The present invention relates generally to a fumigation apparatus. The invention will primarily be described with reference to its use to provide fumigation of timber dunnage and other waste shipping cargo packaging material, but it should be realised that the invention can have broader applications to any other bulk materials, goods or produce which may contain pests or insects or other vermin and which therefore require fumigation.
Large quantities of timber and packing materials are carried all over the world in ships and such goods remain largely useless at the point of arrival of the ship due to the likelihood of it containing pests, parasites, insects or other vermin from another country, such as for example borers, lice, ticks, fleas or termites. It is best that the timber dunnage and other bulk materials do not have to leave the confines of the wharf or port vicinity to travel to a distant site for effective treatment, since this would pose an environmental exposure risk.
Fumigation devices for bulk materials are known in the art that involve placement of a heavy, impervious blanket or other covering article over the materials followed by subsequent addition of toxic gas flow under the blanket to fumigate the covered goods. Current methods of fumigation under blankets are crude, ineffective at fully eliminating insect infestation since no mixing of gases with dunnage can occur, and highly dangerous from an occupational health standpoint since the gases used for effective fumigation are extremely toxic.
U.S. Pat. No. 5,318,789 relates generally to a method for fumigating produce and in particular fruit. U.S. Pat. No. 5,318,789 describes the specific construction of a vented container in which the fruit is packed in preparation for fumigation. The vented fruit containers are stacked in a purpose-built fumigation chamber of a fumigation facility and the fruit fumigated with a gaseous fumigant. The fruit containers are then transported out of the fumigation facility either to a cold storage area of a packing house or directly to shipment vehicles.
According to one aspect of the present invention there is provided a fumigation apparatus including:
a conventional shipping container which at least in part defines a fumigation chamber being adapted to contain produce to be fumigated, and
mobile fumigation means operatively coupled to the conventional shipping container, the mobile fumigation means including:
fumigant inlet means operatively coupled to the container to allow a flow of a fumigant into the fumigation chamber;
extraction means also being operatively coupled to the container to remove a majority of the fumigant from the fumigation chamber; and
absorption means being operatively coupled to the extraction means, the absorption means being designed to absorb substantially all of the fumigant extracted from the fumigation chamber.
Preferably the mobile fumigation means is defined by a shipping container. Typically the fumigation chamber is a pair of shipping containers positioned alongside one another each operatively coupled to the mobile fumigation means. Alternatively the mobile fumigation means is defined by a partition wall in the shipping container, the wall separating the mobile fumigation means and the fumigation chamber.
Preferably the fumigation apparatus further includes control means operatively coupled to the shipping container and arranged to control the flow of fumigant into the container. Typically the mobile fumigation means is a control room in which the control means is located.
Preferably the partition wall and/or the shipping container fumigation chamber itself is secure against the passage of the fumigant. This means that toxic gases from the process in the fumigation chamber will not pose any occupational health risk to operators of the fumigation apparatus during processing, while they may be standing in the adjacent control room. It also provides an all weather secure location for associated control equipment.
Preferably the absorption means comprises an absorption bed including activated carbon to which at least part of the extracted fumigant attaches.
Typically the fumigation apparatus also comprises a sliding bed or floor on which the produce resides, said bed or floor being configured to slide into and out of the fumigation chamber wherein loading and unloading of the produce to be fumigated can be performed externally of said chamber.
Preferably the control room incorporates a source of the fumigant which is preferably directly associated with a heating source, the latter used to convert the fumigant into a gaseous form. The heat energy transferred to the fumigant should be such that it becomes more buoyant than ambient air. In another variant the fumigation apparatus has a source of the fumigant and a heating source which are contained in an appropriate storage box which is secure against the passage of gases. Alternatively the fumigant inlet means is adapted to detachably couple to a mobile source of the fumigant such as a motor vehicle on which a fumigant vessel is mounted.
Preferably the control room incorporates a system control box and a system of fumigant delivery pipes and valves adapted in use to supply fumigant from the supply source to the fumigation chamber.
Preferably the fumigation chamber has openable doors in the container, the end doors when closed being secure against the passage of fumigant and further being fitted with external locking cam devices adapted to be secured with a latch and pin arrangement. More preferably the sliding bed or floor of the fumigation apparatus facilitates loading and removal of produce for fumigation via the end doors.
Preferably the fumigant inlet means includes a dispersion pipe system located in the upper part of the fumigation chamber. Such an arrangement allows the fumigant, which is generally heavier than air, to fall in a dispersed fashion downward over the top of the produce such as the timber and dunnage charge which has been loaded into the fumigation chamber.
