A method and system for rapid circulation mechanical nitrogen filling for closed room atmosphere insect prevention

Abstract

This invention belongs to the field of circulating mechanical nitrogen-filled modified atmosphere insect control technology. It discloses a rapid circulating mechanical nitrogen-filling system for modified atmosphere insect control in sealed warehouses. The system is characterized by: using a vacuum pressure rotary adsorption nitrogen generator connected to a sealed warehouse containing stored materials to construct a closed-loop rapid circulating mechanical nitrogen-filling system; using zeolite molecular sieves as adsorbents to fill the adsorption tower in the nitrogen generator; using a dry vacuum pump to desorb and mechanically heat the nitrogen and water molecules adsorbed in the adsorption tower before directly pumping them into the sealed warehouse; and intermittently extracting and reintroducing a portion of high-temperature product gas into the adsorption tower for "forward thermal purging purification," forming a comprehensive effect supported by "temperature difference effect, humidity effect, and thermal purging purification." This results in multiple benefits, including separation of nitrogen and oxygen in the raw material gas, heating of the product gas, delivery of the heated product gas, stable humidity during circulating mechanical nitrogen filling, improved purity of output nitrogen, and accelerated nitrogen penetration and diffusion.

Description

Technical Field

[0001] This invention belongs to the field of circulating mechanical nitrogen filling technology, specifically relating to a rapid circulating mechanical nitrogen filling method and system for controlled atmosphere insect control in sealed warehouses. Background Technology

[0002] Circulating mechanical nitrogen-filled modified atmosphere storage technology is widely used in enclosed spaces or warehouses that are prone to insect and mold growth, such as storage of grain, feed, tobacco, Chinese medicinal materials, books, archives, cultural relics, clothing, ship cabins, engine rooms, and carriages. The equipment used in this technology mainly includes PSA pressure swing adsorption nitrogen generators, vacuum pressure rotary adsorption nitrogen generators, and membrane separation nitrogen generators. Among these, the vacuum pressure rotary adsorption nitrogen generator is the best match for the circulating mechanical nitrogen filling system under closed-loop conditions.

[0003] The vacuum pressure rotary adsorption nitrogen generator adopts an "atmospheric pressure adsorption + vacuum desorption" operation mode. The system relies on a closed or semi-closed circulating gas extraction mode interconnected with a sealed controlled atmosphere chamber. An atmospheric pressure fan extracts gas and feeds it into the adsorption tower for nitrogen and oxygen separation. Carbon molecular sieves are typically used to adsorb oxygen from the air. A fan serves as the power device for gas extraction and transportation, while a vacuum pump desorbs and removes the oxygen molecules adsorbed by the carbon molecular sieves, discharging the extracted oxygen components. In other words, the process of "fan extraction and transportation of gas into a sealed space into the adsorption tower + carbon molecular sieve adsorption of oxygen + vacuum desorption of oxygen and subsequent venting" achieves the separation of nitrogen and oxygen in the raw gas. The vacuum pressure rotary adsorption nitrogen generator typically uses two sets of adsorption towers connected in parallel. The control program continuously performs atmospheric pressure adsorption, pressure equalization, vacuum desorption, and backflushing regeneration on the carbon molecular sieves according to process requirements to complete nitrogen-oxygen separation and obtain the desired nitrogen-rich gas. The two sets of adsorption towers of the equipment adopt an alternating operation mode of "one tower adsorption + one tower desorption". That is, one set of adsorption towers is used for atmospheric pressure adsorption, and the other set of adsorption towers is used for vacuum desorption. After the process steps are completed, the set of adsorption towers that are used for atmospheric pressure adsorption is switched to vacuum desorption, and so on, alternating continuously.

[0004] The adsorption and desorption process of the vacuum pressure rotary adsorption nitrogen generator includes: First, the fan in the equipment system extracts the air from the sealed chamber as the raw gas for the nitrogen generator. The raw gas enters the adsorption tower through the air inlet valve and the suction valve. The oxygen molecules in the raw gas are adsorbed by the carbon molecular sieve, while the unadsorbed nitrogen molecules are returned to the sealed chamber through the carbon molecular sieve adsorption bed, the exhaust valve, the nitrogen flow control valve, and the gas flow pipeline. At the same time, the vacuum pump performs vacuum desorption on the adsorption tower (which is called the desorption tower at this time) that has adsorbed oxygen. At this time, the oxygen on the carbon molecular sieve in the desorption tower is desorbed by vacuum and discharged into the atmosphere from the exhaust port of the vacuum pump. The entire process generally lasts for tens of seconds. Afterwards, the pressure equalization mode is entered. The upper and lower pressure equalization valves connect the adsorption tower and the desorption tower that has completed vacuum desorption to maintain the pressure balance in the two towers. This lasts for 2-3 seconds. In order to make the release of oxygen from the carbon molecular sieve in the adsorption tower more thorough, some of the nitrogen produced after atmospheric pressure adsorption is purged into the desorption tower through the back purge valve under the negative pressure formed by vacuum desorption. This process blows the oxygen components out of the adsorption tower. This process generally lasts for 1-5 seconds. The above two major steps are repeated alternately. The two sets of adsorption towers continuously alternate as adsorption towers and desorption towers, and continue to cycle to perform the system function.

[0005] Whether it's a PSA pressure swing adsorption nitrogen generator, a membrane nitrogen generator system, or a vacuum pressure rotary adsorption nitrogen generator, although they can all produce high concentrations of nitrogen, when applied to controlled atmosphere storage in closed warehouses for pest control, they all face the challenge of the high density and small porosity of stored agricultural products (mainly boxed tobacco leaves, bulk or bagged grains), resulting in a slow process of nitrogen penetration and diffusion into the stored goods. Nitrogen filling for pest control generally takes at least a month or even longer to complete. For stored goods with fast production pace and difficulty in guaranteeing the sealing period, conventional nitrogen filling controlled atmosphere technology cannot meet the needs of actual production. Maintaining a high concentration of nitrogen for a long time requires continuous operation of the equipment system, resulting in high energy consumption and significant pressure on system process control.

[0006] In addition, due to the inherent limitations of the carbon molecular sieve and membrane separator in the PSA pressure swing adsorption nitrogen generator, membrane nitrogen generator operating system, and traditional vacuum pressure rotary adsorption nitrogen generator, the raw gas must undergo a drying and purification pretreatment process during separation. While producing nitrogen, the equipment system also adsorbs and removes moisture, carbon dioxide, and other substances from the raw gas. This is not conducive to maintaining the moisture content of stored agricultural products (affecting their natural quality under stable moisture conditions) and the stability of environmental humidity. It increases the consumption of adsorbent and electricity during equipment operation and also hinders the diffusion and infiltration of high-concentration nitrogen into the gaps of the stored agricultural products.

[0007] To improve the efficiency of mechanical nitrogen-filled gas regulation for pest control and shorten the pest control time, most of the existing publicly available technologies revolve around the mixed application of carbon dioxide and nitrogen and propose corresponding equipment processes and configuration methods. The common problem with these technologies is that the cost of large-scale application of carbon dioxide is high, which also directly affects the achievement of the goal of "carbon peaking and carbon neutrality".

[0008] Other publicly disclosed methods utilize low-oxygen or heating technologies or devices to increase the speed of nitrogen-filled insecticide application:

[0009] 1) Patent CN 213756415 U employs a combination of high temperature, insecticides, and insect-attracting lamps for pest control. High temperatures are achieved through heating pipes, avoiding the potential fire hazards associated with electric heating or other heating devices, which could cause unnecessary damage to the grain silo. The air inlet pipe is located inside the outlet pipe, saving space and increasing the airflow, allowing for better removal of pests by the exhaust fan. Insecticides are contained in a pressure tank at the bottom of the outlet pipe, killing or reducing the activity of pests and facilitating their removal. A super-slippery coating is applied to the inner and outer walls of the outlet and exhaust pipes to reduce insect adhesion, making it easier for the exhaust fan to remove pests. Insect-attracting lamps effectively lure pests into the outlet pipe. However, this patent still carries the risk of contaminating agricultural products with insecticides. Furthermore, relying solely on insect-attracting lamps is insufficient for the rapid and complete eradication of pests in agricultural products, and it is also ineffective in controlling the main stage of pests—larvae.

[0010] 2) Patent CN 213695389 U addresses the inconvenience of high-temperature insect killing of tobacco by installing a heating device inside the canister; it also addresses the inconvenience of deoxygenation for insect killing by using a vacuum pump to evacuate the canister. However, this patent has a very limited processing capacity per cycle and low deoxygenation efficiency. The vacuum pump process is a cooling process, and the combination of this patent and the heating device configuration results in mutual reduction of process efficiency and high energy consumption.

[0011] 3) Chinese patent CN 111838094 A employs a combination of active and passive oxygen reduction. It uses active nitrogen filling to rapidly lower the oxygen content within the airtight enclosure, followed by passive oxygen reduction using an oxygen scavenger to maintain a low-oxygen state in the airtight enclosure for an extended period, thus achieving the goal of low-oxygen pest control. However, this combined nitrogen filling and oxygen scavenging method suffers from high overall oxygen reduction costs, inconvenient operation, and issues related to the disposal and discharge of oxygen scavenger waste. Furthermore, relying solely on high-purity nitrogen for pest control makes it difficult to significantly shorten the pest control time cycle.

[0012] 4) In their study, "Study on the Lethal Effect and Time of Nitrogen-Induced Hypoxia at Different Temperatures on Various Stages of the Red Flour Beetle," Li Shuangyu et al. summarized that at a nitrogen gas integral of 98%, the delay time for 100% lethality at a low temperature of 18℃ compared to a near-low temperature of 23℃ was 4 days for eggs, 4 days for larvae, 6 days for pupae, and 4 days for adults; at a low temperature of 18℃ and a normal temperature of 28℃, the delay time for 100% lethality was 12 days for eggs, 8 days for larvae, 8 days for pupae, and 4 days for adults. This conclusion suggests that high temperatures are beneficial for shortening the time required for nitrogen-induced controlled atmosphere (MEA) insecticidal treatment. However, this approach relies on increasing the temperature of the pest's living environment and breeding grounds to enhance the pest's respiration intensity and periodic diffusion rate. This temperature increase can only be achieved under the premise of comprehensively improving the temperature of the storage environment and the internal stored materials, which contradicts the environmental protection concept of energy conservation and carbon reduction. Summary of the Invention

[0013] To address the technical problems existing in the prior art, the present invention aims to provide a rapid circulating mechanical nitrogen filling method and system for controlled atmosphere storage and insect control in sealed chambers. The innovative breakthrough focuses on increasing the diffusion and penetration speed of input nitrogen in the chamber. Zeolite molecular sieves are used as adsorbents to fill the adsorption tower in a vacuum pressure rotary adsorption nitrogen generator. Simultaneously, a dry vacuum pump desorbs the nitrogen and water molecules adsorbed in the adsorption tower and directly pumps them into the sealed chamber, forming a system of "dry vacuum pump + zeolite molecular sieve adsorption tower + vacuum pump direct discharge pump". The nitrogen production process of "sending nitrogen to the warehouse" is a mode of mechanically heating the output gas. At this time, the nitrogen and water molecules in the raw gas are adsorbed by the zeolite molecular sieve layer and desorbed by the dry vacuum pump to form a mixed product gas of nitrogen and water molecules. The mixed product gas achieves a temperature increase of up to 20-80°C in the high temperature chamber of the dry vacuum pump and is directly pumped to the sealed warehouse by the dry vacuum pump. As a result, a temperature difference effect of "output nitrogen gas flow temperature > existing normal temperature of agricultural products and their packaging in the sealed warehouse" can be formed.

[0014] The combination of "dry vacuum pump + zeolite molecular sieve adsorption tower" also maintains the existing environmental humidity inside the sealed chamber. The mixed product gas nitrogen with no decrease in humidity or moisture content is more conducive to its rapid diffusion from the high temperature area to the low temperature area when it is input into the sealed chamber.

[0015] When the rapid circulation mechanical nitrogen filling system is started, it uses the negative pressure at the air inlet of its fan to intermittently draw back a portion of the high-temperature nitrogen output from the dry vacuum pump and re-enter the adsorption tower. According to the programmed control, during the intervals when the adsorption tower switches between atmospheric pressure adsorption and vacuum desorption modes, a high-temperature nitrogen "positive thermal purging purification" nitrogen production process is executed, forming an efficient purging, desorption and displacement effect on the residual oxygen in the zeolite molecular sieve adsorption layer.

