DE19513909C1 - Automatic, rapid de-infestation of buildings and storage rooms - Google Patents

Abstract

The procedure de-infests objects or substances stored in the volume under treatment. A nitrogen generator raises the internal nitrogen concn. During a set treatment period, the internal atmosphere is withdrawn, to be depleted in oxygen and returned. In the novel procedure, internal- and ambient air are passed through a molecular sieve- and/or a membrane filter plant (4), removing oxygen from the nitrogen, which is then re-introduced to the treated volume (1). Extraction from the volume is controlled between internal lower- (A) and upper- (B) pressure limits. Recirculation and oxygen extraction continue down to the lower pressure limit. At this point, the plant (4) takes in ambient air, and supplies nitrogen to the volume, until the upper pressure limit (B) is reached. Also claimed is the plant to carry out the procedure.

Description

The invention relates to a method for Pest control on objects or supplies Nitrogen fumigation in a treatment room after Preamble of claim 1. Furthermore, the Invention a device for carrying out the Procedure.

The treatment room is, for example, the interior of a building, such as a church, museum, art gallery or Library where pests are found Objects. The treatment room can also be a Be a film chamber around the infested objects, especially art objects, is built, or in the the items are set. The treatment room can also be a pantry, in which the from the Pest-infested stocks.

Such a method is known from DE 43 08 585 A1 known. It is described that the treatment room for Pest control nitrogen from a gas generator can be supplied and that the atmosphere from the Treatment room aspirated and after in an apparatus oxygen was removed from the treatment room again  can be supplied. In this case there are two plants necessary, namely the nitrogen generator and the oxygen depriving apparatus.

In the company publication "Air Products, nitrogen supply with a system "are a molecular sieve plant (PSA plant) and a membrane filter system for generating nitrogen described. The molecular sieve plant is compacted Ambient air through a carbon granulate bed conducted in which the oxygen in the air is adsorbed. Nitrogen is with a purity of 97 vol .-% to 99.9 Vol .-% gained. The granules are after adsorption automatically regenerated by oxygen.

The membrane filter system compresses Ambient air passed through hollow fiber bundles. Of the Oxygen diffuses through the pores of the Hollow fiber walls, whereas the nitrogen the hollow fibers flows through. In contrast to the molecular sieve system no regeneration required.

EP 0 412 471 A1 describes a method for Pest control in granular foods described their storage in containers. It will Containers supplied for example nitrogen. After a Displacement flushing is used to reduce the Gas consumption a little overpressure in the container maintain. This allows the duration of the Do not shorten displacement flushing. Ambient air should not be sucked in, since it was assumed that in there is sufficient nitrogen available from the gas source.

DE 33 10 012 A1 describes one method and one Device for inerting transport containers for easily perishable goods in air, such as food, Plants and flowers. The device is a PSA system. Is suitable for pest control this procedure is not because a  Residual oxygen concentration of up to 5% by volume Oxygen should be maintained so that Do not spoil food, plants and flowers.

In the 1990 report of the Institute for Stored Goods Protection, Pages 8, 9 is noted that at Wood pests an oxygen content of 4 vol .-% despite longer exposure times to a beetle hatch leads. So to kill wood pests is a much lower oxygen content necessary.

A method similar to DE 33 10 012 A1 is in the DE 42 38 984 A1. There is in the adsorbent bed not oxygen but nitrogen in the cycle adsorbed, whereby the water vapor content and the Carbon dioxide content in the container should not be reduced the freshness of perishable goods such as food and Plants not to interfere. To one in the container To reduce the negative pressure that occurs, the suctioned Container atmosphere mixed with ambient air. For Pest control, especially in art objects, this method is not suitable.

The object of the invention is a method according to the Propose the preamble of claim 1 by which in a plant nitrogen from the ambient air and so on possibly obtained from the atmosphere of the treatment room and by which the residual oxygen concentration in the Treatment room quickly counteracted at the start of the procedure Is brought to zero and run automatically can. It is also an object of the invention to Facility to carry out the procedure to propose.

The above task is in a method according to Preamble of claim 1 by the characterizing Features of claim 1 solved.  