Preferably the fumigation chamber is provided with a plurality of mixing fans adapted to circulate fumigant and gases within the chamber. Such an arrangement allows more even and thorough dispersion of the fumigant and gases as they enter and are dispersed in the fumigation chamber.
Preferably the extraction means includes a pipe attached to an orifice located in a lower region of a partition or a container wall, the pipe being connected in turn to an actuated butterfly valve further connected in turn to a contra-rotating fan adapted to provide suction for the extraction of the fumigant. More preferably the extraction means includes an exhaust stack positioned vertically above the fumigation container, the uppermost terminal of the exhaust stack being fitted with a gas diffuser and appropriate rain guard, and the exhaust stack being arranged to receive the stripped fumigant stream.
Preferably the fumigation chamber contains a plurality of small diameter floor and wall-mounted pipes independently connected via an appropriate system of taps and connectors to a fumigant sampling and detection meter unit located in the control room. More preferably the floor and wall-mounted pipes may be further adapted to be located in recessed grooves which may form part of the construction of the walls or floor of the container.
Preferably the control room includes a system control box which contains the fumigant sampling and detection meter unit and power supply switches for mixing fans, exhaust fan, lights, gas heaters and valve actuators.
In the preferred embodiment of the invention the fumigation apparatus is constructed using at least one conventional shipping container. Such a container is in all respects suitable for handling and use in the wharf or port vicinity. In fact, if available, effective fumigation of dunnage on site at the wharf by skilled operators would allow for the safe treatment and removal of this material for re-use as firewood or for building purposes, would eliminate the possibility of insects or vermin escaping into the environment, would speed up the fumigation processing rate and would provide some enhanced health and safety benefits.
According to another aspect of the invention there is provided a method of fumigating produce, the method comprising the steps of:
providing a fumigation apparatus including a conventional shipping container which at least in part defines a fumigation chamber and a mobile fumigation means operatively coupled to the container;
locating the produce to be fumigated in the fumigation chamber;
providing a flow of a fumigant to the fumigation chamber; extracting at least some of the fumigation from the chamber; and
absorbing at least part of the fumigant extracted from the fumigation chamber.
Preferably the fumigant extracted from the chamber is absorbed on an absorption bed.
Typically the method of fumigating produce further comprises washing at least part of the absorption bed to remove the absorbed fumigant. More typically the absorption bed is washed with a scrubbing solution, such as sodium thiosulphate, to yield one or more salts, such as bromide and sodium methylthiosulphate.
Generally the fumigant includes an alkyl halide such as methyl bromide. The produce is usually timber.
Notwithstanding any other forms which may fall within its scope, preferred forms of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:
As shown in
The control room 12 contains a system control box 26 which functions to control the flow of toxic gas into the fumigation chamber 16. Such an arrangement ensures that at all times the availability of fumigation gases is able to be manually controlled which ensures that highly safe operating procedures can be maintained.
A nominal number of mixing fans, in this case two fans 28 and 30, circulate gases within the fumigation chamber 16 when operating. Mixing fans such as 28 and 30 located by appropriate wall-mountings on the partition wall 14 dividing the container 10 into a fumigation chamber 16 and a control room 12 would provide sufficient circulation to prevent the toxic gases, which are heavier than air, from only locating in the lower portion of the fumigation chamber 16.
Gas-tight end doors 32 provide access to the fumigation chamber 16 when it is not operating. A sliding bed or floor 34 is included in the container 10 to slide in and out of gas-tight end doors 32. Such an arrangement means that bulk quantities of large individual or odd-shaped pieces of timber and dunnage may be conveniently loaded into the fumigation chamber 16 because of the size of the doors 32 and the access provided by the sliding bed or floor 34. Conventional shipping containers such as 10 have gas-tight end doors 32 which makes them very suitable pieces of equipment in this regard.
Extraction means for evacuation of the fumigation chamber gases includes a pipe 36 attached to an orifice 38 located in the lower region of the partition 14, the pipe 36 in turn connected to an actuated butterfly valve 40 and a contra-rotating fan 42 and thence to a pipe exhaust stack 44. The uppermost terminal of the stack 44 is fitted with a gas diffuser and appropriate rain guard 46. Control of the actuated butterfly valve 40 and contra-rotating fan 42 are by means of system control box 26. Such an arrangement allows the toxic, heavier than air gases to be removed by fan induced suction from the fumigation chamber 16 at an appropriate lower height, where said gas molecules will naturally congregate without recirculation, followed by dispersion to the external atmosphere via a stack 44 which is of sufficient height to allow the gas contents of the fumigation chamber 16 to be safely vented without occupational health risk exposure to operators or others located nearby the fumigation apparatus.
