Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F11/00—Control or safety arrangements
  • F24F11/0001—Control or safety arrangements for ventilation
• • A—HUMAN NECESSITIES
  • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
  • A23B—PRESERVING, e.g. BY CANNING, MEAT, FISH, EGGS, FRUIT, VEGETABLES, EDIBLE SEEDS; CHEMICAL RIPENING OF FRUIT OR VEGETABLES; THE PRESERVED, RIPENED, OR CANNED PRODUCTS
  • A23B7/00—Preservation or chemical ripening of fruit or vegetables
  • A23B7/02—Dehydrating; Subsequent reconstitution
• • A—HUMAN NECESSITIES
  • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
  • A23B—PRESERVING, e.g. BY CANNING, MEAT, FISH, EGGS, FRUIT, VEGETABLES, EDIBLE SEEDS; CHEMICAL RIPENING OF FRUIT OR VEGETABLES; THE PRESERVED, RIPENED, OR CANNED PRODUCTS
  • A23B7/00—Preservation or chemical ripening of fruit or vegetables
  • A23B7/14—Preserving or ripening with chemicals not covered by groups A23B7/08 or A23B7/10
  • A23B7/144—Preserving or ripening with chemicals not covered by groups 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 groups 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
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F11/00—Control or safety arrangements
  • F24F11/0001—Control or safety arrangements for ventilation
  • F24F2011/0002—Control or safety arrangements for ventilation for admittance of outside air
  • F24F2011/0004—Control or safety arrangements for ventilation for admittance of outside air to create overpressure in a room

Definitions

• THIS INVENTION relates to a controlled atmosphere storage chamber which may represent a building interior comprising one or more rooms, a vehicle interior, the interior of a container, or a transportable container.
• the storage chamber of Australian Patent 628067 was characterised by the separation of the feed ducts and return ducts in such a manner that the flow of air within the chamber was such as to control heat emission within the vicinity of each lighting strip within a surrounding envelope that represented only a minor proportion of the total volume of the chamber.
• the controlled storage chamber of Australian Patent 628067 was generally constructed as an experimental prototype and during operation it was found to be unsatisfactory in several respects because there was no proper control placed on suitable monitoring of variables which contributed to a controlled atmosphere such as (i) heat, (ii) air pressure, (iii) air velocity, and (iv) humidity. Without such monitoring taking place it was found in practice that "hot spots" or localised heat pockets occurred in the chamber which was extremely deleterious to perishable products placed on the storage shelves leading to product spoilage, lack of germination of plants, lack of proper maintenance of cell cultures and bacterial cultures and introduction of pathogens into a sterile atmosphere.
• the controlled atmosphere storage chamber of the invention therefore includes -
• air supply duct(s) which were tapered or otherwise shaped so as to compensate for the decrease in air velocity from an inlet of the air supply duct to an outlet thereof.
• the return duct(s) had to be of opposite taper to the supply duct(s) to achieve a desirable objective of uniform air distribution throughout the chamber.
• the air supply duct(s) and the air return duct(s) may be of generally conical shape or of a shallow cuboidal shape which is generally trapezoidal in plan.
• the air duct(s) may be of rectangular shape or of a shallow cuboidal shape which is rectangular in plan as described in Australian Patent 628067 in relation to the air supply duct providing that the duct(s) are modified in accordance with the present invention to provide an unrestricted air passage which has a tapered shape wherein the taper extends progressively inwardly from an end adjacent the generation means to an end remote from the generation means in relation to the supply duct(s) and has an opposite taper in relation to the return duct(s) .
• baffles along each opposed side of the rectangular air duct(s) which have a length or height which is progressively shortened or decreased from adjacent the air generation means to the remote end in the case of the air supply ducts and wherein the length or height of the baffles are progressively increased from the end adjacent the air generation means to the remote end in the case of the air return duct(s).
• the baffles are suitably oriented normal to the longitudinal axis of the or each air duct.
