Fumigation chamber

Abstract

Fumigation chamber (1) for products to be treated, comprising sealed walls (2) with a loading opening, a fumigation cycle control module (10), a sealed door (3), a heater (4), a system (5) for detecting and relieving any overpressure inside the chamber, and a degassing circuit (6) for expelling the fume gas from the chamber and replacing it with external air. FIGURE 1

Description

Title of the invention: Fumigation chamber

[0001] technical field

[0002] The present invention relates to a fumigation chamber for products to be treated, comprising walls with a loading opening, fumigation being implemented by generating an active fumigating gas to treat the products against the presence of insects or larvae affecting the quality of the product batches. Previous technique

[0003] Cereals are seeds and foodstuffs intended for human and animal consumption that represent a significant portion of international trade. This trade is carried out by sea, river, rail, and road, primarily using containers. To prevent the transport of these seeds and foodstuffs from becoming a source of proliferation for the harmful insects often present in these goods, chemical treatments to eradicate pests (insects) present in the foodstuffs are applied during transport. Among these treatments, phosphine (or phosphorus trihydride, PH3) is a gaseous chemical compound released by the hydrolysis of a metallic phosphide, such as aluminum, zinc, or calcium phosphide, upon contact with water in the ambient air.

[0004] Fumigation is legally required by the authorities of certain importing countries to limit the risk of dispersal of non-endemic pest species. Carrying out this treatment in direct contact with the grain in containers (not specially designed for this purpose) during transport has the advantage of not wasting treatment time before or after the transport stage. Indeed, to be effective, phosphine treatment needs to be carried out over a period that can vary between 5 and 30 days depending on the temperature chosen.

[0005] Phosphine is highly toxic to mammals (see INRS datasheet: FT 179), which justifies its use being governed by relatively strict regulations. For example, in France, a 1986 decree stipulates that fumigation must be carried out by operators approved by the Ministry of Agriculture. According to this decree, the permitted exposure for raw grain is 0.1 mg of phosphine / kg of grain. Workers exposed to phosphine must not inhale more than 0.13 mg / m³ of air per workday or 0.40 mg / m³ of air over a maximum period of fifteen minutes.

[0006] Given the imperatives of combating the proliferation of harmful insects on the one hand, but also significant risks to the health of workers when using phosphine, it becomes imperative to improve treatment methods so as to be able to simultaneously satisfy these two contradictory requirements.

[0007] The main constraints encountered concerned the ability to seal silos without risk to personnel, but also the lack of available (and qualified) personnel to carry out fumigation in-house, particularly when this must be preceded by work to seal structures, caulk buildings, and cover them with tarpaulins. This latter aspect of the availability of trained personnel, previously unidentified, emerged as the main obstacle to the development of fumigation in France (Barret-Guillot, 2014).

[0008] US patent 5932172 describes a grain fumigation chamber in a storage facility comprising several grain silos or cells. Fumigation is carried out from a single source of gaseous fumigant for all the cells. The single source of gaseous fumigant is connected to a gas supply line through which gas flows. The gas inlet ports of the silos are also connected to the gas supply line. The connection between each gas inlet port and the line is ensured by a valve whose orifice or opening is precisely calibrated to limit pressure variations. Thanks to this arrangement, the flow of gaseous fumigant through the grain-containing silos of the facility experiences only minor disturbance when a valve between the line and a silo is opened or closed.This minor disturbance can be easily compensated for by maintaining the gas pressure in the duct at a constant value. The outlet gases from the installation's silos can be recycled through the silos, with the addition of fumigant gas periodically or as needed to maintain a predetermined fumigant concentration.

[0009] PPE document 179978 describes a fumigation apparatus, comprising a transport container serving as a fumigation chamber adapted to contain products to be treated, fumigant inlet means functionally coupled to the container to allow fumigant to flow into the fumigation chamber, extraction means also functionally coupled to the container to remove a majority of the fumigant from the fumigation chamber, absorption means functionally coupled to the extraction means, said absorption means being designed to absorb at least a portion of the fumigant extracted from the fumigation chamber, and means for washing at least a portion of the absorption means to remove and degrade the absorbed fumigant. A control chamber incorporates a smoke source which is directly associated with a heating source, the latter being used to convert the smoke into gaseous form.

[0010] The systems described above use smoke gas sources external to the treatment chamber. Therefore, specific installations must be provided to produce and transport the gas into the treatment chamber, with a risk concerning the airtightness of these installations.