[0016] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a rapid circulating mechanical nitrogen filling method for controlled atmosphere insect control in a sealed chamber. First, a vacuum pressure rotary adsorption nitrogen generator A is used as the nitrogen filling device in the rapid circulating mechanical nitrogen filling system. The raw material gas inlet A1 of the vacuum pressure rotary adsorption nitrogen generator A is connected to one end of the sealed chamber 1 through the raw material gas extraction pipe L1. The product gas outlet A6 of the vacuum pressure rotary adsorption nitrogen generator A is connected to the other end of the sealed chamber 1 through the product gas transmission pipe L2, thus constructing a rapid circulating mechanical nitrogen filling system that can be used for controlled atmosphere insect control and closed circulation.

[0017] In the rapid circulation mechanical nitrogen charging system, a fresh air duct L3 for replenishing fresh air is connected to the raw material gas extraction duct L1 of the vacuum pressure rotary adsorption nitrogen generator A. When the rapid circulation mechanical nitrogen charging system continuously separates and removes oxygen from the raw material gas, resulting in a decrease in the internal gas pressure of the system duct and thus affecting the stability of the rapid circulation mechanical nitrogen charging system, the control valve installed on the fresh air duct L3 will automatically open according to the programmed procedure and electrical signal to draw gas from the external environment to replenish the gas and maintain the pressure balance inside and outside the rapid circulation mechanical nitrogen charging system.

[0018] The vacuum pressure rotary adsorption nitrogen generator A includes a blower A2, an adsorption tower A3, and a dry vacuum pump A5. The input end of the blower A2 is the raw material gas inlet A1, and the output end of the dry vacuum pump A5 is the product gas outlet A6. The adsorption tower A3 is equipped with an oxygen outlet A4 for discharging oxygen generated during the separation of raw material gas. The outlet of the blower A2 is connected to the raw material gas inlet of the adsorption tower through a connecting pipe L11. The exhaust port of the dry vacuum pump A5, which performs vacuum desorption in the adsorption tower, is connected to the outlet of the adsorption tower during vacuum desorption through a connecting pipe L22. The end outlet of the raw material gas entering the adsorption tower is connected to the oxygen outlet A4 of the adsorption tower through a connecting pipe L33. Control valves are installed on the above-mentioned raw material gas exhaust pipe L1, product gas transmission pipe L2, and fresh air pipe L3.

[0019] Furthermore, in the rapid circulating mechanical nitrogen filling system, the raw gas inlet of the adsorption tower and the outlet of the adsorption tower during vacuum desorption are both located at the same end of the adsorption tower. They can be set independently or share a port (i.e., the raw gas inlet and the outlet during vacuum desorption are the same port connected to a three-way pipe). When the same adsorption tower is used in the operating mode, when this port is connected to the exhaust port of the vacuum pump A5 through the connecting pipe L22 and performs the function of vacuum desorption of nitrogen and water molecules in the adsorption layer of the adsorption tower, the raw gas inlet of the adsorption tower actually becomes the outlet channel of the mixed product gas.

[0020] Zeolite molecular sieves are used as adsorbents to fill the adsorption tower A3 in the vacuum pressure rotary adsorption nitrogen generator A, performing the function of adsorbing and separating nitrogen, oxygen, and water molecules in the raw gas entering the adsorption tower. Zeolite molecular sieves are crystalline microporous materials with unique molecular-size channels and three-dimensional frameworks, which allow zeolite to separate and sieve nitrogen, oxygen, and water molecules in the air according to the size or geometry of the molecules. A dry vacuum pump A5 is used to desorb the nitrogen and water molecules adsorbed in the adsorption tower and directly pump the desorbed gas into the sealed chamber 1, forming a new process combination mode of "zeolite molecular sieve adsorption tower + dry vacuum pump + vacuum pump direct pumping of nitrogen into the sealed chamber" in the vacuum pressure rotary adsorption nitrogen generator, which also has the effect of mechanically heating the output gas.

[0021] When the vacuum pressure rotary adsorption nitrogen generator A in the rapid circulating mechanical nitrogen filling system is started, under the control of the programmed program, the blower A2 in the vacuum pressure rotary adsorption nitrogen generator A extracts the gas from the sealed chamber 1 as raw material gas through the raw material gas extraction pipe L1 and inputs it into the adsorption tower A3 filled with zeolite molecular sieves through the connecting pipe L11. During the process of the raw material gas passing through the zeolite molecular sieve layer, the nitrogen and water molecules in it are adsorbed by the zeolite molecular sieve layer, while the oxygen component in the raw material gas is removed by passing through the packing layer of the adsorption tower A3 and the oxygen discharge port A4 of the adsorption tower. The control valve on the connecting pipe through which the above airflow flows is opened, and the control valves on other connecting pipes are closed. After completing the adsorption step of nitrogen and water molecules in the raw material gas, the vacuum pressure rotary adsorption nitrogen generator A continues to start the adsorption of the gas in the adsorption tower A3. The attached process involves a vacuum desorption process for nitrogen and water molecules. Dry vacuum pump A5 desorbs nitrogen and water molecules from the adsorption layer of the adsorption tower via connecting pipe L22, forming a mixed product gas of nitrogen and water molecules. This mixed product gas experiences a temperature increase of 20-80°C during its passage through the high-temperature chamber of dry vacuum pump A5 and is then input into the sealed chamber 1 via product gas outlet A6 and product gas delivery pipe L2. The control valve of the connecting pipe automatically opens, creating a temperature difference effect where the output nitrogen gas temperature is greater than the existing temperature of the agricultural products and their packaging in the sealed chamber. Simultaneously, it creates a moisturizing effect where water molecules in the raw material gas are not adsorbed during the deoxygenation process of the vacuum pressure rotary adsorption nitrogen generator A, and the existing humidity in the sealed chamber 1 is maintained.

[0022] According to the above technical solution, the adsorption tower A3 in the rapid circulating mechanical nitrogen filling system uses at least two adsorption towers connected in parallel to form an adsorption tower group, so as to perform "one tower adsorption + another tower desorption" and a switchable alternating operation mode; the adsorption tower group includes adsorption tower A3-1 and adsorption tower A3-2. At this time, two branch pipes are branched from the connecting pipe L11 leading out of the air outlet of the blower A2. One branch pipe L11-1 is connected to the raw material gas inlet of adsorption tower A3-1, and the other branch pipe L11-2 is connected to the raw material gas inlet of adsorption tower A3-2. Two branch pipes are branched from the connecting pipe L22 connected to the exhaust port of vacuum pump A5. One branch pipe L22-1 is connected to the exhaust port of adsorption tower A3-1 when it is evacuated and desorbed, and the other branch pipe L22-2 is connected to the exhaust port of adsorption tower A3-2 when it is evacuated and desorbed. The outlets of adsorption towers A3-1 and A3-2 during vacuum desorption and the inlet of the raw material gas output from blower A2 into adsorption towers A3-1 and A3-2 are located at the same end of the adsorption towers. The end outlet of the raw material gas after entering adsorption towers A3-1 and A3-2 is connected to the oxygen discharge port A4, which is used to discharge oxygen generated during the separation of raw material gas in the adsorption towers, through branch pipes L33-1 and L33-2, respectively. Control valves are installed on each of the above connecting pipes, branch pipes, and the exhaust port for discharging oxygen. In the vacuum pressure rotary adsorption nitrogen generator A, which uses zeolite molecular sieve as adsorbent, adsorption towers A3-1 and A3-2 are vacuum desorbed using a dry vacuum pump A5, and the desorbed gas is directly pumped to the sealed chamber 1.

[0023] When the rapid circulating mechanical nitrogen filling system is running, the adsorption towers A3-1 and A3-2 in the vacuum pressure rotary adsorption nitrogen generator A alternately adsorb and desorb nitrogen and water molecules in the raw gas. Under programmed control, the blower A2 in the vacuum pressure rotary adsorption nitrogen generator A extracts gas from the sealed chamber 1 through the raw gas extraction pipe L1 and feeds it into the adsorption tower A3-1, which is filled with zeolite molecular sieves, through the branch pipe L11-1. As the raw gas passes through the zeolite molecular sieve layer, the nitrogen and water molecules are adsorbed by the zeolite molecular sieve layer, while the oxygen in the raw gas passes through the packing layer and branch pipe of the adsorption tower A3-1. L33-1, the oxygen discharge port A4 of the adsorption tower is vented and removed; while the adsorption tower A3-1 completes the adsorption step of nitrogen and water molecules in the raw gas, the vacuum desorption process of nitrogen and water molecules adsorbed in the adsorption tower A3-2 is started simultaneously. At this time, the dry vacuum pump A5 desorbs nitrogen and water molecules in the adsorption layer of the adsorption tower A3-2 through the branch pipe L22-2 and forms a mixed product gas of nitrogen and water molecules. The mixed product gas achieves a temperature increase of up to 20-80°C in the high temperature chamber of the dry vacuum pump A5 and is input into the sealed chamber 1 through the product gas discharge port A6 and the product gas transmission pipeline L2.

[0024] According to the above technical solution, based on the program and electrical control signals of the rapid circulating mechanical nitrogen filling system, the control valves in the above-mentioned connecting pipes and branch pipes automatically open or close to ensure the synchronous operation of the two adsorption towers in the system, namely atmospheric pressure adsorption and vacuum desorption, and to ensure that the system's operating mode automatically and repeatedly alternates between "adsorption tower A3-1 adsorption + adsorption tower A3-2 desorption" and "adsorption tower A3-2 adsorption + adsorption tower A3-1 desorption".

[0025] According to the above technical solution, a "forward thermal purging purification" process is incorporated into the rapid circulating mechanical nitrogen filling system. A product gas return pipeline L4 with a control valve is connected between the raw material gas inlet A1 and the product gas delivery pipeline L2 in the vacuum pressure rotary adsorption nitrogen generator A. After the rapid circulating mechanical nitrogen filling system starts up and completes the adsorption steps of nitrogen and water molecules in the raw material gas by the adsorption tower A3-1 according to the control program, a "forward thermal purging purification" process is initiated on the adsorption layer of the adsorption tower A3-1, followed by a vacuum desorption process for the adsorbed nitrogen and water molecules in the adsorption tower A3-1. At this time, the adsorption tower A3-2 in the rapid circulating mechanical nitrogen filling system is still in the vacuum desorption process step. The process is then performed according to the requirements of the rapid circulating mechanical nitrogen filling system. The programmed program and electrical control signals automatically open the control valves on the product gas return pipeline L4, the air outlet of the blower, and the branch pipes L11-1, L33-1, and L22-2 connecting the adsorption tower A3-1. The blower A2 returns a portion of the mixed product gas formed during the vacuum desorption process of the dry vacuum pump A5 on the adsorption tower A3-2 to the adsorption tower A3-1 through the product gas return pipeline L4 and branch pipe L11-1. This portion of the mixed product gas, which is in a high-temperature state, returns to the adsorption tower A3-1 and effectively imparts heat energy to activate, desorb, and positively purge and replace the residual oxygen in the molecular sieve adsorption layer. The purged oxygen is removed by venting through branch pipe L33-1 and the oxygen discharge port A4 of the adsorption tower.

[0026] The high-temperature mixed product gas fed back into the adsorption tower A3-1 purges and replaces the residual oxygen in the molecular sieve adsorption layer. At the same time, most of the nitrogen and water molecules in the gas are re-adsorbed by the adsorption layer and then re-aggregate to form high-temperature mixed product gas when the adsorption tower A3-1 is alternately evacuated and desorbed. The gas is then fed into the sealed chamber 1 through the product gas outlet A6 and the product gas transmission pipeline L2.

[0027] According to the above technical solution, after the adsorption of nitrogen and water molecules in the raw gas by adsorption tower A3-1, the "forward thermal purging purification" and the vacuum desorption of the adsorbed nitrogen and water molecules by adsorption tower A3-2 are completed, the rapid circulation mechanical nitrogen filling system automatically switches to the adsorption of nitrogen and water molecules in the raw gas by adsorption tower A3-2, the "forward thermal purging purification" and the vacuum desorption of the adsorbed nitrogen and water molecules by adsorption tower A3-1 are completed according to the programmed control program. The above-mentioned high-temperature nitrogen "forward thermal purging purification" process improves the purity of the product gas, shortens the nitrogen filling and insecticidal time, and reduces the operating energy consumption of the circulation mechanical nitrogen filling and air conditioning insect control system.

[0028] According to the above technical solution, a product gas return pipeline L4 with a control valve is connected between the raw material gas inlet A1 and the product gas transmission pipeline L2 of the vacuum pressure rotary adsorption nitrogen generator A. The nitrogen output pipeline of the new nitrogen source B is connected to the product gas return pipeline L4 through a tee D, forming a new structural combination mode of "vacuum pressure rotary adsorption nitrogen generator A of zeolite molecular sieve + new nitrogen source B". When the rapid circulation mechanical nitrogen charging system is started, the adsorption tower A3-1 first completes the adsorption of nitrogen and water molecules in the raw material gas, and then the forward purging process is started. During this period, air is introduced into the blower A2. Under the negative pressure of the suction port, a portion of the nitrogen gas output from the new nitrogen source B flows through the product gas return pipeline L4 between the three-way valve D and the raw material gas inlet A1, and then flows through the blower A2 and branch pipe L11-1 into the adsorption tower A3-1 to purge and replace the oxygen molecules remaining in the zeolite molecular sieve layer. The oxygen that is purged and replaced is discharged through the oxygen discharge port A4 of the adsorption tower. The remaining nitrogen that does not participate in the purging and replacement enters the sealed chamber through the product gas return pipeline L4 between the three-way valve D and the product gas transmission pipeline L2, and the product gas transmission pipeline L2.

