EP3160619A1

EP3160619A1 - Air preparation method and device with a carbon dioxide adsorption and oxygen enrichment process

Info

Publication number: EP3160619A1
Application number: EP15731270.3A
Authority: EP
Inventors: August KRINNER
Original assignee: Krinner Drucklufttechnik GmbH
Current assignee: Krinner Drucklufttechnik GmbH
Priority date: 2014-06-25
Filing date: 2015-06-15
Publication date: 2017-05-03
Also published as: DE102014108874A1; WO2015197418A1

Abstract

The invention relates to a method for generating prepared air. The method has the following steps: providing compressed air, reducing the carbon dioxide content of the compressed air in a carbon dioxide adsorption device (22), introducing the compressed air with an optionally reduced carbon dioxide content into a separating device (20), which contains a membrane (13) for separating nitrogen, conducting prepared air away from the separating device (20), conducting separated nitrogen away from the separating device (20), and at least partly regenerating the carbon dioxide adsorption device (22) using at least one part of the separated nitrogen.

Description

AIR TREATMENT PROCESS AND DEVICE WITH CARBON DIOXIDE ADDITION AND

OXYGEN ENRICHMENT

TECHNICAL FIELD The present invention relates to an air treatment method and an air treatment apparatus.

In different applications of medical and technical nature, the use of treated air with reduced carbon dioxide content has proved advantageous. For example, when diving, the use of oxygen-enriched breathing air, also referred to as NITROX, has proven to be advantageous. The benefits of using oxygen-enriched breathing air during dives are well known. In particular, it has been found that oxygen-enriched breathing air having an oxygen content of 32-40 vol.% Is particularly advantageous. Recycled breathing air can also be used in hospitals for medical treatment. Critical in the generation of treated, in particular oxygen-enriched breathing air is the carbon dioxide content in the gas produced. Also in other fields, the use of air with reduced carbon dioxide content is advantageous, such as in applications where compressed air is used for cleaning purposes.

For the preparation of conditioned air, as used in the exemplary application mentioned above, different devices and methods are known. For example, the air can be generated by mixing certain gases with desired proportions. However, this type of production is complicated, since the respective gases must be provided for mixing in a pure state and must be precisely metered. As a way of producing oxygen-enriched breathing air, it is also known to reduce the amount of nitrogen in the ambient air to thereby obtain a gas having an increased oxygen content. SUMMARY OF THE INVENTION

The basic concept of the present invention provides

Air conditioning method comprising the steps of: - providing compressed air;

Reducing the carbon dioxide content of the compressed air in a carbon dioxide adsorption device;

Introducing at least a portion of the reduced carbon dioxide air into a separator containing a membrane for separating nitrogen;

Discharging oxygen-enriched air from the separator;

Removing separated nitrogen from the separator;

At least partially regeneration of the carbon dioxide adsorption device with at least a portion of the separated nitrogen.

Thus, according to the invention, the carbon dioxide content of the compressed air is reduced before it is introduced into the separation device. The compressed air may for example be provided by a compressed air system. Alternatively, compressed air can also be used by a compressor. By using the carbon dioxide adsorption device to reduce the carbon dioxide content of the compressed air prior to at least partially introducing the air into the separator, it has been found that the carbon dioxide content can be reduced extremely efficiently. The air can thus be introduced under pressure into the carbon dioxide adsorption. It has proven particularly advantageous to introduce the air under pressure in a range from 7 to 13 bar, preferably 7-10 bar, into the carbon dioxide adsorption device. However, these ranges are not meant to be limiting. Rather, it is also possible to deviate from this range, and the carbon dioxide adsorption device can be operated to adsorb carbon dioxide under any other suitable overpressure. The carbon dioxide adsorption device works most efficiently under overpressure. This results in a particularly efficient reduction of the carbon dioxide content in the air. The resulting gas mixture is then at least partially fed to the separator. By previously reducing the carbon dioxide content in the air can be avoided that is generated by the separation of nitrogen in the separator, a gas mixture which has too high a carbon dioxide content. Furthermore, the membrane of the separator can operate more efficiently because there is little or no carbon dioxide in the feed gas. This is because oxygen and carbon dioxide molecules take the same route when separated in the membrane because they have similar properties.

According to the invention, at least part of the separated nitrogen is also used for at least partially regenerating the carbon dioxide adsorption device. This has the advantage that the separated nitrogen can be used at least partially. This further increases the efficiency of the overall system. The process should also be applicable to carbon dioxide adsorption devices which have a plurality of carbon dioxide adsorption units which can adsorb carbon dioxide singly or in groups and be regenerated individually or in groups. An at least partial regeneration should be understood against this background in that at least a part or an element of the carbon dioxide adsorption device is regenerated. If, in the following, therefore, a regeneration of the carbon dioxide adsorption device is mentioned, it is to be understood that this is regenerated at least in sections.

According to another embodiment of the present invention, it is determined in a further step whether a regeneration of the carbon dioxide adsorption device is required. At this time, it is determined that the regeneration of the carbon dioxide adsorption device is required when it is determined that its adsorption performance has deteriorated. Such a determination can be made, for example, at predetermined time intervals. Furthermore, such determination can also be carried out continuously. It is also possible to link the step of determining to certain events, such as switching on a device for carrying out the method. A deterioration of the adsorption performance is to be understood as a reduction of the adsorption under constant conditions. According to another embodiment of the present invention, it is found that the adsorption performance has deteriorated when a certain operating time of the carbon dioxide adsorption has elapsed since the last regeneration. Accordingly, according to this embodiment, the operation time of the carbon dioxide adsorption device can be monitored. This means that, for example, a counter can be reset after each regeneration of the carbon dioxide adsorption device. The predetermined operation time may be set depending on the carbon dioxide adsorption device. Namely, depending on the type of the carbon dioxide adsorption device, the carbon dioxide adsorption device is capable of adsorbing different amounts of carbon dioxide. Conveniently, the predetermined operating time is determined so that a predetermined adsorption capacity is not exceeded. For example, if it is known that the carbon dioxide adsorption device can no longer adsorb carbon dioxide under predetermined conditions after a certain time, the predetermined operating time can be selected, for example, such that it is set half as long as the determined time. The regeneration thus takes place according to this embodiment as a function of the operating time of the carbon dioxide adsorption device. The operating time can be understood as the time at which the carbon dioxide adsorption device actually adsorbs carbon dioxide.

According to a further embodiment, it is found that the

Has deteriorated adsorption performance when the carbon dioxide content of the derived from the carbon dioxide adsorption gas exceeds a predetermined value. For this purpose, the carbon dioxide content of the discharged gas may be measured at an exit of the carbon dioxide adsorption device. Such a measurement can take place at predetermined time intervals or continuously. The predetermined value of the carbon dioxide content of the discharged gas can be set in various ways. So it is possible, for example, to set a predetermined value, which may be exceeded in any case. Alternatively, however, it is also possible to compare the carbon dioxide content of the discharged gas with the carbon dioxide content of the introduced gas and set a predetermined difference of the carbon dioxide contents as a predetermined value. Such monitoring of carbon dioxide content opens the possibility to draw accurate conclusions about the adsorption performance and thereby determine exactly when a regeneration of the carbon dioxide adsorption is necessary.