A plurality of gas sampling lines 48 are mounted on both the walls and floor of the fumigation chamber 16 and connected via an appropriate system of pipes and connectors to a gas flow meter test unit located within system control box 26. Such an arrangement provides a gas sampling system which is connected in use to a gas flow meter test unit which draws small amounts of the gaseous contents of the fumigation chamber 16 and delivers a reading as to the concentration of toxic gas remaining in the fumigation chamber 16 during the venting procedure. This monitoring is carried out to ensure that the main fumigation chamber doors 32 may be safely opened for the purposes of removing the charged timber and dunnage material without occupational health risk exposure to operators or others located nearby the fumigation apparatus.
System control box 26 also includes power supply switches and circuits for operating heating source 18, mixing fans 28 and 30 and, as stated earlier, actuated butterfly valve 40 and contra-rotating fan 42. Interior lights 50 would also be controlled from the system control box 26. Such an arrangement provides a central and securable location for all electrically operated devices, which is important when sequential operational steps are required.
During use, dunnage and timber material for fumigation is loaded onto the sliding floor 34 and then inserted into the fumigation chamber 16 using gas-tight end doors 32 to provide access for the load. The end doors 32 are then sealed and heated toxic gases, generated by warming liquified fumigation reagent 20 by means of heating source 18, directly enter the fumigation chamber 16 via piping means 24. System control box 26 functions to control the flow of toxic gas into the fumigation chamber. As best illustrated in
In this other embodiment of
The control room 120 of the twenty (20) foot container 130 is provided with the heating source or heat exchanger 180 and the source of fumigant, in this embodiment liquified methyl bromide. The piping means (not shown) which is located in a ceiling of each of the fumigation chambers such as 160 is operatively coupled to the heating source 180 and liquified fumigation reagent source 200.
The methyl bromide attaches to the activated carbon of the absorption bed 150 prior to discharge of the fumigant/gas mixture from the fumigation apparatus. The absorption bed 150 is periodically washed with a scrubbing solution, such as sodium thiosulphate. In this embodiment scrubbing of the absorption bed 150 with sodium thiosulphate yields bromide and sodium methylthiosulphate which are non-toxic salts which can be discharged safely to the environment. Thus, the methyl bromide gas is degraded following its fumigation and then extraction from the fumigation apparatus.
Now that several preferred embodiments of the present invention have been described in some detail it would be apparent to those skilled in the art that the fumigation apparatus has at least the following advantages over the admitted prior art;
1. The fumigation apparatus is adapted from a conventional shipping container and thus is relatively convenient and uncomplicated to fabricate;
2. The fumigation apparatus is relatively effective in fumigating produce; and
3. The fumigation apparatus is “environmentally friendly” in its fumigation and discharge of the fumigant.
Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. For example, the source of fumigant need not be located in the fumigation apparatus but rather may be mounted on a mobile vehicle such as a utility truck. The invention need not be restricted to methyl bromide as the fumigant but rather extends to any substance which is suitable in fumigating produce and thus killing pests, parasites, insects, or vermin. The invention need not be restricted to the specific constructional features described and may for example not include the sliding bed or floor.
All such variations and modifications are to be considered within the scope of the present invention the nature of which is to be determined from the foregoing description.