[0029] When the nitrogen flow from the new nitrogen source B is insufficient to meet the gas demand for forward purging of adsorption tower A3-1, blower A2 will simultaneously return a portion of the mixed product gas formed during the vacuum desorption process of adsorption tower A3-2 by dry vacuum pump A5 to adsorption tower A3-1 through product gas return pipeline L4 and branch pipe L11-1. This portion of the high-temperature mixed gas returned to adsorption tower A3-1, together with the nitrogen flow from nitrogen source B, effectively imparts heat energy to activate, desorb, and forward purge and replace the residual oxygen in the molecular sieve adsorption layer. During this period, the control valve on the pipeline through which the nitrogen flow from the new nitrogen source B passes will be opened.

[0030] According to the above technical solution, a product gas return pipeline L4 with a control valve is connected between the raw material gas inlet A1 and the product gas transmission pipeline L2 of the vacuum pressure rotary adsorption nitrogen generator A. The nitrogen output pipeline of the new nitrogen source B is connected to the product gas transmission pipeline L2 through a tee D, thus forming a new structural combination mode of "zeolite molecular sieve vacuum pressure rotary adsorption nitrogen generator A + new nitrogen source B". When the rapid circulation mechanical nitrogen filling system is started, the adsorption tower A3-1 first completes the adsorption of nitrogen and moisture in the raw material gas. After the adsorption of molecules, the forward purging process is started. During this period, the blower A2 will return a portion of the mixed product gas output by the dry vacuum pump A5 to the adsorption tower A3-1 through the product gas return pipeline L4 and the branch pipe L11-1. The high-temperature mixed gas returned to the adsorption tower A3-1 will effectively provide heat energy to activate, desorb and forward purge the oxygen remaining in the molecular sieve adsorption layer. The purged oxygen will be removed by venting through the branch pipe L33-1 and the oxygen discharge port A4 of the adsorption tower.

[0031] The nitrogen flow from the new nitrogen source B replaces the fresh air flow input through the fresh air duct L3, which is used for replenishing fresh air. It enters the sealed chamber through the tee D and the product gas transmission duct L2 to replenish the gas and maintain the pressure balance inside and outside the pipeline system. At the same time, when the mixed product gas output from the extraction dry vacuum pump A5 is insufficient to meet the gas demand for forward purging of the adsorption tower A3-1, a portion of the nitrogen flow from the new nitrogen source B is input into the adsorption tower A3-1 through the product gas transmission duct L2 between the tee D and the raw material gas inlet A1, the product gas return duct L4, and then through the blower A2 and the branch pipe L11-1 between the blower outlet and the adsorption tower. This is to perform the purging and replacement of residual oxygen molecules in the zeolite molecular sieve. At this time, the control valves on the connecting pipes and branch pipes through which the above-mentioned gas flow passes are opened, while the control valves on other connecting pipes and branch pipes are closed.

[0032] According to the above technical solution, a product gas return pipeline L4 with a control valve is connected between the raw material gas inlet A1 and the product gas transmission pipeline L2 of the nitrogen generator in the rapid circulation mechanical nitrogen filling system. A new nitrogen source B is connected to the raw material gas inlet A1 of the blower A2 through the fresh air pipeline L3 to form a new structural combination mode of "zeolite molecular sieve vacuum pressure rotary adsorption nitrogen generator A + new nitrogen source B".

[0033] The rapid circulating mechanical nitrogen charging system is started and running. Under the control of the programmed procedure, the adsorption tower A3-1 in the rapid circulating mechanical nitrogen charging system first completes the adsorption of nitrogen and water molecules in the raw gas. Then, the forward purging process is started. At this time, a portion of the nitrogen gas output from the new nitrogen source B is input into the adsorption tower A3-1 through the fresh air duct L3 and the fan A2 to purge and replace the residual oxygen molecules in the zeolite molecular sieve. The purged oxygen is removed by venting through the oxygen discharge port A4 of the adsorption tower. The remaining nitrogen gas output from the new nitrogen source B, which does not participate in the purging and replacement of the residual oxygen molecules in the zeolite molecular sieve, is then discharged through the fresh air duct L3 and the product gas... The return pipeline L4 and the product gas pipeline L2 enter the sealed chamber to participate in controlled atmosphere pest control. When the nitrogen flow output from the new nitrogen source B cannot meet the gas demand for forward purging of the adsorption tower A3-1, the blower A2 will return a portion of the mixed product gas formed during the vacuum desorption process of the dry vacuum pump A5 on the adsorption tower A3-2 to the adsorption tower A3-1 through the product gas return pipeline L4 and the branch pipe L11-1. This portion of the high-temperature mixed gas returned to the adsorption tower A3-1 will effectively impart heat energy to activate, desorb, and forward purge and replace the residual oxygen in the molecular sieve adsorption layer. At this time, the nitrogen flow output from the new nitrogen source B will be opened through the control valve on the pipeline.

[0034] According to the above technical solution, a new nitrogen source B's nitrogen output pipeline is connected to the rapid circulating mechanical nitrogen charging system, forming a new structural combination mode of "zeolite molecular sieve vacuum pressure rotary adsorption nitrogen generator A + new nitrogen source B". In the rapid circulating mechanical nitrogen charging system, adsorption tower A3-1 adsorbs nitrogen and water molecules from the raw gas and then performs a forward purging process. Meanwhile, adsorption tower A3-2 in the rapid circulating mechanical nitrogen charging system is in the vacuum desorption process step. Under the control of the programmed procedure, the rapid circulating mechanical nitrogen charging... The system operates alternately in the "one tower adsorption + another tower desorption" and switchable modes. The nitrogen gas from the new nitrogen source B that participates in the purging and displacement is adsorbed by the zeolite molecular sieve adsorption layer and desorbed by the dry vacuum pump A5 through the branch pipe L22-1 or branch pipe L22-2 to form a mixed product gas. The remaining nitrogen gas that does not participate in the purging and displacement enters the sealed chamber through the product gas pipeline L2. At this time, the control valve on the pipeline is opened when the nitrogen gas output from the new nitrogen source B flows through it.

[0035] The nitrogen from the new nitrogen source B, which participates in the purging and replacement of nitrogen molecules from the raw material gas in the sealed chamber and is adsorbed by the zeolite molecular sieve adsorption layer, undergoes desorption and heating under the vacuum of the dry vacuum pump A5. In this process, the nitrogen from the new nitrogen source B replaces the product gas returned through the product gas return pipeline L4 to perform forward purging of the molecular sieve in adsorption tower 3, reducing process losses from the returned product gas and increasing the amount of nitrogen supplied to the sealed chamber. The system inputs a higher purity product gas volume. On the other hand, the nitrogen produced by the new nitrogen source B replaces the method of extracting fresh air from the system through the fresh air pipeline L3 of the vacuum pressure rotary adsorption nitrogen generator A. This not only compensates for the pressure loss in the rapid circulation mechanical nitrogen charging system caused by the removal of oxygen from the vacuum pressure rotary adsorption nitrogen generator A, but also increases the nitrogen concentration of the raw material gas input into the adsorption tower A3 by the fan A2, thereby reducing the deoxygenation and nitrogen production load of the vacuum pressure rotary adsorption nitrogen generator A.

[0036] According to the above technical solution, the nitrogen source B used in this technical solution can be selected from one of the following: membrane nitrogen generator, PSA nitrogen generator, deoxygenator, or vacuum pressure rotary adsorption nitrogen generator.

[0037] According to the above technical solution, the dry vacuum pump used in this technical solution can be selected from one of the following: dry screw vacuum pump, claw vacuum pump, Roots vacuum pump, scroll vacuum pump, and water ring vacuum pump.

[0038] The dry vacuum pump A5 can use an SP630 dry screw vacuum pump to extract and desorb nitrogen and water molecules adsorbed in the adsorption tower, and then pump them directly into the sealed chamber 1.

[0039] According to the above technical solution, the blower A2 of the vacuum pressure rotary adsorption nitrogen generator A used in this technical solution is a DG-600-36 type air ring blower.

[0040] According to the above technical solution, this technical solution can be used for rapid and efficient mechanical nitrogen-filled modified atmosphere control to prevent and control pests in agricultural products, books, archives, and household clothing and furniture stored in closed warehouses.

[0041] According to the above technical solution, the rapid circulating mechanical nitrogen filling system for the above method includes a vacuum pressure rotary adsorption nitrogen generator A, a sealed chamber 1, a raw material gas extraction pipeline L1, and a product gas transmission pipeline L2. The vacuum pressure rotary adsorption nitrogen generator A includes a blower A2, an adsorption tower A3 filled with zeolite molecular sieves, a connecting pipeline L11 between the blower outlet and the adsorption tower, a dry vacuum pump A5, and a connecting pipeline L22 between the vacuum pump's extraction port and the adsorption tower. The outlet of the blower A2 and the raw material gas inlet of the adsorption tower A3 are connected via pipeline L11. The outlet of the adsorption tower A3 during vacuum desorption is connected to the dry vacuum pump... The suction ports of vacuum pump A5 are connected by pipe L22. The outlet of adsorption tower A3 when it is evacuated and the inlet of raw material gas output from blower A2 into adsorption tower A3 are both located at the same end of the adsorption tower. The input end of blower A2 is raw material gas inlet A1, and the output end of dry vacuum pump A5 is product gas outlet A6. Adsorption tower A3 is equipped with an oxygen discharge port A4 for discharging oxygen generated during the separation of raw material gas. Raw material gas inlet A1 is connected to sealed chamber 1 through raw material gas suction pipe L1, and product gas outlet A6 is connected to sealed chamber 1 through product gas delivery pipe L2.

[0042] According to the above technical solution, the adsorption tower A3 consists of at least two adsorption towers connected in parallel to form an adsorption tower group. The adsorption tower group includes adsorption tower A3-1 and adsorption tower A3-2. A connecting pipe L11 leading from the outlet of the blower A2 branches into two branches. One branch L11-1 is connected to the raw material gas inlet of adsorption tower A3-1, and the other branch L11-2 is connected to the raw material gas inlet of adsorption tower A3-2. A connecting pipe L22, which connects to the exhaust port of the vacuum pump A5, branches into two branches. One branch L22-1 connects to the exhaust port of adsorption tower A3-1 when it is being evacuated and desorbed, and the other branch L22-2 connects to the exhaust port of the vacuum pump A5. L22-2 is connected to the outlet of adsorption tower A3-2 when it is evacuated and desorbed. The outlets of adsorption towers A3-1 and A3-2 when they are evacuated and desorbed, and the inlets of the raw material gas output from blower A2 into adsorption towers A3-1 and A3-2 are all located at the same end of the adsorption towers. The end outlet of the raw material gas after entering adsorption towers A3-1 and A3-2 is connected to the oxygen discharge port A4, which is used to discharge oxygen generated by the adsorption towers during the separation of raw material gas, through branch pipes L33-1 and L33-2, respectively. Control valves are installed on each of the above connecting pipes, branch pipes, and the exhaust port for discharging oxygen.

[0043] According to the above technical solution, a product gas return pipeline L4 for the "forward thermal purging purification" process is connected between the raw material gas inlet A1 of the blower A2 and the product gas transmission pipeline L2. The product gas return pipeline L4 is equipped with a control valve. The inlet end of the product gas return pipeline L4 is connected to the product gas transmission pipeline L2, and the outlet end of the product gas return pipeline L4 is connected to the raw material gas inlet A1 of the blower A2. The raw material gas outlet of the blower A2 is connected to the raw material gas inlets of the two adsorption towers of the adsorption tower group through branch pipes L11-1 and L11-2, respectively.

[0044] According to the above technical solution, a new nitrogen source B's nitrogen output pipeline can be connected to the rapid circulating mechanical nitrogen charging system through any of the following three methods:

[0045] (1) The nitrogen output pipeline of the new nitrogen source B is connected to the product gas return pipeline L4 through the tee D;

[0046] (2) Connect the nitrogen output pipeline of the new nitrogen source B to the product gas transmission pipeline L2 through the tee D;

[0047] (3) Connect the new nitrogen source B to the raw material gas inlet A1 of the blower A2 through the fresh air duct L3.