According to another embodiment of the present invention, the carbon dioxide adsorption device has at least two carbon dioxide adsorption units containing carbon dioxide adsorption units, wherein at least one of the carbon dioxide adsorption units is regenerated during the regeneration of the carbon dioxide adsorption device. Thus, according to this embodiment, it is not necessary that all the carbon dioxide adsorption units be regenerated at the same time. Rather, it is possible to regenerate only one carbon dioxide adsorption unit while the other carbon dioxide adsorption units are used or unused. However, it is also possible to regenerate several carbon dioxide adsorption units simultaneously. This means in the context of the overall process, as described so far, that the separated nitrogen is passed through at least one of the carbon dioxide adsorption units during the regeneration of the carbon dioxide adsorption device. Overall, according to this embodiment, a regeneration of the carbon dioxide adsorption device is thus to be understood as the state that at least one carbon dioxide adsorption unit is regenerated. The carbon dioxide adsorbent is a known carbon dioxide adsorbent. This may in particular be in granular form and be filled accordingly in a pressure vessel. To reduce the carbon dioxide content, the gas mixture can then be passed through the filled with granular carbon dioxide adsorbent pressure vessel. In this connection, the carbon dioxide adsorbed gas exiting the carbon dioxide adsorption device may be filtered in a further step before being supplied to the separator. By means of such a filtering step, it is possible to prevent particles from the carbon dioxide adsorption device from entering a downstream device, for example the separating device. Thus, the purity of the gas discharged from the carbon dioxide adsorption device is increased and contamination of downstream devices such as the separator is avoided. According to another embodiment of the present invention, at least one of the carbon dioxide adsorption units adsorbs carbon dioxide during the regeneration of the carbon dioxide adsorption device. Adsorption of carbon dioxide by the carbon dioxide adsorption device thus also takes place during the regeneration thereof. This has the advantage that a continuous production of air with reduced carbon dioxide content is possible. Continuously, in this context, it should be understood that there is no significant interruption of the production of treated air. Such interruptions may occur, for example, when it is determined that a carbon dioxide adsorption unit no longer has sufficient carbon dioxide adsorption and therefore needs to be regenerated. For this purpose, it is usually necessary to exchange the deteriorated carbon dioxide adsorption unit for a regenerated carbon dioxide adsorption unit or to redirect a flow of the gas introduced into the carbon dioxide adsorption device accordingly. This switching can lead to a brief drop in pressure or to a short-term reduction in the outflow of air from the carbon dioxide adsorption device. A pressure drop occurs, for example, when a pressure equalization between the carbon dioxide adsorption is effected when switching. However, such a brief interruption is irrelevant to the overall process under certain circumstances. If, for example, the gas discharged from the carbon dioxide adsorption device is fed to a pressure accumulator, a short-term reduction in volume flow or a pressure drop does not have any effect. However, if the carbon dioxide adsorption device is subsequently provided with a compressor for pressurizing the discharged air with reduced carbon dioxide content, then it is necessary to obtain a constant volume flow even over the switching operation of the directional control valves. Usually, such a compressor operates in a specific nominal range and therefore compresses a predetermined amount of air. If too little air is supplied to this compressor, a negative pressure is created in the supply line to this compressor. In order to prevent damage to the device, it is therefore necessary to provide a vacuum valve which opens in the event of excessive negative pressure. However, when the valve opens, more air enters the line. Since this air has no reduced carbon dioxide content, the carbon dioxide content of the air before the compressor increases. It is thus not possible over the switching over a time ensure consistently low carbon dioxide levels in the air. In order to counteract a negative pressure development, an overflow valve can be provided between the inlet line and the carbon dioxide adsorption device. At the inlet, air can then be provided either from the pressure line or from a compressor with an amount which is above the desired amount of air at the inlet of the carbon dioxide adsorption device. The overflow valve thus leaves air in normal operation, so that at the entrance of the carbon dioxide adsorption a predetermined amount of air flow is not exceeded. If a part of the air is branched off in the carbon dioxide adsorption device for pressure equalization purposes, then the volume flow through the carbon dioxide adsorption unit can be maintained due to the overflow valve. Namely, if a larger volume of air flow at the entrance of the carbon dioxide adsorption required, the overflow valve closes accordingly and the volume flow at the exit increases thereby. Thus, by providing an overflow valve in front of the carbon dioxide adsorption device, a continuous operation of a downstream compressor is possible, which is used for example for pressure bottle filling.

According to another embodiment of the present invention, the

Heated carbon dioxide adsorbent of the regenerated carbon dioxide adsorption unit for regeneration. In this case, it is possible, for example, to heat a container in which the carbon dioxide adsorbent is located. For this purpose, a corresponding heating device can be provided. On the other hand, it is possible to heat the carbon dioxide adsorbent by heating the gas to be introduced for regeneration.

According to another embodiment, in this connection, the nitrogen used for the regeneration of the carbon dioxide adsorption device is heated to a predetermined temperature. The predetermined temperature is desirably chosen so that optimal regeneration of the carbon dioxide adsorbent can take place. This is the case when the carbon dioxide adsorbent is heated to a temperature at which the carbon dioxide adsorbent can best deliver the adsorbed carbon dioxide. The heating of the nitrogen can be done for example by a separate heater, through which the nitrogen to be used for the regeneration is passed. It is possible that the heater heats the nitrogen to a constant temperature. Alternatively, however, it is also possible to first heat the nitrogen more strongly at the beginning of each regeneration in order to heat the carbon dioxide adsorbent in the carbon dioxide adsorption unit to be regenerated faster to an optimum temperature for the regeneration. In this connection, it is thus possible to first heat the nitrogen to a higher temperature and, after a predetermined time, to control the temperature of the nitrogen to the temperature corresponding to the temperature to which the carbon dioxide adsorbent is to be brought. As a result, a particularly efficient regeneration of the carbon dioxide adsorption unit is possible. It has been found that the carbon dioxide adsorbed in the carbon dioxide adsorbent can be absorbed particularly well by the gas used for the regeneration when the carbon dioxide adsorbent is heated to 40-70 ° C. To achieve such heating, the gas used for regeneration can be heated to about 40-70 ° C. In this context, the gas used for regeneration can be relaxed, that is, the gas used has a pressure of about 0.5 bar. However, it is possible to deviate from both the above-mentioned temperature range and the stated pressure to the extent that sufficient regeneration is ensured.

According to another embodiment of the present invention, the introduction of the compressed air into the regenerated carbon dioxide adsorption unit takes place only when the temperature of the carbon dioxide adsorbent of the regenerated carbon dioxide adsorption unit is below a predetermined temperature. This step takes account of the fact that optimum regeneration of the carbon dioxide adsorbent occurs at a different temperature level than the adsorption of carbon dioxide from the compressed air. In order to ensure that both the most efficient carbon dioxide adsorption and the most efficient regeneration of the carbon dioxide adsorption takes place, it is advantageous to adjust the temperature of the carbon dioxide adsorbent to the appropriate conditions. This has the advantage that the carbon dioxide adsorption device can be operated more efficiently overall. A lowering of the temperature of the carbon dioxide after the

Regeneration can be done in different ways. For example, it is possible to actively cool the regenerated carbon dioxide adsorption unit by a corresponding cooling device. Alternatively, however, it is also possible to pass the nitrogen used for regeneration after the regeneration of the carbon dioxide adsorbent for a predetermined time by the carbon dioxide adsorbent without heating it. The carbon dioxide adsorbent is thus cooled by the separated nitrogen. This has the advantage that no additional elements for cooling the carbon dioxide adsorbent must be provided. It is also possible to wait a predetermined time before using the regenerated carbon dioxide adsorption unit until it has cooled to ambient temperature.