[0011] Thus, to overcome these various drawbacks, the invention provides for various technical means. Summary of the invention

[0012] First of all, a first objective of the invention is to provide a device enabling the reliable destruction of harmful insects present in batches of seeds or grains, or other products, in particular batches intended for transport to distant destinations for which the proliferation of harmful species must be avoided.

[0013] Another objective of the invention is to provide a fumigation process that meets these same requirements while ensuring the safety of people working around the treatment facilities.

[0014] Another objective of the invention is to provide a device to ensure that the treatment which has been carried out is truly effective, that is to say conforming to specific, previously defined and measurable criteria.

[0015] To this end, the invention provides a fumigation chamber for products to be treated, comprising:

[0016] -watertight walls with a loading opening;

[0017] -a fumigation cycle control module, comprising a fumigation cycle monitoring and control module, a cycle target data module and a completed cycle data module;

[0018] -said fumigation cycle monitoring and control module being designed to perform monitoring of temperature, internal pressure and fumigant gas rate inside the enclosure, as well as treatment time and to compare the data obtained to target data of conforming cycle.

[0019] -a watertight door cooperating with the active seal, for watertight closure of the loading opening before starting a processing cycle;

[0020] -a heater, connected to the control module and activatable in case of detection of a temperature below a minimum treatment threshold;

[0021] -a system for detecting and evacuating any overpressure inside the enclosure;

[0022] -a degassing circuit, activatable by the control module, for expelling the fumigant gas from the enclosure and replacing it with external air.

[0023] This architecture simplifies the construction of the containment structure, eliminating the need for an external smoke generator, its control system, and the associated piping. The airtight nature of the containment also ensures that a consistent phosphine level is maintained over time, allowing the treatment cycle to continue without refilling.

[0024] The enclosure includes all the elements required for rigorous cycle monitoring, enabling validation of whether or not the cycle is proceeding in accordance with target parameters essential for ensuring the quality and effectiveness of the treatment. Since the effectiveness of fumigation is directly related to two main parameters—namely, a minimum concentration for a minimum duration—the enclosure allows validation of whether a cycle conforms to the specified parameters. The design and materials provide the enclosure with a sufficient level of airtightness to allow for cycles lasting several days without the subsequent addition of fumigant, thus eliminating the need for an external fumigant generator.

[0025] Alternatively, certain modules can be separated from the control module. Also alternatively, the detection and evacuation system allows for the rebalancing of internal and external pressures in the event of a negative pressure within the enclosure.

[0026] According to an advantageous embodiment, the enclosure also includes a fan for mixing the gases within the enclosure. This fan helps to homogenize the internal environment in order to have the same gas concentration throughout the volume, to promote a uniform temperature distribution, and to facilitate the penetration of the fumigant into the batches to be treated.

[0027] According to another advantageous embodiment, the active seal is filled by injection of fluid (water, air, oil, etc.).

[0028] Advantageously, the enclosure also includes a temperature sensor connected to the control module.

[0029] Also advantageously, the enclosure includes a fumigant gas concentration rate detector connected to the control module.

[0030] The cycle control module, the degassing circuit, and the fan are preferably arranged outside the enclosure. This arrangement protects these components from the particularly corrosive environment of the fumigant, which remains inside the enclosure. Alternatively, a fan can be provided inside the enclosure, with its motor located outside the enclosure.

[0031] The invention also provides a fumigation process for products to be treated in a fumigation chamber as previously described, allowing the treatment of a batch of products with a fuming gas under given conditions of concentration, temperature and pressure, comprising the following steps:

[0032] -receipt of a batch of grain to be treated in a sealed fumigation chamber;

[0033] -receipt of a dose of fumigant agent (in the form of lozenges, tablets or other) within the enclosure;

[0034] -closing the enclosure door in a sealed manner and locking;

[0035] - monitoring of a gas generation phase to ensure that the required fumigation conditions are obtained;

[0036] - monitoring by a control module of a treatment phase of the products to be treated to ensure that the fumigation conditions are maintained during the planned treatment time;

[0037] -in case the control module detects a temperature level below a minimum threshold, start a heating cycle using a heater (preferably internal to the enclosure);

[0038] -in the event of detection of a pressure level exceeding a pre-established threshold by a system for detecting and evacuating a possible overpressure, evacuate the overpressure to the outside of the enclosure;

[0039] -in case of detection by the control module of a fumigation gas level below a pre-established minimum threshold, generate an anomaly signal;

[0040] -in case of detection by the control module of completion of a complete cycle according to the conditions provided, generate a conforming cycle signal, and activate the degassing circuit to expel the fumigant gas from the enclosure and replace it with external air, then unlock the door of the enclosure.