Already at the start of the process, the Molecular sieve or membrane filter system Aspirated atmosphere from the treatment room and this after oxygen deprivation, continue with nitrogen enriched, returned to the treatment room. The Aspiration of atmosphere from the treatment room is limited by the fact that in the treatment room not one Negative pressure should arise, which leads to a considerable Penetration of ambient air leads. On the other hand, it is Introducing nitrogen limited in that Treatment room should not create any excess pressure a significant diffusion of the atmosphere of the Treatment room should take place in the area.

This ensures that with the molecular sieve or membrane filter system in the treatment room the nitrogen concentration comparatively quickly increased or the residual oxygen concentration decreased to values that are appropriate for a Pest control are suitable. For one effective pest control is one Nitrogen concentration from 96% by volume to preferably at least 99.9% by volume or one Residual oxygen concentration from 4 vol.% To in particular 0.01% by volume is required. At a Nitrogen concentration in the range of just for example The pests survive 90% by volume for months Exposure time. Such long exposure times are in not feasible in practice because at least after about three to four weeks at most Pest control procedures should be completed where it is desirable to kill the pests to keep the necessary exposure time as short as possible.

The fact that in the described method, no pure Displacement flushing of the treatment room The start of the procedure is necessary, the necessary Shorten the exposure time without the need for a system  is necessary, which has such a high performance that it creates a displacement flush in a short time.

In the process, atmosphere is created from the Treatment room and the ambient air cyclically alternately from the molecular sieve or the Membrane filter system sucked in. It is achieved that priority, as far as the pressure conditions in Treatment room possible, its atmosphere quickly with Nitrogen is enriched. It can be cyclical as long as atmosphere is sucked out of the treatment room and nitrogen is supplied to the treatment room until the Vacuum limit is reached. Then from ambient air is sucked into the system and extracted from it Nitrogen supplied to the treatment room until the Overpressure limit is reached. Switching from Aspirate from the treatment room and aspirate from the Ambient air is pressure controlled. Instead, can however, switching suction from the Treatment room and suction from the ambient air too be timed because the pressure profiles in the Treatment room essentially before the start of the procedure can be determined and thus the times for aspirating the atmosphere of the treatment room and Allow ambient air intake to be preset.

Because targeted negative pressure in the treatment room being allowed to the environment is one intensive suction with nitrogen enriched, but not yet for Pest control necessary little Atmosphere of the residual oxygen concentration Treatment room possible, which accelerates the Reaching the low pest control required Residual oxygen concentration leads.

In another version, the Treatment room per unit of time as much nitrogen  supplied as it is withdrawn atmospheric volume, so that the differential pressure between the treatment chamber and the environment remains at around zero, the plant atmosphere from the treatment room and Sucks in ambient air. Instead of a pressure measurement or Differential pressure measurement is preferred in this case Volume flow measurement made because from the Treatment room only as much atmosphere per unit of time is sucked off like nitrogen from the system can be supplied. This process design is suitable preferred for those cases in which the Treatment room, for example a film chamber, not is suitable for absorbing large differential pressures.

As a further development of the process, the system, especially their compressors, in the duration of exposure switched off when there is a lower one in the treatment room Target value of the residual oxygen concentration, for example 0.01 vol .-%, is reached. The system is at one upper setpoint of the residual oxygen concentration, for example 1% by volume for pest control is still suitable to be turned on again. This is ensures that after that for pest control preferred oxygen concentration is reached that System no longer supplies nitrogen to the treatment room and only starts again with a nitrogen supply when the residual oxygen concentration has an upper setpoint reached. This ensures that the system is not is switched on for longer than absolutely necessary, Service life of the system, especially its compressor, significantly extended.

Further refinements of the method and features of the Means for carrying out the procedure arise from the further claims and the following Description. The drawing shows:

Fig. 1, an apparatus for pest schematically

Fig. 2 is a timing diagram of the pressure course in the treatment chamber,

Fig. 3 is a timing diagram of the residual oxygen concentration in the treatment chamber.

