AU2008203480A1

AU2008203480A1 - A device, storage facility and method for aerating or fumigating

Info

Publication number: AU2008203480A1
Application number: AU2008203480A
Authority: AU
Inventors: Anthony Balding; John Peter Knight
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-08-02
Filing date: 2008-08-04
Publication date: 2009-02-19

Description

00

O

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION Standard Patent Applicants: Mr John Peter Knight and Mr Anthony Balding Invention Title: A DEVICE, STORAGE FACILITY AND METHOD FOR AERATING OR

FUMIGATING

The following statement is a full description of this invention, including the best method for performing it known to me/us: P72404.AU.I PmLSeFhVng Applktio 20058.4.doe (M) 00 A DEVICE, STORAGE FACILITY AND METHOD FOR AERATING OR

FUMIGATING

FIELD AND BACKGROUND OF THE PRESENT INVENTION The present invention relates to a device and method suitable for use in venting, aerating and fumigating a storage facility such as a grain silo.

00 At present there are essentially two different forms of silos; sealed silos ¢€3 and unsealed silos. Unsealed silos have been in wide spread use for many decades.

00 However, the current trend is in favour of sealed silos which offer a number of advantages including the ability to fumigate and provide greater control over the conditions under which grain is stored.

Fumigation of silos using phosphide tablets is common practice for Australian growers. Phosphide tablets are often sold in the form of aluminium phosphide, calcium phosphide, or zinc phosphide and all forms yield phosphine when in contact with atmospheric water or ingested. Phosphine is an effective insecticide against rodents, mould, insects and immature insect forms including eggs, larvae and pupae of insects.

On a practical level phosphide tablets are placed on trays or pans suspended in the top space above grain in the silo. Loading phosphide tablets onto the trays can be a dangerous task from the view point of climbing the silos and opening a hatch at the top of the silo. Occupational, Health and Safety (OHS) regulations require safety harnesses to be worn during this task to minimise injury. The fumigation tablets are usually left in the silo for up to 4 weeks and at the end of this period tablet residue in the form of powder is emptied from the pans. Again the danger in carrying out this task is working from the top of the silo and another, sometimes unpredictable risk, is the potential for wind to blow the tablet residue into the face of the operator or being spilt on the grain in the silo.

Control over the aeration of silos is an important parameter affecting the quality of the grain stored in a silo. Generally speaking aerating silo allows greater control over moisture content and temperature of grain inside the silo. In the case of -3oo sealed silos, aeration has been achieved by blowing air into the silo or sucking air out C)of the silo by a motor or engine driven fan. The fan effectively creates air circulation tor turbulence within the silo and due to the silo being sealed or otherwise air tight only nominal discharge or supply of air into the silo occurs.

It is an object of the present invention to provide an alternative means for fumigating or aerating a storage facility such as a silo.

00oO CSUMMARY OF THE INVENTION 00 According to the present invention there is provided a device for Sallowing the passage of air into or out of a silo, shed or other storage facility suitable for containing agricultural chemicals and products such as granular products and which may also be used for fumigating the silo, shed or other storage facility, the device including: a) a passageway through which air can pass in an inward direction from outside to inside the storage facility or in an outward direction from inside to outside the storage facility; b) a chamber for receiving a fumigation agent, the chamber forming part of, or in fluid communication with, the air passageway; and c) a closure that can be opened and closed to control the passage of air through the passageway.

Although the chamber may be provided separately of the passageway, preferably the chamber and passageway co-inside in, or are formed by, a single tubular structure.

Preferably, the passageway and chamber are defined by a tubular structure having openings at opposite ends of the tubular structure and said closure is able to close one of the ends of the tubular structure.

The passageway may have any cross-sectional shape and when the cross-sectional shape is circular, preferably the passageway has an internal diameter in the range of the 50 to 200mm and suitably in the range of the 80 to 120mm.

00 In use, preferably, the fumigation agent can be located in the chamber 0 Sand the closure closed, thereby allowing gas vapours evolved or released from the tb fumigation agent to pass into the storage facility while preventing air from passing through the passageway.

Preferably, the device includes a partition or divider at an outlet of the chamber that is air or gas permeable and allows gas vapour evolved or released by a 00 fumigation agent to pass through the partition and resist the passing of the insects, bugs or granular material. Suitably, the partition or divider is a wire mesh and the 00 mesh has apertures approximately 1.5 mm square in size.