[0048] Compared with the prior art, the advantages of the present invention are as follows:

[0049] 1) Innovatively apply the effect of "the existence of temperature difference, which causes gas molecules in the high-temperature region to diffuse rapidly into the low-temperature region" to solve the technical problem of excessively long mechanical nitrogen-filled modified atmosphere insect control time.

[0050] In addition to the concentration gradient difference formed by mechanically input gas inside the warehouse, and the gas diffusion effect caused by laminar and turbulent flow, the temperature difference between different parts of the stored agricultural products in the warehouse is another driving force for the flow of various gases. Gas molecules can more easily transfer and diffuse rapidly between high-temperature and low-temperature areas. Especially in warehouses with large volumes and in application scenarios where rhythmic operation is required to save equipment energy, it is even more necessary to find new driving forces to promote the rapid diffusion and penetration of gas molecules.

[0051] This invention organically combines the selective adsorption of nitrogen molecules from the air by zeolite molecular sieves with the mechanical heat energy generated by dry vacuum pumps, which do not use oil or water as a medium. This creates a novel nitrogen production process: a dry vacuum pump + zeolite molecular sieve adsorption tower + direct vacuum pump delivery of nitrogen to the storage room. This process mechanically heats the output gas. Under this mode, a temperature difference effect is created where the temperature of the nitrogen gas output from the circulating mechanical nitrogen filling system is greater than the existing temperature of the agricultural products and their packaging in the sealed storage room. Since the normal temperature of the agricultural products and their packaging in the sealed storage room is close to the temperature of the storage environment or the atmospheric environment, the mechanical heat energy generated inside the dry vacuum pump can rapidly raise the temperature of the nitrogen gas passing through the chamber without increasing the storage room equipment configuration or system operating energy consumption. The heated nitrogen gas then facilitates the rapid diffusion of nitrogen molecules from the storage environment into the pores of the stored material, shortens the nitrogen-filled air conditioning and insect-proofing time, improves the insect-proofing effect, and further contributes to the achievement of energy conservation and carbon reduction goals.

[0052] 2) When the raw gas from pneumatic conveying passes through the zeolite molecular sieve layer, the molecular sieve adsorbs most of the nitrogen molecules while also adsorbing a certain number of oxygen molecules. This part is called the residual oxygen molecules in the adsorption layer. When the molecular sieve adsorption layer is desorbed by a vacuum pump, a certain number of residual oxygen molecules will be desorbed along with most of the nitrogen molecules and mixed into the product gas output. This directly affects the nitrogen purity of the product gas.

[0053] This invention utilizes the negative pressure at the air inlet of the equipment fan and the constructed product gas return pipeline to return a portion of the mixed product gas output from the dry vacuum pump to the adsorption tower in the forward direction from the air inlet of the adsorption tower to the product gas outlet A6. Since the zeolite molecular sieve has a much greater capacity to adsorb nitrogen than oxygen, under the driving force of the fan, this returned product will efficiently desorb, purge and displace the oxygen in the zeolite molecular sieve layer.

[0054] This "forward thermal purging purification" process, based on a "dry vacuum pump + zeolite molecular sieve adsorption tower + direct nitrogen delivery to the storage chamber" model, fully utilizes the high temperature generated by the dry vacuum pump itself. The extracted and returned product gas has already undergone temperature enhancement via the dry vacuum pump, and the oxygen molecules remaining in the zeolite molecular sieve layer are more easily activated, desorbed, and displaced under the purging action of high-temperature nitrogen. Compared to traditional nitrogen or air purging purification processes at room temperature, the newly incorporated "forward thermal purging purification" process in the circulating mechanical nitrogen filling system significantly improves the purity and efficiency of nitrogen production in the output product gas without increasing the equipment's operating energy consumption.

[0055] 3) This invention innovatively combines a nitrogen production process of "zeolite molecular sieve adsorption tower + dry vacuum pump + direct vacuum pumping of nitrogen to the storage room" under vacuum pressure rotary adsorption nitrogen production mode. Under the new nitrogen production process mode, the characteristic of zeolite molecular sieve to simultaneously adsorb nitrogen and water molecules in the air is organically combined with the innovative process of direct pumping of product gas to the sealed storage room by dry vacuum pump. This achieves a "moisturizing effect" of synchronously reintroducing nitrogen and water molecules extracted from the raw gas in the sealed storage room. This "moisturizing effect" effectively avoids the decrease in environmental humidity caused by long-term nitrogen filling and pest control in the sealed storage room when using traditional carbon molecular sieve nitrogen generators and membrane separation nitrogen generators, which is conducive to maintaining the original quality of stored agricultural products. Taking grain as an example, the original quality refers to the grain's moisture content, imperfect grains, bulk density, pure grain rate, oil yield, hulling rate, and the content of various components when the grain is stored. Most of these are related to the grain's moisture content. If the humidity of the storage environment is reduced due to the use of a nitrogen generator during the nitrogen filling process, the moisture content of the grain will be reduced, which will in turn affect the deterioration of the grain's quality.

[0056] In addition, the aforementioned "moisturizing effect" can also solve the problem that nitrogen output from traditional nitrogen generators, deoxygenators, and membrane separation nitrogen generators using carbon molecular sieves needs to undergo cleaning, oil removal, and water removal drying processes before entering the storage room, thus opening up a new path for energy conservation and emission reduction.

[0057] The aforementioned "humidifying effect" can also facilitate the rapid horizontal penetration of nitrogen molecules into the pores of stored materials under certain humidity conditions, shortening the insect-prevention time of nitrogen-filled modified atmosphere storage. From April to June 2022, nitrogen-filling technology was used to simultaneously treat two sets of tobacco stacks sealed with nylon composite membranes in the Ningbo Shuguang Road warehouse. Oxygen detection sensors were suspended on the surface of the tobacco boxes, and internal oxygen detection sensors were embedded 15 cm inside the tobacco leaves with insert rods. For each tobacco stack, the ventilation interfaces at both ends of the stacking canopy were connected to the raw material gas extraction pipeline and product gas delivery pipeline of the vacuum pressure rotary adsorption nitrogen generator, constructing a circulating mechanical nitrogen-filled modified atmosphere insect-prevention system. The relevant data collected are summarized below:

[0058] Analysis of Mechanical Nitrogen Filling Treatment Results under Different Environmental Conditions at Ningbo Shuguang Road Warehouse

[0059]

[0060] Test data shows that the same nitrogen generation equipment exhibits higher nitrogen diffusion and permeation rates and nitrogen filling efficiency under increased temperature and humidity: it can process more tobacco leaves, consume less energy, and achieve the required concentration in a shorter time.

[0061] Similar to the above phenomena, Yin Feng and Mei Ning, in their studies "Theoretical and Experimental Research on the Diffusion of Atmospheric Pollutants" and "Research on the Influence of Humidity Changes on the Diffusion of Gaseous Pollutants," respectively, also showed that: ① The molecular diffusion coefficient of oxygen increases with the increase of relative humidity, thus indicating that the greater the humidity, the greater the diffusion rate of oxygen; ② The greater the relative humidity, the lower the concentration of pollutants, thus indicating that the greater the relative humidity, the faster the diffusion rate of CO. The increase of atmospheric relative humidity is conducive to the diffusion of CO. For most gases (that do not react chemically with water vapor), their diffusion coefficient increases with the increase of air humidity.

[0062] Yang Jialing's research in "Study on Concentration Field of Natural Gas Leakage Diffusion under Humidity Gradient" shows that natural gas is less dense than air. Therefore, as humidity increases, air density decreases, and the diffusion area of ​​natural gas in the horizontal direction increases with increasing humidity, resulting in a faster diffusion speed. However, in the vertical direction, air density decreases, and the buoyancy force due to the density difference also decreases, which slows down the diffusion speed in the vertical direction.

[0063] Cao Peng's research in "The Influence of Temperature and Humidity on the Diffusion Process of Hydrogen in the Air" points out that as humidity increases, the concentration of gas decreases more rapidly along the vertical direction. That is, for hydrogen under the same leakage conditions, the height of the potential combustion zone will decrease as the gas diffusion accelerates with the increase of humidity.

[0064] The aforementioned similar research findings indicate that higher relative humidity leads to a higher gas diffusion coefficient and faster gas diffusion, especially in the horizontal direction. The diffusion and permeability characteristics of nitrogen discovered by the inventors during mechanical nitrogen filling are further corroborated from another perspective. Nitrogen also does not chemically react with water vapor and has a slightly lower density than air. Therefore, during the nitrogen filling of a whole warehouse or stack, maintaining stable humidity ensures the rapid horizontal diffusion of nitrogen in a confined space.

[0065] Regarding the diffusion of nitrogen in a closed chamber, there is also an interference effect of the vertical gas density difference buoyancy force. As the gas density decreases, the density difference buoyancy force also decreases, which will slow down the gas diffusion in the vertical direction. This requires process innovation by superimposing mechanical nitrogen filling to reduce this interference.

[0066] 4) The rapid circulation mechanical nitrogen filling system of this invention has a temperature difference effect where "the temperature of the output nitrogen gas flow is greater than the existing temperature of agricultural products and their packaging in the sealed warehouse at room temperature", a "moisturizing effect" from the synchronous return of nitrogen and water molecules extracted from the raw material gas in the sealed warehouse, and a "positive thermal purging purification" process. These factors combine and support each other, resulting in multiple functions such as "separation of nitrogen and oxygen in the raw material gas, heating of the product gas, transportation of the heated product gas, stabilization of humidity during the airflow circulation process, and improvement of the purity of the output nitrogen". This can shorten the nitrogen filling and insecticidal time, reduce the operating energy consumption of the rapid circulation mechanical nitrogen filling system, and avoid the problem of oil mist and water mist leakage pollution that is easily generated by traditional vacuum pumps that use oil and water as working media, thus ensuring the safety and stability of the original quality of the stored goods.

[0067] 5) An innovative structural combination of "zeolite molecular sieve vacuum pressure rotary adsorption nitrogen generator A + new nitrogen source B" is proposed. In this combination, on the one hand, the nitrogen output from the new nitrogen source B replaces the product gas returned through product gas return pipeline L4 to perform forward purging of the molecular sieve in the adsorption tower, reducing process losses from returned product gas and increasing the amount of higher purity product gas input into the sealed chamber. On the other hand, the nitrogen produced by the new nitrogen generator B replaces the method of vacuum pressure rotary adsorption nitrogen generator A extracting fresh air from the system through fresh air pipeline L3. This compensates for the pressure loss in the system caused by the removal of oxygen from the closed-loop deoxygenation nitrogen generation system by vacuum pressure rotary adsorption nitrogen generator A, while increasing the nitrogen concentration of the raw material gas input from fan A2 into adsorption tower A3, reducing the deoxygenation nitrogen generation load of vacuum pressure rotary adsorption nitrogen generator A, further improving nitrogen generation efficiency and shortening the nitrogen filling and insecticidal time.

[0068] 6) This invention gives the vacuum pressure rotary adsorption nitrogen generator a completely new meaning and process mode, making it easier to implement in engineering and applicable to various applications that require improved nitrogen filling efficiency and shortened nitrogen filling time for insect control. Attached Figure Description

[0069] Figure 1 This is a schematic diagram of the nitrogen production process of the present invention, which is "zeolite molecular sieve adsorption tower + dry vacuum pump + vacuum pump direct discharge to nitrogen to the storage room" and the process of mechanically heating the output gas.

[0070] Figure 2 This invention employs two adsorption towers connected in parallel to form an adsorption tower group, with a "one tower adsorption + the other tower desorption" and switchable alternating operation mode.

