JP2684755B2 - Breathing gas supply system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Purpose of the Invention (1) Field of Industrial Application The present invention supplies a gas for breathing to a mask worn by a crew member of an aircraft flying at high altitude where the air is thin. The present invention relates to a breathing gas supply system, and more particularly, to a breathing gas supply system capable of reusing oxygen remaining in the exhaled breath by circulating exhaled breath separated from carbon dioxide in the gas supply passage.

(2) Conventional technology In a conventional aircraft, the in-flight pressure is normally maintained at a value slightly higher than the outside air pressure. Therefore, when the aircraft flies at a high altitude where the air is sparse, the in-flight pressure is reduced and the oxygen partial pressure is also reduced. In this case, there is a problem that the occupant becomes deficient in oxygen and the occupant's judgment becomes dull.

Therefore, an aircraft flying at a high altitude is equipped with a breathing gas supply system that supplies breathing gas from an oxygen supplement mask worn by an occupant. This breathing gas supply system supplies oxygen from an oxygen supply source such as an oxygen cylinder or an oxygen condenser and breathing gas such as air extracted from an engine to the mask, and the pressure of the breathing gas to be supplied. Also decreases as the internal pressure decreases. Then, the oxygen partial pressure of the respiratory gas supplied to the mask is kept substantially constant by increasing the oxygen concentration together with the decrease in the pressure of the respiratory gas. Further, in the conventional breathing gas supply system, the breathing gas supplied to the mask is configured to be discharged into the machine when the mask wearer once inhales and discharges.

However, since the respiratory gas supplied to the mask has a high oxygen concentration, a large amount of oxygen still remains in the gas that the mask wearer inhales once and then exhales, that is, the exhaled breath. Therefore, if such exhaled air containing a large amount of oxygen is directly discharged into the cabin, the produced oxygen is wasted.

To eliminate the waste, the oxygen-rich exhaled air is passed through a carbon dioxide removing device or the like to be regenerated as a gas having a high oxygen ratio, and the regenerated gas is mixed with oxygen from the oxygen supply source to the mask. A circulating breathing gas supply system has been proposed.

(3) Problems to be Solved by the Invention However, in the above-mentioned conventional breathing gas supply system, if the carbon dioxide in the exhaled breath is continuously adsorbed and removed by the adsorbent of the carbon dioxide removing device, There is a problem that the adsorbent gradually deteriorates and the performance deteriorates.

The present invention has been made in view of the above-mentioned circumstances, and by regenerating a carbon dioxide adsorbent that removes carbon dioxide from the breath of a passenger, a respiratory gas supply system that enables continuous use thereof. The challenge is to provide.

B. Configuration of the Invention (1) Means for Solving the Problems In order to solve the problems, the present invention provides a gas supply path for supplying breathing gas extracted from an engine to a mask,
An oxygen supply source connected to the gas supply path to replenish the gas supply path with oxygen, a gas circulation path for circulating the exhaled air discharged into the mask to the gas supply path, and a gas circulation path discharged to the gas circulation path. A carbon dioxide removing device having an adsorbent that adsorbs and removes carbon dioxide in exhaled breath, and a carbon dioxide depleted gas obtained by the carbon dioxide removing device is reused as a breathing gas in a respiratory gas supply system, It is characterized by comprising a regenerating unit for separating carbon dioxide from the adsorbent whose carbon adsorption amount is close to a saturated state, and an exhaust passage for exhausting the separated carbon dioxide from the carbon dioxide removing device.

It is effective that two carbon dioxide removing devices are provided, and one of the carbon dioxide removing devices adsorbs and removes carbon dioxide while the other carbon dioxide removing device regenerates the adsorbent.

Further, as the adsorbent, for example, activated carbon or molecular sieve can be adopted. When these adsorbents are adopted, the regeneration means is composed of a heating tank for heating the adsorbent of the carbon dioxide removing device and a high temperature extraction passage for introducing high temperature air extracted from the engine into the heating tank. be able to.

(2) Operation According to the present invention having the above-described configuration, the breathing gas extracted from the engine to the gas supply path is supplied with oxygen from the oxygen supply source and supplied to the mask, where a part of the oxygen is supplied. Is exhausted into the gas circulation path. The exhaled air discharged to the gas circulation path passes through the adsorbent of the carbon dioxide removing device to become a carbon dioxide depleted gas, is returned to the gas supply path again, and is reused as a breathing gas. When the amount of adsorbed carbon dioxide in the adsorbent of the carbon dioxide removing device approaches a saturated state, the regenerating means separates carbon dioxide from the adsorbent, and the adsorbent is regenerated into a state capable of adsorbing carbon dioxide.

