GB2181364A - Control of atmosphere in fruit stores - Google Patents
Control of atmosphere in fruit stores Download PDFInfo
- Publication number
- GB2181364A GB2181364A GB08623434A GB8623434A GB2181364A GB 2181364 A GB2181364 A GB 2181364A GB 08623434 A GB08623434 A GB 08623434A GB 8623434 A GB8623434 A GB 8623434A GB 2181364 A GB2181364 A GB 2181364A
- Authority
- GB
- United Kingdom
- Prior art keywords
- bed
- atmosphere
- expose
- store
- minutes
- 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.)
- Granted
Links
- 239000012298 atmosphere Substances 0.000 title claims abstract description 28
- 235000013399 edible fruits Nutrition 0.000 title claims abstract description 23
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 21
- 230000000274 adsorptive effect Effects 0.000 claims abstract description 20
- 239000002699 waste material Substances 0.000 claims abstract description 5
- 238000000034 method Methods 0.000 claims description 17
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 abstract description 40
- 229910002092 carbon dioxide Inorganic materials 0.000 abstract description 20
- 239000007789 gas Substances 0.000 abstract description 15
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 abstract description 12
- 239000001301 oxygen Substances 0.000 abstract description 12
- 229910052760 oxygen Inorganic materials 0.000 abstract description 12
- 229910052799 carbon Inorganic materials 0.000 abstract description 7
- 238000010926 purge Methods 0.000 abstract description 3
- 229920006395 saturated elastomer Polymers 0.000 abstract description 3
- 239000001569 carbon dioxide Substances 0.000 abstract description 2
- 241000220225 Malus Species 0.000 description 7
- 235000021016 apples Nutrition 0.000 description 6
- 238000001179 sorption measurement Methods 0.000 description 4
- 238000011144 upstream manufacturing Methods 0.000 description 4
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 3
- 235000011941 Tilia x europaea Nutrition 0.000 description 3
- 239000004571 lime Substances 0.000 description 3
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 2
- 239000000920 calcium hydroxide Substances 0.000 description 2
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 2
- 235000011116 calcium hydroxide Nutrition 0.000 description 2
- 238000011109 contamination Methods 0.000 description 2
- 125000004122 cyclic group Chemical group 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000008929 regeneration Effects 0.000 description 2
- 238000011069 regeneration method Methods 0.000 description 2
- 230000000717 retained effect Effects 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 235000013305 food Nutrition 0.000 description 1
- 238000003306 harvesting Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- 238000005057 refrigeration Methods 0.000 description 1
- 230000001172 regenerating effect Effects 0.000 description 1
- 230000029058 respiratory gaseous exchange Effects 0.000 description 1
- 238000005201 scrubbing Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- 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
- B01D53/02—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 adsorption, e.g. preparative gas chromatography
- B01D53/04—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 adsorption, e.g. preparative gas chromatography with stationary adsorbents
- B01D53/0454—Controlling adsorption
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23B—PRESERVATION OF FOODS, FOODSTUFFS OR NON-ALCOHOLIC BEVERAGES; CHEMICAL RIPENING OF FRUIT OR VEGETABLES
- A23B7/00—Preservation of fruit or vegetables; Chemical ripening of fruit or vegetables
- A23B7/14—Preserving or ripening with chemicals not covered by group A23B7/08 or A23B7/10
- A23B7/144—Preserving or ripening with chemicals not covered by group A23B7/08 or A23B7/10 in the form of gases, e.g. fumigation; Compositions or apparatus therefor
- A23B7/148—Preserving or ripening with chemicals not covered by group A23B7/08 or A23B7/10 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
- B01D2253/00—Adsorbents used in seperation treatment of gases and vapours
- B01D2253/10—Inorganic adsorbents
- B01D2253/102—Carbon
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2256/00—Main component in the product gas stream after treatment
- B01D2256/10—Nitrogen
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2256/00—Main component in the product gas stream after treatment
- B01D2256/12—Oxygen
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2257/00—Components to be removed
- B01D2257/50—Carbon oxides
- B01D2257/504—Carbon dioxide
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2259/00—Type of treatment
- B01D2259/40—Further details for adsorption processes and devices