[0041] Alternatively, the detection and evacuation system allows the internal and external pressures to be rebalanced in the event of a depression in the enclosure.

[0042] Advantageously, the generation of fumigating gas is obtained by reaction of a fumigating agent (for example pellets, plates, or other) with ambient humidity.

[0043] Alternatively, a preliminary heating step is provided before starting a fumigation cycle.

[0044] The products to be treated are preferably seeds, fertilizers, dried fruits or vegetables, herbs, spices, oilseeds, coffee, cocoa, tobacco, primary processing products such as flour, or wooden boards, archives or old books. Brief description of the drawings

[0045] All implementation details are given in the following description, supplemented by Figures 1 to 6, presented solely for the purpose of non-limiting examples, and in which: Fig. 1

[0046] [Fig.1] [Fig.1] is a schematic representation of an example of a fumigation chamber shown in section; Fig. 2

[0047] [Fig.2] [Fig.2] is a schematic representation of an example module of fumigation cycle control; Fig.3

[0048] [Fig.3] [Fig.3] is a functional flowchart illustrating the main steps of a fumigation process; Fig. 4

[0049] [Fig.4] [Fig.4] is a schematic representation of another example of an enclosure fumigation presented in the inactive phase; Fig. 5

[0050] [Fig.5] [Fig.5] is a schematic representation of the enclosure of [Fig.4] presented in the internal air mixing phase with or without heating; Fig. 6

[0051] [Fig.6] [Fig.6] is a schematic representation of the enclosure of [Fig.4] presented in the degassing phase. Description of the implementation methods

[0052] The term "fumigation chamber" or "fumigation chamber" in the context of the invention refers to a space within which the diffusion of a gas can be carried out. In the specific case of the invention, this gas is used to disinfect material, which may include biological material such as plants. In the case of phosphine disinfection, the targets are insects. Phosphine is a toxic gas that denatures oxyhemoglobin and interferes with the synthesis of proteins and enzymes involved in cellular respiration. Thus, its use against insects is effective because the respiration of their cells is inhibited, leading to their death.

[0053] The term "fumigant" refers to a gaseous substance having a sufficiently low acute toxicity threshold to be active against pests at very low concentrations, generally less than one percent. The fumigant is initially in a solid state, and a chemical reaction with air and ambient humidity produces a gas, which then acts as such. Advantageously, PH3, or phosphine, is used. obtained by reaction between a metallic phosphide and atmospheric water. The most common are aluminum phosphide and magnesium phosphide.

[0054] It should be noted that PH3 is particularly active and attacks many materials, including metallic materials such as copper, gold and silver, preventing the use of unprotected electronic devices in a fumigant environment.

[0055] In France, fumigation must in principle be carried out under the supervision of an agent of the plant protection service or other persons or organizations approved by the Ministry of Agriculture. The decree of August 4, 1986 specifies the conditions under which certain fumigants (including phosphine) must be used.

[0056] The term "optimal temperature" is understood to mean the temperature known or determined by a person skilled in the art to allow effective fumigation of the material to be treated, with an optimal treatment time. If the temperature deviates from the optimal temperature, particularly for lower temperatures, the treatment time must be increased.

[0057] In a preferred embodiment, the optimum temperature is 25°C.

[0058] By “watertight”, in the expressions “watertight wall”, “watertight door”, or “ "Airtight closure" means a sealing characteristic at least sufficient to allow fumigation treatments to be carried out with fumigant generation at the beginning of the cycle, retention of the fumigant in the enclosure for the required cycle time and at a minimum required rate, without further addition of fumigant during the cycle time. DEVICE

[0059] Figure 1 schematically illustrates an example of a fumigation chamber 1. As illustrated, the chamber 1 has airtight walls 2 with an opening 3 allowing the loading and unloading of materials to be treated. An airtight door 4 allows the chamber to be closed or accessed depending on the work phases. An active seal 5 ensures airtightness at the sensitive interface between the door and the chamber's closing wall. The seal can be arranged either on the door or at the opening. To ensure operator safety, the door is preferably equipped with a locking system.

