CA2482868A1 - Method and device for creating an artificial atmosphere in a storage or transport container - Google Patents
Method and device for creating an artificial atmosphere in a storage or transport container Download PDFInfo
- Publication number
- CA2482868A1 CA2482868A1 CA002482868A CA2482868A CA2482868A1 CA 2482868 A1 CA2482868 A1 CA 2482868A1 CA 002482868 A CA002482868 A CA 002482868A CA 2482868 A CA2482868 A CA 2482868A CA 2482868 A1 CA2482868 A1 CA 2482868A1
- Authority
- CA
- Canada
- Prior art keywords
- gas
- membrane
- dehumidification
- backflush
- separation membrane
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23L—FOODS, FOODSTUFFS, OR NON-ALCOHOLIC BEVERAGES, NOT COVERED BY SUBCLASSES A21D OR A23B-A23J; THEIR PREPARATION OR TREATMENT, e.g. COOKING, MODIFICATION OF NUTRITIVE QUALITIES, PHYSICAL TREATMENT; PRESERVATION OF FOODS OR FOODSTUFFS, IN GENERAL
- A23L3/00—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs
- A23L3/34—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs by treatment with chemicals
- A23L3/3409—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs by treatment with chemicals in the form of gases, e.g. fumigation; Compositions or apparatus therefor
- A23L3/3418—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs by treatment with chemicals in the form of gases, e.g. fumigation; Compositions or apparatus therefor in a controlled atmosphere, e.g. partial vacuum, comprising only CO2, N2, O2 or H2O
- A23L3/3427—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs by treatment with chemicals in the form of gases, e.g. fumigation; Compositions or apparatus therefor in a controlled atmosphere, e.g. partial vacuum, comprising only CO2, N2, O2 or H2O in which an absorbent is placed or used
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23L—FOODS, FOODSTUFFS, OR NON-ALCOHOLIC BEVERAGES, NOT COVERED BY SUBCLASSES A21D OR A23B-A23J; THEIR PREPARATION OR TREATMENT, e.g. COOKING, MODIFICATION OF NUTRITIVE QUALITIES, PHYSICAL TREATMENT; PRESERVATION OF FOODS OR FOODSTUFFS, IN GENERAL
- A23L3/00—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs
- A23L3/34—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs by treatment with chemicals
- A23L3/3409—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs by treatment with chemicals in the form of gases, e.g. fumigation; Compositions or apparatus therefor
- A23L3/3418—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs by treatment with chemicals in the form of gases, e.g. fumigation; Compositions or apparatus therefor in a controlled atmosphere, e.g. partial vacuum, comprising only CO2, N2, O2 or H2O
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/22—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by diffusion
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Polymers & Plastics (AREA)
- Life Sciences & Earth Sciences (AREA)
- Nutrition Science (AREA)
- Food Science & Technology (AREA)
- Health & Medical Sciences (AREA)
- Analytical Chemistry (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
- Warehouses Or Storage Devices (AREA)
- Drying Of Gases (AREA)
- Manipulator (AREA)
- Storage Of Harvested Produce (AREA)
- Filling Or Discharging Of Gas Storage Vessels (AREA)
Abstract
The invention relates to a method and a device for creating an artificial atmosphere in a storage or transport container. According to said method, compressed air supplied by an air compressor (3) is conveyed into the storag e or transport container (28) via a gas separation membrane (11) in order to create an artificial atmosphere with an increased nitrogen content, whereby the humidity content of the supplied compressed air is reduced by means of a dehumidification device (10). The invention is characterised in that the supplied compressed air is dehumidified by means of a dehumidification membrane (10) prior to penetrating the gas separation membrane (11).
Description
WO 031088874 ~ PCTIDE03/01248 METHOD AND APPARATUS FOR PRODUCING AN ARTIFICIAL ATMOS-PHERE IN A STORAGE OR TRANSPORT CONTAINER
The invention relates to a method for producing an artificial atmosphere in a storage or transport container according to the preamble of claim 1. The invention further relates to an apparatus for carrying out such a method according to the preamble of claim 8.
Long known has been the practice of increasing the quality of perishable products in transport or storage containers over a long period of time through exposing the product to an atmosphere, the nitrogen content of which is up to 99%. Under such conditions the product is put, as it were, into a deep sleep and during this time undergoes no putrefaction and after-ripening.
Thus, under such conditions products that would otherwise be spoiled within a few days can be transported over longer time periods and greater distances.
Known from EP 357 949 B1 is a device for producing an artificial atmosphere in a transport con-tainer, in which device the nitrogen is acquired from the ambient air by means of a nitrogen-generator unit and is continuously conveyed into the transport container. The production of the high nitrogen concentration takes place here by means of an apparatus for separation of the es-sential gas constituents of the ambient air, namely nitrogen and oxygen, into a component that contains approximately 99% nitrogen and a component that consists essentially of oxygen (per-meate).
By means of such gas-separation membrane, a continuous gas stream can be generated. Also known are apparatuses for discontinuous nitrogen generation, in particular molecular sieves;
however, the apparatus-technology structure of these is of a considerably higher level, due to the requirement of a backflushing of the molecular sieve. Thus, for the purpose of generating an arti-ficial atmosphere, gas-separation membranes have essentially prevailed.
Known from EP 224 469 is a transportable cooling container in which, in addition to the genera-tion of an elevated nitrogen component in the transport container, a humidification of the artificial atmosphere is carried out. Thus, an optimal humidity level in the transport container can be set in accordance with the product to be transported. Such a system requires the accompaniment of water container, which must constantly be tested for germ formation and must be disinfected from time to time.
In general, gas-separation membranes react sensitively to moisture. The impingement by moist pressurized air has a negative effect on the service life of these membranes.
Thus, for their pro-tection gas-separation membranes are often protected by suitable devices, for example cyclone separators that separate the free water.
In gas-separation membranes known until now, an unavoidable dehumidification of the supplied pressurized air takes place during the gas separation. The water vapour separated off is dis-charged together with the permeate. However, this discharge of water vapour negatively affects the output of the nitrogen production.
Also known is the practice of connecting an energy-consuming heat apparatus upstream to the gas-separation membrane, in order to raise the temperature of the fed pressurized air and thereby lower the relative humidity, in order to protect the gas-separation membrane from being impinged upon by free water.