- B01D2259/40003—Methods relating to valve switching
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2259/00—Type of treatment
- B01D2259/40—Further details for adsorption processes and devices
- B01D2259/40083—Regeneration of adsorbents in processes other than pressure or temperature swing adsorption
- B01D2259/40086—Regeneration of adsorbents in processes other than pressure or temperature swing adsorption by using a purge gas
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02C—CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]
- Y02C20/00—Capture or disposal of greenhouse gases
- Y02C20/40—Capture or disposal of greenhouse gases of CO2
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Wood Science & Technology (AREA)
- Zoology (AREA)
- Food Science & Technology (AREA)
- Polymers & Plastics (AREA)
- Storage Of Fruits Or Vegetables (AREA)
Abstract
In e.g. a refrigerated fruit store 1, the atmosphere is controlled to low levels of oxygen and carbon dioxide using an activated carbon bed 2, by continuously repeating the following cycle of operations: (1) expose the carbon in the bed 2 to the atmosphere in the fruit store 1, until saturated with CO2 (e.g. 12 minutes); (2) evacuate the bed 2, down to 7 kPa, to the gas reservoir 5, whereby the O2 and N2 (but not CO2) are released in "fruit store" proportions into the reservoir (e.g. 2 minutes); (3) expose the bed 2 to air to purge it of the CO2 (e.g. 18 minutes); (4) evacuate the bed 2 to waste (7ka is adequate) to remove O2 and N2, which would otherwise remain in the bed in substantially "air" proportions (i.e. excessive oxygen) (e.g. 2 minutes); (5) expose the bed 2 to the gas put in the reservoir 5 at operation (2) above, so that the bed 2 now contains O2 and N2 in "fruit store" proportions (e.g. 2 minutes); (1) expose the adsorptive medium to chamber atmosphere whilst releasing the gas from step (5) to the fruit store; and so forth indefinitely. <IMAGE>
Description
SPECIFICATION
Control of Atmosphere In For Example Fruit Stores
This invention relates to a method and apparatus for controlling an atmosphere, such as the atmosphere in a fruit store.
Considering apples as an example, apples are harvested over only a few weeks in the year but must be available to the retail market all year round. Apples may be satisfactorily stored at low temperature in a modified atmosphere. Typically, UK grown Cox's Orange Pippin is stored for 7-8 months at 3.5~4.0 C, in a nitrogen atmosphere containing 1 to 141% 02 and containing under 1% CO2. Apples respire even after they are picked, consuming 02 and producing CO2. Hence, in a sealed store, this 02 concentration is reached by itself (after about 8 days) and is maintained simply by the controlled admission of air (21% 2); the problem is to remove excess CO2.
For removing CO2, the most commonly used scrubbing technique (in the UK) is the addition to the store of dry, bagged, hydrated lime (Ca(OH)2) which absorbs CO2 by chemical reaction. This is simple, reliable, and requires no capital outlay. However, the running costs are high, about 300 per year for a 100 tonne fruit store. Additionally, the labour costs are high, the lime being messy and awkward to handle.
Furthermore, the entire annual demand for lime for this purpose arises over a few weeks, which makes it unattractive for manufacturers to cater specially for this demand.
A common, more convenient, alternative to the use of lime is a mechanical activated carbon adsorber.
This works by passing store atmosphere through a bed containing activated carbon so that CO2 is adsorbed and the remaining gas returned to the store. Typically after 510 minutes, the activated carbon becomes saturated with CO2. It is then regenerated by passing fresh air through the bed, whereupon CO2 is desorbed into the air stream. Once the bed is free of CO2 it is ready for a further adsorption phase.
This simple adsorber suffers the important shortcoming that, following regeneration, the bed is left full of air, which in the ensuing adsorption phase is discharged into the store. In this way, oxygen is repeatedly discharged into the store, often at a faster rate than the fruit consumes it, so that the optimum oxygen concentration becomes exceeded.
To reduce this shortcoming, most scrubber manufacturers adopt a valve control sequence whereby, between regenerating the bed and the next adsorption phase, the bed is briefly purged with store atmosphere (which is then vented to exhaust) to remove excess oxygen from the bed. An inverse sequence is organised between adsorption and regeneration so that store atmosphere remaining in the bed (with its valuable low oxygen concentration) is not expelled to waste.