[0071] Figure 3 This is a schematic diagram of the "forward thermal purging purification" process constructed in the rapid circulating mechanical nitrogen charging system of the present invention;

[0072] Figure 4 This is one of the structural combination diagrams of the present invention, "Zeolite molecular sieve vacuum pressure rotary adsorption nitrogen generator A + new nitrogen source B";

[0073] Figure 5 This is the second schematic diagram of the structural combination of the "zeolite molecular sieve vacuum pressure rotary adsorption nitrogen generator A + new nitrogen source B" of the present invention;

[0074] Figure 6 This is the third schematic diagram of the structural combination of the "zeolite molecular sieve vacuum pressure rotary adsorption nitrogen generator A + new nitrogen source B" of the present invention;

[0075] In the diagram: 1--Sealed chamber, L1--Raw gas extraction pipeline, L2--Product gas transmission pipeline, L3--Fresh air pipeline, L4--Product gas return pipeline, A--Vacuum pressure rotary adsorption nitrogen generator, A1--Raw gas inlet, A2--Fan, A3--Adsorption tower, A3-1--First adsorption tower of the adsorption tower group, A3-2--Second adsorption tower of the adsorption tower group, L11--Connecting pipeline between fan outlet and adsorption tower, L11---First branch pipe of the connecting pipeline between fan outlet and adsorption tower, L11---Second branch pipe of the connecting pipeline between fan outlet and adsorption tower, L22--Connecting pipeline between vacuum pump extraction port and adsorption tower. Pipeline, L22-1---First branch pipe connecting the vacuum pump's extraction port and the adsorption tower, L22-2---Second branch pipe connecting the vacuum pump's extraction port and the adsorption tower, A4--Oxygen discharge port of the adsorption tower, L33--Connecting pipe between the end outlet of the raw material gas after entering the adsorption tower and the oxygen discharge port, L33-1--First branch pipe connecting the end outlet of the raw material gas after entering the adsorption tower and the oxygen discharge port, L33-2--Second branch pipe connecting the end outlet of the raw material gas after entering the adsorption tower and the oxygen discharge port, A5--Dry vacuum pump, A6--Product gas outlet, B--New nitrogen source, D--Tee;

[0076] The arrows in the diagram represent the airflow direction inside the sealed compartment (sealed chamber), pipes, and equipment ports during the operation of the rapid circulating mechanical nitrogen filling system. The diagram focuses on illustrating the system layout and process implementation; the structures of related equipment and components are not shown in detail. Detailed Implementation

[0077] The following description, in conjunction with the accompanying drawings and specific embodiments, further illustrates a rapid circulating mechanical nitrogen filling system for controlled atmosphere pest control in enclosed warehouses, as proposed in this invention.

[0078] The accompanying drawings are simplified for the purpose of illustrative purposes only, to clearly illustrate the relevant embodiments of the present invention. The related simple descriptions and illustrations are merely embodiments and are not intended to limit the invention. In particular, the development of automated control programs for equipment systems is a method commonly understood by those skilled in the art. The following embodiments are merely exemplary implementations used to illustrate the principles of the invention; however, the invention is not limited thereto. For those skilled in the art, various component selections, combinations, and process improvements can be made to serve the functional realization of the system without departing from the technical route of the present invention, and these modifications and improvements are also considered within the scope of protection of the present invention.

[0079] Example 1

[0080] like Figure 1 As shown, a vacuum pressure rotary adsorption nitrogen generator A is first used as the nitrogen filling device in the circulating mechanical nitrogen filling system. The raw material gas inlet A1 of the vacuum pressure rotary adsorption nitrogen generator A is connected to one end of the sealed chamber 1 through the raw material gas extraction pipe L1. The product gas outlet A6 of the vacuum pressure rotary adsorption nitrogen generator A is connected to the other end of the sealed chamber 1 through the product gas transmission pipe L2, thus constructing a closed-loop rapid circulating mechanical nitrogen filling system that can be used for controlled atmosphere insect control.

[0081] One to ten product gas transmission pipes L2 and one to ten raw material gas extraction pipes L1 are respectively led out from any two symmetrical sides or the top and bottom surfaces of the sealed chamber 1. The raw material gas extraction pipes L1 are selected according to the size of the sealed chamber 1, and are made of plastic, rubber or metal pipes with an inner diameter of 10 to 100 mm. The product gas transmission pipes L2 are selected according to the size of the sealed chamber 1, and are made of high temperature resistant pipes with an inner diameter of 10 to 100 mm, and are insulated.

[0082] In the rapid circulation mechanical nitrogen charging system, a fresh air duct L3 for replenishing fresh air is connected to the raw material gas extraction duct L1 of the vacuum pressure rotary adsorption nitrogen generator A. When the rapid circulation mechanical nitrogen charging system continuously separates and removes oxygen from the raw material gas, resulting in a decrease in the internal gas pressure of the system duct and thus affecting the stability of the rapid circulation mechanical nitrogen charging system, the control valve installed on the fresh air duct L3 will automatically open according to the programmed procedure and electrical signal to draw gas from the external environment to replenish the gas and maintain the pressure balance inside and outside the duct system.

[0083] The vacuum pressure rotary adsorption nitrogen generator A includes a blower A2, a cylindrical adsorption tower A3 with a steel plate structure, and a dry vacuum pump A5. The input end of the blower A2 is the raw material gas inlet A1, and the output end of the dry vacuum pump A5 is the product gas outlet A6. The adsorption tower A3 is equipped with an oxygen discharge port A4 for discharging oxygen generated during the separation of the raw material gas. The outlet of the blower A2 is connected to the raw material gas inlet of the adsorption tower via a connecting pipe L11. The suction port of the dry vacuum pump A5, which performs vacuum desorption in the adsorption tower, is connected to the outlet of the adsorption tower during vacuum desorption via a connecting pipe L22. The connection is made by connecting the end outlet of the raw gas after it enters the adsorption tower and the oxygen discharge port A4 of the adsorption tower through a connecting pipe L33. The raw gas extraction pipe L1, product gas transmission pipe L2, fresh air pipe L3 and other pipes are equipped with control valves. The adsorption tower in the rapid circulation mechanical nitrogen filling system adopts a vertical arrangement and bottom filling and top discharge process. The raw gas inlet of the adsorption tower and the outlet of the adsorption tower when it is vacuumed and desorbed are both located at the same bottom end of the adsorption tower. The oxygen outlet formed after the raw gas enters the adsorption tower and is separated and the oxygen discharge port A4 of the adsorption tower are located at the top of the adsorption tower.

[0084] In the aforementioned adsorption tower, the outlet during vacuum desorption and the feed gas inlet are both located at the same end of the tower. When the tower is vertical, both the outlet during vacuum desorption and the feed gas inlet are located at the bottom. During the adsorption stage, driven by fan A2, the feed gas enters the tower from bottom to top and passes through the adsorption layer. Oxygen passes through the zeolite molecular sieve packing adsorption layer and is discharged through oxygen outlet A4. Simultaneously, nitrogen and water molecules in the feed gas are adsorbed by the packing layer, with the adsorption amount gradually decreasing from bottom to top. Therefore, when desorbing the adsorbed nitrogen and water molecules, a bottom-to-outward extraction mode is preferentially adopted to maximize the desorption effect. When the tower is being vacuumed and desorbed, the outlet and the raw material gas inlet of the adsorption tower can be set independently or share a port. When using the same adsorption tower for alternating adsorption and desorption in an intermittent operation mode, when this port is connected to the exhaust port of vacuum pump A5 through the connecting pipe L22 to perform vacuum desorption of nitrogen and water molecules in the adsorption layer of the adsorption tower, the raw material gas inlet of the adsorption tower actually becomes the outlet channel of the mixed product gas. When the adsorption tower is being vacuumed and desorbed, and the raw material gas inlet of the adsorption tower is used as the outlet connected to the exhaust port of the vacuum pump, a three-way pipe with a control valve can be connected to this port. The three-way pipe is connected to the exhaust port of blower A2, the bottom end of adsorption tower A3, and the exhaust port of vacuum pump A5 respectively.

[0085] The blower A2 of the vacuum pressure rotary adsorption nitrogen generator A adopts a DG-600-36 type air ring blower. The adsorption tower A3 in the vacuum pressure rotary adsorption nitrogen generator A uses JLOX-103 type zeolite molecular sieve as adsorbent. The dry vacuum pump (or: dry vacuum pump, vacuum pump) A5 uses an SP630 type dry screw vacuum pump to extract and desorb the nitrogen and water molecules adsorbed in the adsorption tower, and directly pump them to the sealed chamber 1. This forms a nitrogen generation process that is different from the traditional vacuum pressure rotary adsorption nitrogen generator, namely "zeolite molecular sieve adsorption tower + dry vacuum pump (or: dry screw vacuum pump) + vacuum pump direct pumping of nitrogen to the chamber", which is a mode of mechanically heating the output gas.

[0086] Leakage and repair work was carried out on the pipes, joints, and sealed compartments of the completed rapid circulating mechanical nitrogen filling system (or the construction of a circulating mechanical nitrogen controlled atmosphere pest control system). The airtightness of the sealed space was tested using the negative pressure test method. The airtightness of the pipes and sealed compartments was monitored using the pressure decay test (Pt test). The specific monitoring method was in accordance with the relevant provisions of the People's Republic of China National Standard GB / T25229—2010 "Grain and Oil Storage - Airtightness Requirements for Flat Warehouses". The controlled atmosphere device was ensured to meet the Class II airtightness standard. If the airtightness was insufficient, it was resolved by checking for leaks and repairing holes or replacing the sealing materials.

[0087] When the vacuum pressure rotary adsorption nitrogen generator A in the rapid circulating mechanical nitrogen filling system is started, under the control of the programmed program, the fan A2 in the vacuum pressure rotary adsorption nitrogen generator A extracts the gas in the sealed chamber 1 as raw material gas through the raw material gas extraction pipe L1 and inputs it into the adsorption tower A3 filled with zeolite molecular sieves through the connecting pipe L11. During the process of the raw material gas passing through the zeolite molecular sieve layer, the nitrogen and water molecules in it are adsorbed by the zeolite molecular sieve layer, while the oxygen component in the raw material gas is removed by passing through the packing layer of the adsorption tower A3 and the oxygen discharge port A4 of the adsorption tower. The control valves on the pipes through which the above airflow flows are opened, and the control valves on other pipes are closed. After completing the adsorption step of nitrogen and water molecules in the raw material gas, the vacuum pressure rotary adsorption nitrogen generator A continues to start the adsorption of the adsorbed gas in the adsorption tower A3. The process involves vacuum desorption of nitrogen and water molecules. In this process, the dry vacuum pump A5 desorbs nitrogen and water molecules in the adsorption layer of the adsorption tower through the connecting pipe L22, forming a mixed product gas of nitrogen and water molecules. The mixed product gas achieves a temperature increase of 20-80°C during the process of passing through the high temperature chamber of the dry vacuum pump A5 and is then input into the sealed chamber 1 through the product gas outlet A6 and the product gas transmission pipe L2. The control valve of the above mixed product gas flow is automatically opened through the pipeline. At this time, a temperature difference effect is formed where "the temperature of the output nitrogen gas flow is greater than the existing temperature of the agricultural products and their packaging in the sealed chamber at room temperature". A moisturizing effect is also formed where water molecules in the raw material gas are not adsorbed during the deoxygenation and nitrogen generation process of the vacuum pressure rotary adsorption nitrogen generator A, and the existing environmental humidity in the sealed chamber 1 is maintained.

[0088] When the internal air pressure of the pipeline system (which includes the raw gas extraction pipeline L1, the product gas transmission pipeline L2, the connecting pipeline L11 between the blower outlet and the adsorption tower, the connecting pipeline L22 between the vacuum pump outlet and the adsorption tower, and the connecting pipeline L33; or system pipeline) continuously decreases, it will affect the stability of the rapid circulation mechanical nitrogen filling system (which includes the vacuum pressure rotary adsorption nitrogen generator A, the raw gas extraction pipeline L1, and the product gas transmission pipeline L2). At this time, the control valve installed on the fresh air pipeline L3 will automatically open according to the programmed procedure and electrical signal to draw air from the external environment to maintain the pressure balance between the inside and outside of the pipeline system.

[0089] The adsorption tower is equipped with control valves for its inlet pipe, vacuum desorption pipe, and oxygen discharge port. The adsorption tower achieves "alternating and intermittent operation of adsorption and desorption" by switching the control valves. The pipeline system can be opened and closed according to the programmed procedure and electrical signals to realize the automatic opening and closing of each pipeline, so as to ensure the realization of system functions. The specifications and control methods of the above-mentioned control valves are adapted and combined according to the market supply situation, and are not listed one by one.

[0090] Example 2

[0091] like Figure 2 As shown, it is basically the same as Example 1, except that: in order to improve the operating speed of the circulating mechanical nitrogen filling system used for controlled atmosphere insect control in a closed warehouse, the adsorption tower A3 uses at least two adsorption towers connected in parallel to form an adsorption tower group to perform "one tower adsorption + another tower desorption" and switchable alternating operation modes. The adsorption tower group includes adsorption tower A3-1 and adsorption tower A3-2. At this time, two branch pipes are branched from the connecting pipe L11 led out from the air outlet of the blower A2. One branch pipe L11-1 is connected to the raw material gas inlet of adsorption tower A3-1, and the other branch pipe L11-2 is connected to the raw material gas inlet of adsorption tower A3-2. The ports are connected; the connecting pipe L22, which is connected to the suction port of vacuum pump A5, branches off into two branches. One branch, L22-1, is connected to the outlet of adsorption tower A3-1 when it is evacuated and desorbed, and the other branch, L22-2, is connected to the outlet of adsorption tower A3-2 when it is evacuated and desorbed. The end outlet of the raw material gas after entering adsorption tower A3-1 and adsorption tower A3-2 is connected to the oxygen emission port A4, which is used to discharge oxygen generated by the adsorption tower during the separation of raw material gas, through branch pipes L33-1 and L33-2, respectively. Control valves are installed on each of the above connecting pipes, branch pipes, and oxygen emission ports.