• the baffles may extend at an acute angle to the longitudinal axis provided that their effective height (ie. their distance from their free ends to an adjacent side wall of the air duct measured normal to the plane of the side wall) progressively decreases or increases as described above.
• the air generation means used in the invention may be of any suitable type and thus correspond to air conditioning means as described in Australian Patent 628067 and in one form may comprise a centralised air conditioning system using refrigerated cooling coils or a decentralised air conditioning system using an evaporative cooling system.
• the air outlet means of the air supply duct(s) may comprise one or more elongate slots extending substantially the length of the storage chamber or alternatively may comprise one or more rows of outlet apertures.
• air inlet means of the or each return duct may comprise one or more elongate slots extending substantially the length of the storage chamber or alternatively may comprise one or more rows of inlet apertures.
• the elongate storage members utilised in the controlled storage chamber of the present invention may comprise an elongate box of any suitable shape to thereby form a storage shelf with perishable products stored on a top surface of the elongate box.
• the heat sources utilised in the present invention may be of any suitable type but suitably include electrical lighting in the form of a row of light globes but more suitably strip lighting in the form of fluorescent tubes. Such strip lighting may be attached to the underside of each storage member.
• humidifying means for the storage chamber may comprise a water supply or water source heated by suitable heating means.
• the air supply duct(s) may be utilised for supply of humidified air to the chamber.
• the storage chamber may also be supplied with at least one heat sensor or probe which is suitably located adjacent the storage shelves. More preferably there may be utilised a plurality of heat sensors wherein such heat sensors are located adjacent each shelf in the storage chamber.
• At least one air pressure sensor located in the air supply duct or air return duct.
• at least one air pressure sensor located in the air supply duct or air return duct.
• a plurality of air pressure sensors which are located in both the air supply duct(s) and air return duct(s) .
• At least one air velocity sensor which may be provided in the air supply duct or the air return duct.
• at least one air velocity sensor may be provided in the air supply duct or the air return duct.
• a plurality of air velocity sensors located in the air supply duct(s) and the air return duct(s).
• each sensor is electrically connected to one or more microprocessors which may be interfaced to a computer at a location remote from the storage chamber.
• microprocessors which may be interfaced to a computer at a location remote from the storage chamber. This means that predetermined values of temperature, pressure, velocity and humidity may be provided to the storage chamber and it is the function of the microprocessor(s ) to maintain the predetermined values. When it is required to change these values it is then necessary to carry out such change by use of the computer.
• FIG 1 refers to a perspective view of a transportable container containing a controlled atmosphere storage chamber in accordance with the present invention taken from one end of the container;
• FIG 2 is a perspective view of the transportable container of FIG 1 taken from an opposite end of the container to that shown in FIG 1 ;
• FIG 3 is a side sectional view through the storage chamber of FIG 1 showing the arrangement of an air supply duct and air return ducts in fluid communication with an air conditioner;
• FIG 4 is a plan view of the storage chamber of FIG 1 showing the arrangement of an air supply duct and air return ducts;
• FIG 5 is a perspective view of an air return duct utilised in the storage chamber of FIG 1 ;
• FIG 6 is a plan view of the air return duct shown in FIG 5;
• FIG 7 is a view of an alternative form of air return duct to that shown in FIGS 5 or 6;
• FIG 8 is a view of an alternative form of air supply duct to that shown in FIG 4;
• FIG 9 is a block diagram concerning the electrical circuit used for operation of electrical componentry in the storage chamber.
• FIG 10 is a cut away perspective view showing the circulation of air flow throughout the storage chamber of the invention; and FIG 11 is a transverse section taken through the air supply duct shown in FIG 4.
• the container 10 is transportable and includes feet 11 which may be adjustable in height, a retractable crane hook assembly 12 which may be pulled out if required so that the container 10 may be lifted by crane if desired, a step 13 which may be extended or retracted as the case may be, a door 14 having window 14A, ramp 15, lock 16, a pair of side walls 17, a front wall 18 and a roof 19 having an air vent 20.
• lugs 21 for attachment of cables or chains (not shown) when the container 10 is transported by truck.