Preferably, the device includes a second partition or divider capable of withstanding downward load of granular material in the silo. Suitably the second partition or divider is a convex shaped member. Even more preferably, the second partition protrudes from one end of the passageway.

Preferably, the closure is a cap or lid that can be placed over one end of the passageway.

Preferably, the device also includes an annular flange extending outwardly of the device for butting against a wall of a storage facility.

According to a preferred embodiment of the present invention, the device includes: a tubular passageway having opposite ends; a closure in the form of a cap that is screw threadably attached to one end of the passageway; and a partition located over the passageway which is spacing from the end having said screw threaded cap, therein defining an openable chamber between the cap and the partition, and the partition having openings that allow fumigation gas to pass yet prevent granular material from entering into the passageway.

According to the present invention there is also provided a device for supplying or dispensing a fumigating agent into a silo, shed or other storage facility 00 suitable for containing agricultural chemicals and products such as grain, the 0 Sapparatus including a chamber into which a fumigation agent can be located; a tresealable opening that allows access to the chamber and through which the Z fumigation agent can be loaded into the chamber; an outlet that allows gas vapours evolved or released from the chamber to flow or exit from the chamber and prevent a granular, powder or particulate material to enter the chamber via the outlet.

00 According to the present invention there is provided a storage facility for containing agricultural chemicals or produce such as grain, the storage facility 00 including: Sa) a sealed or unsealed housing or container for storing agricultural chemicals or granular material; b) one or more than one upper outlet through which air in the storage facility can exit the storage facility; c) one or more than one lower inlet through which air can enter the storage facility; and d) a chamber having an opening that can be opened and closed to allow a fumigation agent to be placed inside the chamber, the chamber also being in fluid communication with the storage facility that allows gas vapours evolved or released from the fumigation agent to pass into the storage facility; wherein the inlets and outlets include a closure means that can be operated to allow or prevent air from passing through the inlets and outlets without allowing the passage of granular material into or out of the storage facility.

Preferably, the lower inlet through which air enters or is drawn into the storage facility without a fan, blower or any other air movement means associated with the inlet.

Preferably the inlet defines a passageway through which air can enter into the storage facility.

Preferably, the chamber is in fluid communication with the inlet and when a fumigation agent is located in the chamber, the inlet is located in a closed 00 position. In other words, fumigation agent is prevented from flowing into the 0 Ssurrounding or exiting the storage facility via the inlet.

The inlet of the storage facility may also have any one or a combination of the features of the device for aerating the storage facility or the device for fumigating a storage facility.

00oO According to the present invention there is provided a storage facility ¢€3 Sfor containing agricultural chemicals or produce such as grain, the storage facility 00oO including: Sa) a sealed or unsealed housing for storing agricultural chemicals or grain; b) one or more than one upper outlet through which air in the storage facility exits the storage facility; c) one or more than one lower inlet through which air is drawn into the storage facility without a fan, blower or any other air movement means associated with the inlet; wherein the inlets and outlets include a closure means that can be operated to prevent air passing through the inlets and outlets without allowing the passage of granular material into or out of the storage facility.

The upper outlet may or may not have a fan, blower or air movement means associated therewith. In the situation where the upper outlet does include a fan or blower, preferably, the fan or blower is power by an electric motor powered by a rechargeable battery, suitably the battery is recharged by a solar panel.

According to the present invention there is provided a method of operating a sealed storage facility suitable for containing agricultural grain, the method including the steps of: a) loading or supplying a solid fumigation agent into an enclosure in fluid communication with the storage facility so that fumes or gaseous vapour of the fumigation agent can pass from the enclosure into the storage facility for a desired period during which the fumigation agent can take effect; b) venting air into the storage facility after step a) without the use of the blower or fan feeding air into the facility; and -7- 0 c) venting air out of the storage facility after step a); In other words, the step b) involves passively venting air into the storage facility without an external power source forcing air into the storage facility.

Venting air out of the storage facility according to step c) may be carried out with or without air being blown, sucked, drawn or forced out of the storage 00oO facility by a fan or blower. It is also possible that a wind powered fan may assist in Sdrawing air out of the storage facility or into the storage facility.

oO 00 SPreferably, the method also includes step d) of stopping fumes or gaseous vapour from the fumigation agent passing from the enclosure into the storage facility.

Although step d) may be involve operating an air valve blocking communication between the enclosure and the storage facility, preferably step d) involves removing the fumigation agent and/or residue thereof from the enclosure.