These sequences do indeed decrease the mass of oxygen added to the store via the scrubber, but at the cost of subjecting the store to a slight cyclic vacuum and overpressure. Hence if the store is not absolutely gas-tight, air gain or store-atmosphere loss will occur through leaks in the structure of the store and around doors and hatches.
Scrubbers operating in this way are satisfactory for use at 1% CO2+141% 2, only if they are well maintained. In one trial, such a scrubber, operated with great care, did keep the CO2 down to 0.8%. In practice, however, the performance of many commercial scrubbers is such that higher CO2 concentrations have to be accepted in orderto maintain low oxygen concentrations.
According to the present invention, a method of controlling an atmosphere in a chamber comprises indefinitely repeating the following sequence of operations (1) to (5): (1) expose an adsorptive medium to the chamber atmosphere; (2) evacuate the adsorptive medium to a gas reservoir; (3) expose the adsorptive medium to air; (4) evacuate the adsorptive medium to waste; (5) expose the adsorptive medium to the gas reservoir.
This method may find application where the chamber atmosphere contains components X, Y and Z, of which X and Y are present in air but in the wrong proportions and of which Z has to be kept below a maximum level (which is however higher than in air); in such a case, the adsorptive medium may be chosen to adsorb Z preferentially. Operation (3) will rid the adsorptive medium of Z. The gas reservoir will in time contain X and Yin the correct proportions, with which it replenishes the adsorptive medium during operation (5).
The evacuation in operations (2) and/or (4) is preferably to a pressure of under 50 kPa (l atmosphere), more preferably under 20 kPa, most preferably under 10 kPa. Pressures under about 5 kPa, though they will work, are expensive and unnecessary, and preclude water-sealed pumps, which are advantageous over high-vacuum oil-sealed pumps in the context of food-related processes because accidental contamination of the atmosphere by water is immaterial but contamination by oil may be harmful.
The gas reservoir may be a flexible bag, thus under atmospheric pressure at all times regardless of the mass of gas in it. This avoids the disadvantageous cyclic vacuum and overpressure referred to above.
Where the chamber atmosphere is to be controlled to maintain carbon dioxide below a certain concentration, the adsorptive medium is preferably activated carbon. Carbon, unlike adsorptive media such as alumina, can cope with the high (90%) relative humidity expected when the chamber is a fruit store.
The invention extends to apparatus for controlling an atmosphere arranged to operate as set forth above.
The invention will now be described by way of example with reference to the accompanying drawing, which shows schematically a fruit store with apparatus for controlling its atmosphere.
A fruit store 1, with a capacity of 100 tonne apples (a common size in Britain), is held at 3.5 C by conventional refrigeration equipment (not shown). The best temperature will depend on apple variety, time of harvesting, growing conditions that year, and so on, as is well known.
A bed 2 of activated carbon, as an adsorptive medium, is connected to the fruit store 1 through one-way controllable valves B, E and A and a fan 3. (All components designated by letters are on/off valves, passing gas in only the direction shown). Air can be admitted to the upstream end of the bed 2 through J, and to the upstream side of the fan 3 through D. The fan 3 can pass 210 m3 air per hour against an overpressure of 1.9 kPa. The bed 2 is in a rigid tube of 600 mm diameter and 1340 mm length (approximately 380 litres), and the carbon is steam-activated extruded carbon as used in some conventional scrubbers, type Norit R2030.
The bed 2 can be vented to exhaust th rough its downstream end through C. The bed 2 can be evacuated through its upstream and via F and a water-sealed vacuum pump 4 capable of evacuating to 7 kPa. The evacuation can be directed either to exhaust via I orto a gas reservoir 5 via G. The gas reservoir may be emptied through H to the upstream end of the bed 2. The gas reservoir 5 is a flexible collapsible bag of impervious material of capacity 2 m3, subject externally to ordinary atmospheric pressure. The impervious material of the bag is a nylon-reinforced PVC sheeting, such as is sometimes used as campers' groundsheet.
Other valves (not shown) may be provided if desired at appropriate locations, for start-up or purging or exceptional purposes, but the apparatus as shown will perform the essential steps of the method satisfactorily.