According to another embodiment of the present invention, the

Monitored temperature of the carbon dioxide adsorption. This makes it possible to continuously detect the temperature of the carbon dioxide adsorption units and to provide these detected values to a control. Thus it is possible to regulate the temperature of the carbon dioxide adsorption units to those for the current process, ie the adsorption of carbon dioxide or the regeneration, to the optimum temperature. This makes it possible to make both the adsorption of carbon dioxide, as well as the regeneration of the respective carbon dioxide adsorption as efficient as possible. Further, by monitoring the temperature of the carbon dioxide adsorption units, it is possible to avoid overheating of the carbon dioxide adsorption units. For example, if the temperature of the nitrogen exceeds a predetermined value due to malfunction of an upstream heater for heating the nitrogen to be introduced, it is possible that the carbon dioxide adsorbent in the carbon dioxide adsorption units is excessively heated, thereby deteriorating its adsorbing ability of carbon dioxide. Accordingly, the temperature monitoring of the carbon dioxide adsorption units may be coupled to such a heater and shut off according to the detected temperature, if necessary. With appropriate monitoring of the temperature of the carbon dioxide adsorption units, overheating and resulting damage to the carbon dioxide adsorption units can thus be avoided. [0017] According to another embodiment of the present invention, the compressed air is introduced into the regenerated carbon dioxide adsorption unit when a predetermined time has elapsed since the regeneration of the regenerated carbon dioxide adsorption unit. The predetermined time since the regeneration can be set so that the regenerated carbon dioxide adsorption unit, or its carbon dioxide adsorbent, cools to such an extent that at least a predetermined temperature of the carbon dioxide adsorption unit is not exceeded for efficient carbon dioxide adsorption. The predetermined time is thus set so that a corresponding cooling is done safely. This has the advantage that an exact monitoring of the temperature of the carbon dioxide adsorption units is not required. Thus, it can be ensured in a cost effective manner that the carbon dioxide adsorption units operate in the adsorption of carbon dioxide in an optimal temperature range.

According to another embodiment of the present invention, to reduce the temperature of the regenerated carbon dioxide adsorption unit, nitrogen separated from the separator is used at a temperature lower than the temperature of the carbon dioxide adsorbent of the regenerated one

Carbon dioxide adsorption unit is. Accordingly, to cool the temperature of the carbon dioxide adsorption unit, the separated nitrogen may be used if it has a temperature lower than the temperature level of the regenerated carbon dioxide adsorption unit or the carbon dioxide adsorbent contained therein. For example, the separated nitrogen from the separator may be directly supplied to the regenerated carbon dioxide adsorption unit. This accelerates the cooling of the regenerated carbon dioxide adsorption unit.

According to another embodiment of the present invention, the

Method have a step to dehumidify the compressed air. Dehumidification has the advantage that the carbon dioxide adsorption device can work more efficiently. In addition, it is possible to introduce compressed ambient air into the device.

According to another aspect of the present invention there is provided an air handling apparatus comprising the following elements: a compressor for pressurizing ambient air, an inlet line for pressurized air,

a separator disposed downstream of the inlet conduit for reducing the nitrogen content of at least a portion of the pressurized air, the separator comprising a nitrogen blanking membrane, a second increased oxygen content gas exit, and a first nitrogen outlet gas outlet.

According to the invention in the flow path between the inlet pipe and the

Separator arranged a regenerable carbon dioxide adsorption device. In this case, its input can be connected to the inlet line and its output can be connected to the separating device.

Furthermore, the regenerable carbon dioxide adsorption device may comprise at least two carbon dioxide adsorption units containing carbon dioxide adsorbents. Each of these carbon dioxide adsorption units may have an inlet and an outlet. Also, the regenerable carbon dioxide adsorption device may include a directional control valve mechanism configured such that the inlets of the at least two carbon dioxide adsorption units are alternately connectable to the inlet of the carbon dioxide adsorption device and the environment and their outlets are alternately connectable to the exit of the carbon dioxide adsorption device and the second exit of the separation device. By this way valve mechanism, it is therefore possible to provide different gas flow paths.

On the one hand, the entrance of a carbon dioxide adsorption unit with the

Entrance of the carbon dioxide adsorption device are connected. As already described above, according to the invention, the carbon dioxide adsorption device is located between the dryer and the separating device. Accordingly, pressurized and dehumidified ambient air is introduced into the inlet of the carbon dioxide adsorption device. If the input of a carbon dioxide adsorption unit is now connected to the inlet of the carbon dioxide adsorption device, then the pressurized and dehumidified ambient air introduced into this carbon dioxide adsorption.

On the other hand, the inlet of the carbon dioxide adsorption unit with the

Connected to the environment. This means that a gas contained in the carbon dioxide adsorption unit can escape into the environment.

The outlet of the carbon dioxide adsorption unit can be connected to the outlet of the carbon dioxide adsorption unit. If this is the case, due to the arrangement of the carbon dioxide adsorption device, the gas guided through the carbon dioxide adsorption unit is then discharged through the outlet of the carbon dioxide adsorption device and fed to the separation device in the further course of the system. The gas exiting the exit of the carbon dioxide adsorption device thus has a reduced carbon dioxide content.

On the other hand, the outlet of the carbon dioxide adsorption unit is also connectable to the second outlet of the separation device. As already described above, separated nitrogen is discharged through the second outlet of the separator. That is, in the case where the outlet of the carbon dioxide adsorption unit is connected to this second outlet of the separator, the separated nitrogen is supplied to the carbon dioxide adsorption unit. The separated nitrogen is thus used as a regenerant for regenerating the carbon dioxide absorption unit. Thus, as is apparent from the above-described circuit of the directional control valve mechanism, the ambient air may be passed through the carbon dioxide adsorption unit for reducing the carbon dioxide content in one direction, while the separated nitrogen may be passed in the opposite direction through the carbon dioxide adsorption unit to regenerate it. According to the above structure, the directional control valve mechanism may connect one or more inlets to the inlet of the carbon dioxide adsorption device or the environment and connect one or more outlets to the exit of the carbon dioxide adsorption device or the second outlet of the separation device. This makes it possible to simultaneously introduce ambient air into a plurality of carbon dioxide adsorption units or to simultaneously introduce nitrogen into a plurality of carbon dioxide adsorption units. Thus, for example, it is possible to increase the carbon dioxide adsorption performance of the carbon dioxide adsorption device by connecting several carbon dioxide adsorption units in parallel. On the other hand, it is also possible to carry out a regeneration of several carbon dioxide adsorption units by connecting several carbon dioxide adsorption units in parallel.

According to another embodiment of the present invention, has

The apparatus further comprises a compressor for pressurizing ambient air, wherein the compressor is disposed upstream of the inlet duct to supply pressurized ambient air to the inlet duct.

According to a further embodiment of the invention, the apparatus has a dryer disposed upstream of the carbon dioxide adsorption device for dehumidifying the pressurized air, the dryer being connected to the inlet duct to supply dehumidified air to the inlet duct.

