JP7434438B2 - oxygen reduction system - Google Patents

Description

TECHNICAL FIELD This invention relates to an oxygen reduction system for reducing oxygen.

Conventionally, oxygen reduction systems have been disclosed in, for example, Patent No. 5045758 (Patent Document 1), Patent No. 5021750 (Patent Document 2), Patent No. 4809077 (Patent Document 3), and Patent No. 4679113 (Patent Document 4). ing.

Patent No. 5045758 Patent No. 5021750 Patent No. 4809077 Patent No. 4679113

The problem with conventional systems was that the oxygen concentration in the room became too low.

An oxygen reduction system is a system that reduces oxygen in a room where air is supplied from the outside, and it sucks in the air in the room, reduces oxygen from that air, and supplies nitrogen-enriched air with reduced oxygen to the room. It is also equipped with a device that sends oxygen-enriched exhaust gas to the outside of the room.

In an oxygen reduction system configured in this way, nitrogen-enriched air with reduced oxygen is supplied from the device to the room, but the room is supplied with atmospheric air, so if the system continues to operate, the oxygen concentration will reach an equilibrium state. It can prevent oxygen from decreasing too much. At the beginning of operation, the oxygen percentage in the air in the room is the oxygen percentage in the atmosphere. As operation continues, the oxygen percentage in the room gradually decreases. As a result, the oxygen content of the oxygen-enriched exhaust gas also gradually decreases. When the oxygen percentage of the oxygen-enriched exhaust gas becomes the same as the oxygen percentage of the atmosphere, the oxygen percentage of the atmosphere supplied from the outside to the room and the oxygen percentage of the oxygen-enriched exhaust gas discharged from the room to the outside become the same, and the oxygen percentage in the room becomes the same. The oxygen ratio (nitrogen ratio) is in equilibrium. Therefore, excessive decrease in oxygen can be prevented.

Preferably, the device is located within a room. In this case, by providing the device in the room, it becomes possible to simplify or omit piping between the device and the room.

Preferably, the device is located outside the room, with a first path connecting the room and the device to convey room air to the device, and a first path connecting the room and the device to convey oxygen-depleted air to the room. and a second route for sending. In this case, since no device is installed in the room, the room can be used efficiently. Furthermore, the device can be maintained without entering the room.

FIG. 1 is a schematic diagram of an oxygen reduction system 1 having a nitrogen generator 3 provided inside a room 2 according to a first embodiment. FIG. 2 is a schematic diagram of an oxygen reduction system 1 having a nitrogen generator 3 provided outside a room 2 according to a second embodiment.

Hereinafter, embodiments will be described with reference to the drawings. Identical or corresponding parts are given the same reference numerals and their explanations will not be repeated. It is also possible to combine each embodiment.

(Embodiment 1)
FIG. 1 is a schematic diagram of an oxygen reduction system 1 having a nitrogen generator 3 provided inside a room 2 according to a first embodiment. As shown in FIG. 1, the oxygen reduction system 1 according to the first embodiment is an oxygen reduction system 1 that reduces oxygen in a room 2 to which air is supplied from the outside as shown by an arrow 4. The oxygen reduction system 1 sucks air from a room 2 as shown by an arrow 5, reduces oxygen from the air, and supplies nitrogen-enriched air with reduced oxygen to the room 2 as shown by an arrow 6. A nitrogen generator 3 is provided as a device for sending the increased oxygen-enriched exhaust gas out of the room as indicated by an arrow 7. The nitrogen generator 3 is provided inside the room 2.

Fire prevention systems include equipment such as sprinklers that extinguish fires after they occur, but there are also systems that prevent fires from occurring in advance.

The inert system (Fig. 1), which is one of the systems for preventing fires, is a fire protection system for the interior of the room 2, and is a method of keeping the oxygen concentration in the room lower than that in the atmosphere. The oxygen concentration in the atmosphere is approximately 21% by volume, but if this decreases to around 15%, it becomes difficult to ignite. This property is used to prevent fires by artificially constantly lowering the oxygen concentration in the indoor air that you want to protect. Furthermore, if the oxygen concentration is too low, people and living creatures will suffocate and die, so areas where people may enter and exit are often set at an oxygen concentration of around 12% or higher.

