional gas supply links with independent processes and no signal intercommunication among six working procedures. The main unit always operates at full load, resulting in extremely high annual invalid loss of nitrogen and electricity. Besides, delayed pressure response may trigger potential tank safety risks. Supported by seamlessly connected six processes and bidirectional signal feedback closed-loop links, this dedicated nitrogen gas generator realizes integrated linkage covering air intake, purification, gas production, buffering, pressure regulation and signal feedback. The whole process has no transfer breakpoints, no air pressure loss and no signal delay. It improves tank pressure response speed by 85%, reduces overall nitrogen loss by 36%, and cuts annual unplanned equipment downtime by 90%. Suitable for diversified blanketing scenarios including chemical anti-corrosion, oil explosion prevention, pharmaceutical raw material isolation and sewage tank sealing, this closed-loop linkage gas supply process requires no manual pressure and flow adjustment, automatically adapting to dynamic tank gas demand 24/7. It provides safe, energy-saving, zero-delay and zero-waste professional inert gas supply solutions for industrial storage tanks relying on complete closed-loop technological links.