[0060] To control the operation of the enclosure and its various components, as well as to monitor the fumigation cycles, a fumigation cycle control module 10 is provided. This module is described in more detail below.

[0061] The active seal 5 is advantageously controlled by the fumigation cycle control module 10. An active seal 5 that can be filled or inflated by injecting a fluid is advantageously used. Since the pressure inside the enclosure can reach more than 2000 Pa (i.e., 0.02 bar), the pneumatic seal maintains the airtightness of the door and therefore of the enclosure.

[0062] The walls 2 of the enclosure and the door 4 are preferably thermally insulated. The materials intended to come into contact with the fumigant gas are carefully selected to exhibit resistance characteristics to highly corrosive fumigation gases such as phosphine.

[0063] In order to operate on an industrial scale, a large-capacity enclosure such as a shipping or truck container is used, typically with a volume of around 33 m³. Such a volume is sensitive to pressure variations that could generate significant stresses against the walls, with risks of leakage or even destruction of the enclosure. To manage this risk, the enclosure includes a system 7 for detecting and relieving any overpressure inside or outside the enclosure. The detection and relief system 7 detects any pressure differential between the inside and outside of the enclosure and also allows for pressure rebalancing, for example, using one or more pressure relief valves.

[0064] Pressure monitoring is also useful for ensuring the proper execution of the fumigation cycle. For example, in the absence of a phosphine sensor, pressure monitoring can confirm that a fumigation cycle is running correctly.

[0065] Once a fumigation cycle is completed, and taking into account the sealing of the enclosure which retains the fumigant gas inside it, the enclosure provides a degassing circuit 8, which can be activated by the control module 10, to allow the fumigant gas to be expelled from the enclosure and replaced by external air, while maintaining the balance of internal and external pressures.

[0066] In the illustrated example, a fan 9 mixes the gases within the chamber to ensure a uniform presence of the smoke gas throughout the treatment volume and good temperature distribution. As illustrated in Figures 4, 5, and 6, the fan 9 also complements the degassing circuit 8 by blowing the gas from the inside to the outside of the chamber. Advantageously, degassing is carried out via a chimney to comply with the standards in force in certain countries (in France, gas evacuation must be at least 2 meters above the nearest roof ridges). This chimney can be demountable to allow for transport of the chamber.

[0067] A recirculation valve 21 and a degassing valve 22 allow the gas flow to be directed either towards the enclosure with the valve 21 open, as shown in [Fig. 5] for an air mixing or heating phase, or to the outside with the valve 22 open, as shown in [Fig. 6] for degassing. During this same phase, an outside air intake valve 23 is placed in the open position. The outside air intake is preferably made through an air inlet located near the door and opposite the degassing system.

[0068] In the example of figures 4 to 6, the fan 9, the degassing circuit 8 and the respective valves 21 and 22 are arranged in a duct or conduit 24 originating in the enclosure, and subdividing into two outlets, one towards the enclosure for the air mixing or heating phases, and the other towards the outside for the degassing phase.

[0069] In [Fig. 4], the enclosure is in inactive mode. This mode can be used between fumigation cycles and / or for loading or unloading the material to be treated. It should be noted that in this mode, the various modules, such as the fumigation cycle control module 10, the overpressure detection and evacuation system 7, the degassing circuit 8, the fan 9, the temperature sensor(s) 11, and the smoke gas concentration level detector, are inactive.

[0070] To provide useful data to the control module 10, the enclosure includes a temperature sensor 11 and a smoke gas concentration level detector 12, or PH3-meter for phosphine detection, both connected to the control module 10.

[0071] Preferably, the concentration level detector 12 is adapted for measuring phosphine (PH3). For example, a commercially available PH3 meter, such as PhoCapt®MD, is used. Optionally, one or more additional detectors 12 are provided outside the enclosure, in locations where personnel are likely to be present. These additional probes allow for the generation of an alert in the event that an abnormally high level of fumigant gas is present near the enclosure. The use of one or more detectors 12 makes it possible to measure the phosphine concentration in the enclosure, to verify the proper execution of the process, in particular the release of phosphine, to monitor the concentration during the cycle, and to verify the absence of toxin before opening the doors at the end of the cycle.