A compressor ( 3 ) of a molecular sieve system ( 4 ) is connected to a treatment room ( 1 ) via a hose line ( 2 ). The treatment room ( 1 ) is a sealed building interior, for example a church room, or a film chamber installed in a building room. The treatment room ( 1 ) contains or contains the objects or supplies infested with pests.

In the molecular sieve system ( 4 ) known per se, a molecular sieve ( 6 ) is connected to the compressor ( 3 ) via a moisture separator ( 5 ) and is filled with a carbon granulate. A nitrogen reservoir ( 7 ) is connected to the molecular sieve ( 6 ). Air sucked in by the compressor ( 3 ) is compressed and fed to the molecular sieve ( 6 ). Oxygen is retained in the molecular sieve ( 6 ). The nitrogen in the air enters the reservoir ( 7 ). When the molecular sieve ( 6 ) is regenerated, the oxygen dissolves from it and is discharged via an outlet ( 8 ). Nitrogen is continuously available at elevated pressure, for example 5 to 6 bar, on a pipeline ( 9 ) connected to the store ( 7 ). Instead of the molecular sieve system ( 4 ), a membrane filter system, which is also known, can also be used to generate nitrogen.

In the hose line ( 2 ) there is a valve ( 10 ) with a filter ( 42 ) as a suction opening. The hose line ( 2 ) is connected to the environment via a branch ( 11 ) in which a valve ( 12 ) and a filter ( 13 ) are located.

The pipeline ( 9 ) opens into the treatment room ( 1 ) at the top, whereas the hose line ( 2 ) is connected to the treatment room ( 1 ) at the bottom. A branch ( 14 ) with a valve ( 15 ) is provided on the pipeline ( 9 ). A nitrogen buffer store ( 17 ) is located in the bypass ( 16 ) in the pipeline ( 9 ). The bypass ( 16 ) can be switched via valves ( 18 , 19 , 20 ).

In addition, a further bypass ( 21 ) is arranged in the pipeline ( 9 ) in which a heatable humidifier ( 22 ) is located. The bypass ( 21 ) can be switched by means of valves ( 23 , 24 ). The humidifier ( 22 ) is connected to the water network ( 26 ) via a water pipe ( 25 ). An oxygen separator ( 27 ) and a switching valve ( 28 ) are provided in the water line ( 25 ), with which the water level in the humidifier ( 22 ) can be controlled.

On the treatment room ( 1 ), a drain port ( 29 ) with a shut-off valve ( 30 ) is installed.

Sensors ( 31 to 34 ) are arranged in the treatment room ( 1 ) for detecting the residual oxygen concentration, the temperature, the relative humidity and the pressure or differential pressure. The sensors ( 31 to 34 ) are connected to an electrical control device ( 35 ) with which the valves ( 10 , 12 , 15 , 18 to 20 , 23 , 24 , 28 , 30 ) can be controlled. In addition, a switching relay ( 36 ) can be controlled by means of the control device ( 35 ), with which the compressor ( 3 ) can be switched on and off.

A fan ( 37 ) is installed in the treatment room ( 1 ). In addition, a heater ( 38 ), a dehumidifier ( 39 ) and a humidifier ( 40 ) can be provided in the treatment room ( 1 ).

The functionality of the described device is essentially as follows:
After installation of the units and lines described in the treatment room ( 1 ) at the start of the process (cf. time t0 in FIG. 2, FIG. 3), the valve ( 10 ) is opened and the valve ( 12 ) is closed. The compressor ( 3 ) therefore sucks in air or treatment room atmosphere from the treatment room ( 1 ) and not from the surroundings. The valves ( 19 , 24 ) are open. The valves ( 15 , 18 , 23 , 30 ) are closed. At the time (t0), the normal air-oxygen concentration of approximately 21% by volume is present in the treatment room ( 1 ).

Oxygen is adsorbed in the molecular sieve ( 6 ). Nitrogen is returned to the treatment room ( 1 ) through the pipeline ( 9 ). The regeneration of the molecular sieve ( 6 ) is not described in detail since it is an integral function of the system ( 4 ). For example, the plant ( 4 ) has two molecular sieves ( 6 ) for this purpose, which alternately adsorb and regenerate oxygen. The store ( 7 ) ensures an even supply of nitrogen.