• the container 10 contains a controlled atmosphere storage chamber 22 which has a plurality of storage members 23 including a shelf surface 24 which may be utilised for supporting products such as plants 25, support uprights 26 for supporting storage members 23, strip lighting 27, air supply duct 28 which is of shallow cuboidal shape as shown and air return ducts 29. There are also provided heat sensors 30 as well as aisle 31. There is also shown forklift retaining members 32.
• the container 10 includes grilles 32A adjacent an inlet grille 33 of air conditioner 34 located in rear chamber 9 of container 10.
• Chamber 9 also contains microprocessor control module 36, outlet duct 37 for discharging spent air from air.
• conditioner 34 through air vent 20, control cabinet 38 which contains relevant electrical componentry for operation of storage chamber 22, humidifier 39, power inlet or switchboard 40, cabinet 41 containing manual override switches for the lighting strips 27 and communication cable 42 for connection of the microprocessor(s) to a computer 43 having keyboard 44 and visual display unit 45.
• the switchboard 40 may connect the storage chamber 22 to an external power supply.
• Heat sensors 30 are, as well as the air pressure sensors, air velocity sensors and humidity sensors referred to hereinafter, electrically connected to the microprocessor(s) .
• the communication cable 42 may be replaced by a radio link if required.
• FIGS 3-4 there is shown the flow of air indicated by arrows through air supply duct 28 and return of the air through return ducts 29. Also illustrated are heating elements 46 as well as air supply plenum 47 and return air plenum 48 as well as air pressure sensor 49 and air velocity sensor 50.
• FIG 4 there is shown the outlet slot 51 for air supply duct 28 which extends substantially the length of storage chamber 22. Humidity sensor 51A is also shown .
• FIGS 5-6 there are shown views of a return duct 29 and associated plenum 47. Air as indicated by the arrows flows through inlet slots 52 which may be arranged in a pair of rows 53 as shown.
• Inlet slots 54 of a longer length may also be utilised if required.
• the air may extend through outlet aperture 54A and return to air conditioner 34 through plenum 48 as shown and also as indicated by the arrows.
• the air return duct may also include boosters 55, electrical connections 56 and wiring 57.
• baffles 58 which as best shown in FIG 6 taper progressively inwardly toward plenum 48 or alternatively may be considered to taper progressively outwardly towards remote end 59 from air conditioner 34 or plenum 48.
• FIG 7 there is shown a modified return duct 29A which may include an unrestricted air flow passage 60 which tapers progressively inwardly towards the end 59 remote from plenum 47 or air conditioner 34.
• Air flow passage 60 may include tapered side walls 29B and be supported in rectangular housing 29C.
• FIG 8 there is shown a modified air supply duct 28A having a plurality of baffles 60A each having a length or height which progressively increases toward a remote end 61A from air conditioner 34.
• inlet slot 61 which may, if desired, be one or more rows of apertures 62.
• the switchboard 40 as best shown in FIG 9 contains a power inlet, power isolation switches and fuses and control cabinet 38 includes a light control module 64 which interprets control signal from the microprocessor(s) in relation to actuation and control of light parameters, contactors 65 which are microprocessor controlled switches actuating and controlling power supply to the strip lighting 27, air conditioner 34 shown in FIGS 2-3, humidifier 39 and other electrically operated componentry used in relation to storage chamber 22, transformer(s) 66 for supplying components such as certain parts of the air conditioner 34 with direct current and fuse ⁇ s) 67 for the transformer(s) 66.
• a light control module 64 which interprets control signal from the microprocessor(s) in relation to actuation and control of light parameters
• contactors 65 which are microprocessor controlled switches actuating and controlling power supply to the strip lighting 27, air conditioner 34 shown in FIGS 2-3, humidifier 39 and other electrically operated componentry used in relation to storage chamber 22, transformer(s) 66 for supplying components such as certain parts of the air conditioner 34 with direct current and fuse ⁇
• the microprocessor control module 36 contains microprocessor(s) which have a function to calculate, monitor, control and relay all variables or parameters detected by sensors 30, 49, 50 and 51A to maintain predetermined values. Control module 36 also contains relays which relay control signals calculated and interpreted by the microprocessor(s) to relevant electrical componentry.