In addition to the upstream-connection of heat apparatuses, also known is the practice of dehu-midifying the pressurized air through upstream-connected absorption dryers.
However, these consume a portion of the supplied pressurized air and thus lower the pressurized-air feed supply to the gas-separation membrane. Thus, the efficiency of the nitrogen production is reduced.
The invention is based on the object of specifying a method and an apparatus for producing an artificial atmosphere in a storage or transport container whereby, with a high efficiency of the sys-tem, a setting of the moisture level in the transport or storage container is possible without requiring an additional fluid supply.
This object is achieved through the method specified in claim 1. An apparatus according to the invention is specified in claim 8.
The invention originates from a method for producing an artificial atmosphere in a storage or transport container, in which method the pressurized air supplied by an air compressor is con-veyed via a gas-separation membrane into the storage or transport container to produce an artificial atmosphere with increased nitrogen portion, the moisture content of the supplied pressur-ized air being reduced by means of a dehumidification apparatus.
According to the invention, the pressurized air fed to the gas-separation membrane is dehumidi-fied before its entrance into the gas-separation membrane by means of a dehumidification membrane.
The application, according to the invention, of a dehumidification membrane reduces the humidity of the pressurized air and thereby increases the nitrogen production. Through the decreased moisture of the pressurized air fed to the gas separation membrane, the service life and efficiency of the latter can be increased.
In order to set the artificial atmosphere in the storage or transport container to a desired moisture level, the moisture removed from the pressurized air in the dehumidification membrane is pref-erably introduced into the storage or transport container in a controlled manner.
This has the advantage that the moisture required in the storage or transport container can be obtained from the dehumidification membrane, without requiring separate fluid containers. Re-duced thereby are, on the one hand, the equipment complexity and, on the other hand, the logistic complexity necessary to keep the otherwise-necessary fluid reservoir filled during a trans-port of long duration.
The moisture to be transferred into the storage or transport container can be directly supplied to the container; however, it can also be added to the gas stream leaving the gas-separation mem-brane.
In a first preferred embodiment form of the invention, a portion of the gas stream leaving the gas-separation membrane is guided by a shunt via the backflush section to the dehumidification mem-brane, before the gas stream is fed to the storage or transport container.
Through this means, nitrogen is used as rinsing air for the dehumidification membrane and, in common with the water vapour separated by the dehumidification membrane, is fed to the atmosphere of the transport or storage container.
Through a suitable valve control, the portion of the nitrogen stream that is guided over the dehu-midification membrane can be adjusted, in order to thereby adjust the moisture content of the artificial atmosphere fed to the container as required.
In an alternative embodiment form, the permeate leaving the gas-separation membrane is, at least in part, guided via the backflush section to the dehumidification membrane and only then discharged to the ambient atmosphere. Through this measure, in contrast to the absorption dryer, no consumption of pressurized air takes place and the nitrogen production of the gas-separation membrane is correspondingly increased.
The above-mentioned alternatives can also be activated in an alternating manner through a suit-able valve control. Through this means, in particular in the initialization phase of a transport or storage container, the time required for adjusting the artificial atmosphere to the desired state can be considerably reduced.
In a more far-reaching embodiment form, a cooling of the pressurized air supplied to the dehu-midification membrane can take place. Through this cooling, the membrane, in the presence of a cyclone separator and a subsequent warming, is protected from being acted on by free water and the associated negative consequences.
The apparatus according to the invention for carrying out the specified method contains the se-ries-connected arrangement of an air compressor, a dehumidification membrane, and a gas-separation membrane. The dehumidification membrane preferably contains a backflush section, via which either at least a portion of the permeate separated at the gas-separation membrane or at least a portion of the nitrogen exiting the gas-separation membrane is conducted.
In an embodiment form in which the permeate is conducted through the backflush section to the dehumidification membrane, the permeate is subsequently discharged to the environment. In an alternative embodiment form, at least a portion of the nitrogen exiting the gas-separation mem-brane is conveyed to the dehumidification membrane via the backflush section and then back into the transport or storage container. The invention can contain a valve control by means of which, in an alternating manner, a flushing of the dehumidification membrane with permeate or with ni-trogen can be carried out. In the case of a flushing of the backflush section of the dehumidification membrane with nitrogen, a control valve can be connected between the inlet and outlet of the backflush section, by the aid of which valve the magnitude of the partial stream con-ducted through the backflush section to the dehumidification membrane can be adjusted.
Between the pressurized-air generator and the dehumidification membrane, a cooling apparatus can be connected, in order to facilitate, through temperature lowering, a removal of excess water.
In the following, the invention is explained in detail with reference to an embodiment example. In the drawings:
Fig. 1: shows a schematic diagram of the invention according to a first embodiment form;
Fig. 2: shows a schematic diagram of the invention according to Fig. 1 with a changed valve position;
Fig. 3: shows a schematic diagram of a simplified embodiment form of the invention.
Represented in Fig. 1 is an apparatus for producing an artificial atmosphere in a transport con-tainer 34. The container 34 can be a stationary storage space, but it can also be a transportable vessel (e.g. container), such as are used in air transport, on ocean ships, as road-transport vehi-cles, or as rail-associated vehicles. As a rule, such containers are temperature-insulated and essentially hermetically sealed. When they are used as food-transport or -storage containers, WO 03/086874 5 PCTlDE03101248 they are often associated with a cooling system, in order to lower the temperature in the interior of the container.
In the method according to the invention, the atmosphere to be conveyed into the container is generated essentially from the ambient air. For this purpose, ambient air is drawn in by a com-pressor 3 driven by a drive 2. Optionally, a controllable suction device 1 in the container with a downstream-connected filter 35 can be provided in order to use a proportionate amount of air from the container. This proportionate amount of air, mixed with the ambient air, can be fed to the compressor 3. Especially in the starting phase of the initialization of a container, the time needed to adjust the atmosphere in the container 34 can thereby be shortened.
The air compressed in the compressor is now fed to a heat exchanger 4, in which the tempera-ture of the pressurized air emerging from the compressor is cooled. For further cooling of the pressurized-air temperature, the pressurized air is guided through an air cooler 5, in which the pressurized air is cooled by means of a cooling fan 6 in order to generate a cooled pressurized-air stream. Alternatively, the cool air stream can be produced through an air-current generator coupled to the drive of the compressor or to the compressor itself.