Since with the open valve ( 10 ) and the closed valve ( 12 ) more treatment room atmospheric volume is sucked off than nitrogen is returned to the treatment room ( 1 ) in the circuit, a negative pressure is created in the treatment room ( 1 ). If a vacuum limit value (A) of, for example, -30 Pa is reached, which is the case in FIG. 2 at time (t1), then the control device ( 35 ), which detects the pressure conditions by means of the sensor ( 34 ), controls the valve ( 10 ) closed and the valve ( 12 ) opened. The compressor ( 3 ) now draws in ambient air and supplies the treatment room ( 1 ) with nitrogen obtained from it. This increases the pressure in the treatment room ( 1 ). If an overpressure limit value (B), in the example +30 Pa, is reached, which is the case in FIG. 2 at time (t2), then the valves ( 10 , 12 ) are switched over again so that atmosphere from the treatment room ( 1 ) is suctioned off. These processes are repeated cyclically, the atmosphere in the treatment room ( 1 ) being enriched with nitrogen and the residual oxygen concentration accordingly falling.

The control device ( 35 ) controls the switching of the valves ( 10 , 12 ) as a function of pressure. However, it is also possible to carry out the switching in a time-controlled manner. For this purpose, pressure profile measurements are carried out on the sealed treatment room ( 1 ) before the start of the process. The times after which the switchover should take place are derived from these. These times are given to the control device ( 35 ) as setpoints.

After repeating the switching processes mentioned several times, an upper target value (C) of the residual oxygen concentration of about 1% by volume is reached in the treatment room ( 1 ), which is suitable for killing pests. According to FIG. 3, this is given at the time (t3). Depending on the circumstances, the time (t3) is about 1/2 to 3 days after the time (t0); at time (t3) begins the essential, predetermined duration of action, which is necessary to kill the pests.

The system ( 4 ) continues to operate after the time (t3) in the switching cycles described. After the point in time (t3), the residual oxygen concentration continues to decrease until a lower target value (D) of the residual oxygen concentration of approximately 0.01% by volume is reached. This is the case in FIG. 3 at time (t4).

At time (t4), the compressor ( 3 ) could be switched off immediately. However, after reaching (t4), it is preferable to wait until the overpressure limit value (B) in relation to the ambient air pressure is reached again in the treatment room ( 1 ). This is favorable because it prevents subsequent diffusion of oxygen from the environment. Then - at time (t5) in Fig. 2 and in Fig. 3 - the compressor ( 3 ) and thus the nitrogen production is switched off.

After time (t5), the overpressure drops to zero due to inevitable leaks in the treatment room ( 1 ) (cf. FIG. 2). The residual oxygen concentration in the treatment room ( 1 ) increases accordingly. This takes place very slowly because there is overpressure in the treatment room ( 1 ) at time (t5). The compressor ( 3 ) can therefore remain switched off for a long time based on the duration of the treatment, which considerably increases the service life of the system ( 4 ).

Is then the upper limit value (C, 1 vol .-%) of the residual oxygen concentration reached (time t6 in Fig. 2 and Fig. 3), the compressor (3) is switched on again, whereby the plant (4) again Supplies nitrogen to the treatment room ( 1 ). As described above, the compressor ( 3 ) first draws atmosphere from the treatment room ( 1 ) until the negative pressure limit value (A) mentioned is reached (cf. time t7 in FIG. 2). Then, by closing the valve ( 10 ) and the valve ( 12 ), ambient air is sucked in again until the overpressure limit (B) is reached (cf. time t8 in FIG. 2). The residual oxygen concentration accordingly drops again (see FIG. 3). The described switching on and switching off of the compressor, the valves ( 10 , 12 ) being switched over as described when the compressor ( 3 ) is switched on, are repeated until the specified end of the desired duration of action is reached, which is the case, for example, after 2 to 3 weeks is.