BRIEF DESCRIPTION OF THE DRAWINGS Preferred embodiments of the present invention will now be described with reference to the accompanying drawings, of which: Figure 1 is a perspective view of a silo containing grain including a vent in a bottom wall of the silo in the form of air inlets and an exhaust vent in the top wall of the silo having an internal fan; Figure 2a is a cross-sectional side view of the silo shown in Figure 1, with the air inlet and exhaust vent opened to allow air in and out of the silo; Figures 2b is a cross-sectional side view of an alternative silo that is supported off the ground which includes vents in the form of air inlets in a bottom wall of the silo and an exhaust vent in the top wall of the silo; Figure 2c is a cross-sectional side view of an alternative silo located on a concrete base or slab which includes vents in the form of air inlets in a side wall of the silo and an exhaust vent in the top wall of the silo; Figure 3 is a cross-sectional side view of the silo shown in the figure 1 with the air inlet in the bottom wall of the silo closed and without the upper exhaust fan; 00 Figures 4 and 5 are exploded perspective views of the air inlets fitted to the 0 Ssilos shown in Figures 1 to 3; Figure 6 is a cross-sectional side view of one the air inlets while closed; Figure 7 is a perspective view of an air inlet according to an alternative embodiment of the invention; and Figure 8 is a cross sectional side view of a silo with air inlets in the bottom wall and side walls of the silo and with and air movement or current represented by 00 the direction of the arrows.

00 DETAILED DESCRIPTION SThe present invention will now be described with reference to the preferred embodiments shown in the Figures. The preferred embodiments have a number of features that are the same or substantially the same and as a matter of convenience the same features have been used through the drawings to identify the same or substantially the same features.

The present invention will now be described with reference to a cylindrical silo as shown in the drawings. However, it will be appreciated that the silo could be in the form of any storage facility such a shed or drum and may be any shape or size and may be used for storing any type of material including agricultural chemicals and produce.

Figure 1 illustrates a silo 10 supported above the ground by four legs 11.

The silo 10 is a steel vessel having top and bottom walls 12 and 13 in a frusto-conical shape and a cylindrical side wall 14. An upper hatch 15 in the top wall 12 allows granular material to be loaded into the silo 10 and a bottom hatch 16 allows material to be discharged. The upper hatch 15 may also be used for man-hole access into the silo 10. Ideally a ladder 17 and safety rail 18 to which a safety line and harness can be attached extends up the side of the silo We have found that the ventilation of sealed silos 10 is important in producing high quality grain. In particular, managing temperature, moisture and water condensation inside the silo 10 are important in preventing prematuring or germination of grain which will prevent the grain from growing when sown. In -9- 0 addition, managing the temperature and moisture in the silo reduces insect infestation 0 and mould growth and, therefore, can help minimise the use of insecticides.

Ventilation of the silo shown in Figure 1 is controlled by means of vents or air inlets 20 in the bottom wall 13 of the silo 10. The inlets 20 have a screw threaded cap 21 that can be manually removed to open the inlet 20 and thereafter Sreplaced to close the inlet 20. Although not shown in the Figures, it is possible for the 00 cap 21 or any other closure means to be automatically opened and closed by an Cactuator that is operated based on programmable timer or in response to conditions 00 inside or outside the silo 10. The silo 10 also includes another vent outlet 22 in the Oupper wall 12 of the silo 10. The outlet 22 may be any suitable outlet including conventional wind driven spinning tops 23. The outlet 22 shown in Figure 1 is a specialised wind driven top that spins when the wind blows and also includes an internal fan 23 and a butterfly valve 24 for sealing the outlet 22 when the outlet 22 is not in use. Ideally the internal fan 23 is powered by a chargeable battery (not shown) that is recharged by means of connection to an electric solar powered panel Figure 2a illustrates a vertical cross-section of the silo 10 shown in Figure 1 with the inlets 20 and outlet 22 opened and air movement in the silo is shown by the direction of the arrows. The arrows are typical of the situation in which the side walls 14 of the silo 10 are warmer than the central region of the silo 10 and thereby creates circular convection currents in the direction shown in Figure 2. In addition to the convection current inside the silo 10, warm air rising in the silo 10 may also induce air to pass out of the outlet 22 and in the inlets 20. In the situation where wind is blowing or the internal fan 23 of the outlet 22 is operating, air will also be drawn out through the outlet 22. In either situation, air enters the inlet 20 without external fans, blowers or alike air movement means associated with the air inlet.