According to another embodiment of the present invention, the

Directional control valve mechanism, a first directional control valve, which is arranged so that it simultaneously connects one of the inlets of the carbon dioxide adsorption with the entrance of the carbon dioxide adsorption and another of the inlets with the environment. Further, the directional control valve mechanism according to this embodiment has a second directional control valve arranged to simultaneously connect one of the outlets of the carbon dioxide adsorption units to the exit of the carbon dioxide adsorption device and another one of the outlets to the second outlet of the separator. The first directional control valve is thus designed such that whenever the inlet of a carbon dioxide adsorption unit is connected to the inlet carbon dioxide adsorption device, the inlet of another carbon dioxide adsorption unit the environment is connected. Likewise, coupling one outlet of a carbon dioxide adsorption unit to the exit of the carbon dioxide adsorption device through the second directional control valve results in communication of another outlet with the second outlet of the separation device.

According to a further embodiment of the invention, the first and the second directional control valve are coupled in such a manner that the outlet of the carbon dioxide adsorption unit, whose inlet is connected to the environment, is connected to the second outlet of the separation device, whereby this carbon dioxide adsorption unit is brought into a regeneration state and that the outlet of the carbon dioxide adsorption unit whose inlet is connected to the inlet of the carbon dioxide adsorption device is connected to the outlet of the carbon dioxide adsorption device, whereby this carbon dioxide adsorption unit is brought into an adsorption state. The two-way valves are thus switched so that one carbon dioxide adsorption unit is in the regeneration state, while another carbon dioxide adsorption unit is in an adsorption state.

In the regeneration state, the carbon dioxide adsorption unit of the

Separating device derived nitrogen supplied through the outlet. This flows through the carbon dioxide adsorption unit and the carbon dioxide adsorbent contained therein thus leaves the carbon dioxide adsorption unit through its inlet and is discharged into the environment.

In the carbon dioxide adsorption unit which is in the adsorption state, pressurized and dehumidified ambient air is introduced through the inlet thereof. This is passed through the carbon dioxide adsorption unit or the carbon dioxide adsorbent therein and fed through the outlet of the separator. By this switching arrangement of the two-way valves therefore a continuous operation of the device is possible. It can be switched between different carbon dioxide adsorption without significant interruption of the production of treated air, with a Carbon dioxide adsorption unit is a carbon dioxide adsorption while another carbon dioxide adsorption unit is regenerated.

According to a further embodiment of the invention, the

Carbon dioxide adsorption device further comprises heating means for heating the carbon dioxide adsorbent of the carbon dioxide adsorption unit to be regenerated. For each carbon dioxide adsorbent there is a temperature at which carbon dioxide adsorption is particularly efficient. In particular, in cold environments where the device is operated, it may therefore be advantageous to heat the carbon dioxide adsorbent to ensure optimal carbon dioxide adsorption. Furthermore, the carbon dioxide adsorbent for regeneration can be heated to an optimum temperature. This temperature for regeneration may be above the temperature for adsorbing carbon dioxide. If so, it is advantageous to use the heating means to heat the carbon dioxide adsorbent to the desired temperature for regeneration. It is advantageous if the heating means has a heater for heating the separated nitrogen, which is arranged between the second output of the separator and the second directional control valve. By this arrangement, the heated nitrogen can be used to heat the carbon dioxide adsorbent of the carbon dioxide adsorption unit to be regenerated. If the carbon dioxide adsorbent is a granulate which is in the carbon dioxide adsorption unit, this has the advantage that the heated nitrogen flows through this granulate and good heating of the carbon dioxide adsorbent can be achieved.

Alternatively or additionally, the heating means a heater for direct

Heating the carbon dioxide adsorbent have. Such a heater may, for example, heat the carbon dioxide adsorption unit as a whole. For example, when the carbon dioxide adsorption unit is a container in which granules are contained as a carbon dioxide adsorbent, the container can be heated by the heater. Of course, it is also possible to heat further heating elements, which are provided in the granules, in order to achieve the most uniform possible heating of the carbon dioxide adsorbent. According to another embodiment of the present invention, each has

Carbon dioxide adsorption unit a pressure vessel in which the carbon dioxide adsorbent is housed in opposite directions permeable. In the case where a granulate is used as the carbon dioxide adsorbent, it may be arranged between two screens to prevent the carbon dioxide adsorbent from escaping from the pressure vessel. Preferably, the pressure vessels are connected to each other by a pressure equalization line. The connection of the pressure vessel with each other by a pressure equalization line is advantageous because this allows that when switching the pressure vessel from a regeneration state into an adsorption state, the pressure of one container can be compensated with the pressure of the other container. Furthermore, a pressure compensation valve is provided in the pressure equalization line, which is a shut-off valve. By opening and closing this shut-off valve, pressure equalization can be enabled or prevented.

Advantageously, the first directional control valve is connected via a drain line to the environment. At the end of this drain line, a silencer may be provided. Furthermore, a bleed valve, which is a shut-off valve, may be provided in the bleed line. Opening and closing the drain valve can break a connection with the environment.

An advantageous switching operation in the carbon dioxide adsorption apparatus in which the carbon dioxide adsorption units are brought from the adsorption state to the regeneration state by the directional control valves, and vice versa, can be carried out as follows. First, the pressure equalization valve is opened and preferably at the same time the drain valve is closed. As a result, pressurized air from the carbon dioxide adsorption unit to be regenerated flows into the regenerated carbon dioxide adsorption unit, whereby pressure equalization takes place between both carbon dioxide adsorption units.

Once the pressure is equalized, the two directional control valves are switched so that the inlet of the regenerated carbon dioxide adsorption unit is connected to the inlet of the carbon dioxide adsorption device and the outlet of the regenerated carbon dioxide adsorption unit is connected to the outlet of the carbon dioxide adsorption unit. adsorption device is connected. Due to the pressure equalization before switching over the directional control valves, the regenerated carbon dioxide adsorption unit already has an internal pressure which corresponds to the pressure at the inlet of the carbon dioxide adsorption device. Once the inlet and outlet of the regenerated carbon dioxide adsorption unit are connected to the inlet and outlet of the carbon dioxide adsorption apparatus, the carbon dioxide adsorption is continued and the discharged gas is immediately discharged at a pressure prevailing before switching at the outlet of the carbon dioxide adsorption apparatus. The carbon dioxide adsorption unit to be regenerated also has a pressure level when switching, which corresponds to the pressure level at which the compressed air is introduced into the carbon dioxide adsorption device. Immediately after switching the directional control valves, in which the carbon dioxide adsorption unit to be regenerated is brought to the regeneration state, the pressure compensation valve is closed and the drain valve is opened. The gas which is to be regenerated in the carbon dioxide adsorption unit which is to be regenerated is thus released into the environment extremely rapidly. It can come to a kind of bang. This rapid pressure reduction in the regenerated state carbon dioxide adsorption unit has the advantage that a part of the bound carbon dioxide is entrained by the gas flow.

In order to avoid a reduction in the volume flow at the outlet of the carbon dioxide adsorption in the above-described switching with pressure equalization, may be provided in the flow path before the carbon dioxide adsorption and after the inlet, a spill valve. This is important, for example, when a compressor is arranged downstream of the carbon dioxide, which requires a continuous inlet flow. The spill valve may regulate the amount of air introduced into the carbon dioxide adsorption device to a predetermined value. In this case, part of the air can be released to the environment. Thus, the overflow valve can be supplied with a larger amount of air than the amount desired in the carbon dioxide adsorption device. If pressure equalization takes place between the carbon dioxide adsorption units, the upstream overflow valve can compensate for the reduced volume flow at the outlet by correspondingly less air to the environment. As a result, a reduced volume flow at the outlet of the carbon dioxide adsorption device can be avoided.

According to another embodiment of the present invention, the method described above is performed in the apparatus described above.