In the presence of a cooling system in the container 34, an air cooler 5a can also be used to lower the temperature of the pressurized air. In this case, the pressurized-air stream is guided through the blower-free air cooler in the container.
After the compression to, for example, 7.5 bar, the compressed air contains a large amount of water. Through cooling of the air, the storage capacity of the air can be reduced, forming free wa-ter that can be separated in a cyclone separator.
Thus, following the cooler 5 is a water separator 7 for removing free water from the pressurized air. The discharging of the separated water takes place through the opening of a water-removal device (e.g, by means of a magnetic valve) through the pressure of the pressurized air.
There follows a pressurized-air filter 8 for cleaning the pressurized air, in particular of oil residues.
The water and/or oil separated here can likewise be removed electrically/electronically.
The pressurized air thus cleaned is guided in reverse flow through the heat exchanger 4, in the process of which the air is again heated somewhat, in order to keep the content of free water por-tions low in the following dehumidification membrane.
In order to regulate the pressurized-air temperature before entrance into the following stages, a bypass valve 9 can be provided, which controls through more or fewer openings and closings the portion of the pressurized air fed back through the heat exchanger 4 and thus adjusts the tem-perature of the air supplied to the dehumidification membrane.
The pressurized air is now fed to a dehumidification membrane (10), known in itself, for dehumidi-fication of the pressurized air. The dehumidification membrane displays a pressurized-air inlet or a pressurized-air outlet, as well as a backflush section with an inlet 37 and an outlet 36, from which the separated moisture can be discharged.
An applicable dehumidification membrane is formed by a cylinder filled with hollow fibres, whereby the water-vapour molecules can be diffused through the hollow fibres and discharged via the so-called backflush section.
The pressurized-air outlet of the dehumidification membrane leads to the input of the gas-separation membrane 11, which is likewise constructed in a manner known in itself. This displays an inlet and two outlets. The pressurized air fed to the inlet is divided into a nearly oxygen-free nitrogen stream (approximately 30% of the introduced pressurized air) and an oxygen-rich air stream (permeate). The nitrogen gas stream is conveyed into the container 34 via the outlet 39.
In the embodiment form represented in Fig. 1, the oxygen discharged from the permeate outlet 38 of the gas-separation membrane 11 is released to the environment via a humidification valve 15, which is electrically actuable as a 3/2-port directional control valve, and via the backflush section of the dehumidification membrane 10 as well as the humidification valve 16, which is likewise electrically actuable as a 3/2-port directional control valve. In order to set the required flow rate of the permeate through the dehumidification section of the dehumidification membrane 10, a per-meate valve 14 designed as a controllable throttle is provided, which valve discharges a portion of the permeate to the environment directly after emergence from the gas-separation membrane 11.
The nitrogen stream exiting the gas-separation membrane 11 at the outlet 39 is fed, via an op-tional pressure accumulator 12 with built-in check valve for storage of nitrogen, and via an electrically controllable nitrogen control valve 13 to the container 34. The control valve 13 serves to adjust the nitrogen stream or rather the nitrogen purity, in that the adjustment of the volume flow effected thereby adjusts the relationship between the volume of the nitrogen stream and the volume of the permeate. The control valve 13 can also be manually operated.
The connecting line between the gas-separation membrane 11 and the container 34 contains a pressure gauge 21 for monitoring the system pressure, an oxygen gauge 22 for monitoring the nitrogen production of tt~e system, as well as moisture/temperature gauge 23 for monitoring the moisture of the nitrogen stream to the container 34. Corresponding sensors 24, 25 for oxygen and moisture/temperature, respectively, are arranged directly in the container 34, in order to ob-serve the atmospheric conditions at the stored product. Additionally, C02 sensors 26 and CZH4 sensors 27 as well additional sensors for additional gases or conditions (e.g.
temperature) can be assigned to the storage space.
For the transport or storage of certain products, a COZ feed into the container 28 can be provided;
this takes place through the conveying of a desired COZ volume flow from a C02 supply bottle into the container 34 via a pressure-reduction valve 32 to reduce the supply-container pressure to an operating pressure measured at the pressure gauge 28 and via a controllable shut-off valve 33.
Sensors, valves, and switching elements connected in common through control lines 41 are con-trolled and monitored through a system control 100 for a quick and efficient setup of the artificial atmosphere in the container. The collected data can be displayed or transmitted via data commu-nication to a control center, which, if necessary, can carry out via data retransmission a parameter change of the atmosphere to be adjusted.
In the operating position of the apparatus represented in Fig. 2, valves 15 and 16 are switched over with respect to the switch position of Fig. 1. Through this, a partial stream of the nitrogen stream exiting the gas-separation membrane 11 from the outlet 39 is guided through the nitrogen valve 17 formed as a controllable throttle and the humidification valve 15, through the dehumidifi-cation section of the dehumidification membrane 11, and back through the humidification valve 16, so that this partial stream is mixed again with the nitrogen stream to be fed to the container 34.
In this operating position, the partial stream led through the dehumidification membrane is humidi-fied with the moisture separated in the latter, so that through this means the moisture level in the container 34 can be adjusted.
The nitrogen valve 17 serves to set the required nitrogen flow rate in collaboration with the nitro-gen control valve 13. In the switch position of the humidification valve 15 shown in Fig. 2, the permeate flow to the valve 15 is blocked, so that the permeate is discharged directly to the envi-ronment via the permeate valve 14.
The operating position of valves 15 and 16 can be adjusted in a temporally-controlled manner according to the degree of the desired humidity in the container 34. A large number of different operating parameters can be adjusted through the setting of the operating durations of the switch-WO 03/086874 $ PCTIDE03101248 ing positions of valves 15 and 16, through the appropriate adjusting of the nitrogen control valve 13 and the permeate valve 14, or through the regulating of the nitrogen valve 17 according to re-quirement.
With the aid of a suitably programmed system control 100, temporal variations of the operating parameters can also be set, for example oscillating gas-portion values of nitrogen, oxygen, or COZ in the atmosphere of the container 34. The control 100 can also be used to regulate the temperature in the container, since the cooling unit is coupled to the control of the atmosphere.
Fig. 3 shows a simplified embodiment form of the invention in which the humidification valves 15 and 16 are eliminated. In this embodiment form, the permeate leaving the gas-separation mem-brane at the connector 38 is released directly to the environment. By means of an electrically-operable nitrogen bypass valve 18, a specific nitrogen flow rate in the nitrogen partial stream flowing through the dehumidification section of the dehumidification membrane 10 and an ad-justment of the moisture level of the atmosphere supplied to the container 34 can be achieved.