In such an oxygen reduction system 1, even if the inert gas (nitrogen) is continuously fed as shown by the arrow 6, the oxygen concentration inside the room 2 will never drop as much as expected. Air as a raw material flowing in the direction shown by the arrow 5 is supplied from inside the chamber 2. Inert gas is supplied inside the room. By discharging the oxygen-enriched exhaust gas to the outside as shown by arrow 7, a negative pressure is created inside the room 2, and suction air is generated from gaps in the room 2 as shown by arrow 4.

Now consider the material balance regarding the amount of oxygen.

Table 1 shows the data when the aforementioned raw material air amount/product _N2 amount = A/N = 3.5.

Since the amount of raw air shown by arrow 5 is 3.5, and the amount of nitrogen shown by arrow 6 is 1, the amount of oxygen-enriched exhaust gas shown by arrow 7 is 2.5. Furthermore, since the oxygen-enriched exhaust gas indicated by arrow 7 should match the amount of intake air indicated by arrow 4, the amount of intake air is also 2.5.

Assume that the nitrogen concentration is 100% (oxygen concentration 0%) as indicated by arrow 6, and the oxygen concentration in the intake air and the initial room 2 as indicated by arrow 4 is 21%. The amount and concentration of oxygen in the oxygen-enriched exhaust gas at the time of starting the nitrogen generator 3 can be calculated as shown in Table 1. In this state, the amount of oxygen contained in the oxygen-enriched exhaust gas is greater than the amount of oxygen contained in the intake air, so the oxygen concentration in the room 2 decreases. Further, when the oxygen concentration of the air in the room 2 decreases, the amount of raw material air does not change, so the oxygen in the oxygen-enriched exhaust gas also decreases.

When the indoor oxygen concentration drops to 15%, the amount of oxygen in the oxygen-enriched exhaust gas and the amount of oxygen in the intake air match, and the indoor oxygen concentration reaches equilibrium. In other words, even if the nitrogen generator 3 as an inert gas generator continues to operate, in this system, the indoor oxygen concentration will not decrease any further due to physical principles, and it is safe for the human body.

Table 2 shows the amount of oxygen at equilibrium when the flow rate of each gas was changed.

Since the target oxygen concentration is reached simply by continuing to operate the nitrogen generator 3, there is no need to install control based on the indoor oxygen concentration. (However, it may be installed due to running costs). Without control, the number of devices such as oxygen concentration meters, bypasses, and automatic valves would be reduced, resulting in a simple structure. Therefore, the possibility of failure is reduced and the initial cost is reduced. Further, since the tank and indoor air supply line (or oxygen enriched gas line) used in Patent Documents 1 to 4 are not required, space is saved.

Furthermore, with this system, if you place a device such as an N ₂ PSA with an integrated compressor in the room you want to protect, you can complete the inert system by simply attaching a duct to send oxygen-enriched exhaust gas outside. It is only necessary to prepare a device in which only the A/N (flow rate indicated by arrow 5/flow rate indicated by arrow 6) is adjusted in advance, and the system can be installed more easily than a conventional inert system that requires laying piping.

Since oxygen is consumed when humans are active indoors, ventilation (supplying outside air into room 2) is always required. In Patent Documents 1 and 2, ventilation is substantially performed by sending compressed air into the room. Even if other inert systems are not mentioned, the oxygen concentration will decrease unless there is a ventilation fan installed in the room.

In the oxygen reduction system 1 of the embodiment, outdoor air is naturally taken in through the vents or gaps in the room 2 because the indoor pressure is negative, even without installing a ventilation line or the like. There is no need for a separate ventilation system.

The set oxygen concentration is determined only by the A/N and is not affected by the size or shape of the room 2. The speed at which air is replaced in the room 2 changes depending on the flow rate, so by creating a lineup of several flow rates, it can be adapted to any room 2 without changing the design.