According to an alternative embodiment of the present invention is a

Air treatment process provided with the following steps:

Providing compressed air;

Introducing at least a portion of the compressed air into a separator containing a membrane for separating nitrogen;

Discharging oxygen-enriched air from the separator;

Reducing the carbon dioxide content of the oxygen-enriched air in a carbon dioxide adsorption device;

In this embodiment, therefore, the compressed air in the

Separator introduced without passing through the carbon dioxide adsorption. All method steps and procedures described above are also applicable to this alternative.

According to an alternative embodiment of the present invention, there is provided an air conditioning apparatus comprising the following elements:

a compressor for pressurizing ambient air, an inlet line for pressurized air,

a separator arranged downstream of the inlet duct for reducing the nitrogen content of at least a portion of the pressurized air, the separator comprising a membrane for separating nitrogen, a second outlet for the recovered gas with increased Oxygen content, a first output for discharging the separated nitrogen and having an inlet connected to the inlet line. In this alternative, a regenerable carbon dioxide adsorption device for reducing the carbon dioxide content of the oxygen-enriched air is also connected to the inlet line. Furthermore, in this alternative, an arrangement is provided for at least partially regenerating the carbon dioxide adsorption device with at least a portion of the separated nitrogen.

This arrangement can be arranged as in the above

Embodiments is defined, in which the separation device is connected in the flow downstream of the carbon dioxide adsorption. In particular, the arrangement for regenerating the carbon dioxide adsorption device described in the above embodiments can be applied to this embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows schematically the structure of a device for producing conditioned air according to a first embodiment.

Figure 2 shows schematically the structure of a carbon dioxide adsorption device which can be used in the construction shown in Figure 1.

FIG. 3 shows the carbon dioxide adsorption device of FIG. 2 in another

Switching state.

FIG. 4 schematically shows an alternative construction of a device for producing conditioned air.

FIG. 5 schematically shows a further alternative construction of a device for

Production of recycled air.

EMBODIMENTS

In the following, embodiments of the invention will be explained with reference to the figures.

An embodiment of the present invention will be described with reference to FIG. Fig. 1 is a schematic view showing the structure of a conditioned air producing apparatus. The structure described below is particularly well suited for generating oxygen-enriched breathing air. First, the basic structure of the apparatus will be explained with reference to the illustration in FIG.

The illustrated in Fig. 1 apparatus for producing conditioned air has a compressor VI, which is connected to an inlet or inlet 21 for compressed ambient air. The compressor has predetermined characteristics which include the rated pressure as well as the throughput of the compressed air. In the flow direction after the inlet 21 for compressed ambient air, a refrigerant dryer 4 is arranged. This refrigeration dryer 4 may have an integrated Kondensatabieiter. The derived condensate is fed to a collecting container 19. Of the Refrigeration dryer 4 cools the incoming compressed ambient air so far that falls below the dew point, the water contained in the air and thus can be removed from the air.

In the flow direction after the refrigerant dryer 4, a carbon dioxide adsorption device 22 is provided. In this carbon dioxide adsorption device 22, the pressurized and dehumidified ambient air flows. The carbon dioxide adsorption device 22 reduces the carbon dioxide content of the introduced ambient air.

In the flow direction after the carbon dioxide adsorption device 22, a separator 20 is arranged. The separator has an inlet 13a for the compressed and dehumidified ambient air, a membrane 13 for separating nitrogen, a first outlet 13b for discharging the separated nitrogen and a second outlet 13c for the recovered gas with increased oxygen content. As shown in FIG. 1, the first exit 13b is connected to the carbon dioxide adsorption device 22. Thereby, it is possible to supply the carbon dioxide adsorption device 22 with the nitrogen separated in the membrane 13. The oxygen-enriched breathing air is released via the second outlet 13c. The inventive arrangement of the system components described above thus results in a reduction of the carbon dioxide content before separation in the membrane 13. Desirably, the carbon dioxide adsorption device 22 operates in an overpressure range of about 7 to 13, preferably 7 to 10 bar.

The structure and operation of the carbon dioxide adsorption device 22 will be explained below with reference to FIGS. 2 and 3.

The structure of the carbon dioxide adsorption device 22 will first be explained in detail with reference to FIG. As shown in FIG. 2, the carbon dioxide adsorption device 22 has a first carbon dioxide adsorption unit 23 and a second carbon dioxide adsorption unit 24.

The first carbon dioxide adsorption unit 23 has a pressure vessel 23c, an inlet 23a and an outlet 23b. Furthermore, the first carbon dioxide adsorption unit 23 has a thermometer 23d and a pressure gauge 23e. Of the Pressure vessel 23c of the first carbon dioxide adsorption unit 23 is filled with a carbon dioxide adsorbent (not shown). The carbon dioxide adsorbent may be granular. In this case, advantageously, in each case a sieve can be arranged before and after the carbon dioxide adsorbent in order to prevent the carbon dioxide adsorbent from escaping from the pressure vessel 23c. In practice, the pressure vessel 23c may be a stationary pressure vessel. According to an advantageous embodiment, the inlet of such a stationary pressure vessel 23c is located at the lower end, so that the gas introduced into the inlet flows through this vessel from the bottom to the top. The screen between the carbon dioxide adsorbent and the inlet 23a may conveniently be formed as a sieve bottom which traps the carbon dioxide adsorbent and evenly distributes the incoming gas to the carbon dioxide adsorbent. In a vertical arrangement of the pressure vessel 23c, the outlet 23b is expediently arranged at the upper end of the pressure vessel 23c. There, the second screen may be mounted to prevent the carbon dioxide adsorbent from being entrained by the flow. A particulate filter 34 is disposed in the outlet 22b of the carbon dioxide adsorption device 22.

The second carbon dioxide adsorption unit has according to this

Embodiment an identical structure. More specifically, the second carbon dioxide adsorption unit 24 has a pressure vessel 24c, an inlet 24a, an outlet 24b, and a thermometer 24d and a pressure gauge 24e. The internal structure or the filling of the pressure vessel 24c with carbon dioxide adsorbent corresponds to that of the first carbon dioxide adsorption unit 23. The inlet 23a of the first carbon dioxide adsorption unit 23 and the inlet 24a of the second carbon dioxide adsorption unit 24 are connected to a first directional control valve 25 via pressure lines 38, 39. The first directional control valve 25 is connected to the inlet 22 a of the carbon dioxide adsorption device 22. Furthermore, the first directional control valve 25 is connected to the environment via a discharge line 37. In the discharge line 37, a drain valve 31 and a muffler 30 are arranged, through which the gas flowing from the first directional control valve 25 can be discharged into the environment.

The first directional control valve 25 is switchable between two switching positions. In

Fig. 2 shows a first switching position is shown. Is the first directional control valve 25 in this In the first switching position, the inlet 22a of the carbon dioxide adsorption device 22 is connected to the pressure line 38, and the outlet line 37 is connected to the pressure line 39 leading to the inlet 24a of the second carbon dioxide adsorption unit 24.