The method according to the invention and the apparatus according to the invention accelerate the formation of a nitrogen atmosphere, improve the nitrogen yield, and lower the energy use and system costs. During the operation of the system according to the invention, a fixed pressure is maintained in the storage space. After the pressure is first built up, an amount of atmosphere equalling the amount of nitrogen supplied in each case is correspondingly released from the con-tainer 34, so that a slight overpressure constantly prevails The application of a suction device 1 increases the efficiency of the system through the fact that an oxygen-poor atmosphere mixture is formed from the atmosphere in the container and the am-bient air. This formed atmosphere is compressed and separated in the gas-separation membrane 11. Through this means, the desired oxygen-poor atmosphere is formed in the container in a short time.
REFERENCE NUMBERS
1 Suction device 2 Drive 3 Compressor 4 Heat exchanger Air cooler WO 031086874 9 PCT/DE03l01248 5a Alternative air cooler 6 Cooling fan 7 Water separator 8 Pressurized-air filter 9 Bypass valve Dehumidification membrane 11 Gas-separation membrane 12 Pressure accumulator 13 Nitrogen control valve 14 Permeate valve Humidification valve 16 Humidification valve 17 Nitrogen valve 18 Nitrogen bypass valve 21 Pressure gauge 22 Oxygen gauge 23 Moisture/temperature gauge 24 Oxygen gauge Moisture/temperature gauge 26 COz gauge 27 Ethylene gauge 28 Pressure gauge 29 Filter 31 COZ container 32 Pressure reduction valve 33 Blocking valve 34 Storage and transport container Filter 36 Outlet 37 Inlet WO 031086874 ~ ~ PCTIDE03101248 38 Permeate outlet 39 Gas outlet 40 Shunt 41 Control line 100 System control
The invention relates to a method for producing an artificial atmosphere in a storage or transport container according to the preamble of claim 1. The invention further relates to an apparatus for carrying out such a method according to the preamble of claim 8.
Long known has been the practice of increasing the quality of perishable products in transport or storage containers over a long period of time through exposing the product to an atmosphere, the nitrogen content of which is up to 99%. Under such conditions the product is put, as it were, into a deep sleep and during this time undergoes no putrefaction and after-ripening.
Thus, under such conditions products that would otherwise be spoiled within a few days can be transported over longer time periods and greater distances.
Known from EP 357 949 B1 is a device for producing an artificial atmosphere in a transport con-tainer, in which device the nitrogen is acquired from the ambient air by means of a nitrogen-generator unit and is continuously conveyed into the transport container. The production of the high nitrogen concentration takes place here by means of an apparatus for separation of the es-sential gas constituents of the ambient air, namely nitrogen and oxygen, into a component that contains approximately 99% nitrogen and a component that consists essentially of oxygen (per-meate).
By means of such gas-separation membrane, a continuous gas stream can be generated. Also known are apparatuses for discontinuous nitrogen generation, in particular molecular sieves;
however, the apparatus-technology structure of these is of a considerably higher level, due to the requirement of a backflushing of the molecular sieve. Thus, for the purpose of generating an arti-ficial atmosphere, gas-separation membranes have essentially prevailed.
Known from EP 224 469 is a transportable cooling container in which, in addition to the genera-tion of an elevated nitrogen component in the transport container, a humidification of the artificial atmosphere is carried out. Thus, an optimal humidity level in the transport container can be set in accordance with the product to be transported. Such a system requires the accompaniment of water container, which must constantly be tested for germ formation and must be disinfected from time to time.
In general, gas-separation membranes react sensitively to moisture. The impingement by moist pressurized air has a negative effect on the service life of these membranes.
Thus, for their pro-tection gas-separation membranes are often protected by suitable devices, for example cyclone separators that separate the free water.
In gas-separation membranes known until now, an unavoidable dehumidification of the supplied pressurized air takes place during the gas separation. The water vapour separated off is dis-charged together with the permeate. However, this discharge of water vapour negatively affects the output of the nitrogen production.
Also known is the practice of connecting an energy-consuming heat apparatus upstream to the gas-separation membrane, in order to raise the temperature of the fed pressurized air and thereby lower the relative humidity, in order to protect the gas-separation membrane from being impinged upon by free water.
In addition to the upstream-connection of heat apparatuses, also known is the practice of dehu-midifying the pressurized air through upstream-connected absorption dryers.
However, these consume a portion of the supplied pressurized air and thus lower the pressurized-air feed supply to the gas-separation membrane. Thus, the efficiency of the nitrogen production is reduced.
The invention is based on the object of specifying a method and an apparatus for producing an artificial atmosphere in a storage or transport container whereby, with a high efficiency of the sys-tem, a setting of the moisture level in the transport or storage container is possible without requiring an additional fluid supply.
This object is achieved through the method specified in claim 1. An apparatus according to the invention is specified in claim 8.
The invention originates from a method for producing an artificial atmosphere in a storage or transport container, in which method the pressurized air supplied by an air compressor is con-veyed via a gas-separation membrane into the storage or transport container to produce an artificial atmosphere with increased nitrogen portion, the moisture content of the supplied pressur-ized air being reduced by means of a dehumidification apparatus.
According to the invention, the pressurized air fed to the gas-separation membrane is dehumidi-fied before its entrance into the gas-separation membrane by means of a dehumidification membrane.
The application, according to the invention, of a dehumidification membrane reduces the humidity of the pressurized air and thereby increases the nitrogen production. Through the decreased moisture of the pressurized air fed to the gas separation membrane, the service life and efficiency of the latter can be increased.
In order to set the artificial atmosphere in the storage or transport container to a desired moisture level, the moisture removed from the pressurized air in the dehumidification membrane is pref-erably introduced into the storage or transport container in a controlled manner.
This has the advantage that the moisture required in the storage or transport container can be obtained from the dehumidification membrane, without requiring separate fluid containers. Re-duced thereby are, on the one hand, the equipment complexity and, on the other hand, the logistic complexity necessary to keep the otherwise-necessary fluid reservoir filled during a trans-port of long duration.
The moisture to be transferred into the storage or transport container can be directly supplied to the container; however, it can also be added to the gas stream leaving the gas-separation mem-brane.