Figure 2b illustrates a cross-section of a silo according to an alternative embodiment of the present invention. The silo is indicative of a silo that is supported on stilts above the ground and includes inlets 20 and an outlet 22 that are opened. Air movement in the silo is shown by the direction of the arrows which represents the situation in which the side walls 14 of the silo are colder than the central region of the silo 10. As can be seen, colder air at the walls of the silo settles downward and moves oo00 toward the centre of the silo, together with fresh air entering from the inlet 20 and O rises upwardly in the centre of the silo. The silo also includes a wind turbine outlet 22

(N

tbthat draws air out of the silo when spun by wind. In addition, although not shown in Figure 2b, the wind turbine may also be fitted with a fan, such as a solar powered fan to help draw air of the silo 10 and may include an isolation valve or flap to seal off the wind turbine 22. The formation of condensation in the silo is minimised by air being Cdrawn into the silo via inlets 20 and discharged from the outlet 22. Grain is 00oO discharged downwardly from the silo via the bottom hatch in the usual manner.

00 Figure 2c illustrates a silo according to yet another embodiment of the Sinvention. The silo of Figure 2c is essentially the same as the silo shown in Figure 2b, save for the silo being located on a concrete base or slab. The arrows in Figure 2c show the direction of air movement in the silo which is typical of the situation in which the outside air is colder that the grain at the centre of the silo. Ordinarily under these conditions, the grain can be exposed to water dripping from the ceiling of the silo. However, by allowing fresh air to enter the silo at the inlet 22 and discharging of air from the silo via outlet 22 in the manner shown in Figure 2c, the formation of condensation on the ceiling of the silo is reduced.

Figure 3 illustrates a silo that is structurally the same as the silo shown in Figure 2a, however in use, the inlets 20 are closed and the outlet 22 has been removed to provide a fully sealed silo. Rather than removing the outlet 22, it is also possible for the butterfly valve 24 or any other suitable closure associated with the outlet 22 to be closed. In addition, Figure 3 illustrates the situation in which the inlet may be used to release or dispense a fumigation agent into the silo 10. Further detail relating to the structure of the inlets 20 and how the inlets 20 can be used for fumigating will now be described with reference to Figures 4 and Specifically, the inlets 20 include a tubular passageway 25 having a screw threaded cap 21 at one end and a dome or semi-circular partition 26 at the other end of the passageway 25. The partition 26 includes a series of openings 27 sized to allow the passage of the air through the partition 26 but prevent granular material from entering the passageway 25. In addition, as can be seen in Figure 5, a wire screen 28 or partition, suitably having apertures approximately 1.5 mm square, is -11- 00 spaced from the screw threaded end of the passageway 25. When the cap 21 is fitted Sto the passageway 25; the cap 21, passageway 25 and wire screen 28 form a compartment into which a fumigation agent, preferably in tablet or solid form can be ;loaded and the cap closed. Suitably, the fumigation agent is in the form of a phosphide tablet that releases a phosphine gas that seeps into the silo through the passageway 25 and is circulated therein via convection currents as shown in Figure 3.

It is standard practice to allow fumigation of the silo using tablets for a period of 1 to 00 2 weeks, following which residue from the tablet is withdraw from the compartment.

COnce the residue has been withdrawn, the cap 21 may be placed back on the inlet

(N

00oO to maintain the silo 10 in a sealed state or alternatively, the cap 21 removed to allow aeration of the silo The inlet 20 also includes a collar or annular flange 29 that is fitted to the outside wall of the tubular passageway 25. The flange 29 forms a seal with the wall of the silo 10 when installed.

Figure 6 illustrates a cross-section view of the inlet 20 shown in Figures 4 and 5 installed to the bottom wall 13 of a silo 10 with a cap 21 fitted in closed position and an addition wire mesh or non-permeable membrane 30 between the compartment 31 in which the fumigation agent and the removable cap 21. An additional annular flange 32 is also provided such that the flanges are located on both the inside and outside of the silo The tubular passageway 25, cap 21 and dome 26 may be made of any material including moulded metal or plastic including PVC. Preferably, the tubular passageway 25 has an internal diameter in the range of the 50 to 200mm and suitably approximately 100mm.