Number | Date | Country | Kind |
---|---|---|---|
PP9857 | Apr 1999 | AU | national |
47412/99 | Sep 1999 | AU | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/AU00/00336 | 4/19/2000 | WO | 00 | 5/9/2002 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO00/62607 | 10/26/2000 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
1849194 | McCurrie | Mar 1932 | A |
3736792 | Poulsen | Jun 1973 | A |
3811579 | Black | May 1974 | A |
4018704 | Kuragano | Apr 1977 | A |
4215508 | Allen et al. | Aug 1980 | A |
4716676 | Imagawa | Jan 1988 | A |
4748013 | Saito et al. | May 1988 | A |
4892456 | Hodgetts | Jan 1990 | A |
4961283 | Forbes | Oct 1990 | A |
4966755 | Smith | Oct 1990 | A |
4989363 | Doernemann | Feb 1991 | A |
5055277 | Gunn | Oct 1991 | A |
5194147 | Augustine et al. | Mar 1993 | A |
5203108 | Washburn, Jr. | Apr 1993 | A |
5312034 | Nakagawa et al. | May 1994 | A |
5318789 | Nakagawa et al. | Jun 1994 | A |
5417921 | Dove et al. | May 1995 | A |
5436268 | Ohama et al. | Jul 1995 | A |
5505908 | Nagji | Apr 1996 | A |
5556595 | Suzuki et al. | Sep 1996 | A |
5565178 | Dove et al. | Oct 1996 | A |
5607652 | Hellmuth et al. | Mar 1997 | A |
5678352 | Leitner et al. | Oct 1997 | A |
5791150 | Bosher et al. | Aug 1998 | A |
5792419 | Williamson et al. | Aug 1998 | A |
5904909 | Yates et al. | May 1999 | A |
5932172 | Winks | Aug 1999 | A |
5965185 | Bianco | Oct 1999 | A |
6047496 | Leitner et al. | Apr 2000 | A |
6047497 | Smithyman et al. | Apr 2000 | A |
6051198 | Sano et al. | Apr 2000 | A |
6146600 | Williamson | Nov 2000 | A |
6171561 | Williamson et al. | Jan 2001 | B1 |
6227002 | Bianco et al. | May 2001 | B1 |
6279261 | Binker et al. | Aug 2001 | B1 |
6447737 | Williamson et al. | Sep 2002 | B1 |
6462250 | Kuriyama et al. | Oct 2002 | B1 |
6513282 | Schott et al. | Feb 2003 | B2 |
6588140 | Johnson et al. | Jul 2003 | B1 |
6612067 | Topp | Sep 2003 | B2 |
6615534 | Smithyman et al. | Sep 2003 | B1 |
6941727 | Villers et al. | Sep 2005 | B2 |
6955786 | Carman et al. | Oct 2005 | B2 |
7090812 | Joyce et al. | Aug 2006 | B2 |
7311743 | Deshusses | Dec 2007 | B2 |
7682560 | Brash | Mar 2010 | B2 |
20010034963 | Jones | Nov 2001 | A1 |
20030026727 | Topp | Feb 2003 | A1 |
20030118474 | Brash | Jun 2003 | A1 |
20040035044 | Topp | Feb 2004 | A1 |
20050108920 | Takenoshita et al. | May 2005 | A1 |
20060010791 | Topp | Jan 2006 | A1 |
20060086038 | Mosher | Apr 2006 | A1 |
20060088462 | Joyce et al. | Apr 2006 | A1 |
20070084105 | Lindsay et al. | Apr 2007 | A1 |
20070163435 | Brash | Jul 2007 | A1 |
20070283986 | Baum | Dec 2007 | A1 |
20080107563 | Ivanine et al. | May 2008 | A1 |
20080146137 | Mosunic | Jun 2008 | A1 |
20080251514 | Fitzpatrick et al. | Oct 2008 | A1 |
20080257893 | Podd et al. | Oct 2008 | A1 |
20080257894 | Podd et al. | Oct 2008 | A1 |
20090211148 | McCarty | Aug 2009 | A1 |
20090272024 | Rogacki et al. | Nov 2009 | A1 |
Number | Date | Country |
---|---|---|
A-3280195 | Apr 1996 | AU |
2038328 | Sep 1992 | CA |
132 809 | Nov 1978 | DE |
4134093 | Apr 1993 | DE |
4428915 | Feb 1996 | DE |
19506200 | Aug 1996 | DE |
19744939 | Apr 1999 | DE |
19936417 | Feb 2001 | DE |
19950634 | May 2001 | DE |
10301570 | Aug 2004 | DE |
626190 | Nov 1994 | EP |
72017988 | May 1972 | JP |
58024319 | Feb 1983 | JP |
01030532 | Feb 1989 | JP |
02-013341 | Jan 1990 | JP |
02013341 | Jan 1990 | JP |
02219535 | Sep 1990 | JP |
02-303442 | Dec 1990 | JP |
02303442 | Dec 1990 | JP |
05236857 | Sep 1993 | JP |
08024572 | Jan 1996 | JP |
08-322449 | Dec 1996 | JP |
08322449 | Dec 1996 | JP |
09-249288 | Sep 1997 | JP |
10052625 | Feb 1998 | JP |
10151320 | Jun 1998 | JP |
10156139 | Jun 1998 | JP |
10156139 | Jun 1998 | JP |
2000300144 | Oct 2000 | JP |
2007143410 | Jun 2007 | JP |
2007259861 | Oct 2007 | JP |