[0092] When zeolite molecular sieves are used as adsorbents to fill adsorption towers A3-1 and A3-2, and the rapid circulating mechanical nitrogen filling system is running, adsorption towers A3-1 and A3-2 in the vacuum pressure rotary adsorption nitrogen generator A alternately adsorb and desorb nitrogen and water molecules in the raw gas. Under the control of the programmed procedure, the blower A2 in the vacuum pressure rotary adsorption nitrogen generator A extracts gas from the sealed chamber 1 through the raw gas extraction pipe L1 and inputs it into the adsorption tower A3-1 filled with zeolite molecular sieves through the branch pipe L11-1. During the process of the raw gas passing through the zeolite molecular sieve layer, the nitrogen and water molecules in the raw gas are adsorbed by the zeolite molecular sieve layer, while the oxygen component in the raw gas is desorbed. The nitrogen and water molecules in the raw gas are removed by venting through the packing layer of adsorption tower A3-1, branch pipe L33-1, and oxygen discharge port A4 of the adsorption tower. While adsorption tower A3-1 completes the adsorption step of nitrogen and water molecules in the raw gas, the vacuum desorption process of nitrogen and water molecules adsorbed in adsorption tower A3-2 is started simultaneously. At this time, dry vacuum pump A5 desorbs nitrogen and water molecules in the adsorption layer of adsorption tower A3-2 through branch pipe L22-2 to form a mixed product gas of nitrogen and water molecules. The mixed product gas achieves a temperature increase of up to 20-80°C in the high temperature chamber of dry vacuum pump A5 and is input into the sealed chamber 1 through product gas discharge port A6 and product gas transmission pipe L2.

[0093] According to the above technical solution, in the rapid circulating mechanical nitrogen filling system, the adsorption tower raw material gas inlet, which is connected to the air outlet of the blower A2 via the connecting pipe L11, and the adsorption tower outlet, which is connected to the vacuum pump A5 via the connecting pipe L22, are both located at the same end of the adsorption tower. They can be set independently or share a port (i.e., the raw material gas inlet and the raw material gas outlet can be the same port). When this port is connected to the vacuum pump A5 via the connecting pipe L22 and performs the function of vacuum desorption of nitrogen and water molecules in the adsorption layer of the adsorption tower, the raw material gas inlet of the adsorption tower becomes the outlet channel of the mixed product gas. If the raw material gas inlet of the adsorption tower is also used as the outlet that connects to the vacuum pump outlet, a three-way pipe with a control valve is connected to this port. The three-way pipe is connected to the bottom of the adsorption tower, the air outlet of the vacuum pump A5, and the air outlet of the blower A2, respectively.

[0094] The aforementioned rapid circulating mechanical nitrogen charging system operates automatically according to the programmed control program and electrical control signals. The control program meets different system operation requirements such as time-limited control, sequence control, and conditional control, enabling the control valves in each pipeline passage of the system to automatically open or close according to the prescribed logic and program. The basis and purpose of the control program is to ensure the synchronous operation of the two adsorption towers in the system for atmospheric pressure adsorption and vacuum desorption, and to ensure that the system's operating mode automatically and repeatedly alternates between "adsorption tower A3-1 adsorption + adsorption tower A3-2 desorption" and "adsorption tower A3-2 adsorption + adsorption tower A3-1 desorption". In order to serve the realization of the system's functions, the control program and electrical control signals for the automatic operation of the rapid circulating mechanical nitrogen charging system can be edited, revised, and improved.

[0095] Example 3

[0096] like Figure 3As shown, it is basically the same as Examples 1 and 2, except that: firstly, a product gas return pipeline L4 with a control valve is connected between the raw material gas inlet A1 and the product gas transmission pipeline L2. When the rapid circulation mechanical nitrogen charging system is started and completes the adsorption steps of nitrogen and water molecules in the raw material gas by the adsorption tower A3-1 according to the programmed procedure, and then enters the intermittent process of vacuum desorption of the adsorbed nitrogen and water molecules, the "forward thermal purging purification" process is started. At this time, the adsorption tower A3-2 in the rapid circulation mechanical nitrogen charging system is still in the vacuum desorption process step. The product gas return pipeline L4, the branch pipe L11-1 between the air outlet of the blower and the adsorption tower A3-1 in the rapid circulation mechanical nitrogen charging system, and the branch pipe L11-1 between the air outlet of the blower and the adsorption tower A3-1 are all connected. The control valves on pipe L33-1 and branch pipe L22-2 open automatically. Fan A2 pumps a portion of the mixed product gas formed during the vacuum desorption process of dry vacuum pump A5 on adsorption tower A3-2 back to adsorption tower A3-1 through product gas return pipeline L4 and branch pipe L11-1. This portion of the mixed product gas, which is in a high-temperature state and is returned to adsorption tower A3-1, effectively imparts heat energy to activate, desorb, and positively purge and displace the oxygen remaining in the molecular sieve adsorption layer. The purged oxygen is removed by venting through branch pipe L33-1 and oxygen discharge port A4 of the adsorption tower. The aforementioned product gas return pipeline L4 is made of high-temperature resistant pipe with an inner diameter of 10-100mm and is insulated.

[0097] After the adsorption of nitrogen and water molecules in the raw gas by adsorption tower A3-1, the "forward thermal purging purification," and the vacuum desorption of the adsorbed nitrogen and water molecules by adsorption tower A3-2 are completed, the equipment system automatically switches to the adsorption of nitrogen and water molecules in the raw gas by adsorption tower A3-2, the "forward thermal purging purification," and the vacuum desorption of the nitrogen and water molecules adsorbed by adsorption tower A3-1, according to the programmed control program. The above-mentioned high-temperature nitrogen "forward thermal purging purification" process improves the purity of the product gas, shortens the nitrogen-filling insecticidal time, and reduces the operating energy consumption of the circulating mechanical nitrogen-filled air-conditioning insect control system.

[0098] The high-temperature mixed product gas fed back into the adsorption tower A3-1 purges and replaces the residual oxygen in the molecular sieve adsorption layer. At the same time, most of the nitrogen and water molecules in the gas are re-adsorbed by the adsorption layer and then re-aggregate to form high-temperature mixed product gas when the adsorption tower A3-1 is alternately evacuated and desorbed. The gas is then fed into the sealed chamber 1 through the product gas outlet A6 and the product gas transmission pipeline L2.

[0099] Example 4

[0100] like Figure 4As shown, it is basically the same as Examples 1 and 2, except that: a product gas return pipeline L4 with a control valve is connected between the raw material gas inlet A1 and the product gas transmission pipeline L2, and the nitrogen output pipeline of the new nitrogen source B is connected to the product gas return pipeline L4 through the tee D to form a new "vacuum pressure rotary adsorption nitrogen generator A of zeolite molecular sieve + new nitrogen source B" structural combination mode.

[0101] When the rapid circulating mechanical nitrogen charging system is started, the adsorption tower A3-1 first completes the adsorption of nitrogen and water molecules in the raw gas. Then, the forward purging process is started. During this period, a portion of the nitrogen flow from the new nitrogen source B is fed into the adsorption tower A3-1 through the product gas return pipeline L4 between the tee D and the raw gas inlet A1, and through the blower A2 and branch pipe L11-1 to perform the purging and replacement of oxygen molecules remaining in the zeolite molecular sieve layer. The oxygen purged and replaced is discharged through the oxygen discharge port A4 of the adsorption tower. The remaining nitrogen that does not participate in the purging and replacement enters the sealed chamber 1 through the product gas return pipeline L4 between the tee D and the product gas transmission pipeline L2, and through the product gas transmission pipeline L2.

[0102] Using a PSA nitrogen generator manufactured by Guangzhou Weitong Industrial Gas Technology Co., Ltd. as a new nitrogen source B, when the nitrogen flow output from the new nitrogen source B cannot meet the gas demand for forward purging of adsorption tower A3-1, blower A2 will return a portion of the mixed product gas formed during the vacuum desorption process of adsorption tower A3-2 by dry vacuum pump A5 to adsorption tower A3-1 through product gas return pipeline L4 and branch pipe L11-1. This portion of the high-temperature mixed gas returned to adsorption tower A3-1, together with the nitrogen flow output from nitrogen source B, effectively imparts heat energy to activate, desorb, and forward purge and replace the residual oxygen in the molecular sieve adsorption layer. During this period, the control valve on the pipeline through which the nitrogen flow output from the new nitrogen source B passes is opened.

[0103] In this embodiment, a new nitrogen source B's nitrogen output pipeline is connected to the rapid circulating mechanical nitrogen charging system. In this new structural combination of "zeolite molecular sieve vacuum pressure rotary adsorption nitrogen generator A + new nitrogen source B," adsorption tower A3-1 in the rapid circulating mechanical nitrogen charging system adsorbs nitrogen and water molecules from the raw gas and then performs a forward purging process. Meanwhile, adsorption tower A3-2 in the rapid circulating mechanical nitrogen charging system is in the vacuum desorption process step. Under the control of the programmed procedure, the rapid circulating mechanical nitrogen charging system... The system operates alternately in a "one tower adsorption + another tower desorption" and switchable modes. The nitrogen gas from the new nitrogen source B that participates in the purging and displacement is adsorbed by the zeolite molecular sieve adsorption layer and desorbed by the dry vacuum pump A5 through branch pipe L22-1 or branch pipe L22-2 to form a mixed product gas. The remaining nitrogen gas that does not participate in the purging and displacement enters the sealed chamber through the product gas pipeline L2. At this time, the control valve on the pipeline of the nitrogen gas output from the new nitrogen source B is opened.

[0104] The nitrogen from the new nitrogen source B, which participates in the purging and replacement of nitrogen molecules from the raw material gas in the sealed chamber and is adsorbed by the zeolite molecular sieve adsorption layer, undergoes desorption and heating under the vacuum of the dry vacuum pump A5. In this process, the nitrogen from the new nitrogen source B replaces the product gas returned through the product gas return pipeline L4 to perform forward purging of the molecular sieve in adsorption tower 3, reducing process losses from the returned product gas and increasing the amount of nitrogen supplied to the sealed chamber. The system inputs a higher purity product gas volume. On the other hand, the nitrogen produced by the new nitrogen source B replaces the method of extracting fresh air from the system through the fresh air pipeline L3 of the vacuum pressure rotary adsorption nitrogen generator A. This not only compensates for the pressure loss in the rapid circulation mechanical nitrogen charging system caused by the removal of oxygen from the vacuum pressure rotary adsorption nitrogen generator A, but also increases the nitrogen concentration of the raw material gas input into the adsorption tower A3 by the fan A2, thereby reducing the deoxygenation and nitrogen production load of the vacuum pressure rotary adsorption nitrogen generator A.

[0105] Example 5

[0106] like Figure 5 As shown, it is basically the same as Example 4, except that: a product gas return pipeline L4 with a control valve is connected between the raw material gas inlet A1 and the product gas transmission pipeline L2 of the vacuum pressure rotary adsorption nitrogen generator A, and the nitrogen output pipeline of the new nitrogen source B is connected to the product gas transmission pipeline L2 through the tee D to form a new "vacuum pressure rotary adsorption nitrogen generator A of zeolite molecular sieve + new nitrogen source B" structural combination mode.

[0107] When the rapid circulation mechanical nitrogen charging system is started, the adsorption tower A3-1 first completes the adsorption of nitrogen and water molecules in the raw gas, and then the forward purging process is started. During this period, the blower A2 returns a portion of the mixed product gas output by the dry vacuum pump A5 to the adsorption tower A3-1 through the product gas return pipeline L4 and the branch pipe L11-1. The high-temperature mixed gas returned to the adsorption tower A3-1 effectively imparts heat energy to activate, desorb and forward purge the oxygen remaining in the molecular sieve adsorption layer. The purged oxygen is removed by venting through the branch pipe L33-1 and the oxygen discharge port A4 of the adsorption tower.

[0108] The nitrogen flow from the new nitrogen source B replaces the fresh air flow input through the fresh air duct L3, which is used for replenishing fresh air. It enters the sealed chamber through the tee D and the product gas transmission duct L2 to replenish the gas and maintain the pressure balance inside and outside the pipeline system. At the same time, when the mixed product gas output from the extraction dry vacuum pump A5 is insufficient to meet the gas demand for forward purging of the adsorption tower A3-1, a portion of the nitrogen flow from the new nitrogen source B is input into the adsorption tower A3-1 through the product gas transmission duct L2 between the tee D and the raw material gas inlet A1, the product gas return duct L4, and the fan A2. The branch pipe L11-1 between the fan outlet and the adsorption tower is then used to purge and replace the residual oxygen molecules in the zeolite molecular sieve. At this time, the control valves on the pipelines through which the above-mentioned gas flow passes are opened, while the control valves on other pipelines are closed.