In operation, the fruit store 1 is loaded with 100 tonne freshly picked Cox's Orange Pippin and cooled to 3.5 C. The atmosphere in the fruit store is, of course, air at this stage, i.e. containing 21% 02. Fruit respiration consumes the oxygen naturally, to an equilibrium level of 1.25% 02 in about eight days with this variety of apples. Trials have shown little commercial advantage in artificially faster oxygen removal.
The apparatus continuously repeats the following cycle of operations, the indicated durations of each operation being improvable in any specific installation by trial and error: (1) expose the carbon in the bed 2 to the atmosphere in the fruit store 1, until saturated with CO, (12
minutes); (2) evacuate the bed 2, down to 7 kPa, to the gas reservoir 5, whereby the 02 and N2 (but not CO2) are
released in "fruit store" proportions into the reservoir (2 minutes); (3) expose the bed 2 to airto purge it of the CO, (18 minutes); (4) evacuate the bed 2 to waste (7 kPa is adequate) to remove O2 and N2, which would otherwise remain in
the bed in substantially "air" proportions (i.e. excessive oxygen) (2 minutes);; (5) expose the bed 2 to the gas put in the reservoir Sat operation (2) above, so that the bed 2 now contains
02 and N2 in "fruit store" proportions (2 minutes); (1) expose the adsorptive medium to chamber atmosphere; and so forth indefinitely.
At the start of operation (3), the bed 2 is refilled with air slowly, to avoid stirring it up, using the air admission value J, taking =1 minute.
Note that the bed, being at atmospheric pressure after operation (5), imposes no pressure variation in operation (1) on the store, and that, due to operation (5), the bed does not contain excessive oxygen which would otherwise exude undesirably into the fruit store. It is a property of the carbon in the bed that CO2 is more strongly retained than O2 or N2, which are themselves about equally strongly retained. Thus, under the conditions of operation (2), the CO2 remains safely in the bed, while in operations (5) and (1) the desirable "fruit store" proportions of 02 and N2 are maintained.
To achieve this cycle of operations, the components are switched as follows:
Component A B C D E F G H I J Fan 3 Pump 4
Operation(1) X X X X
Operation (2) XX X
Operation (3)
first: X
then: XXX X
Operation (4) X X X
Operation (5) X
X=on or open
Blank=off or closed
Claims (12)
1. A method of controlling an atmosphere in a chamber, comprising indefinitely repeating the following sequence of operations (1) to (5): (1) expose an adsorptive medium to the chamber atmosphere; (2) evacuate the adsorptive medium to a gas reservoir; (3) expose the adsorptive medium to air; (4) evacuate the adsorptive medium to waste; (5) expose the adsorptive medium to the gas reservoir.
2. A method according to Claim 1, wherein the chamber atmosphere contains components X, Y and Z, of which X and Y are present in air but in the wrong proportions and of which Z has to be kept below a maximum level (which is however higher than in air).
3. A method according to Claim 2, wherein the adsorptive medium is chosen to adsorb Z preferentially.
4. A method according to any preceding claim, wherein the evacuation in operations (2) and/or (4) is to a pressure of under 50 kPa.