In a first preferred embodiment form of the invention, a portion of the gas stream leaving the gas-separation membrane is guided by a shunt via the backflush section to the dehumidification mem-brane, before the gas stream is fed to the storage or transport container.
Through this means, nitrogen is used as rinsing air for the dehumidification membrane and, in common with the water vapour separated by the dehumidification membrane, is fed to the atmosphere of the transport or storage container.
Through a suitable valve control, the portion of the nitrogen stream that is guided over the dehu-midification membrane can be adjusted, in order to thereby adjust the moisture content of the artificial atmosphere fed to the container as required.
In an alternative embodiment form, the permeate leaving the gas-separation membrane is, at least in part, guided via the backflush section to the dehumidification membrane and only then discharged to the ambient atmosphere. Through this measure, in contrast to the absorption dryer, no consumption of pressurized air takes place and the nitrogen production of the gas-separation membrane is correspondingly increased.
The above-mentioned alternatives can also be activated in an alternating manner through a suit-able valve control. Through this means, in particular in the initialization phase of a transport or storage container, the time required for adjusting the artificial atmosphere to the desired state can be considerably reduced.
In a more far-reaching embodiment form, a cooling of the pressurized air supplied to the dehu-midification membrane can take place. Through this cooling, the membrane, in the presence of a cyclone separator and a subsequent warming, is protected from being acted on by free water and the associated negative consequences.
The apparatus according to the invention for carrying out the specified method contains the se-ries-connected arrangement of an air compressor, a dehumidification membrane, and a gas-separation membrane. The dehumidification membrane preferably contains a backflush section, via which either at least a portion of the permeate separated at the gas-separation membrane or at least a portion of the nitrogen exiting the gas-separation membrane is conducted.
In an embodiment form in which the permeate is conducted through the backflush section to the dehumidification membrane, the permeate is subsequently discharged to the environment. In an alternative embodiment form, at least a portion of the nitrogen exiting the gas-separation mem-brane is conveyed to the dehumidification membrane via the backflush section and then back into the transport or storage container. The invention can contain a valve control by means of which, in an alternating manner, a flushing of the dehumidification membrane with permeate or with ni-trogen can be carried out. In the case of a flushing of the backflush section of the dehumidification membrane with nitrogen, a control valve can be connected between the inlet and outlet of the backflush section, by the aid of which valve the magnitude of the partial stream con-ducted through the backflush section to the dehumidification membrane can be adjusted.
Between the pressurized-air generator and the dehumidification membrane, a cooling apparatus can be connected, in order to facilitate, through temperature lowering, a removal of excess water.
In the following, the invention is explained in detail with reference to an embodiment example. In the drawings:
Fig. 1: shows a schematic diagram of the invention according to a first embodiment form;
Fig. 2: shows a schematic diagram of the invention according to Fig. 1 with a changed valve position;
Fig. 3: shows a schematic diagram of a simplified embodiment form of the invention.
Represented in Fig. 1 is an apparatus for producing an artificial atmosphere in a transport con-tainer 34. The container 34 can be a stationary storage space, but it can also be a transportable vessel (e.g. container), such as are used in air transport, on ocean ships, as road-transport vehi-cles, or as rail-associated vehicles. As a rule, such containers are temperature-insulated and essentially hermetically sealed. When they are used as food-transport or -storage containers, WO 03/086874 5 PCTlDE03101248 they are often associated with a cooling system, in order to lower the temperature in the interior of the container.
In the method according to the invention, the atmosphere to be conveyed into the container is generated essentially from the ambient air. For this purpose, ambient air is drawn in by a com-pressor 3 driven by a drive 2. Optionally, a controllable suction device 1 in the container with a downstream-connected filter 35 can be provided in order to use a proportionate amount of air from the container. This proportionate amount of air, mixed with the ambient air, can be fed to the compressor 3. Especially in the starting phase of the initialization of a container, the time needed to adjust the atmosphere in the container 34 can thereby be shortened.
The air compressed in the compressor is now fed to a heat exchanger 4, in which the tempera-ture of the pressurized air emerging from the compressor is cooled. For further cooling of the pressurized-air temperature, the pressurized air is guided through an air cooler 5, in which the pressurized air is cooled by means of a cooling fan 6 in order to generate a cooled pressurized-air stream. Alternatively, the cool air stream can be produced through an air-current generator coupled to the drive of the compressor or to the compressor itself.
In the presence of a cooling system in the container 34, an air cooler 5a can also be used to lower the temperature of the pressurized air. In this case, the pressurized-air stream is guided through the blower-free air cooler in the container.
After the compression to, for example, 7.5 bar, the compressed air contains a large amount of water. Through cooling of the air, the storage capacity of the air can be reduced, forming free wa-ter that can be separated in a cyclone separator.
Thus, following the cooler 5 is a water separator 7 for removing free water from the pressurized air. The discharging of the separated water takes place through the opening of a water-removal device (e.g, by means of a magnetic valve) through the pressure of the pressurized air.
There follows a pressurized-air filter 8 for cleaning the pressurized air, in particular of oil residues.
The water and/or oil separated here can likewise be removed electrically/electronically.
The pressurized air thus cleaned is guided in reverse flow through the heat exchanger 4, in the process of which the air is again heated somewhat, in order to keep the content of free water por-tions low in the following dehumidification membrane.
In order to regulate the pressurized-air temperature before entrance into the following stages, a bypass valve 9 can be provided, which controls through more or fewer openings and closings the portion of the pressurized air fed back through the heat exchanger 4 and thus adjusts the tem-perature of the air supplied to the dehumidification membrane.
The pressurized air is now fed to a dehumidification membrane (10), known in itself, for dehumidi-fication of the pressurized air. The dehumidification membrane displays a pressurized-air inlet or a pressurized-air outlet, as well as a backflush section with an inlet 37 and an outlet 36, from which the separated moisture can be discharged.
An applicable dehumidification membrane is formed by a cylinder filled with hollow fibres, whereby the water-vapour molecules can be diffused through the hollow fibres and discharged via the so-called backflush section.
The pressurized-air outlet of the dehumidification membrane leads to the input of the gas-separation membrane 11, which is likewise constructed in a manner known in itself. This displays an inlet and two outlets. The pressurized air fed to the inlet is divided into a nearly oxygen-free nitrogen stream (approximately 30% of the introduced pressurized air) and an oxygen-rich air stream (permeate). The nitrogen gas stream is conveyed into the container 34 via the outlet 39.