[0109] Example 6

[0110] like Figure 6 As shown, it is basically the same as Examples 4 and 5, except that: a product gas return pipeline L4 with a control valve is connected between the raw material gas inlet A1 and the product gas transmission pipeline L2. A new nitrogen source B is connected to the raw material gas inlet A1 of the blower A2 through the fresh air pipeline L3. The rapid circulation mechanical nitrogen charging system is started and running. Under the control of the programmed program, the adsorption tower A3-1 in the system first completes the adsorption of nitrogen and water molecules in the raw material gas. Then, the forward purging process is started. At this time, a part of the nitrogen gas output from the new nitrogen source B is input into the adsorption tower A3-1 through the fresh air pipeline L3 and the blower A2 to perform purging and replacement of the oxygen molecules remaining in the zeolite molecular sieve. The purged oxygen is discharged through the oxygen discharge port A4 of the adsorption tower and removed.

[0111] The remaining nitrogen flow from the new nitrogen source B, which does not participate in the purging and replacement of residual oxygen molecules in the zeolite molecular sieve, enters the sealed chamber through the fresh air duct L3, product gas return duct L4, and product gas supply duct L2 to participate in controlled atmosphere pest control. When the nitrogen flow from the new nitrogen source B cannot meet the gas demand for forward purging of adsorption tower A3-1, the blower A2 will return a portion of the mixed product gas formed during the vacuum desorption process of adsorption tower A3-2 by the dry vacuum pump A5 to adsorption tower A3-1 through the product gas return duct L4 and branch pipe L11-1. This portion of the high-temperature mixed gas returned to adsorption tower A3-1 effectively imparts heat energy to activate, desorb, and forward purge and replace the residual oxygen in the molecular sieve adsorption layer. At this time, the nitrogen flow from the new nitrogen source B is opened through the control valve on the pipeline.

[0112] Example 7

[0113] The process is basically the same as Examples 1, 2, 3, 4, 5, and 6, except that the new nitrogen source B used is a vacuum pressure rotary adsorption nitrogen generator with a nitrogen generation process mode of "zeolite molecular sieve adsorption tower + dry vacuum pump + vacuum pump direct discharge to pump nitrogen into the sealed chamber".

[0114] Example 8

[0115] It is basically the same as Examples 4, 5, 6 and 7, except that the new nitrogen source B used is a membrane nitrogen generator.

[0116] Example 9

[0117] It is basically the same as Examples 1, 2, 3, 4, 5, 6, 7, and 8, except that the dry vacuum pump A5 used is a vortex vacuum pump.

[0118] Example 10

[0119] It is basically the same as Examples 1, 2, 3, 4, 5, 6, 7, 8, and 9, except that the dry vacuum pump A5 used is a Roots vacuum pump;

[0120] Example 11

[0121] It is basically the same as Examples 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10, except that the dry vacuum pump A5 used is a claw vacuum pump.

[0122] Example 12

[0123] It is basically the same as Examples 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11, except that: Enclosed Warehouse 1 is an enclosed warehouse with a brick-concrete structure.

[0124] Example 13

[0125] It is basically the same as Examples 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11, except that: the sealed compartment 1 is a sealed compartment, carriage, engine room, or ship cabin with a steel plate structure.

[0126] Example 14

[0127] It is basically the same as Examples 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11, except that: the sealed compartment 1 is a storage space formed by sealing with a plastic tent or air film with good airtightness.

[0128] Example 15

[0129] It is basically the same as Examples 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11, except that: the sealed compartment 1 is a storage warehouse for books, archives, and cultural relics with good airtightness.

Claims

1. A rapid circulating mechanical nitrogen filling method for controlled atmosphere insect control in a sealed chamber, comprising using a vacuum pressure rotary adsorption nitrogen generator (A) as the nitrogen filling device in a rapid circulating mechanical nitrogen filling system, wherein the raw material gas inlet (A1) of the vacuum pressure rotary adsorption nitrogen generator (A) is connected to one end of the sealed chamber (1) through a raw material gas extraction pipe (L1), and the product gas outlet (A6) of the vacuum pressure rotary adsorption nitrogen generator (A) is connected to the other end of the sealed chamber (1) through a product gas transmission pipe (L2), thereby constructing a closed circulating system that can be used for controlled atmosphere insect control. The rapid circulating mechanical nitrogen charging system is connected to a fresh air duct (L3) for replenishing fresh air. When the rapid circulating mechanical nitrogen charging system continuously separates and removes oxygen from the raw gas, the internal air pressure of the system duct decreases, which affects the stability of the rapid circulating mechanical nitrogen charging system. The control valve installed on the fresh air duct (L3) will automatically open according to the programmed procedure and electrical signal to draw gas from the external environment to replenish the gas and maintain the pressure balance inside and outside the rapid circulating mechanical nitrogen charging system. Its features are: The vacuum pressure rotary adsorption nitrogen generator (A) includes a blower (A2), an adsorption tower (A3), and a dry vacuum pump (A5). The input end of the blower (A2) is the raw material gas inlet (A1), and the output end of the dry vacuum pump (A5) is the product gas outlet (A6). The adsorption tower (A3) is equipped with an oxygen discharge port (A4) for discharging oxygen generated during the separation of the raw material gas. The outlet of the blower (A2) and the raw material gas inlet of the adsorption tower are connected by a connecting pipe (L11). The exhaust port of the dry vacuum pump (A5) is connected to the exhaust port of the adsorption tower during vacuum desorption via a connecting pipe (L22). The exhaust port of the adsorption tower (A3) during vacuum desorption and the inlet of the raw material gas output by the blower (A2) into the adsorption tower (A3) are both located at the same end of the adsorption tower. After the raw material gas enters the adsorption tower and completes adsorption and separation, the oxygen gas outlet is connected to the oxygen discharge port (A4) of the adsorption tower via a connecting pipe (L33). Control valves are installed on the above-mentioned raw material gas extraction pipeline (L1), product gas transmission pipeline (L2), and fresh air pipeline (L3); zeolite molecular sieve is used as adsorbent to fill the adsorption tower (A3) in the vacuum pressure rotary adsorption nitrogen generator (A) to complete the adsorption and separation of the raw material gas entering the adsorption tower. A dry vacuum pump (A5) is used to desorb the nitrogen and water molecules adsorbed in the adsorption tower and directly pump the desorbed gas to the sealed chamber (1), forming a new process combination mode of "zeolite molecular sieve adsorption tower + dry vacuum pump + vacuum pump direct pumping of nitrogen into the sealed chamber" of the vacuum pressure rotary adsorption nitrogen generator and the effect of mechanical heating of the output gas; When the vacuum pressure rotary adsorption nitrogen generator (A) in the rapid circulation mechanical nitrogen filling system is started, under the control of the programmed program, the fan (A2) in the vacuum pressure rotary adsorption nitrogen generator (A) extracts the gas in the sealed chamber (1) as raw material gas through the raw material gas extraction pipe (L1) and inputs it into the adsorption tower (A3) filled with zeolite molecular sieve through the connecting pipe (L11). During the process of the raw material gas passing through the zeolite molecular sieve layer, the nitrogen and water molecules in it are adsorbed by the zeolite molecular sieve layer. The oxygen component in the raw gas is removed by venting through the packing layer of the adsorption tower (A3) and the oxygen discharge port (A4) of the adsorption tower. The control valve on the connecting pipe through which the gas flows is opened, and the control valves on other connecting pipes are closed. After completing the adsorption steps of nitrogen and water molecules in the raw gas, the vacuum pressure rotary adsorption nitrogen generator (A) then starts the vacuum desorption process for the nitrogen and water molecules adsorbed in the adsorption tower (A3). At this time, the dry vacuum pump (A5) is connected through the connecting pipe (L22). The nitrogen and water molecules in the adsorption layer of the adsorption tower are desorbed by vacuum and a mixed product gas of nitrogen and water molecules is formed. The mixed product gas achieves a temperature increase of up to 20-80°C in the high temperature chamber of the dry vacuum pump (A5) and is input into the sealed warehouse (1) through the product gas outlet (A6) and the product gas transmission pipeline (L2). The control valve of the pipeline is automatically opened. At this time, a temperature difference effect is formed, that is, "the temperature of the output nitrogen gas flow is greater than the existing temperature of the agricultural products and their packaging in the sealed warehouse at room temperature". A moisturizing effect is formed, that is, the water molecules in the raw gas are not adsorbed during the deoxygenation and nitrogen generation process of the vacuum pressure rotary adsorption nitrogen generator (A) and the existing environmental humidity in the sealed warehouse (1) is maintained. The two effects are superimposed to help the mixed product gas of nitrogen and water molecules input into the sealed warehouse to diffuse and penetrate into the pores of the stored items in the sealed warehouse, shorten the nitrogen filling and insect prevention time, and ensure the stability of the original moisture and quality of the stored items.

2. The rapid circulating mechanical nitrogen filling method for controlled atmosphere insect control in a sealed warehouse according to claim 1, characterized in that: The adsorption tower (A3) comprises at least two adsorption towers connected in parallel to form an adsorption tower group, enabling a switchable alternating operation mode of "one tower adsorption + another tower desorption". The adsorption tower group includes a first adsorption tower (A3-1) and a second adsorption tower (A3-2). A connecting pipe (L11) leading from the outlet of the blower (A2) branches into two gas delivery branches. One branch (L11-1) is connected to the raw material gas inlet of adsorption tower (A3-1), and the other branch (L11-2) is connected to the raw material gas inlet of adsorption tower (A3-2). A connecting pipe (L22) connected to the exhaust port of the vacuum pump (A5) branches into two gas delivery branches. One branch (L22-1) is connected to the exhaust port of adsorption tower (A3-1) during vacuum desorption, and the other branch (L22-2) is connected to the exhaust port of adsorption tower (A3-2) during vacuum desorption. The outlets of the adsorption towers (A3-1) and (A3-2) during vacuum desorption and the inlet of the raw material gas output by the blower (A2) into the adsorption towers (A3-1) and (A3-2) are located at the same end of the adsorption towers. The outlet of the raw material gas after entering the adsorption towers (A3-1) and (A3-2) is connected to the oxygen discharge port (A4) generated by the adsorption towers during the separation of raw material gas through branch pipes (L33-1) and another branch pipe (L33-2), respectively. Control valves are installed on each connecting pipe, branch pipe and exhaust port for oxygen discharge. Zeolite molecular sieves are used as adsorbents to fill the adsorption towers (A3-1) and (A3-2). A dry vacuum pump (A5) is used to vacuum desorb the nitrogen and water molecules adsorbed by the adsorption towers and pump the desorbed gas directly into the sealed chamber (1). During operation of the rapid circulation mechanical nitrogen filling system, the adsorption towers (A3-1) and (A3-2) in the vacuum pressure rotary adsorption nitrogen generator (A) alternately adsorb and desorb nitrogen and water molecules in the raw material gas: Under the control of the programmed program, the blower (A2) in the vacuum pressure rotary adsorption nitrogen generator (A) extracts the gas in the sealed chamber (1) as raw material gas through the raw material gas extraction pipe (L1) and inputs it into the adsorption tower (A3-1) filled with zeolite molecular sieve through the branch pipe (L11-1). During the process of the raw material gas passing through the zeolite molecular sieve layer, the nitrogen and water molecules in it are adsorbed by the zeolite molecular sieve layer, while the oxygen component in the raw material gas will pass through the packing layer and branch pipe (L11-1) of the adsorption tower (A3-1). L33-1), the oxygen discharge port (A4) of the adsorption tower is emptied and removed; while the adsorption tower (A3-1) adsorbs nitrogen and water molecules in the raw gas, the vacuum desorption process of the adsorbed nitrogen and water molecules in the adsorption tower (A3-2) is started simultaneously. At this time, the dry vacuum pump (A5) desorbs nitrogen and water molecules in the adsorption layer of the adsorption tower (A3-2) through the branch pipe (L22-2) and forms a mixed product gas of nitrogen and water molecules. The mixed product gas achieves a temperature increase of up to 20-80°C in the high temperature chamber of the dry vacuum pump (A5) and is input into the sealed chamber (1) through the product gas discharge port (A6) and the product gas transmission pipeline (L2); According to the programmed procedure and electrical control signals, the control valves in the above-mentioned connecting pipes and branch pipes automatically open and close to ensure that there are two or more adsorption tower groups in the system that can perform synchronous operation of atmospheric pressure adsorption and vacuum desorption respectively, and to ensure the automated alternating operation of the "one tower adsorption + one tower desorption" mode.