Figure 7 illustrates a silo 10 similar to the silo 10 shown in Figure 3 with two vents or inlets 20a in the bottom wall 13 of the silo 10, and in addition, two further vents or inlets 20b located in the side walls 14 of the silo 10. The convection currents in the silo 10 are such that it induces air in the silo 10 to exit the silo 10 via the vent located in the bottom wall of the silo and enter via the vents in the side wall of the silo -12- 00 O The passageways 25 of the inlets 20 may be of any length and may, for tbexample, protrude into silo by a length in the range of 0.1 to 1.Smeters and suitably, in ;Z the range of 0.3 to Figure 7 illustrates an air inlet 20 according to an embodiment of the Cinvention comprising a tubular passageway 25 having a screw threaded cap 21 at one 00 end and a cylindrical partition 26 at the other end of the passageway 25. The partition 26 includes a series of columns and a wire mesh having a series of openings that are 00oO sized to allow the passage of the air through the partition 26 but prevent granular Smaterial from entering the passageway 25. The columns provide structural support to the material in the silo. Although not shown in Figure 7, another partition or internal wire screen, suitably having apertures approximately 1.5 mm square, is located inside the tubular passageway 25 and spaced from the screw threaded end of the passageway When the cap 21 is fitted to the passageway 25; the cap 21, passageway 25 and internal wire screen form a compartment into which a fumigation agent, preferably in tablet or solid form can be loaded and the cap closed. Suitably, the fumigation agent is in the form of a phosphide tablet that releases a phosphine gas that seeps into the silo along the passageway 25 and through the cylindrical partition 26 into the silo where the gas is circulated via convection currents as shown in Figure 3. It is standard practice to allow fumigation of the silo using tablets for a period of 1 to 2 weeks, following which residue from the tablet is withdraw from the compartment.

Once the residue has been withdrawn, the cap 21 may be placed back on the inlet to maintain the silo 10 in a sealed state or alternatively, the cap 21 removed to allow fresh air to enter into the silo The inlet 20 also includes a collar or annular flange 29 that is fitted to the outside wall of the tubular passageway 25. The flange 29 forms a seal with the wall of the silo 10 when installed.

The inlets 20 shown in Figures 4 to 7 have essentially two modes of operation. One mode being when the cap 21 is closed and a fumigation agent inside the inlet fumigates the silo. Ideally the inlets 20 containing the fumigation agent are located in the bottom wall 13 of the silo 10 which can be accessed by ladder or on the 13- 00 back of a vehicle. This avoids the standard, but some what hazardous practice, of

O

Sclimbing to the top of the silo to place fumigation on trays suspended in the silo bIn addition, removing residue of the fumigation agent by opening the cap 21 avoids the risk of the spilling residue onto the grain inside the silo 10 and is more easily managed in terms of preventing the residue from being blown into the grain or into an operator's face. The second mode of operating involves the cap 21 being removed to Sallow aeration of the silo 10 which can reduce the formation of condensation on the 00 silo.

00 Those skilled in the art of the present invention will appreciate that many modifications and variations may be made to the preferred embodiment described above without departing from the spirit and scope of the present invention.

For example, it is possible for the length of the passageway of the inlets to be adjustable using any suitable means such two tubular members in which one fits inside the other and can be advance and retracted as desired.

According to another example, the cap may be in the form of any closure means included automated or programmable closures that open and shut as desired to allow aeration of the silo.

Claims

1. A device for allowing the passage of air into or out of a storage facility such as a silo or shed suitable for containing agricultural chemicals and products such as granular products and which may also be used for fumigating the storage facility, the device including: a) a passageway through which air can pass in an inward direction from 00 0outside to inside the storage facility or pass in an outward direction from inside to outside the storage facility; 00 b) a chamber for receiving a fumigation agent, the chamber forming part of, or in fluid communication with, the air passageway; and c) a closure that can be opened and closed to control the passage of air through the passageway.

2. The device according to claim 1, wherein the passageway and chamber are defined by a tubular structure having openings at opposite ends of the tubular structure and said closure is able to close one of the ends of the tubular structure.

3. The device according to claim 2, wherein the passageway has an internal diameter in the range of the 50 to 200mm.

4. The device according to any one of claims 1 to 3, whereby when in use a fumigation agent can be located in the chamber and the closure closed, thereby allowing gas vapours evolved or released from the fumigation agent to pass into the storage facility while preventing air from passing through the passageway. The device according to any one of claims 1 to 4, wherein the device includes a partition or divider at an outlet of the chamber that is air or gas permeable and allows gas vapour evolved or released by a fumigation agent to pass through the partition and resist the passage of insects, bugs or granular material.