A measuring device for measuring the oxygen concentration within the room 2 may be provided. The measuring device continuously measures the oxygen concentration, for example, once every minute. When the oxygen measured by the measuring device falls below a predetermined value, a control device connected to the measuring device can stop the operation of the nitrogen generator 3.

When the acidity concentration measured by the measuring device falls below a predetermined value, an alarm or warning can be given to people in the room 2. The alarm or warning can be provided, for example, by sound or light.

Signs indicating a reduced oxygen atmosphere may be placed at all entrances to the room 2.

The control device that controls the operation of the nitrogen generator 3 collects, processes, and transmits oxygen or other substance measurement results, alarms, failure status indications on monitoring devices, status changes, and resource management information as appropriate. do. The control device can monitor the wiring to safety-related components for breaks and short circuits.

The control device may be capable of recording and storing data of at least one of average oxygen concentration, alarm, warning, failure indication, operating time, and standby time for a predetermined period of time. By retaining these data, it is possible to investigate the cause of an abnormality in the room 2, for example, when a person becomes unwell.

(Embodiment 2)
FIG. 2 is a schematic diagram of an oxygen reduction system 1 having a nitrogen generator 3 provided outside a room 2 according to a second embodiment.

As shown in FIG. 2, the oxygen reduction system 1 according to the second embodiment differs from the oxygen reduction system 1 according to the first embodiment in that the nitrogen generator 3 is placed outside the room 2. different. The room 2 and the nitrogen generator 3 are connected by a pipe 8 as a second route that connects the room 2 and the nitrogen generator 3 and sends nitrogen-enriched air to the room, and a pipe 8 that connects the room 2 and the nitrogen generator 3. The air in the room 2 is then connected to the nitrogen generator 3 by a pipe 9 as a first route.

Air within the room 2 flows within the pipe 9 as indicated by an arrow 5. Air is supplied to the nitrogen generator 3. Nitrogen-enriched air flows through the pipe 8 as shown by arrow 6.

By placing the nitrogen generator 3 outside the room 2 in this manner, the inside of the room 2 can be fully utilized. Furthermore, vibrations and noise of the nitrogen generator 3 can be prevented from being transmitted to the room 2. Even if the nitrogen generator 3 overheats, it will not affect the inside of the room 2.

Although the embodiments of the present invention have been described above, the embodiments shown here can be modified in various ways. First, this oxygen reduction system 1 is used to protect protected areas such as museums and warehouses.

Conversely, by sending oxygen-enriched air into the interior of room 2 and sending nitrogen-enriched air outside of room 2, an oxygen enrichment system can be constructed in FIGS. 1 and 2. Even in this case, external air flows into the room 2 as shown by arrow 4. Air within the room 2 is supplied to the nitrogen generator 3 as indicated by an arrow 5.

This increases the oxygen concentration in the room 2. However, if the operation continues, the oxygen concentration in the nitrogen-enriched air becomes the same as the oxygen concentration in the atmosphere, so the oxygen concentration in the room 2 becomes in an equilibrium state. As a result, it is possible to prevent the concentration of oxygen from increasing excessively.

The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims rather than the above description, and it is intended that all changes within the meaning and range equivalent to the claims are included.

1 Oxygen reduction system, 2 Room, 3 Nitrogen generator, 4-7 Arrow, 8,9 Piping.

Claims (3)

A system for reducing oxygen in a room where air is supplied from the outside,
a device for sucking in air from the room, reducing oxygen from the air, supplying nitrogen-enriched air with reduced oxygen to the room, and sending oxygen-enriched exhaust gas with increased oxygen to the outside of the room; If you continue to do this, the oxygen concentration will reach an equilibrium state, an oxygen reduction system. 2. The oxygen reduction system of claim 1, wherein the device is located within the room. The device is provided outside the room, and a first path connects the room and the device to send air from the room to the device, and a first path connects the room and the device to enrich the air with nitrogen. and a second path for delivering air to the room.

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