3. The rapid circulating mechanical nitrogen filling method for controlled atmosphere pest control in a closed warehouse according to claim 2, characterized in that: In a rapid circulating mechanical nitrogen charging system, a "forward thermal purging purification" process is incorporated. First, a product gas return pipeline (L4) with a control valve is connected between the raw material gas inlet (A1) and the product gas delivery pipeline (L2). When the rapid circulating mechanical nitrogen charging system starts up and completes the adsorption step of nitrogen and water molecules in the raw material gas by the adsorption tower (A3-1) according to the programmed procedure, and then transitions to a vacuum desorption process for the adsorbed nitrogen and water molecules, the "forward thermal purging purification" process is then initiated. At this time, the adsorption tower (A3-2) in the rapid circulating mechanical nitrogen charging system is still in the vacuum desorption process step. The product gas return pipeline (L4), the blower outlet, and the adsorption tower (A3-1) in the rapid circulating mechanical nitrogen charging system are connected. The control valves on the branch pipes (L11-1), (L33-1), and (L22-2) between 3-1) are automatically opened. The blower (A2) returns a portion of the mixed product gas formed during the vacuum desorption process of the dry vacuum pump (A5) on the adsorption tower (A3-2) to the adsorption tower (A3-1) through the product gas return pipeline (L4) and the branch pipe (L11-1). This portion of the mixed product gas, which is in a high-temperature state and is returned to the adsorption tower (A3-1), effectively imparts heat energy to activate, desorb, and positively purge and replace the oxygen remaining in the molecular sieve adsorption layer. The purged oxygen is removed by venting through the branch pipe (L33-1) and the oxygen discharge port (A4) of the adsorption tower. The high-temperature mixed product gas fed back into the adsorption tower (A3-1) purges and replaces the residual oxygen in the molecular sieve adsorption layer. At the same time, most of the nitrogen and water molecules in the gas are re-adsorbed by the adsorption layer and, when the process is switched to vacuum desorption of the adsorption tower (A3-1), high-temperature mixed product gas is formed again and fed into the sealed chamber (1) through the product gas outlet (A6) and the product gas transmission pipeline (L2).

4. A rapid circulating mechanical nitrogen filling method for controlled atmosphere insect control in a sealed warehouse according to any one of claims 1, 2, and 3, characterized in that: After connecting a product gas return pipeline (L4) with a control valve between the raw gas inlet (A1) and the product gas delivery pipeline (L2) of the vacuum pressure rotary adsorption nitrogen generator (A), the nitrogen output pipeline of a new nitrogen source (B) is connected to the rapid circulation mechanical nitrogen charging system through any of the following three forms to form a new "zeolite molecular sieve vacuum pressure rotary adsorption nitrogen generator (A) + new nitrogen source (B)" structural combination mode: (1) Connect the nitrogen output pipeline of the new nitrogen source (B) to the product gas return pipeline (L4) through the tee (D). When the rapid circulation mechanical nitrogen charging system is started, the adsorption tower (A3-1) first completes the adsorption of nitrogen and water molecules in the raw material gas, and then the forward purging process is started. During this period, a part of the nitrogen flow from the new nitrogen source (B) passes through the section of the product gas return pipeline (L4) between the tee (D) and the raw material gas inlet (A1) and flows through The blower (A2) and branch pipe (L11-1) are fed into the adsorption tower (A3-1) to purge and replace the oxygen molecules remaining in the zeolite molecular sieve layer. The oxygen that is purged and replaced is discharged through the oxygen discharge port (A4) of the adsorption tower. The remaining nitrogen that does not participate in the purging and replacement is sent to the sealed chamber through the product gas return pipeline (L4) between the tee (D) and the product gas transmission pipeline (L2). When the nitrogen flow from the new nitrogen source (B) is insufficient to meet the gas demand for forward purging of the adsorption tower (A3-1), under the control of the programmed procedure, the blower (A2) uses the negative pressure at the air inlet to return a portion of the mixed product gas output from the dry vacuum pump (A5) to the adsorption tower (A3-1) through the product gas return pipeline (L4) and branch pipe (L11-1). This portion of the high-temperature mixed gas returned to the adsorption tower (A3-1) combines with the nitrogen flow from the new nitrogen source (B) to effectively provide heat energy to activate, desorb, and forward purge the oxygen remaining in the molecular sieve adsorption layer. (2) Connect the nitrogen output pipeline of the new nitrogen source (B) to the product gas transmission pipeline (L2) through a tee (D). When the rapid circulation mechanical nitrogen charging system is started, the adsorption tower (A3-1) first completes the adsorption of nitrogen and water molecules in the raw material gas, and then starts the forward purging process. During this period, the blower (A2) returns a portion of the mixed product gas output by the dry vacuum pump (A5) to the adsorption tower (A3-1) through the product gas return pipeline (L4) and branch pipe (L11-1). This portion of the high-temperature mixed gas returned to the adsorption tower (A3-1) effectively imparts heat energy to activate, desorb and forward purge the oxygen remaining in the molecular sieve adsorption layer. The purged oxygen is removed by venting through the branch pipe (L33-1) and the oxygen discharge port (A4) of the adsorption tower. The nitrogen flow output from the new nitrogen source (B) The nitrogen gas is collected through the tee (D) and enters the product gas transmission pipeline (L2) to replenish the gas and maintain the pressure balance inside and outside the pipeline system. This avoids the fresh air flow from the fresh air pipeline (L3) used for replenishing fresh air, so as to ensure the purity of the nitrogen flow entering the sealed chamber. At the same time, when the mixed product gas output from the dry vacuum pump (A5) is insufficient to meet the gas consumption for forward purging of the adsorption tower (A3-1), a portion of the nitrogen flow from the new nitrogen source (B) is fed into the adsorption tower (A3-1) through the product gas transmission pipeline (L2) between the tee (D) and the raw material gas inlet (A1), the product gas return pipeline (L4), and the fan (A2). The branch pipe (L11-1) connecting the fan outlet and the adsorption tower is then used to purge and replace the oxygen molecules remaining in the zeolite molecular sieve. (3) Connect the new nitrogen source (B) to the raw material gas inlet (A1) of the blower (A2) through the fresh air duct (L3). Start the rapid circulation mechanical nitrogen charging system. Under the control of the programmed program, the adsorption tower (A3-1) in the rapid circulation mechanical nitrogen charging system first completes the adsorption of nitrogen and water molecules in the raw material gas. Then, the forward purging process is started. At this time, part of the nitrogen gas output from the new nitrogen source (B) is input into the adsorption tower (A3-1) through the fresh air duct (L3) and the blower (A2) to purge and replace the oxygen molecules remaining in the zeolite molecular sieve. The purged oxygen is discharged through the oxygen discharge port (A4) of the adsorption tower and removed. The nitrogen output from the new nitrogen source (B) does not participate in the purge of the oxygen molecules remaining in the zeolite molecular sieve. The remaining nitrogen flow after the gas molecules are purged and replaced is introduced into the sealed chamber through the fresh air duct (L3), product gas return pipeline (L4), and product gas supply pipeline (L2) to participate in controlled atmosphere pest control. When the nitrogen flow output from the new nitrogen source (B) cannot meet the gas demand for forward purging of the adsorption tower (A3-1), the blower (A2) will return a portion of the mixed product gas formed during the vacuum desorption process of the adsorption tower (A3-2) by the dry vacuum pump (A5) to the adsorption tower (A3-1) through the product gas return pipeline (L4) and branch pipe (L11-1). This portion of the high-temperature mixed gas returned to the adsorption tower (A3-1) will work together to give heat energy to activate, desorb, and forward purge and replace the remaining oxygen molecules in the molecular sieve adsorption layer. In the above three forms (1), (2), and (3), the nitrogen gas that comes from the new nitrogen source (B) and participates in the purging and replacement will be adsorbed by the zeolite molecular sieve adsorption layer. Under the vacuum action of the dry vacuum pump (A5) through the branch pipe (L22-1) or the branch pipe (L22-2), it will be desorbed again and collected into the mixed product gas. The remaining nitrogen gas that does not participate in the purging and replacement will enter the sealed chamber through the product gas transmission pipeline (L2).

5. The rapid circulating mechanical nitrogen filling method for controlled atmosphere pest control in a closed warehouse according to claim 4, characterized in that: The nitrogen source (B) mentioned is one of the following: membrane nitrogen generator, PSA nitrogen generator, deoxygenator, and vacuum pressure rotary adsorption nitrogen generator.

6. The rapid circulating mechanical nitrogen filling method for controlled atmosphere pest control in a closed warehouse according to claim 1, characterized in that: The dry vacuum pump mentioned includes one of the following: dry screw vacuum pump, claw vacuum pump, Roots vacuum pump, and scroll vacuum pump.

7. A rapid circulating mechanical nitrogen filling system for implementing the method of claim 1, characterized in that: The system includes a vacuum pressure rotary adsorption nitrogen generator (A), a sealed chamber (1), a raw material gas extraction pipeline (L1), and a product gas transmission pipeline (L2). The vacuum pressure rotary adsorption nitrogen generator (A) includes a blower (A2), an adsorption tower (A3) filled with zeolite molecular sieves, a connecting pipeline (L11) between the blower outlet and the adsorption tower, a dry vacuum pump (A5), and a connecting pipeline (L22) between the vacuum pump extraction port and the adsorption tower. The blower outlet (A2) and the raw material gas inlet of the adsorption tower (A3) are connected by a pipeline (L11), and the outlet of the adsorption tower (A3) during vacuum desorption is connected to the extraction port of the dry vacuum pump (A5) by a pipeline. (L22) are connected. The outlet of the adsorption tower (A3) when it is vacuumed and desorbed and the inlet of the raw material gas output by the blower (A2) into the adsorption tower (A3) are both located at the same end of the adsorption tower. The input end of the blower (A2) is the raw material gas inlet (A1), and the output end of the dry vacuum pump (A5) is the product gas outlet (A6). The adsorption tower (A3) is provided with an oxygen discharge port (A4) for discharging the oxygen generated in the adsorption tower during the separation of raw material gas. The raw material gas inlet (A1) is connected to the sealed chamber (1) through the raw material gas extraction pipe (L1), and the product gas outlet (A6) is connected to the sealed chamber (1) through the product gas transmission pipe (L2).

8. The rapid circulating mechanical nitrogen charging system according to claim 7, characterized in that: The adsorption tower (A3) comprises at least two adsorption towers connected in parallel to form an adsorption tower group. The adsorption tower group includes adsorption tower (A3-1) and adsorption tower (A3-2). Two branch pipes branch off from the connecting pipe (L11) leading from the outlet of the blower (A2). One branch pipe (L11-1) is connected to the raw material gas inlet of adsorption tower (A3-1), and the other branch pipe (L11-2) is connected to the raw material gas inlet of adsorption tower (A3-2). Two branch pipes branch off from the connecting pipe (L22) connected to the exhaust port of the vacuum pump (A5). One branch pipe (L22-1) is connected to the exhaust port of adsorption tower (A3-1) during vacuum desorption, and the other branch pipe (L22-2) is connected to the exhaust port of adsorption tower (A3-1) during vacuum desorption. 22-2) Connect to the outlet of the adsorption tower (A3-2) when it is evacuated and desorbed. The outlet of the adsorption tower (A3-1) and the adsorption tower (A3-2) when they are evacuated and desorbed are located at the same end of the adsorption tower. The outlet of the raw material gas output by the blower (A2) into the adsorption tower (A3-1) and the adsorption tower (A3-2) is connected to the discharge port (A4) for discharging oxygen through branch pipes (L33-1) and branch pipes (L33-2), respectively. Control valves are installed on each connecting pipe, branch pipe and discharge port for discharging oxygen.

9. The rapid circulating mechanical nitrogen charging system according to any one of claims 7 and 8, characterized in that: A product gas return pipeline (L4) for the "forward thermal purging purification" process is connected between the raw material gas inlet (A1) of the blower (A2) and the product gas transmission pipeline (L2). The product gas return pipeline (L4) is equipped with a control valve. The inlet end of the product gas return pipeline (L4) is connected to the product gas transmission pipeline (L2), and the outlet end of the product gas return pipeline (L4) is connected to the raw material gas inlet (A1) of the blower (A2). The raw material gas outlet of the blower (A2) is connected to the raw material gas inlets of the two adsorption towers of the adsorption tower group through branch pipes (L11-1) and (L11-2), respectively.

10. The rapid circulating mechanical nitrogen charging system according to claim 4, characterized in that: Connect the nitrogen output pipe of a new nitrogen source (B) to the rapid circulating mechanical nitrogen charging system using any of the following three methods: (1) The nitrogen output pipeline of the new nitrogen source (B) is connected to the product gas return pipeline (L4) through a tee (D); (2) Connect the nitrogen output pipeline of the new nitrogen source (B) to the product gas transmission pipeline (L2) through a tee (D); (3) Connect the new nitrogen source (B) to the raw material gas inlet (A1) of the blower (A2) through the fresh air duct (L3).

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