The outlets of the carbon dioxide adsorption units 23b, 24b are connected via pressure lines 40, 41 to a second directional control valve 26. Furthermore, the second output 13b of the separation device 20 is connected to the second directional control valve. In the line of the second output 13b, a heater 27 is arranged. Furthermore, the second directional control valve 26 is connected to the outlet 22b of the carbon dioxide adsorption device 22. The second directional valve 26 is also switchable between two positions. In a first position, as shown in FIG. 2, the second directional valve 26 is switched so that the first outlet 13b is connected to the pressure line 41 and thus to the outlet 24b of the second carbon dioxide adsorption unit 24. At the same time, in this switching position, the outlet 22b of the carbon dioxide adsorption device 22 is connected via the pressure line 40 to the outlet 23b of the first carbon dioxide adsorption unit 23. In the second switching position of the second directional control valve 26, as shown in FIG. 3, the second carbon dioxide adsorption unit 24 is in communication with the outlet 22b of the carbon dioxide adsorption device 22 and the first outlet 13b of the separator 20 is connected to the first carbon dioxide adsorption unit 23. The switching of the first directional control valve 25 is coupled to the switching of the second directional control valve 26. By switching over the two directional control valves accordingly, it is possible to switch over between the state shown in FIG. 2 and the state shown in FIG. 3.

As is apparent from Fig. 2 directly, are shown by the there

Switching state of the two-way valves 25, 26 sets two flow paths. On the one hand, a flow can take place from the inlet 22a through the first carbon dioxide adsorption unit 23 to the outlet 22b. On the other hand, a flow from the first exit 13 b through the second carbon dioxide adsorption unit 24 into the discharge line 37 is possible. In the overall system of FIG. 1, this means that the ambient air pressurized by the compressor VI and dried by the refrigerant dryer 4 flows through the first carbon dioxide adsorption unit 23 and then exits the carbon dioxide adsorption device 22 through the outlet 22b. The carbon dioxide content of the pressurized and dehumidified ambient air is thus flowing through reduced by the carbon dioxide adsorption unit 23. The first carbon dioxide adsorption unit 23 is therefore in an adsorption state.

In addition, in this switching state, the nitrogen separated in the separator 20 flows through the second carbon dioxide adsorption unit 24, exiting through the inlet 24a thereof, and discharged through the discharge pipe 37 to the outside. As also shown in Fig. 2, the flow direction of the nitrogen through the second carbon dioxide adsorption unit 24 is opposite to the flow direction of the ambient air through the first carbon dioxide adsorption unit 23. By passing nitrogen through the second carbon dioxide adsorption unit 24, the carbon dioxide bound in the carbon dioxide adsorbent is dissolved out of the second carbon dioxide adsorption unit 24. The second carbon dioxide adsorption unit 24 is therefore in a regeneration state.

As is apparent from Fig. 3, by switching the two

Directional valves 25, 26, the conditions prevailing in Fig. 2 states of the two carbon dioxide adsorption 23, 24 also switched. More specifically, in the valve switching state shown in Fig. 3, the first carbon dioxide adsorption unit 23 is in a regeneration state, and the second carbon dioxide adsorption unit 24 is in an adsorption state. By alternately switching back and forth between the two states shown in Figs. 2 and 3, it is possible to continuously reduce the carbon dioxide content of the ambient air while simultaneously regenerating a carbon dioxide adsorption unit.

The operation of the above-described carbon dioxide adsorption device 22 will be described below. The carbon dioxide adsorption device 22 is initially in the state shown in FIG. More specifically, the first carbon dioxide adsorption unit 23 is in an adsorption state and the second carbon dioxide adsorption unit 24 is in a regeneration state. Both carbon dioxide adsorption units 23, 24 are designed such that in the adsorption state each carbon dioxide adsorption unit is capable of adsorbing carbon dioxide over a period of 60 minutes, for example. At the same time the system is designed so that a regeneration and subsequent cooling of the Carbon dioxide adsorption units 23, 24 is also possible within this time. After an operating time of 60 minutes, the system shown in Fig. 2 is thus switched to the state shown in Fig. 3. Within the above operating time, carbon dioxide adsorption is continuously performed in the first carbon dioxide adsorption unit 23. The carbon dioxide content of the gas flowing through is reduced. At the same time, the second carbon dioxide adsorption unit 24 is regenerated by supplying this separated nitrogen through the first outlet 13b to the separating device 20. The nitrogen is heated by a heater 27 to accelerate the regeneration process. In the present exemplary embodiment, heating of the separated nitrogen takes place for a period of 45 minutes before it is introduced into the second carbon dioxide adsorption unit 24. The carbon dioxide adsorbent contained in the carbon dioxide adsorption unit is thereby brought to a predetermined temperature, which enables efficient regeneration of the carbon dioxide adsorbent. Following the last described heating of the separated nitrogen for 45 minutes, also referred to as heating cycle, according to the present embodiment, a cooling cycle which lasts 15 minutes follows. In this cooling cycle, the heater 27 is deactivated, so that the separated nitrogen is introduced into the second carbon dioxide adsorption unit 24 at a lower temperature. As a result, the temperature of the second carbon dioxide adsorption unit 24 or the carbon dioxide adsorbent contained therein is reduced. The system can be tuned so that even during the cooling, a further regeneration of the carbon dioxide adsorbent takes place. It is also possible to design the system so that a complete regeneration takes place during the heating cycle.

After the operating time of 60 minutes mentioned here by way of example, it is now necessary to regenerate the first carbon dioxide adsorption unit 23. For this purpose, a changeover of the two-way valves 25, 26 takes place in the positions shown in Fig. 3. This is followed by another operating cycle of 60 minutes, in which case the second carbon dioxide adsorption unit 24 adsorbs carbon dioxide and the first carbon dioxide adsorption unit 23 is regenerated. In the above-described Construction takes less than one minute to switch over. Hereinafter, the switching operation will be described in more detail.

If it is determined that a switch is required, so will first

Pressure compensation valve 29, which is located in a pressure equalization line 28, opened. The pressure equalization line 28 connects the first carbon dioxide adsorption unit 23 to the second carbon dioxide adsorption unit 24. If the pressure compensation valve 29 is now open, the pressurized air supplied to the first carbon dioxide adsorption unit 23 can flow through the equalization line 28 and enter the second carbon dioxide adsorption unit 24. At the same time, with the opening of the pressure compensating valve 29, a drain valve 31, which is located in the drain line 37, is closed. A portion of the air pressurized in the first carbon dioxide adsorption unit 23 thus leaves it via the equalization line 28 and flows into the second carbon dioxide adsorption unit 24. Advantageously, the lines and carbon dioxide adsorption units are selected such that pressure equalization is possible within 30 to 60 seconds. As a result of the pressure compensation described above, the pressure in the second carbon dioxide adsorption unit 24 increases. Such an increase can be detected, for example, by corresponding sensors. After pressure equalization, the first directional control valve 25 and the second directional control valve 26 are switched over and subsequently the discharge valve 31 is opened and the pressure compensation valve 29 is closed. The first carbon dioxide adsorption unit 23 is now in the regeneration state and the second carbon dioxide adsorption unit 24 is now in the adsorption state. After another lapse of the cycle time from here, for example, 60 minutes, a renewed switching of the system takes place in the switching state shown in Fig. 2. The cycle time is set here by way of example to 60 minutes. Depending on the configuration of the carbon dioxide adsorption units, however, different cycle times can be selected. It is only important in this context that the adsorption time and the regeneration time of the two carbon dioxide adsorption units are coordinated so that a complete regeneration of a carbon dioxide adsorption unit is possible, while the other carbon dioxide adsorption unit adsorbs carbon dioxide. Instead of a rigid time cycle, a sensor may also be provided which detects the deterioration state of the adsorbing carbon dioxide adsorption unit. If a regeneration of this carbon dioxide adsorption unit is required, this sensor outputs a corresponding signal which triggers a corresponding switchover process.