• the manual override switches in cabinet 41 provide a manual control of the light parameters if the light control module 64 fails.
• the lines in phantom in FIG 9 illustrate electrical connections which may include a plurality of electrical connections where required.
• FIG 10 The overall circulation of air in storage chamber 22 is shown in FIG 10 with only a part of return duct(s) 29 being shown for convenience and a transverse section of the supply duct 28 is shown in FIG 11 wherein supply duct 28 is attached to roof 19 at 73. Insulation layers 71 and 72 are also shown.
• sensors 30, 49, 50 and 51 in conjunction with appropriate computer software continually adjusts and updates air supply parameters.
• the air supply duct is suitably configured so that air volume in the supply duct is approximately 10% of the total return air duct volume.
• the supply volume is based on maximum heat loads per level of storage members 23 and is updated and managed by on line optimal set point control software modifying both air velocity and pressure.
• a series of heating elements 46 facilitate the obtaining of variable settings for minimum temperatures that may be set in the storage chamber such as minimum diurnal temperature.
• the installation of the heating elements also automatically counteract any heat losses that may be experienced in the storage chamber. Thus, for example, if during a night time cycle the temperature is below a required minimum temperature then the heating elements may be actuated automatically to achieve the desired minimum temperature.
• the storage chamber of the invention has also had incorporated in its computer software a series of alarm parameters programmed to update at regular intervals within the system to advise by visual and telephone link of any abnormal activity outside the environmental settings. The alarm system also notifies of sensor malfunction or mechanical breakdown within the storage chamber and automatically manages and shuts down components so as not to cause damage to valuable product.
• the storage chamber of the invention may also be programmed to continually and automatically update parameters that cost effectively and efficiently manage the use of all energy requirements.
• new climatic settings are requested for example variations from temperature through to tropical environments the relevant computer software shut down sections of the control system to achieve new settings which are calculated to use absolute minimum energy and at the same time avoid trauma damage.
• the invention is a cost effective method and functionally efficient means of providing a controlled atmosphere storage chamber with a facility of providing optimisation of all relevant parameters in regard to storage of a variety of products that may include: (i) plant growth at defined temperature, relative humidity light, and gas levels; (ii) seed germination; (iii) mushroom growing;
• chamber includes within its scope a plurality of rooms or a single room in a building interior or one or more compartments in a vehicle interior.
• the invention also includes within its scope a method of operation of a controlled atmosphere storage chamber which includes the steps of: (i) generating cooled and pressurised air; (ii) causing said cooled and pressurised air to flow throughout the chamber to obtain a balanced distribution within said chamber wherein said cooled and pressurised air adopts an initial supply flow path which path has a transverse dimension or width which tapers progressively inwardly throughout its length towards an end remote from a location where said cooled and pressurised air is generated; (m) causing said cooled and pressurised air to flow downwardly from said initial supply flow path towards storage members located in said controlled atmosphere storage chamber having associated therewith one or more heat sources whereby said cooled and pressurised air flows around said one or more heat sources to thereby cause said air to become spent and heat laden; and (iv) effecting said spent and heat laden air to adopt a return flow path towards said location where said cooled and pressurised air is generated which return flow path is of opposite taper to said initial supply flow path.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Zoology (AREA)
• General Chemical & Material Sciences (AREA)
• Wood Science & Technology (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Food Science & Technology (AREA)
• Polymers & Plastics (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Duct Arrangements (AREA)

Applications Claiming Priority (1)

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• 1994
  • 1994-09-14 EP EP94927452A patent/EP0783654A4/de not_active Withdrawn
  • 1994-09-14 WO PCT/AU1994/000548 patent/WO1996008681A1/en not_active Application Discontinuation
  • 1994-09-14 JP JP8509754A patent/JPH10511764A/ja active Pending

Non-Patent Citations (2)

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