The valve ( 15 ) can be opened as long as the system ( 4 ) does not produce enough pure nitrogen after switching on. It is thereby avoided that oxygen is conveyed into the treatment room ( 1 ) in an undesirable manner. If, for example, a very low residual oxygen concentration has already been reached in the treatment room ( 1 ) and the electrical network from which the compressor ( 3 ) of the system ( 4 ) is operated fails for a longer period of time, ambient air and thus oxygen also diffuse into the lines. After the mains return, the valve ( 15 ) is then opened so that a diffused oxygen does not get into the treatment room ( 1 ) into the system.

The buffer store ( 17 ) is filled from the system ( 4 ) with nitrogen at system pressure (e.g. 5 to 6 bar) before the start of the process or at times when the treatment room ( 1 ) does not require any nitrogen. The valves ( 18 , 19 , 20 ) are switched over accordingly. The valve ( 18 ) is opened. The valves ( 19 , 20 ) are closed. This is the case, for example, between times (t5 and t6) (cf. FIG. 3). At times when the system ( 4 ) is not working, for example due to a power failure, it is then possible to deliver nitrogen from the buffer store ( 17 ) to the treatment room ( 1 ). For this, the valves ( 18 , 19 ) are closed and the valve ( 20 ) is opened. The system pressure (5 to 6 bar) is significantly higher than the overpressure limit (30 Pa). The valves ( 19 , 20 ) are pressure reducing valves. The volume of the buffer store ( 17 ) is greater than that of the store ( 7 ) of the system ( 4 ).

If necessary, the nitrogen supplied to the treatment room ( 1 ) can be humidified by means of the humidifier ( 22 ). If the relative atmospheric humidity in the treatment room ( 1 ) detected by the sensor ( 33 ) is too low, the valve ( 23 ) is opened and the valve ( 24 ) is closed. The nitrogen now takes moisture from the water in the humidifier ( 22 ). The water level in the humidifier ( 22 ) can be maintained via a level control. When the switching valve ( 28 ) opens, water that is free of oxygen flows into the humidifier ( 22 ).

If the temperature in the treatment room ( 1 ) is too low, which is determined by the sensor ( 32 ), the nitrogen fed to the treatment room ( 1 ) is heated. This can be done by heating the humidifier ( 22 ) and / or the line section ( 9 ') opening into the treatment room ( 1 ).

If necessary, the heater ( 38 ) and / or the dehumidifier ( 39 ) or the humidifier ( 40 ) can also be switched on.

The fan ( 37 ) is switched on in order to achieve a uniform atmosphere in the treatment room ( 1 ). Since the nitrogen is introduced into the treatment room ( 1 ) at the top, it rests on top of the oxygen-containing atmosphere and presses it down, where it is sucked off via the open valve ( 10 ) in the times mentioned. During the introduction of nitrogen, the fan ( 37 ) is preferably not switched on, so that it does not swirl the stratification, which is favorable for the rapid suction extraction of an oxygen-containing atmosphere. This applies in particular to the time between the times (t0 and t3). The fan ( 37 ) is preferably switched on when no nitrogen is supplied, which is particularly the case between the times (t5 and t6).

The shut-off valve ( 30 ) is usually closed. It can be opened briefly if nitrogen is supplied to the treatment room ( 1 ) and the atmosphere in the treatment room ( 1 ) is too dry or too humid and the humidifier ( 40 ) or the dehumidifier ( 39 ) is accordingly switched on. It is avoided that too dry or too humid atmosphere in the circuit through the system ( 4 ) is fed to the treatment room ( 1 ). By opening the shut-off valve ( 30 ), a dilution rinse can also be carried out by passing nitrogen through line ( 9 ) into chamber ( 1 ) and possibly oxygen-containing treatment room atmosphere via valve ( 30 ) or line ( 29 ) in the environment is headed. The valve ( 10 ) is then closed, however. Excessively humid atmospheres can also be expelled via the line ( 29 ) via the valve ( 30 ).

With the system ( 4 ) in the treatment room ( 1 ), a lower limit value of the residual oxygen concentration of about 0.01% by volume can be achieved. If an even lower residual oxygen concentration is desired to further shorten the necessary exposure time, a catalyst ( 41 ) can also be connected to the treatment room ( 1 ), through which the atmosphere of the treatment room ( 1 ) is also promoted in the circuit. The residual oxygen is converted chemically in the catalyst ( 41 ), whereas oxygen and nitrogen are physically separated in the system ( 4 ). A residual oxygen concentration of below 0.0001% by volume can be achieved by means of the catalyst ( 41 ). Such a catalyst is described for example in the older patent application DE 44 41 797 A1. The catalyst ( 38 ) is switched on when the said lower limit value (D) of the residual oxygen concentration is reached by means of the system ( 4 ).

In the exemplary embodiment described above, the pressure in the treatment room ( 1 ) oscillates in a pressure-controlled or time-controlled manner between the negative pressure limit value (A) and the positive pressure limit value (B). In another exemplary embodiment, however, it is also possible to largely avoid overpressure and underpressure in the treatment room with respect to the environment. For this purpose, only as much atmospheric volume is withdrawn from the treatment room as nitrogen is supplied to it at the same time. If the system ( 4 ) produces 4 l / min of nitrogen from 80 l / min of air, for example, about 4 l / min of atmosphere are drawn off from the treatment room ( 1 ) via the hose line ( 2 ). The remaining air (76 l / min) is drawn in from the surroundings via the branch ( 11 ). The desired conditions can be set using the appropriate flow meter and the valves ( 10 , 12 ). The differential pressure between the treatment room and the environment remains essentially zero. A control dependent on atmospheric pressure is not necessary. For the rest, reference is made to the above description of this exemplary embodiment.

The electrical energy for operating the compressor ( 3 ) of the system ( 4 ) can be obtained from the electrical network. However, it is also possible to provide a solar generator.

Overall, it is achieved that during the period of action necessary for pest control, it is not necessary to repeatedly bring newly filled nitrogen pressure containers to the treatment room ( 1 ). The necessary nitrogen supply to the treatment room ( 1 ) is automatically guaranteed. The desired low residual oxygen concentration in the treatment room ( 1 ) is achieved relatively quickly by the method and the device. The same system ( 4 ) creates the low residual oxygen concentration and maintains it during the exposure period. The compressor ( 3 ) rarely switches on and off during the period of action, which improves the economic use of the system ( 4 ).

Claims (22)

1. A method for pest control of objects or supplies by nitrogen fumigation of a treatment room, the atmosphere of the treatment room being enriched with nitrogen by means of a nitrogen generator and withdrawn from the treatment room with a nitrogen-enriched atmosphere during the specified exposure period, this oxygen being withdrawn and being withdrawn from the treatment room is supplied again, characterized in that atmosphere from the treatment room ( 1 ) and ambient air through a molecular sieve system ( 4 ) and / or through a membrane filter system ( 4 ), which separate oxygen from nitrogen, and from the system ( 4 ) nitrogen the treatment room ( 1 ) is supplied and that the suction of atmosphere from the treatment room ( 1 ) is controlled so that in the treatment room ( 1 ) a negative pressure limit value (A) and an overpressure limit value (B) are not exceeded or below, whereby until reaching one lower setpoint of the residual oxygen concentration cyclically aspirated atmosphere from the treatment room ( 1 ) and this nitrogen is supplied until the negative pressure limit value (A) is reached and that when the negative pressure limit value (A) ambient air is sucked in by the system ( 4 ) and nitrogen is supplied to the treatment room ( 1 ) until an overpressure limit (B) is reached. 2. The method according to claim 1, characterized in that atmosphere from the treatment room ( 1 ) and ambient air is cyclically sucked in alternately from the molecular sieve or membrane filter system ( 4 ). 3. The method according to claim 2, characterized in that the switching of suction from the treatment room ( 1 ) and suction from the ambient air is pressure controlled. 4. The method according to claim 2, characterized in that the switching of suction from the treatment room ( 1 ) and suction from the ambient air is time-controlled. 5. The method according to the preamble of claim 1, characterized in that atmosphere from the treatment room ( 1 ) and ambient air through a molecular sieve system ( 4 ) and / or through a membrane filter system ( 4 ), which separate oxygen from nitrogen, are passed on and off the system ( 4 ) is supplied with nitrogen to the treatment room ( 1 ) and that the suction of the atmosphere from the treatment room ( 1 ) is controlled so that a negative pressure limit value (A) and an overpressure limit value (B) are not lower in the treatment room ( 1 ). or exceeded, with the same amount of atmospheric volume being sucked out of the treatment room ( 1 ) per unit of time as nitrogen is supplied to it from the system ( 4 ), so that the differential pressure between the treatment room ( 1 ) and the environment remains approximately zero, whereby the system ( 4 ) simultaneously sucks in atmosphere from the treatment room ( 1 ) and ambient air. 6. The method according to any one of the preceding claims, characterized in that the system ( 4 ), in particular its compressor ( 3 ), is switched off in the duration of action when in the treatment room ( 1 ) a lower target value (D) of the residual oxygen concentration is reached and that the system ( 4 ) is then switched on again at an upper target value (C) of the residual oxygen concentration, which is still suitable for pest control. 7. The method according to claim 6, characterized in that the shutdown of the system ( 4 ) takes place when there is an overpressure (B) in your treatment room ( 1 ). 8. The method according to any one of the preceding claims, characterized in that the nitrogen is introduced into the top of the treatment room ( 1 ) and the atmosphere is extracted from the bottom of the treatment room ( 1 ). 9. The method according to any one of the preceding claims, characterized in that the atmosphere of the treatment room ( 1 ) is swirled by means of a fan ( 37 ). 10. The method according to claim 9, characterized in that the atmosphere of the treatment room ( 1 ) is swirled when the system ( 4 ) is switched off in the exposure period. 11. The method according to any one of the preceding claims, characterized in that the system ( 4 ) by means of a compressor ( 3 ) promotes the atmosphere from the treatment room ( 1 ) and the ambient air through the molecular sieve ( 6 ) or the membrane filter. 12. The method according to any one of the preceding claims, characterized in that the nitrogen from the system ( 4 ) via a humidifier ( 22 ) is fed to the treatment room ( 1 ). 13. The method according to any one of the preceding claims, characterized in that nitrogen produced by the system ( 4 ) is passed into a buffer store ( 17 ) at times in which there is no need for nitrogen in the treatment room ( 1 ). 14. The method according to any one of the preceding claims, characterized in that the nitrogen supplied to the treatment room ( 1 ) is heated. 15. A device for performing the method according to claim 1, characterized in that a molecular sieve or membrane filter system ( 4 ) is connected to the treatment room ( 1 ), the compressor ( 3 ) atmosphere from the treatment room ( 1 ) and ambient air through a hose line ( 2 ) via valves ( 10 , 12 ) which can be switched by a control device ( 35 ) and that the control device ( 35 ) detects an overpressure or underpressure of the treatment room ( 1 ) and evaluates them to control the valves ( 10 , 12 ). 16. The device according to claim 15, characterized in that between the nitrogen outlet of the system ( 4 ) and the treatment room ( 1 ) in a bypass ( 16 ), a buffer memory ( 17 ) is connected. 17. Device according to one of the preceding claims 15 and 16, characterized in that a humidifier ( 22 ) is connected between the system ( 4 ) and the treatment room ( 1 ) in a bypass ( 21 ). 18. Device according to one of the preceding claims 15 to 17, characterized in that a heater for the nitrogen is provided between the system ( 4 ) and the treatment room ( 1 ). 19. Device according to one of the preceding claims 15 to 18, characterized in that between the system ( 4 ) and the treatment room ( 1 ) a branching into the environment ( 14 ) is provided, which can be shut off by means of a valve ( 15 ). 20. Device according to one of the preceding claims 15 to 19, characterized in that a pressure reducing valve ( 19 , 20 ) is connected between the system ( 4 ) and the treatment room ( 1 ). 21. Device according to one of the preceding claims 15 to 20, characterized in that a discharge nozzle ( 29 ) with a shut-off valve ( 30 ) is connected to the treatment room ( 1 ). 22. Device according to one of the preceding claims 15 to 21, characterized in that in the treatment room ( 1 ) sensors ( 31 to 34 ) for the pressure and / or the oxygen concentration and / or the relative atmospheric humidity and / or the temperature are arranged are connected to the control device ( 35 ).