6. The device according to claim 5, wherein the partition or divider is a wire mesh and the mesh has apertures approximately 1.5mm square or smaller in size. 00 7. The device according to any one of claims 1 to 6, wherein the device includes 0 a second partition or divider capable of withstanding downward load of granular material in the storage facility.

8. The device according to any one of claims 1 to 7, wherein the closure is a cap or lid that can be placed over one end of the passageway. 00 0 9. The device according to any one of claims 1 to 8, wherein the device also includes an annular flange extending outwardly of the device for butting against a 00 wall of a storage facility. A device for supplying or dispensing a fumigating agent into a silo, shed or other storage facility suitable for containing agricultural chemicals and products such as grain, the apparatus including a chamber into which a fumigation agent can be located; a resealable opening that allows access to the chamber from outside the silo and through which the fumigation agent can be loaded into the chamber; an outlet that allows gas vapours evolved or released from the chamber to flow or exit from the chamber and prevent a granular, powder or particulate material to enter the chamber via the outlet.

11. A storage facility for containing agricultural chemicals or produce such as grain, the storage facility including: a) a sealed or unsealed housing or container for storing agricultural chemicals or granular material; b) one or more than one upper outlet through which air in the storage facility can exit the storage facility; c) one or more than one lower inlet through which air can enter the storage facility; and d) a chamber having an opening that can be opened and closed to allow a fumigation agent to be placed inside the chamber, the chamber also being in fluid communication with the storage facility that allows gas vapours evolved or released from the fumigation agent to pass into the storage facility; wherein either one or a combination of the inlets or outlets include a closure that can be operated to allow or prevent air from passing through the inlets and/or -16- 00 outlets without allowing the passage of granular material into or out of the storage 0 0facility. (N ;Z 12. The storage facility according to claim 11, wherein the lower inlet through which air enters or is drawn into the storage facility is without a fan, blower or any other air movement means associated with the inlet. 00

13. The storage facility according to claim 11 or 12, wherein the lower inlet defines a passageway through which air can enter into the storage facility. 00

14. The storage facility according to claim 11 to 13, wherein the chamber is in fluid communication with the inlet and when a fumigation agent is located in the chamber, the inlet is closed, thereby preventing the fumigant from being released into the surrounding environment. A storage facility for containing agricultural chemicals or produce such as grain, the storage facility including: a) a sealed or unsealed housing for storing agricultural chemicals or grain; b) one or more than one upper outlet through which air in the storage facility exits the storage facility; c) one or more than one lower inlet through which air is drawn into the storage facility without a fan, blower or any other air movement means associated with the inlet, wherein either one or a combination of the inlets and outlets include a closure means that can be operated to prevent air passing through the inlets and outlets without allowing the passage of granular material into or out of the storage facility.

16. The storage facility according to claim 15, wherein the upper outlet includes a fan, blower or air movement means for drawing air out of the storage facility.

17. The storage facility according to claim 16; wherein the fan, blower or air movement means is powered by a rechargeable battery that is recharged by a solar panel. -17- 00

18. The storage facility according to any one of claims 15 to 17, wherein the Supper outlet is in the form of a wind turbine driven fan.

19. A method of operating a sealed storage facility suitable for containing agricultural grain, the method including the steps of: a) loading or supplying a solid fumigation agent into an enclosure in fluid oO 0 communication with the storage facility so that fumes or gaseous vapour of the fumigation agent can pass from the enclosure into the storage facility for a desired 00oO period during which the fumigation agent can take effect; b) venting air into the storage facility after step a) without the use of the blower or fan feeding air into the facility; and c) venting air out of the storage facility after step a); The method according to claim 18, wherein the step b) involves passively venting air into the storage facility without an external power source forcing air into the storage facility.

21. The method to claim 19 or 20, wherein step c) involves air being blown, sucked, drawn or forced out of the storage facility by either one or a combination of a wind driven turbine or a solar powered fan.

22. The method according to any one of claims 19 to 21, wherein the method also includes step d) of stopping fumes or gaseous vapour from the fumigation agent passing from the enclosure into the storage facility.

23. The method according to claim 22, wherein step d) involves removing the fumigation agent and/or residue thereof from the enclosure.