5. A method according to Claim 4, wherein said evacuation is to under 20 kPa.
6. A method according to Claim 5, wherein said evacuation is to under 10 kPa.
7. A method according to any preceding claim, wherein the gas reservoir is a flexible bag.
8. A method according to any preceding claim, wherein the adsorptive medium is activated carbon.
9. A method according to any preceding claim, wherein the chamber is a fruit store.
10. A method according to Claim 1, substantially as hereinbefore described.
11. Apparatus for controlling an atmosphere, arranged to operate a method according to any preceding claim.
12. Apparatus for controlling an atmosphere, substantially as hereinbefore described with reference to and as shown in the accompanying drawing.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08623434A GB2181364B (en) | 1985-10-08 | 1986-09-30 | Control of atmosphere in for example fruit stores |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB858524740A GB8524740D0 (en) | 1985-10-08 | 1985-10-08 | Control of atmosphere in fruit stores |
| GB08623434A GB2181364B (en) | 1985-10-08 | 1986-09-30 | Control of atmosphere in for example fruit stores |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB8623434D0 GB8623434D0 (en) | 1986-11-05 |
| GB2181364A true GB2181364A (en) | 1987-04-23 |
| GB2181364B GB2181364B (en) | 1989-01-25 |
Family
ID=26289862
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08623434A Expired GB2181364B (en) | 1985-10-08 | 1986-09-30 | Control of atmosphere in for example fruit stores |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2181364B (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0565827A1 (en) * | 1992-03-16 | 1993-10-20 | Isolcell Italia S.P.A. | Refrigeration compartment and process for maintaining a controlled atmosphere |
| NL9300368A (en) * | 1993-02-26 | 1994-09-16 | Electrotechnisch Bureau T C Va | Method and apparatus for controlling the CO2/O2 concentration of a gas mixture in a space |
| WO1995005753A1 (en) * | 1993-08-21 | 1995-03-02 | The Dow Chemical Company | Control of the atmosphere in produce storage rooms |
| EP0749692A2 (en) * | 1995-06-19 | 1996-12-27 | Pebaco B.V. | Method and apparatus for controlling the atmosphere in a gas filled closable space |
| EP1016346A1 (en) * | 1998-12-30 | 2000-07-05 | Dunkelmann & Pollakowski GbR | Method for treatment of biological material , especially fresh fish |
| NL1021970C2 (en) * | 2002-11-21 | 2004-05-26 | Tno | Method for regulating the CO2 concentration of the air within a closed space where crops are grown. |
| US20160157438A1 (en) * | 2012-07-17 | 2016-06-09 | Antecy B.V. | Method for accelerating growth of plants in a controlled environment |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1251719A (en) * | 1968-02-02 | 1971-10-27 | Improvements in methods of and apparatus for absorbing carbon dioxide for use in installations for preserving horticultural products including flowers and fruit | |
| GB1314101A (en) * | 1969-04-17 | 1973-04-18 | Sulzer Ag | Process and plant for the adsorption of carbon dioxide from a gas mixture |
-
1986
- 1986-09-30 GB GB08623434A patent/GB2181364B/en not_active Expired
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1251719A (en) * | 1968-02-02 | 1971-10-27 | Improvements in methods of and apparatus for absorbing carbon dioxide for use in installations for preserving horticultural products including flowers and fruit | |
| GB1314101A (en) * | 1969-04-17 | 1973-04-18 | Sulzer Ag | Process and plant for the adsorption of carbon dioxide from a gas mixture |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0565827A1 (en) * | 1992-03-16 | 1993-10-20 | Isolcell Italia S.P.A. | Refrigeration compartment and process for maintaining a controlled atmosphere |
| NL9300368A (en) * | 1993-02-26 | 1994-09-16 | Electrotechnisch Bureau T C Va | Method and apparatus for controlling the CO2/O2 concentration of a gas mixture in a space |
| WO1995005753A1 (en) * | 1993-08-21 | 1995-03-02 | The Dow Chemical Company | Control of the atmosphere in produce storage rooms |
| EP0749692A2 (en) * | 1995-06-19 | 1996-12-27 | Pebaco B.V. | Method and apparatus for controlling the atmosphere in a gas filled closable space |
| EP0749692A3 (en) * | 1995-06-19 | 1997-11-12 | Pebaco B.V. | Method and apparatus for controlling the atmosphere in a gas filled closable space |
| EP1016346A1 (en) * | 1998-12-30 | 2000-07-05 | Dunkelmann & Pollakowski GbR | Method for treatment of biological material , especially fresh fish |
| NL1021970C2 (en) * | 2002-11-21 | 2004-05-26 | Tno | Method for regulating the CO2 concentration of the air within a closed space where crops are grown. |
| WO2004057945A1 (en) | 2002-11-21 | 2004-07-15 | Nederlandse Organisatie Voor Toegepast- Natuurwetenschappelijk Onderzoek Tno | Method for regulating the co2 concentration of the air within an enclosed space within which crops are grown |
| US20160157438A1 (en) * | 2012-07-17 | 2016-06-09 | Antecy B.V. | Method for accelerating growth of plants in a controlled environment |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8623434D0 (en) | 1986-11-05 |
| GB2181364B (en) | 1989-01-25 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19940930 |