In the embodiment form represented in Fig. 1, the oxygen discharged from the permeate outlet 38 of the gas-separation membrane 11 is released to the environment via a humidification valve 15, which is electrically actuable as a 3/2-port directional control valve, and via the backflush section of the dehumidification membrane 10 as well as the humidification valve 16, which is likewise electrically actuable as a 3/2-port directional control valve. In order to set the required flow rate of the permeate through the dehumidification section of the dehumidification membrane 10, a per-meate valve 14 designed as a controllable throttle is provided, which valve discharges a portion of the permeate to the environment directly after emergence from the gas-separation membrane 11.
The nitrogen stream exiting the gas-separation membrane 11 at the outlet 39 is fed, via an op-tional pressure accumulator 12 with built-in check valve for storage of nitrogen, and via an electrically controllable nitrogen control valve 13 to the container 34. The control valve 13 serves to adjust the nitrogen stream or rather the nitrogen purity, in that the adjustment of the volume flow effected thereby adjusts the relationship between the volume of the nitrogen stream and the volume of the permeate. The control valve 13 can also be manually operated.
The connecting line between the gas-separation membrane 11 and the container 34 contains a pressure gauge 21 for monitoring the system pressure, an oxygen gauge 22 for monitoring the nitrogen production of tt~e system, as well as moisture/temperature gauge 23 for monitoring the moisture of the nitrogen stream to the container 34. Corresponding sensors 24, 25 for oxygen and moisture/temperature, respectively, are arranged directly in the container 34, in order to ob-serve the atmospheric conditions at the stored product. Additionally, C02 sensors 26 and CZH4 sensors 27 as well additional sensors for additional gases or conditions (e.g.
temperature) can be assigned to the storage space.
For the transport or storage of certain products, a COZ feed into the container 28 can be provided;
this takes place through the conveying of a desired COZ volume flow from a C02 supply bottle into the container 34 via a pressure-reduction valve 32 to reduce the supply-container pressure to an operating pressure measured at the pressure gauge 28 and via a controllable shut-off valve 33.
Sensors, valves, and switching elements connected in common through control lines 41 are con-trolled and monitored through a system control 100 for a quick and efficient setup of the artificial atmosphere in the container. The collected data can be displayed or transmitted via data commu-nication to a control center, which, if necessary, can carry out via data retransmission a parameter change of the atmosphere to be adjusted.
In the operating position of the apparatus represented in Fig. 2, valves 15 and 16 are switched over with respect to the switch position of Fig. 1. Through this, a partial stream of the nitrogen stream exiting the gas-separation membrane 11 from the outlet 39 is guided through the nitrogen valve 17 formed as a controllable throttle and the humidification valve 15, through the dehumidifi-cation section of the dehumidification membrane 11, and back through the humidification valve 16, so that this partial stream is mixed again with the nitrogen stream to be fed to the container 34.
In this operating position, the partial stream led through the dehumidification membrane is humidi-fied with the moisture separated in the latter, so that through this means the moisture level in the container 34 can be adjusted.
The nitrogen valve 17 serves to set the required nitrogen flow rate in collaboration with the nitro-gen control valve 13. In the switch position of the humidification valve 15 shown in Fig. 2, the permeate flow to the valve 15 is blocked, so that the permeate is discharged directly to the envi-ronment via the permeate valve 14.
The operating position of valves 15 and 16 can be adjusted in a temporally-controlled manner according to the degree of the desired humidity in the container 34. A large number of different operating parameters can be adjusted through the setting of the operating durations of the switch-WO 03/086874 $ PCTIDE03101248 ing positions of valves 15 and 16, through the appropriate adjusting of the nitrogen control valve 13 and the permeate valve 14, or through the regulating of the nitrogen valve 17 according to re-quirement.
With the aid of a suitably programmed system control 100, temporal variations of the operating parameters can also be set, for example oscillating gas-portion values of nitrogen, oxygen, or COZ in the atmosphere of the container 34. The control 100 can also be used to regulate the temperature in the container, since the cooling unit is coupled to the control of the atmosphere.
Fig. 3 shows a simplified embodiment form of the invention in which the humidification valves 15 and 16 are eliminated. In this embodiment form, the permeate leaving the gas-separation mem-brane at the connector 38 is released directly to the environment. By means of an electrically-operable nitrogen bypass valve 18, a specific nitrogen flow rate in the nitrogen partial stream flowing through the dehumidification section of the dehumidification membrane 10 and an ad-justment of the moisture level of the atmosphere supplied to the container 34 can be achieved.
The method according to the invention and the apparatus according to the invention accelerate the formation of a nitrogen atmosphere, improve the nitrogen yield, and lower the energy use and system costs. During the operation of the system according to the invention, a fixed pressure is maintained in the storage space. After the pressure is first built up, an amount of atmosphere equalling the amount of nitrogen supplied in each case is correspondingly released from the con-tainer 34, so that a slight overpressure constantly prevails The application of a suction device 1 increases the efficiency of the system through the fact that an oxygen-poor atmosphere mixture is formed from the atmosphere in the container and the am-bient air. This formed atmosphere is compressed and separated in the gas-separation membrane 11. Through this means, the desired oxygen-poor atmosphere is formed in the container in a short time.
REFERENCE NUMBERS
1 Suction device 2 Drive 3 Compressor 4 Heat exchanger Air cooler WO 031086874 9 PCT/DE03l01248 5a Alternative air cooler 6 Cooling fan 7 Water separator 8 Pressurized-air filter 9 Bypass valve Dehumidification membrane 11 Gas-separation membrane 12 Pressure accumulator 13 Nitrogen control valve 14 Permeate valve Humidification valve 16 Humidification valve 17 Nitrogen valve 18 Nitrogen bypass valve 21 Pressure gauge 22 Oxygen gauge 23 Moisture/temperature gauge 24 Oxygen gauge Moisture/temperature gauge 26 COz gauge 27 Ethylene gauge 28 Pressure gauge 29 Filter 31 COZ container 32 Pressure reduction valve 33 Blocking valve 34 Storage and transport container Filter 36 Outlet 37 Inlet WO 031086874 ~ ~ PCTIDE03101248 38 Permeate outlet 39 Gas outlet 40 Shunt 41 Control line 100 System control
Claims (14)
1. Method for producing an artificial atmosphere in a storage or transport container (34), in which method pressurized air supplied by an air compressor (3) is conveyed via a gas-separation membrane (11) into the storage or transport container (34) in order to produce an artificial atmosphere having an increased nitrogen portion, the moisture content of the supplied pressurized air being reduced by means of a dehumidification apparatus, charac-terized in that the pressurized air is dehumidified by means of a dehumidification membrane (10) prior to its entrance into the gas-separation membrane (11 ).