By the system described above is thus a continuous

Production of oxygen-enriched breathing air possible. The system described above has been described in terms of its essential features. However, as shown in Fig. 1, the system may include additional elements which will be described below.

As shown in Fig. 1, after the inlet or inlet 21 for compressed ambient air, a filter device 2 may be provided with an electronic Kondensatabieiter. The filter device 2 can be designed to filter solids and other foreign substances, such as liquids, from the compressed ambient air and remove it from the flow. The discharged solids and liquids in the form of the condensate can be fed to a condensate separator, which is designated in FIG. 1 by the reference numeral 19.

In the flow direction after the filter device 2, a safety valve 3 may be provided that opens when a set pressure is exceeded and the compressed air blows into the environment. For example, the safety valve can be set up with an opening pressure of 11 bar. Both elements can thus be arranged after the compressor VI and before the refrigerant dryer 4.

In the flow direction after the refrigerant dryer 4, an overflow valve 5 may be connected. This overflow valve 5 is provided in the example shown in Fig. 1 with a muffler. The function of the overflow valve 5 is related to the operation of the compressor VI to be connected. The overflow valve 5 causes an intermittent operation of the connected compressor VI can be avoided. By accepting a slightly reduced efficiency, the service life of the compressor can thus be increased by avoiding intermittent operating situations. In the flow direction after the overflow valve 5, a filter cascade can be provided. In the embodiment shown in Fig. 1, the filter cascade of three filter elements 6, 7, 8. The filter elements are arranged in the embodiment in Fig. 1 with respect to the flow directions in series. The filtering can be carried out in stages by the three filter elements connected in series. In the first filter element 6 can thus be made a rough prefiltering. In the subsequent filter element 7, a finer filtering can be performed. Very fine filtering can be carried out in the adjoining filter element 8. The filter element 8 may be formed as an activated carbon filter. In the embodiment shown in FIG. 1, the filter cascade is located immediately in front of the carbon dioxide adsorption device 22.

Downstream of the carbon dioxide adsorption device 22 is a

Pressure reducing valve 9 is provided. This pressure reducing valve 9 can be adjustable and causes a predetermined outlet pressure at the outlet of the pressure reducing valve 9 to be maintained. This pressure can be monitored by a pressure gauge 10 that detects the pressure downstream of the pressure reducing valve 9.

Following the pressure reducing valve 9, a compressed air heater 11 may be provided. The compressed air heater 11 may be an electric heater with an electric heating element. By the compressed air heating, it is possible to regulate the outlet temperature at the outlet of the compressed air heater 11 to a predetermined temperature. A monitoring of the temperature of the compressed air at the outlet of the compressed air heater 11 can be done by a thermometer 12.

The separation device 20 described above is at the exit of the

Compressed air heater 11 connected.

On the line of the second output 13c of the separator 20 may be a

Safety valve 15 must be connected for overpressure. This safety valve 15 opens as soon as the pressure exceeds a predetermined value to protect the device from overpressure.

Further, a safety valve 16 for negative pressure or vacuum may be connected to the line of the second output 13c. This safety valve 16 opens as soon as the pressure falls below a predetermined value in order to protect the device from negative pressure or vacuum. In particular, in case of failure of the compressor VI or blockage of the system should be prevented that a vacuum is generated by operation of a filling device V2 described later, which could damage the device.

In addition, on the line of the second output 13c, a pressure gauge 17 for measuring the pressure in the second output 13c may be connected. With this gauge 17, the pressure within the conduit can be measured, is derived in the oxygen-enriched air. At the outlet of the second outlet 13c, a filling device V2 may be connected, which essentially comprises a compressor. In particular, the entry of a compressor is connected to the outlet of the second outlet 13c. This compressor can absorb the oxygen-enriched breathing air and can this in a compressed state for further processing, in particular for the filling of diving bottles o.a. hand off. If such a compressor is used at the outlet of the second outlet 13c, it is important to provide a constant volume flow in the second outlet 13c. In order to ensure this, it is necessary to avoid a pressure drop or a reduced volume flow at the outlet of the carbon dioxide adsorption device during a switching process in the carbon dioxide adsorption device, and that the compressor V2 generates a vacuum. This can be avoided by providing the overflow valve 5 described above. In the carbon dioxide adsorption device, when part of the pressurized air for pressure equalization is branched off, the above-described spill valve 5 can cause the carbon dioxide adsorption device to be supplied with more pressurized air to equalize the branched air amount.

The first output 13b may include a throttle valve 14. This

Throttling valve 14 may cause sufficient pressure prevails in the separation device 20, in particular at the inlet 13 a of the membrane 13, which is suitable for the function of the selective membrane 13. By the throttle valve 14 can be particularly effected that the compressed ambient air into the input 13 a of the separation device 20th enters, can be passed through the selective membrane with pressure. The outlet of the throttle valve 14 is connected to the carbon dioxide adsorption device 22 to guide the gas stream mainly of nitrogen into the carbon dioxide adsorption device 22. As already described above, the gas stream consisting mainly of nitrogen, also referred to as separated nitrogen, is used to regulate the carbon dioxide adsorption device 22.

The entire device, as described above, has a defined mode of operation, which was previously not possible in the prior art. In particular, by the targeted arrangement of the carbon dioxide adsorption device 22, it is possible to produce oxygen-enriched breathing air with greatly reduced carbon dioxide content. At the same time, by using multiple carbon dioxide adsorption units, it is possible to continuously produce oxygen-enriched breathing air with reduced carbon dioxide content. The use of regeneratable carbon dioxide adsorption units also has the advantage that the entire plant can be operated cost-effectively for a long time, since the regeneratable carbon dioxide adsorption units can be used for a long time.

While in Fig. 1, a system is shown, which is the

Carbon dioxide adsorption device supplies pressurized and dehumidified ambient air, the carbon dioxide adsorption device 22 can also be connected directly to a compressed air system, which provides pressurized and dehumidified air. In this case, the compressor and the dryer before the carbon dioxide adsorption can be dispensed with.

Also, it is not necessary, the entire from the

Carbon dioxide adsorption device derived volume flow into a separator. Rather, it is also possible to supply only a partial flow of the air with reduced carbon dioxide content of a separator in order to separate the nitrogen required for the regeneration therein. Such a construction is shown in FIG. In the construction shown there, a compressed air system which provides pressurized and dehumidified ambient air is connected to the inlet 21 of the air treatment device. The inlet 21 is connected to a carbon dioxide adsorption device, as they are is described above with reference to Figures 2 and 3. The outlet 22b of the carbon dioxide adsorption device may be connected to an end user or a buffer and discharges the recovered air with reduced carbon dioxide content. In contrast to the device described above with reference to FIG. 1, the input 13a of the separation device branches off from the output 22b, thus making it possible to remove a partial flow from line 22b. This partial flow is then fed to the membrane 13. The separated nitrogen is then supplied via the first outlet 13b of the carbon dioxide adsorption device. The separated residual gas with reduced nitrogen content is discharged via the second output 13 c and via the discharge line 37 into the environment.

In Fig. 5 is a schematic view of a further alternative

Design shown. In this alternative embodiment, the input of the separator 13 is not connected to the output 22b as shown in FIG. Rather, in the embodiment of FIG. 5, the input of the separator is connected to the inlet 21. Thus, in this embodiment, the pressurized air may be introduced directly into the separator without passing through the carbon dioxide adsorption device 22. The procedure and the specific embodiment of the device with regard to the regeneration of the carbon dioxide adsorption device can be provided according to the above embodiments and adapted accordingly.