If two carbon dioxide removing devices are provided and the adsorbent is regenerated alternately, one of the carbon dioxide removing devices always functions and carbon dioxide can be removed continuously.

Furthermore, if activated carbon or molecular sieve is adopted as the adsorbent, and the regeneration means is constituted by a heating tank for heating the adsorbent of the carbon dioxide removing device and a high temperature extraction passage for introducing high temperature air extracted from the engine, Heat regeneration of the adsorbent can be performed without using a special heat source.

(3) Example Hereinafter, an example of the present invention will be described with reference to the drawings.

A breathing gas supply system S according to an embodiment of the present invention shown in FIG. 1 is a mask for an occupant of a breathing gas extracted from a compressor of an engine through a contaminant removal filter (not shown), a flow rate adjusting valve 1 and the like. Gas supply path L1 to supply to M
It has. An oxygen supply source 3 such as an oxygen cylinder is connected to a mixing chamber 2 provided in the middle of the gas supply passage L1 via a flow rate adjusting valve 4, and oxygen is supplied to the bleed air from the engine in the mixing chamber 2. The breathing gas is supplied to the inside of the mask M through the gas supply valve 5 and used for breathing of the occupant. Exhaled air of the passenger discharged into the mask M is discharged to the gas circulation path L2 through the gas discharge valve 6 and circulates to the mixing chamber 2 through the gas circulation path L2. Then, part of the exhaled air is discharged into or out of the machine via the exhaust valve 7 provided in the gas circulation path L2.

Two branch passages L2a and L2b are arranged in parallel between a pair of rotary switching valves 8 and 9 which are interlocked with each other and which are interposed in the gas circulation passage L2, and carbon dioxide is provided in each of the branch passages L2a and L2b. Removal devices 10a and 10b are provided. The carbon dioxide removing devices 10a and 10b are selectively connected to the gas circulation path L2 by opening and closing the rotary switching valves 8 and 9. Also,
Gas circulation path L2 connecting the rotary switching valve 9 and the mixing chamber 2
From the above, an auxiliary passage L3 having an orifice 11 in the middle is feedback-connected to the switching valve 9, and an exhaust passage L4 communicating with the outside of the low-pressure machine is connected to the other switching valve 8. In addition,
This exhaust path L4 can be communicated with the inside of the aircraft.

Inside the carbon dioxide removal device 10a, 10b, for example, activated carbon, molecular sieve 4A, molecular sieve 5A,
Alternatively, it is filled with a carbon dioxide adsorbent 12 such as a molecular sieve 13X. As shown in FIG. 2, the adsorbent 12 has a characteristic that the maximum amount of carbon dioxide that can be adsorbed decreases as the temperature rises at any partial pressure of carbon dioxide. Therefore, when the adsorbent 12 that has adsorbed carbon dioxide and reached a saturated state is heated, the adsorbed carbon dioxide is separated and released, and the carbon dioxide is regenerated into a state capable of adsorbing carbon dioxide.

Heating tanks 13a and 13b are provided on the outer circumferences of the carbon dioxide removing devices 10a and 10b so as to surround the adsorbent 12. This heating tank 1
3a, 13b, the interlocking mechanism 14 in the pair of rotary switching valve 8,
A high temperature extraction passage L5a, L5b that guides the high temperature air extracted from the engine through the rotary switching valve 15 that opens and closes in conjunction with 9, and
The high temperature exhaust paths L6a and L6b for discharging the high temperature air to the outside of the machine are connected. The heating tanks 13a and 13b and the high-temperature extraction passages L5a and L5b constitute adsorbent regeneration means.

Next, the operation of the embodiment of the present invention having the above-described configuration will be described.

The breathing gas extracted from the compressor of the engine to the gas supply path L1 reaches the mixing chamber 2 via the flow rate adjusting valve 1,
Here, after oxygen is supplied from the oxygen supply source 3, the oxygen is supplied into the mask M of the occupant through the gas supply valve 5. On the other hand, the breath of the passenger passes through the gas exhaust valve 6 and the gas circulation path L2.
Are discharged to the outside of the machine through the exhaust valve 7.

Most of the exhaled air discharged to the gas circulation path L2 is introduced into one of the carbon dioxide removal devices 10a via the rotary switching valve 8 and the branch path L2a at the positions shown in the figure, and the adsorbent 12 filled in the inside of the carbon dioxide removal apparatus 10a. Pass through. At that time, carbon dioxide contained in the exhaled air is adsorbed and removed by the adsorbent 12, and the air having an increased oxygen ratio is circulated to the mixing chamber 2 through the branch passage L2a, the rotary switching valve 9, and the gas circulation passage L2. , Used again for breathing passengers.

At this time, the heating tank 13b of the other carbon dioxide removing device 10b
Into, the high temperature air extracted from the engine is introduced through the rotary switching valve 15 and the high temperature extraction passage L5b in the illustrated position, and the adsorbent 12 heated by this high temperature air releases the carbon dioxide adsorbed up to that time. To do. Then, a part of the air circulating from the rotary switching valve 9 to the mixing chamber 2 is
The auxiliary passage L3 having the orifice 11, the rotary switching valve 9, and the branch passage L2b are introduced into the carbon dioxide removing device 10b, and the carbon dioxide separated by heating is branched together with the carbon dioxide, the branch passage L2b, the rotary change valve 8, and the exhaust passage. It is released to the outside of the aircraft via L4.

As described above, while performing the adsorption removal of carbon dioxide by the adsorbent 12 of the one carbon dioxide removal device 10a,
The adsorbent 12 of the other carbon dioxide removing device 10b is heated and regenerated. Then, the adsorbent 12 of the carbon dioxide removing device 10a
When the carbon dioxide adsorbs carbon dioxide and approaches a saturated state, the three rotary switching valves 8, 9, 15 are simultaneously switched by the interlocking mechanism 14, and this time the carbon dioxide removing device 10b performs the carbon dioxide adsorption removal. At the same time, the adsorbent 12 of the carbon dioxide removing device 10a is heated and regenerated. By alternately switching the rotary switching valves 8, 9, 15 in this manner, carbon dioxide can be adsorbed and removed by either of the carbon dioxide removing devices 10a, 10b.

According to the above-described embodiment, since two carbon dioxide removing devices are provided to heat and regenerate the adsorbent alternately, one of the carbon dioxide removing devices always functions to continuously remove carbon dioxide. Can be done by

Furthermore, since the high temperature air extracted from the engine is introduced into the heating tank that comes into contact with the adsorbent of the carbon dioxide removing device, the adsorbent can be heated and regenerated without using a special heat source.

As described above, the embodiments of the present invention have been described in detail. However, the present invention is not limited to the embodiments, and various small design changes may be made without departing from the present invention described in the claims. It is possible to do.

For example, the number of carbon dioxide removing devices 10a and 10b does not necessarily have to be two, and can be one or three or more. In addition, the hot air that heats the adsorbent 12 is heated in the heating tank.
Instead of introducing into the inside of 13a, 13b, it is also possible to pass this high temperature air through a pollutant removing filter and then directly introduce into the inside of the carbon dioxide removing devices 10a, 10b filled with the adsorbent 12. By doing so, the separated carbon dioxide can be released to the outside of the machine together with the hot air. Further, instead of heating the adsorbent 12 with the high temperature air extracted from the engine, another heat source such as an electric heater is used.
It is also possible to carry out 12 heatings. Furthermore, as a means for regenerating the adsorbent, carbon dioxide removal devices 10a, 10b
It is also possible to employ a means for sucking and discharging the gas inside to reduce the partial pressure of carbon dioxide inside the gas.

C. Effects of the Invention According to the above-described breathing gas supply system of the present invention, the adsorbent for carbon dioxide that has reached a saturated state is regenerated by the regenerating means into a state capable of adsorbing carbon dioxide. Can be used repeatedly. Therefore,
Not only is it unnecessary to frequently replace the adsorbent of the carbon dioxide removing device, but it is possible to reduce the amount of the adsorbent and downsize the carbon dioxide removing device.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a respiratory gas supply system according to an embodiment of the present invention, and FIG. 2 is a graph showing a temperature characteristic of an adsorbent. M ... Mask, L1 ... Gas supply path, L2 ... Gas circulation path,
L5a, L5b …… High temperature extraction passage, L6a, L6b …… High temperature discharge passage, 3 ...
… Oxygen source, 11a, 11b …… Carbon dioxide remover, 12…
… Adsorbent, 13a, 13b …… Heating tank

Claims (1)

(57) [Claims] 1. A gas supply passage for supplying a breathing gas extracted from an engine to a mask, an oxygen supply source connected to this gas supply passage for supplying oxygen to the gas supply passage, and discharged into the mask. A gas circulation path for circulating exhaled air in the gas supply path, and a carbon dioxide removing device having an adsorbent for adsorbing and removing carbon dioxide in the exhaled air discharged to the gas circulation path are obtained by this carbon dioxide removing device. In the respiratory gas supply system for reusing the obtained carbon dioxide depleted gas as a respiratory gas, a regeneration means for separating carbon dioxide from the adsorbent whose adsorbed amount of carbon dioxide is close to a saturated state, and the separated carbon dioxide A breathing gas supply system comprising a discharge passage for discharging from a carbon dioxide removing device.