2. Method according to claim 1, characterized in that at least a portion of the moisture sepa-rated from the pressurized air in the dehumidification membrane (10) is introduced into the storage or transport container (34).
3. Method according to claim 2, characterized in that the moisture is added to the gas stream leaving the gas-separation membrane (11).
4. Method according to claim 1, 2, or 3, characterized in that at least a portion of the gas stream leaving the gas-separation membrane is guided through a backflush section of the dehumidification membrane (10) before this gas-stream portion is fed to the storage or transport container (34).
5. Method according to claim 1, 2, or 3, characterized in that at least a portion of the permeate leaving the permeate outlet (38) of the gas-separation membrane (11) is guided through the backflush section of the dehumidification membrane (10).
6. Method according to claims 4 and 5, characterized through temporally-controlled alternation of the operating steps according to claims 4 and 5.
7. Method according to one or several of the claims 1 - 6, characterized in that a cooling of the pressurized air supplied to the dehumidification membrane (10) takes place.
8. Apparatus for carrying out a method according to claim 1, having an air compressor (3), the outlet air of which is fed to a gas-separation membrane (11) for separation of oxygen, the gas stream, consisting essentially of nitrogen, leaving the gas-separation membrane being fed to a storage or transport container (34), in order to produce in the latter an artificial at-mosphere with a nitrogen portion that is elevated with respect to the ambient air, characterized in that a dehumidification membrane (10) is connected upstream to the gas-separation membrane (11), in order to dehumidify the pressurized air prior to its entrance into the gas-separation membrane (11).
9. Apparatus according to claim 8, characterized in that the dehumidification membrane (10) displays a backflush section, and that at least a portion of the gas stream conducted through the backflush section can be conveyed into the storage or transport container (34) with moisture received in the backflush section.
10. Apparatus according to claim 8 or 9, characterized in that the permeate outlet (38) of the gas-separation membrane (11) can be connected to the backflush section of the dehumidi-fication membrane (10), in order to conduct the permeate separated in the gas-separation membrane (11) to the environment via the backflush section of the dehumidification mem-brane (10).
11. Apparatus according to claim 9, characterized in that the outlet (39) of the gas-separation membrane (11) displays a shunt (40) for the backflush section of the dehumidification membrane (10), and that the outlet (36) of the backflush section of the dehumidification membrane (10) is connected to the inlet of the storage or transport container (34), in order to humidify at least a portion of the gas stream leaving the gas-separation membrane (11) by means of the backflush section of the dehumidification membrane (10).
12. Apparatus according to claims 10 and 11, characterized in that the backflush section of the dehumidification membrane (10) is assigned switchover valves (15, 16), in order to connect the backflush section of the dehumidification membrane (10) to the permeate outlet (38) of the gas-separation membrane (11) and to the environment or, alternatively, to the outlet (39) of the gas-separation membrane (11) and to an inlet of the storage or transport con-tainer (34).
13. Apparatus according claim 11, characterized in that a control valve (13) is connected be-tween the inlet and outlet of the backflush section of the dehumidification membrane (10).
14. Apparatus according to one of the claims 8 - 13, characterized in that a cooling unit (4 - 9) for cooling the pressurized air is connected between the pressurized-air generator (3) and the dehumidification membrane (10).
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE10216518.1 | 2002-04-15 | ||
| DE10216518A DE10216518B8 (en) | 2002-04-15 | 2002-04-15 | Method and device for creating an artificial atmosphere in a storage or transport container |
| PCT/DE2003/001248 WO2003086874A2 (en) | 2002-04-15 | 2003-04-14 | Method and device for creating an artificial atmosphere in a storage or transport container |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2482868A1 true CA2482868A1 (en) | 2003-10-23 |
Family
ID=28685044
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002482868A Abandoned CA2482868A1 (en) | 2002-04-15 | 2003-04-14 | Method and device for creating an artificial atmosphere in a storage or transport container |
Country Status (12)
| Country | Link |
|---|---|
| EP (1) | EP1494786B1 (en) |
| CN (1) | CN1646208A (en) |
| AT (1) | ATE408444T1 (en) |
| AU (1) | AU2003243883A1 (en) |
| BR (1) | BR0309204A (en) |
| CA (1) | CA2482868A1 (en) |
| DE (4) | DE10216518B8 (en) |
| ES (1) | ES2314228T3 (en) |
| MX (1) | MXPA04010204A (en) |
| RU (1) | RU2004133337A (en) |
| WO (1) | WO2003086874A2 (en) |
| ZA (1) | ZA200408234B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022051806A1 (en) * | 2020-09-08 | 2022-03-17 | Avcatech Laboratories Pty Ltd | System and method for conditioning a compressed airstream |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102005045760B4 (en) * | 2005-09-23 | 2008-12-24 | Hoffmann Consorten Hamburg Gmbh | Method and apparatus for producing a conditioned atmosphere |
| DE102005051184B4 (en) * | 2005-10-26 | 2012-07-12 | Daimler Ag | Device for protecting metallic surfaces of products such as components, aggregates or semi-finished products |
| WO2008055524A1 (en) * | 2006-11-07 | 2008-05-15 | Liebherr-Transportation Systems Gmbh | Process and apparatus for producing a conditioned atmosphere |