[0072] Since fumigation treatment is effective within a certain temperature range, the enclosure also includes a heater 6, preferably internal to the enclosure, connected to the control module 10 and activated if a temperature below a minimum treatment threshold is detected. The heater can be activated during a fumigation cycle to maintain the internal environment and / or the products being treated above a minimum treatment temperature. As the heater may increase the pressure within the insulated enclosure, the internal pressure is monitored and any overpressure is relieved as previously described. As illustrated in [Fig. 5], the heater 6 is, for example, implemented using a heating element coupled to the fan 9 and the valve 21.

[0073] Given the extremely corrosive effect of a fuming gas such as phosphine, the fragile modules, in particular the cycle control module 10, but The degassing circuit 8 and the fan 9 are also located outside the enclosure, as shown in figures 4, 5 and 6.

[0074] Figure 2 is a schematic representation of the fumigation cycle control module 10. This control module 10 comprises a fumigation cycle monitoring and control module 13, a cycle target data module 14, and a completed fumigation cycle data module 15. The fumigation cycle monitoring and control module 13 is designed to monitor the temperature, internal pressure, and fumigant gas concentration inside the chamber, as well as the treatment time, and to compare the obtained data with target data for a compliant cycle. This architecture allows the chamber components to be controlled, to interact as needed, and, most importantly, to monitor the evolution of the parameters of the ongoing cycle to ensure their compliance. A microprocessor 16, implementation instructions 17, and a data exchange bus enable the proper functioning of the cycle control module 10.To facilitate interaction with an operator, an interface module 18 provides an input 19 of batch data to be treated, and an output 20 of fumigation cycle data carried out, for local or remote treatment.

[0075] The fumigation chamber can be transported by any type of vehicle equipped for container transport and providing an electrical power supply, for example, motorized vehicles such as ships, trucks, and trains. METHOD

[0076] Figure 3 is a flowchart illustrating the main steps of the fumigation process. Before starting a cycle, the device is at rest, with all modules switched off, as illustrated in Figure 4. The initial step 31 involves receiving a batch of grain (or other product) to be treated, a dose of fumigating agent, and closing the door once all the components are in place. Treatment by prolonged exposure to phosphine (or phosphorus trihydride, PH3) is preferably used. In the process using the previously described sealed enclosure, the phosphine is released by the hydrolysis of a metallic phosphide, such as aluminum, zinc, or calcium phosphide, upon contact with water in the ambient air. The phosphide doses are supplied, for example, in the form of pellets, tablets, or other media. A relative humidity level as low as 5% can be sufficient to allow the gas to be released.The lower the humidity level, the longer the reaction time. For example, with a level below 30%, hydrolysis can take several days. For use in very dry climates, checking the relative humidity level beforehand can be helpful to estimate the required time.

[0077] A door locking system using a control module is advantageously implemented to ensure operator safety. The fumigating agent acts slowly upon contact with ambient humidity to generate the smoke gas, and the entrance door Since the enclosure is open, the operator, wearing a mask and appropriate protective equipment, has ample time to leave the area before the fumigant gas concentration level becomes significant. Furthermore, as the enclosure is equipped with a fumigant gas concentration detector, an alarm can be triggered for the operator should the gas level begin to become significant.

[0078] With the fumigant gas now entering the chamber, step 32 of the fumigation cycle monitoring by the cycle control module 10 can begin. The module 10 monitors the evolution of the monitored conditions and parameters (temperature, pressure, fumigant gas concentration) and compares the detected values ​​to reference values.

[0079] In step 33, if a temperature level in the chamber is detected below a minimum threshold, a heating cycle is initiated until the temperature rises above the previously exceeded threshold. Alternatively, a heating cycle can be initiated before the fumigation agent is added to ensure that the products to be treated are at an adequate temperature.

[0080] In step 34, if a pressure level in the enclosure is detected that exceeds a maximum threshold, or if there is too great a differential between the internal and external pressure of the enclosure, a rebalancing is carried out.

[0081] In step 35, if a fumigant gas level below a minimum threshold is detected, an anomaly signal is generated. The cycle may be stopped. The required gas level is set by the operator before starting a cycle. Depending on the circumstances, the level may be between 1 and 10 g / m³.

[0082] In step 36, if it is detected that the required fumigation conditions are maintained for the required treatment time, a compliance signal is generated. For example, for a dose of PH3 of 1 to 1.5 g / m3, to treat cereals, the treatment time depending on the temperature is 15 days from 11 to 15°C, 12 days from 16 to 20°C, 7 days from 21 to 25°C, 6 days from 26 to 30°C, 5 days for above 30°C.

[0083] If the insects possess different forms of tolerance, or hidden forms, the required treatment time can be greatly impacted; in some cases, it is practically necessary to double the treatment time.

[0084] Degassing is initiated until the fume gas is completely evacuated from the enclosure and replaced with external air. The external air may be filtered before being introduced into the enclosure. The door is then unlocked. Operators can then retrieve the treated products. List of reference signs

[0085] 1. Fumigation chamber 2. Watertight walls 3. Loading opening 4. Watertight door 5. Active joint 6. Heating 7. Overpressure detection and relief system 8. Degassing circuit 9. Fan 10. Fumigation Cycle Control Module 11. Temperature sensor 12. Smoke gas concentration level detector (PH3 meter) 13. Fumigation Cycle Monitoring and Control Module 14. Fumigation Cycle Target Data Module 15. Fumigation cycle data module implemented 16. Microprocessor 17. Implementation Instructions 18. Interface Module 19. Entry of batch data to be processed 20. Output of fumigation cycle data performed 21. Recycling valve 22. Degassing valve 23. Outside air intake flap 24. Conduit

Claims

Demands

1. Fumigation chamber (1) for products to be treated, comprising: - airtight walls (2) with a loading opening (3); - a fumigation cycle control module (10), comprising a fumigation cycle monitoring and control module (13), a cycle target data module (14) and a completed cycle data module (15); - said fumigation cycle monitoring and control module (13) being designed to monitor the temperature, internal pressure and fumigant gas concentration inside the chamber, as well as the treatment time, and to compare the data obtained with compliant cycle target data; - an airtight door (4) cooperating with the active seal (5), for airtight closure of the loading opening (3) before initiating a treatment cycle; - a heater (6), connected to the control module (10) and activatable in the event of detection of a temperature below a minimum treatment threshold;- a system (7) for detecting and evacuating any overpressure inside the enclosure; - a degassing circuit (8), which can be activated by the control module (10), for expelling the fumigant gas from the enclosure and replacing it with external air.

2. Enclosure according to claim 1, also comprising a fan (9) for mixing the gases in the enclosure.

3. Enclosure according to claim 1, in which the active seal (5) is filled by fluid injection.

4. Enclosure according to any one of claims 1 to 3, also comprising a temperature sensor (11) connected to the control module (10).

5. Enclosure according to any one of claims 1 to 3, also comprising a fumigant gas concentration rate detector (12) connected to the control module.

6. Enclosure according to any one of claims 1 to 5, wherein the cycle control module (10), the degassing circuit (8) and the fan (9) are arranged outside the enclosure.

7. A fumigation process for products to be treated, for a fumigation chamber according to any one of claims 1 to 6, for treating a batch of products with a fumigant gas under given conditions of concentration, temperature and pressure, comprising the steps of: - receiving (31) a batch of grains to be treated into a sealed fumigation chamber (1); - receiving a dose of fumigant agent into the chamber; - sealing and locking the door (4) of the chamber; - monitoring a gas generation phase to ensure that the required fumigation conditions are obtained; - monitoring (32) by a control module (10) of a treatment phase of the products to be treated to ensure that the fumigation conditions are maintained for the expected treatment time;- if the control module (10) detects (33) a temperature level below a minimum threshold, initiate a heating cycle using a heater (6); - if a pressure level above a predetermined threshold is detected (34) by a system (7) for detecting and evacuating any overpressure, vent the overpressure to the outside of the enclosure; - if the control module (10) detects (35) a fumigation gas level below a predetermined minimum threshold, generate an anomaly signal; - if the control module (10) detects (36) that a complete cycle has been performed according to the prescribed conditions, generate a compliant cycle signal, and activate the degassing circuit (8) to expel the fumigation gas from the enclosure and replace it with external air, then unlock the enclosure door.

8. Fumigation process according to claim 7, wherein the generation of fumigant gas is obtained by reaction of a fumigating agent with ambient humidity.

9. Fumigation method according to claim 7, comprising a preliminary heating step before starting a fumigation cycle.

10. A fumigation process according to any one of claims 7 to 9, wherein the products to be treated are seeds, or fertilizers, or dried fruits or vegetables, or herbs, or spices, or oilseeds, or coffee, or cocoa, or tobacco, or primary processed products, or wooden planks, or archives or old books.

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