Overall, therefore, a method and an apparatus are provided which allow a highly efficient generation of oxygen-enriched breathing air.

Claims

1. Air treatment process with the steps

Providing compressed air,

Reducing the carbon dioxide content of the compressed air in a carbon dioxide adsorption device (22),

Introducing at least a portion of the reduced carbon dioxide air into a separator (20) including a membrane (13) for separating nitrogen, discharging oxygen-enriched air from the separator (20),

Removing separated nitrogen from the separator (20), and

at least partially regenerating the carbon dioxide adsorption device (22) with at least a portion of the separated nitrogen.

2. Air treatment process with the steps

Providing compressed air,

Introducing at least a portion of the compressed air into a separator (20) containing a membrane (13) for separating nitrogen,

Deriving oxygen-enriched air from the separator (20),

Deriving separated nitrogen from the separator (20)

Reducing the carbon dioxide content of at least a portion of the compressed air in a carbon dioxide adsorption device (22), and

The method of claim 1 or 2, further comprising the step of determining whether regeneration of the carbon dioxide adsorption device (22) is required, and it is determined that regeneration of the carbon dioxide adsorption device (22) is required if it is determined that its adsorption performance has deteriorated ,

4. The method of claim 3, wherein it is determined that the adsorption performance has deteriorated when a predetermined operating time of the Carbon dioxide adsorption device (22) has elapsed since the last regeneration.

5. The method according to claim 3, wherein it is determined that the adsorption performance has deteriorated when the carbon dioxide content of the gas discharged from the carbon dioxide adsorption device (22) exceeds a predetermined value.

A method according to any one of claims 1 to 5, wherein the carbon dioxide adsorption device (22) comprises at least two carbon dioxide adsorption units (23, 24) containing carbon dioxide adsorbent, and wherein at least one of the carbon dioxide adsorption units (23, 24) is regenerated during regeneration of the carbon dioxide adsorption device (22) ,

The method of claim 6, wherein during the regeneration of the carbon dioxide adsorption device (22) at least one of the carbon dioxide adsorption units (23, 24) adsorbs carbon dioxide.

A method according to any one of claims 6 or 7, wherein the carbon dioxide adsorbent of the carbon dioxide adsorption unit (23, 24) to be regenerated is heated for regeneration.

A method according to any one of claims 1 to 8, wherein the nitrogen used for the regeneration of the carbon dioxide adsorption device (22) is heated to a predetermined temperature.

10. The method of claim 8 or 9, wherein an introduction of the compressed and dehumidified ambient air in the regenerated carbon dioxide adsorption (23, 24) takes place only when the temperature of the carbon dioxide adsorbent of the regenerated carbon dioxide adsorption (23, 24) is below a predetermined temperature.

The method of claim 10, wherein the temperature of the carbon dioxide adsorption units (23, 24) is monitored.

The method of claim 10, wherein the compressed air is introduced into the regenerated carbon dioxide adsorption unit (23, 24) when a predetermined time has elapsed since regeneration of the regenerated carbon dioxide adsorption unit (23, 24).

13. The method according to any one of claims 10 to 12, wherein for reducing the temperature of the regenerated carbon dioxide adsorption unit (23, 24), separated nitrogen from the separator (20) is used at a temperature lower than the temperature of the carbon dioxide adsorbent of the regenerated carbon dioxide adsorption unit (23 , 24).

14. A method according to any one of the preceding claims, further comprising the step of dehumidifying the compressed air prior to introducing the air into the carbon dioxide adsorption device (22).

15. Device for air conditioning, with:

a pressurized air inlet line, a separator (20) located downstream of the inlet line for reducing the nitrogen content of at least a portion of the pressurized air, the separator (20) including a nitrogen purge membrane (13), a first exit (13b) for discharge of the separated nitrogen and a second outlet (13c) for the recovered gas having increased oxygen content, wherein in the flow path between the inlet line and the separating device (20) or downstream of the inlet line and the separating device (20) a regeneratable carbon dioxide adsorption device (22) whose inlet is connected to the inlet line and whose outlet is connectable to the separation device (20) or to the environment, the regeneratable carbon dioxide adsorption device comprising at least two carbon dioxide adsorption units (23, 24) containing carbon dioxide adsorbents, each of which has an inlet (23a, 24a) and an outlet (23b, 24b) and a directional valve mechanism, wherein the directional control valve mechanism is arranged such that the inlets (23a, 24a) of the at least two carbon dioxide adsorption units (23, 24) alternately with the entrance (22a) of Carbon dioxide adsorption device (22) and the environment are connectable and their outlets (23b, 24b) alternately with the output (22b) of the carbon dioxide adsorption device (22) and the first output (13b) of the separating device (20) are connectable.

The apparatus of claim 15, further comprising a compressor (VI) for pressurizing ambient air, wherein the compressor (VI) is disposed upstream of the inlet duct to supply pressurized ambient air to the inlet duct.

17. The apparatus of claim 15 or 16, wherein upstream of the carbon dioxide adsorption means, a dryer (4) is arranged for dehumidifying the pressurized air, wherein the dryer (4) is connected to the inlet line to supply the intake duct pressurized and dehumidified ambient air.

18. Device according to one of claims 14 to 17, wherein the directional control valve mechanism comprises a first directional control valve (25) which is arranged so that it simultaneously one of the inlets (23a, 24a) of the carbon dioxide adsorption (23, 24) with the input (22a ) of the carbon dioxide adsorption device (22) and another of the inlets (23a, 24a) communicates with the environment, and a second directional control valve (26) arranged to simultaneously control one of the outlets (23b, 24b) of the carbon dioxide adsorption units (23 , 24) to the outlet (22b) of the carbon dioxide adsorption device (22) and another of the outlets (23b, 24b) to the first outlet (13b) of the separator (20).

The apparatus of claim 18, wherein the first and second directional control valves (25, 26) are switch coupled such that the outlet of the carbon dioxide adsorption unit whose inlet is connected to the atmosphere is connected to the first outlet (13b) of the separator (20) whereby this carbon dioxide adsorption unit is brought into a regeneration state and that the outlet of the carbon dioxide adsorption unit whose inlet is connected to the inlet of the carbon dioxide adsorption device (22) is connected to the outlet Carbon dioxide adsorption device (22) is connected, whereby this carbon dioxide adsorption unit is brought into an adsorption state.

The apparatus according to claim 19, wherein the carbon dioxide adsorbing device (22) further comprises heating means for heating the carbon dioxide adsorbent of the carbon dioxide adsorption unit (23, 24) to be regenerated.

21. The apparatus of claim 20, wherein the heating means comprises a heater (27) for heating the separated nitrogen, which is arranged between the first output (13 b) of the separating device (20) and the second directional control valve (26).

The apparatus of claim 20 or 21, wherein the heating means comprises a heater for directly heating the carbon dioxide adsorbent.

23. The device according to any one of claims 15 to 22, wherein each carbon dioxide adsorption (23, 24) comprises a pressure vessel in which the carbon dioxide adsorbent is housed in opposite directions permeable, wherein the pressure vessel preferably via a pressure equalization line (28) are interconnected.

24. The method according to any one of claims 1 to 14, which is carried out in a device according to one of claims 15 to 23.