| DE102007013114A1 (en) | 2007-03-20 | 2008-11-20 | Cargofresh Ag | Artificial atmosphere producing and maintaining device for use in e.g. storage container, has compressed air conditioning device compressing and drying surrounding air, where air is guided into container over nitrogen producing device |
| DE102007020625A1 (en) * | 2007-04-30 | 2008-11-06 | Khs Ag | Process for processing, in particular for packaging products using an oxygen-free process gas |
| CN101497387B (en) * | 2008-02-02 | 2011-01-12 | 亚泰半导体设备股份有限公司 | Chemical barrel trough atmosphere retaining device and method thereof |
| DE102014223982B3 (en) | 2014-11-25 | 2016-04-28 | Volkswagen Aktiengesellschaft | Process arrangement for producing a fiber-reinforced plastic component |
| CN110921635B (en) * | 2019-12-13 | 2023-09-26 | 南京航空航天大学 | Airborne nitrogen production device combining air flushing and membrane separation and application method thereof |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT384668B (en) * | 1985-11-28 | 1987-12-28 | Welz Franz Transporte | TRANSPORTABLE COOLING CONTAINER |
| US4783201A (en) * | 1987-12-28 | 1988-11-08 | Rice Arthur W | Gas dehydration membrane apparatus |
| DE3829435A1 (en) * | 1988-08-31 | 1990-03-08 | Horst Qualmann | DEVICE FOR GENERATING AN ARTIFICIAL ATMOSPHERE IN A TRANSPORT CONTAINER |
| US5034025A (en) * | 1989-12-01 | 1991-07-23 | The Dow Chemical Company | Membrane process for removing water vapor from gas |
| ATE131690T1 (en) * | 1990-07-19 | 1996-01-15 | Boc Group Plc | STORAGE AND TRANSPORT OF GOODS UNDER A CONTROLLED ATMOSPHERE |
| GB9713989D0 (en) * | 1997-07-02 | 1997-09-10 | Boc Group Plc | Controlling atmospheres in containers |
-
2002
- 2002-04-15 DE DE10216518A patent/DE10216518B8/en not_active Expired - Fee Related
-
2003
- 2003-04-14 DE DE10391507T patent/DE10391507D2/en not_active Expired - Fee Related
- 2003-04-14 AU AU2003243883A patent/AU2003243883A1/en not_active Abandoned
- 2003-04-14 EP EP03746238A patent/EP1494786B1/en not_active Expired - Lifetime
- 2003-04-14 BR BR0309204-6A patent/BR0309204A/en not_active Application Discontinuation
- 2003-04-14 RU RU2004133337/15A patent/RU2004133337A/en not_active Application Discontinuation
- 2003-04-14 CA CA002482868A patent/CA2482868A1/en not_active Abandoned
- 2003-04-14 AT AT03746238T patent/ATE408444T1/en not_active IP Right Cessation
- 2003-04-14 ES ES03746238T patent/ES2314228T3/en not_active Expired - Lifetime
- 2003-04-14 CN CN03808548.8A patent/CN1646208A/en active Pending
- 2003-04-14 WO PCT/DE2003/001248 patent/WO2003086874A2/en active IP Right Grant
- 2003-04-14 DE DE20321621U patent/DE20321621U1/en not_active Expired - Lifetime
- 2003-04-14 DE DE50310514T patent/DE50310514D1/en not_active Expired - Lifetime
- 2003-04-14 MX MXPA04010204A patent/MXPA04010204A/en not_active Application Discontinuation
-
2004
- 2004-10-12 ZA ZA200408234A patent/ZA200408234B/en unknown
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022051806A1 (en) * | 2020-09-08 | 2022-03-17 | Avcatech Laboratories Pty Ltd | System and method for conditioning a compressed airstream |
Also Published As
| Publication number | Publication date |
|---|---|
| ES2314228T3 (en) | 2009-03-16 |
| DE10216518B8 (en) | 2004-07-22 |
| ZA200408234B (en) | 2005-06-30 |
| ATE408444T1 (en) | 2008-10-15 |
| EP1494786A2 (en) | 2005-01-12 |
| DE20321621U1 (en) | 2008-07-03 |
| AU2003243883A1 (en) | 2003-10-27 |
| DE10391507D2 (en) | 2005-03-10 |
| WO2003086874A3 (en) | 2003-12-31 |
| CN1646208A (en) | 2005-07-27 |
| AU2003243883A8 (en) | 2003-10-27 |
| MXPA04010204A (en) | 2005-06-08 |
| DE10216518B4 (en) | 2004-03-04 |
| DE10216518A1 (en) | 2003-10-30 |
| BR0309204A (en) | 2005-02-09 |
| EP1494786B1 (en) | 2008-09-17 |
| WO2003086874A2 (en) | 2003-10-23 |
| RU2004133337A (en) | 2005-04-20 |
| DE50310514D1 (en) | 2008-10-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4829774A (en) | Transportable refrigerating container | |
| US6158147A (en) | Method and apparatus for drying of grain and other particulates using a membrane | |
| JP4867075B2 (en) | Storage that can control humidity and / or oxygen gas concentration in the storage | |
| US5249428A (en) | Method and apparatus for establishing a controlled atmosphere in the compartments of a vessel for conserving fresh vegetables | |
| FI93164C (en) | Method for drying plant or animal materials | |
| US7472494B2 (en) | Adsorption dehumidifier for granules of plastics materials | |
| EP0605819A2 (en) | Multistage membrane control system and process | |
| US5152966A (en) | Apparatus for producing a controlled atmosphere | |
| CA2482868A1 (en) | Method and device for creating an artificial atmosphere in a storage or transport container | |
| CA2239047C (en) | Controlling atmospheres in containers | |
| WO2014078833A1 (en) | Membrane separation process for controlling gas concentrations within produce shipping or storage containers | |
| JP2003240432A (en) | Method and device for drying crop | |
| AU737782B2 (en) | Apparatus and method for treating the atmosphere contained in enclosed spaces | |
| CN104460720B (en) | A kind of nitrogen controlled atmosphere control method and system | |
| US20220322687A2 (en) | Transport container with gas selective membrane exhaust | |
| JP3596292B2 (en) | Nitrogen enrichment equipment | |
| JPH04158739A (en) | Apparatus for preserving food | |
| JPH02200144A (en) | Freshness-keeping and preservation apparatus for green vegetable | |
| JP2519833B2 (en) | Storage device | |
| JP2003284916A (en) | Method for manufacturing low temperature drying gas and apparatus therefor | |
| JP2019515649A (en) | Closed processing system and method for processing elongated food products | |
| CN116728786A (en) | 3D printing system and method | |
| JPH0940405A (en) | Air compressor built-in type gaseous nitrogen generator | |
| CA3088987A1 (en) | Adjustable inert gas generation assembly for water-based fire protection systems | |
| JPH07114602B2 (en) | Storage device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |