METHOD FOR TREATMENT WITH AT LEAST ONE HIGHLY VOLATILE BIOCID AND / OR PLANT PROTECTION PRODUCT, CORRESPONDING TREATMENT ORDER AND STORAGE ORDER

Description

[0001] The present invention relates to treatments with moderately volatile biocidal and / or phytoprotective products, in particular to improve the preservation of plant products such as cereals or for the disinfection of premises.

[0002] More specifically, the invention relates, according to a first aspect, to a treatment process using at least one moderately volatile biocidal and / or phytoprotective product.

[0003] It is known that certain volatile products, whether synthetic or of natural origin, such as essential oils, have interesting biocidal or phytoprotective properties. They are notably used to treat plant products in order to improve their preservation.

[0004] The techniques used so far to apply these products to plants are as follows: immersion of plant products in a hot or cold aqueous dispersion containing the product; spraying of premises, for example plant storage rooms, in order to sanitize them; micro-nebulization at the entry of plant products into storage rooms.

[0005] The quantities of products applied are high and can lead to significant concentrations in plant products.

[0006] Furthermore, current grain sterilization processes rely on spraying highly toxic products, generally organophosphates, at the time of ensiling. In the event of a significant insect infestation during storage, the grain is subsequently treated with a gaseous or volatile gaseous product. Commonly used sterilization products include phosphine, methyl bromide, and ethyl formate. Both the incoming and in-storage treatments are highly toxic and sometimes ineffective, primarily due to resistance issues.

[0007] There is therefore a need for a treatment process that would be usable for the application of moderately volatile products of natural origin, for example essential oils, or synthetic with the same volatility characteristics and that would have excellent effectiveness for the protection of plant products and / or the sanitation of premises, in particular premises intended for the storage of plant products.

[0008] To this end, the invention relates to a treatment process using at least one moderately volatile biocidal and / or phytoprotective product, with a boiling point between 150 and 280°C, the process comprising a treatment step in which a liquid containing a product or a mixture of biocidal and / or phytoprotective products is evaporated and injected into the internal atmosphere of a room, the liquid being evaporated at a temperature below 50°C, the concentration of product vapor in the internal atmosphere of the room being maintained above 10% of a saturation concentration of the vapor of said product in said atmosphere at said temperature for a saturation period of more than 12 hours, in which the room (2) has an internal volume greater than 200 m³;in which the liquid is stored in a reservoir (7) and is evaporated in an evaporation device (8) comprising a packed evaporator (10) (11) by contacting an airflow in said packing (11), the airflow containing the product vapors being injected into the room (2), said evaporation device (8) further comprising: - a device (12) for injecting a flow of the liquid into the packed evaporator (10); - an element (13) for circulating the airflow in the packed evaporator (10), the reservoir (7) being a tank placed vertically under the packing (11), the injection device (12) being arranged to inject the liquid above the packing (11).

[0009] Indeed, the applicant is convinced that only the vapors of moderately volatile biocidal and / or plant protection products have activity, specifically fungicidal, bactericidal, and insecticidal activity. Liquids containing moderately volatile biocidal and / or plant protection products are only active as a source of vapors.

[0010] Consequently, the biocidal and / or phytoprotective effect is maximized when the vapor concentration is controlled at a high value in the atmosphere of the room to be treated.

[0011] To achieve the best results, it is essential that these products be used in vapor form. Only vapor is immediately active and has the capacity to treat the air volume, penetrate the mass of stored plant products (grains in silos, fruit in crates, potatoes in piles) and thoroughly treat the walls of the premises.

[0012] The use of hot vaporization to achieve high vapor concentrations in the atmosphere is strongly discouraged. In fact, either the saturation concentration is not reached, or it is exceeded, leading to recondensation of the vapor into liquid as it cools after injection into the indoor atmosphere, particularly on cold surfaces. To ensure a high vapor concentration, large quantities of product would need to be injected, which can lead to high concentrations on plant products, rendering these products phytotoxic. This also results in a much greater consumption of volatile biocides and / or plant protection products than with cold evaporation.

[0013] Thermal fogging presents similar problems. The product is injected in liquid form, as a mist of droplets. Some of the product is lost as it settles on surfaces in the room. Another portion settles in liquid form on the plants. The product is ineffective in this form. Only the fraction of the product that vaporizes is effective, but controlling the vapor concentration is extremely difficult. Again, the consumption of volatile biocide and / or plant protection product is much greater than with cold evaporation.

[0014] With the process of the invention, evaporation is carried out at room temperature, which allows for excellent control of the product vapor concentration in the internal atmosphere of the room. This concentration can be maintained at a high level, close to saturation if necessary, to maximize the product's effect. The consumption of volatile biocide and / or plant protection product is moderate compared to thermal fogging or hot vaporization, because the entire quantity of the biocide exerts its activity.

[0015] Product consumption is self-regulated. Since the biocide and / or plant protection product is sprayed at ambient temperature, below 50°C, it evaporates until it reaches maximum atmospheric saturation without risk of oversaturation. Once this maximum is reached, evaporation stops naturally, without any external intervention, even if the evaporation device continues to operate.

[0016] The treatment's effectiveness also stems from maintaining a high concentration of product vapor in the atmosphere for a significant saturation period, exceeding 12 hours. The treatment can be carried out either by rapidly injecting a large quantity of product or by staggering injections to maintain a high concentration for a sufficient duration to ensure effectiveness.

[0017] Three preferred application methods were considered, based either on the principle of a shock effect, with a product vapor concentration close to saturation for a short period, or with a lower concentration for longer periods. Indeed, the effectiveness of these products depends on the concentration in the air and the contact time with the plant material.

[0018] The first method of application is by single injection, the vapor concentration of the product or products in the internal atmosphere of the premises being maintained between 50 and 100% of the saturation concentration for a period of between 12 and 240 hours in order to obtain a complete sterilization effect of the plant products.

[0019] The second method of application is by maintaining, for most or even substantially all of the storage period, a lower concentration of vapor of the product or each product in the internal atmosphere of the premises, between 10 and 50% of the saturation concentration.

[0020] According to a third method of application, injections of the same type as in the first method of application are carried out periodically, either when the increase in risk has been observed visually, or according to a predetermined program, for example 5 days of injection every month of storage.

[0021] For these three application methods, the control of the injected quantity can be done in different ways.

[0022] According to one method, the injected quantity is controlled by allowing evaporation to cease naturally when the internal atmosphere of the room reaches saturation. The amount of liquid evaporated depends on the quantities of air and liquid in contact and the contact surface area of ​​the evaporation device.

[0023] According to a second method, the control of the injected quantity is done by following a predetermined operating program, indicating the duration of operation per day and the quantity of liquid evaporated per unit volume of the room during said duration of operation.

[0024] According to a third method, the concentration of the product or products in the air is analyzed, with the injection device being controlled using the result of the analysis, typically to maintain the concentration of the product or products within a predetermined range.

[0025] The treatment process may also have one or more of the following characteristics, considered individually or in all technically possible combinations: at least one of the products is chosen from the following list of plant protection or biocidal products: essential oil; terpene; saturated or unsaturated C6-C10 short-chain alcohol, such as octanol, 2-ethylhexanol; volatile synthetic product, such as hexanal, dimethylnaphthalene and 3-decene-2-one; high-boiling liquid organic acids, such as pelargonic acid and parabenic acid; esters with biocidal activity, such as isoamyl isovalerate; the premises contain plant products, such as cereals, stored for a storage time (SD), normally exceeding one month; the treatment step includes a continuous injection phase lasting more than 50% of the storage time (SD), preferably more than 75% of the storage time (SD) and even more preferably more than 90% of the storage time;The treatment step comprises a single continuous injection phase with an injection duration of 12 to 240 hours, or comprises several continuous injection phases separated by waiting phases without injection of biocidal and / or phytoprotective product, each continuous injection phase having an injection duration (ID) between 12 and 240 hours; the liquid comprises several moderately volatile biocidal and / or phytoprotective products, having different respective vapor pressures at ambient temperature; the respective vapor pressures of the volatile biocidal and / or phytoprotective products are spread over a pressure range between 1.3 x 10⁻⁵ bar and 4 x 10⁻³ bar; the internal atmosphere of the room is heated during the injection of the product vapor, to a temperature between the normal room temperature and the normal temperature plus 5°C;The room is a grain silo with an air inlet communicating with the outside and an air outlet communicating with the outside, the silo including forced ventilation designed to ensure air circulation from the air inlet to the air outlet through the grains, the forced ventilation being stopped during the injection of the biocide and / or phytoprotective product(s); the room has an internal volume greater than 200 m³; the liquid is evaporated by contact with an airflow in a packing, the airflow containing the product vapors being injected into the room; the room is substantially airtight, the airflow circulating in the packing having a flow rate of between 1 and 10 m³ per hour per m³ of internal volume of the room; The airflow circulating in the lining has a flow rate of between 1 and 6 m3 per hour per 100 m3 of internal volume of the room.

[0026] According to a second aspect, the invention relates to a processing unit, the unit comprising: a liquid reservoir containing at least one product or mixture of moderately volatile biocidal and / or phytoprotective products, with a boiling point between 150 and 280°C; a device for evaporating the liquid stored in the reservoir and injecting the evaporated liquid into the internal atmosphere of a room, the evaporation device being configured to evaporate the liquid at a temperature below 50°C, a controller controlling the evaporation device, configured so that the vapor concentration of the product or each product in the internal atmosphere of the room is maintained above 10% of a saturation concentration of the vapor of said product in said atmosphere for a saturation period of more than 12 hours; in which the room (2) has an internal volume greater than 200 m³;in which the evaporation device (8) comprises a packed evaporator (10) in which the liquid is evaporated by contact with an airflow in said packing (11), the evaporator (10) being configured to inject the airflow containing the product vapors into the room (2), said evaporation device (8) further comprising: - a device (12) for injecting a flow of the liquid into the packed evaporator (10); - an element (13) for circulating the airflow in the packed evaporator (10); 22 the reservoir (7) being a tank placed vertically below the packing (11), the injection device (12) being arranged to inject the liquid above the packing (11).

[0027] The processing system may also exhibit one or more of the following characteristics, considered individually or in all technically possible combinations: at least one of the products is chosen from the following list of plant protection or biocidal products: essential oil; terpene; saturated or unsaturated C6-C10 short-chain alcohol, such as octanol, 2-ethylhexanol; volatile synthetic product, such as hexanal, dimethylnaphthalene and 3-decene-2-one; high-boiling liquid organic acids, such as pelargonic acid and parabenic acid, esters with biocidal activity such as isoamyl isovalerate; the premises contain plant products, for example potatoes, stored for a storage period exceeding one month, the controller being configured to carry out a continuous injection phase with an injection duration exceeding 50% of the storage period, preferably exceeding 75% of the storage period and even more preferably exceeding 90% of the storage period;the room contains plant products, for example cereals, the controller being configured to carry out a single continuous injection phase with an injection duration of 12 to 240 hours, or several continuous injection phases separated by waiting phases without injection of biocide and / or plant protection product, each continuous injection phase having an injection duration of 12 to 240 hours; the liquid comprises several moderately volatile biocides and / or plant protection products, having different respective vapor pressures; the respective vapor pressures of the moderately volatile biocides and / or plant protection products are spread over a pressure range between 1.3 x 10⁻⁵ bar and 4 x 10⁻³ bar;The treatment system includes a heater for the internal atmosphere of the room, configured to heat said internal atmosphere during the injection of the product vapor, to a temperature between the normal room temperature and the normal temperature plus 5°C; the evaporation device includes a packed evaporator in which the liquid is evaporated by contact with an airflow in said packing, the evaporator being configured to inject the airflow containing the product vapors into the room.

[0028] According to a third aspect, the invention relates to a plant product storage unit, the storage unit comprising: a room, preferably containing plant products; and a treatment unit as in claim 7, configured to inject the evaporated liquid into the internal atmosphere of the room.

[0029] The storage system may also exhibit one or more of the following characteristics, considered individually or in all technically possible combinations: the room has an internal volume greater than 200 m3< ; the room is substantially airtight, the treatment unit comprising a packed evaporator in which the liquid is evaporated by contact with an airflow in said packing, the evaporator being configured to inject the airflow containing the product vapors into the room, the controller being programmed so that the airflow circulating in the packing has a flow rate between 1 and 10 m3< per hour and per m3< of internal volume of the room; The room is a grain silo with an air inlet communicating with the outside and an air outlet communicating with the outside. The silo includes forced ventilation designed to ensure air circulation from the air inlet to the air outlet through the grain. The forced ventilation is capable of being switched off during the injection of the biocide and / or plant protection product(s). The controller is programmed so that the airflow circulating in the silo has a flow rate between 1 and 6 m³ / s 3 per hour and per 100 m 3 of the internal volume of the premises.

[0030] Other features and advantages of the invention will become apparent from the description below, given by way of example only and not by way of limitation, with reference to the attached figures, including: there figure 1 is a simplified schematic representation of a storage system conforming to a first embodiment of the invention; and the figure 2 is a simplified schematic representation of a storage assembly according to a second embodiment of the invention.

[0031] Storage unit 1 shown on the figure 1 includes a room 2 and a processing unit 3.

[0032] The treatment unit 3 is configured to evaporate a liquid containing at least one moderately volatile biocide and / or phytoprotectant and to inject the evaporated liquid into the internal atmosphere of room 2.

[0033] The treatment is a disinfection treatment and / or a phytoprotective treatment.

[0034] In the first embodiment, the room is substantially airtight. The room is a closed enclosure, in the sense that exchanges between the atmosphere of the room and the outside, in particular gas exchanges, are reduced, so as, for example, not to jeopardize the preservation of plant products that would be stored there.

[0035] In the case of a disinfection treatment, the area to be treated is, for example, a storage facility intended for plant products, but which does not contain any plant products at the time of treatment. Alternatively, the area could be part of a hospital, school, industrial facility, or any other type of premises. The area could also be a tank, a storage or transport cistern, or any other type of enclosure to be disinfected.

[0036] In the case of plant protection treatment, the premises are, for example, a room, a greenhouse, or any premises intended for the storage of plant products such as cereal grains, fruits, or vegetables. Such premises are shown on the figure 1 The treatment is applied while the plant products 5 are stored in the room. Alternatively, it is applied while the room is empty.

[0037] The treatment unit 3 is specifically designed for treating the atmosphere of a large room. The room volume is typically greater than 200 m³, preferably greater than 500 m³, and even more preferably greater than 1000 m³.

[0038] Processing set 3 includes: a reservoir 7 storing a liquid containing at least one moderately volatile biocide and / or plant protection product, with a boiling point between 150 and 280°C, preferably between 150 and 260°C; a device 8 for evaporating the liquid stored in the reservoir 7 and injecting the evaporated liquid into the internal atmosphere of the room 2, the evaporation device 8 being configured to evaporate the liquid at a temperature below 50°C, a controller 9 controlling the evaporation device 8.

[0039] The evaporation device 8 preferably comprises an evaporator 10 with packing 11 in which the liquid is evaporated by contact with an airflow in said packing 11.

[0040] Evaporator 10 is configured to inject the airflow containing product vapors into room 2.

[0041] The evaporation device 8 further comprises: a device 12 for injecting a flow of liquid into the packed evaporator 10; an element 13 for circulating the air flow in the packed evaporator 10.

[0042] The evaporator can be of any suitable type. For example, the evaporator is a packed tower, with a vertical axis in the example shown.

[0043] Here, packing refers to any type of structure that provides a large contact surface between a liquid phase and a gaseous phase, thereby improving the exchanges between the liquid and gaseous phases.

[0044] The filling can therefore be a bulk type filling or a structured type filling.

[0045] In this case, the packing is for example of the Raschig ring type or Pall ring type, or is a packing structured in honeycombs.

[0046] It is typically made of a plastic material.

[0047] The contact allows for particularly efficient transfers between the liquid flow and the air flow.

[0048] Advantageously, the evaporation device is placed in room 2. The circulation unit 13 directly draws in the internal atmosphere of the room and circulates it through the lining, this atmosphere thus constituting the airflow.

[0049] The storage atmosphere here corresponds to the volume of gases filling the room and, where applicable, bathing the plant products.

[0050] This atmosphere typically includes air, plus, where applicable, gases and products released by plant products during their maturation. It also includes water vapor.

[0051] Alternatively, the atmosphere is a modified atmosphere, for example, the air is depleted of oxygen. This is particularly the case for the storage of certain plant products such as apples.

[0052] The reserve 7 is typically a tray, placed vertically under the filling 11.

[0053] The injection device 12 is arranged to inject the liquid above the packing 11.

[0054] For this purpose, it typically includes one or more spray rails 17, placed above the packing, and a transfer device 19, such as a pump, drawing the liquid from the reservoir 7 and expelling it into the rail or rails 17.

[0055] The circulation device 13 is arranged to create an upward circulation of air inside the evaporator 10.

[0056] To do this, the evaporation device 8 includes one or more inlets 21 for the atmosphere opening into the inside of the evaporator 10, under the packing 11.

[0057] Each entrance 21 communicates smoothly with the interior of room 2.

[0058] The evaporation device 8 has an outlet 23 for the atmosphere charged with evaporated liquid, located in the upper part of the evaporator 10, above the packings 11. The outlet 23 is fluidly connected with the interior of the room 2.

[0059] The circulation device 13 includes for example a circulation element 24 such as a fan or blower, placed above the packing 11, typically at the top of the evaporation device 10.

[0060] The circulation unit 24 draws in the atmosphere charged with evaporated liquid above the packing 11, and forces it into or towards the outlet 23.

[0061] Preferably, the evaporation device 8 includes a droplet separator 25, placed above the spray rails 17, and more precisely between the spray rails 17 and the circulation element 24.

[0062] In one embodiment, the evaporation device 8 has a roughly constant square horizontal cross-section of 700 x 700 mm. The reservoir 7 has the same horizontal cross-section and a height between 500 and 700 mm. The device has four inlets 21, each located on one of its sides. The packing 11 has a height of approximately 1 m. The packing is positioned, for example, 700 mm below the liquid inlet, with the droplet separator 25 positioned 300 mm above the liquid inlet.

[0063] The treatment unit 1 preferably includes a sensor 27 for measuring the concentration of the moderately volatile biocide and / or phytoprotectant in the atmosphere, the controller 9 being informed by the sensor 27.

[0064] The controller 9 is programmed to control the injection device 12 and / or the circulation component 24.

[0065] The controller 9 is, for example, a computer or part of a computer. Alternatively, the electronic control device 29 is implemented as a field-programmable gate area (FPGA) or as an application-specific integrated circuit (ASIC). The electronic device 29 is programmed to implement a processing strategy.

[0066] When the product is a biocidal product, the treatment aims to sanitize the premises.

[0067] When the product is a plant protection product, which can also be called a plant protection product, the treatment aims to protect plant products by preventing the development of diseases and / or rots, and by eliminating insects, fungi and parasites, including fungi that cause mycotoxins.

[0068] The liquid contains only biocidal products, or only plant protection products, or includes one or more biocidal products mixed with one or more plant protection products.

[0069] At least one of the products is chosen from the following list: essential oil; terpenes; saturated or unsaturated C6-C10 alcohol, such as octanol, 2-ethylhexanol; volatile synthetic products, such as hexanal, dimethylnaphthalene and 3-decene-2-one; high boiling point liquid organic acids, such as pelargonic acid and parabenic acid, esters with biocidal activity such as isoamyl isovalerate.

[0070] The essential oil is, for example, chosen from the group consisting of peppermint oil, clove oil, rose oil, thyme oil, oregano oil, eucalyptus oil, pine oil, and cinnamon oil. Alternatively, the liquid contains one of the constituents of these oils, chosen from the group consisting of L-carvone, eugenol, geraniol, thymol, carvacrol, eucalyptol, pinene, and cinnamaldehyde.

[0071] Each biocidal and / or phytoprotective product typically has a vapor pressure between 0.01 mmHg and 3 mmHg, i.e. between 1.3 and 400 Pa.

[0072] Typically, the liquid contains only the product(s), without solvent or adjuvant. Alternatively, the liquid contains an aqueous or organic solvent in which the product(s) and one or more adjuvants are dissolved. The aqueous solvent is, for example, water. The organic solvent is, for example, a solvent of the type described in FR 2 791 910 or glycols, diglycols, and their related esters. Adjuvants are, for example, substances capable of carrying the active ingredient(s) or capable of providing a diluting effect.

[0073] In any event, the liquid during the contacting step is vaporized at a temperature below 50°C, preferably below 20°C, in particular between -2°C and +12°C, and especially between 0 and 10°C. For example, the liquid is evaporated at room temperature.

[0074] Controller 9 is configured so that the concentration of product vapor in the internal atmosphere of room 2 is maintained above 10% of a saturation concentration of the vapor of said product in said atmosphere for a saturation period of more than 12 hours.

[0075] Preferably, controller 9 is configured so that the concentration of product vapor in the internal atmosphere of room 2 is maintained above 30% of the saturation concentration of the vapor of said product in said atmosphere for a saturation period of more than 12 hours, preferably maintained above 50%, even more preferably above 80%, and ideally above 90% of saturation.

[0076] The saturation concentration of each product depends on the product and the temperature in the room. It corresponds to the maximum possible concentration of product vapor in the atmosphere, as no further evaporation of the product is possible once saturation is reached, at a constant temperature.

[0077] The saturation time is equal to the sum of all periods during which the concentration remains above the target limit, namely 10% of the saturation concentration, or 30%, 50%, 80%, or 90%. This time may be continuous or consist of several periods separated by periods during which the product vapor concentration is below the target limit.

[0078] Preferably, the saturation period is greater than 2 days per month, and even more preferably greater than 5 days per month.

[0079] Piloting can be done in different ways.

[0080] According to a first variant, the controller 9 operates the evaporation device 8 continuously. The concentration of vapor from the biocide and / or plant protection product or mixture in the room increases rapidly until it reaches saturation. Evaporation then stops naturally, although the evaporation device continues to operate. Only small quantities of product are evaporated, compensating for absorption by plant matter and leakage to the outside of the room. The vapor concentration of the biocide and / or plant protection product or mixture is maintained close to 100% of saturation at all times.

[0081] According to a second variant, the controller 9 is programmed to regulate the liquid flow rate based on the concentration measured by sensor 27. Preferably, it also controls the circulation element 24 in the same way. It therefore controls the amount of biocide and / or plant protection product evaporated to maintain the product vapor concentration measured by sensor 27 within a pre-programmed time diagram corresponding to the desired treatment strategy. The time diagram indicates the desired change in product vapor concentration over time.

[0082] According to a third variant, controller 9 is programmed to regulate the liquid flow rate according to a pre-programmed time diagram, corresponding to the desired treatment strategy. Preferably, it also controls circulation element 24 in the same way. Controller 9 therefore controls the quantity of biocide and / or plant protection product evaporated according to the pre-programmed time diagram. This diagram indicates the desired change in the quantity of product vapor evaporated over time.

[0083] Several application methods are being considered, as mentioned above.

[0084] According to the first application method, the controller 9 is configured to perform a single steam injection phase of the product(s), maintaining a concentration between 50% and 100% of the saturation concentration in the internal atmosphere of the room continuously for a period of 12 to 240 hours to achieve complete sterilization of the plant products or the premises. The duration is preferably between 24 and 120 hours, and even more preferably between 24 and 72 hours. The target concentration is preferably greater than 70%, and even more preferably greater than 90% of saturation.

[0085] According to this method of application, the time diagram includes a single, short-duration slot.

[0086] According to a second application mode, the controller 9 is configured to perform a single, continuous injection phase.

[0087] In the case where the premises contain plant products, for example potatoes, stored for a storage time DS, the continuous injection phase typically has an injection time DI greater than 50% of the storage time DS, preferably greater than 75% of the storage time DS and even more preferably greater than 90% of the storage time DS.

[0088] Typically the storage period is more than one month, and is for example between one and nine months.

[0089] According to this application method, the timing diagram consists of a single, continuous, long-duration period. The concentration of vapor of each biocide and / or plant protection product in the internal atmosphere of the room is maintained between 10 and 50% of saturation for virtually the entire duration of the injection.

[0090] According to a third application mode, the controller 9 is configured to carry out several continuous injection phases separated by waiting phases without injection of biocide and / or phytoprotectant product.

[0091] Each continuous injection phase is of the type described for the first application method. It has an injection duration (ID) of between 12 and 240 hours, preferably between one and five days. The vapor concentration of each biocide and / or plant protection product is therefore maintained in the internal atmosphere of the room between 50% and 100% of saturation at each injection phase for a saturation duration exceeding 12 hours, preferably between one and five days.

[0092] The waiting phases, for example, have a duration of between 10 days and 2 months, preferably between 20 days and 40 days, and a length typically equal to 30 days minus the duration of the injection phase.

[0093] The injection phases typically all have the same duration. Similarly, the waiting phases typically all have the same duration.

[0094] Alternatively, the injection phases and / or waiting phases have different durations from each other.

[0095] According to this strategy, the time diagram includes several successive slots.

[0096] The quantities of each biocidal and / or phytoprotective product evaporated at each injection phase, and the duration of each injection phase, are chosen to quickly reach the target vapor concentration limit, and to maintain this concentration long enough to achieve the desired biocidal and / or phytoprotective effect.

[0097] The duration of each waiting phase is chosen to be short enough so that diseases, rots, insects, fungi or parasites cannot develop significantly before the next injection phase.

[0098] As mentioned above, a new injection phase is initiated when an increased risk is visually observed. Alternatively, the injection and waiting phases follow a predetermined schedule, for example, 5 days of injection every month of storage, followed by 25 days without injection.

[0099] Thus, the invention aims to rapidly achieve the target vapor concentration limit. The goal is to perfectly treat the entire room and its contents by saturating the atmosphere very quickly, with the product vapor acting immediately and optimally at all points within the room.

[0100] This effect can be achieved because the contact surface between the liquid and the atmosphere is large, due to the presence of the packing. The treatment assembly of the present invention provides a contact surface between the gas and the liquid that can, for example, reach up to 300 m².

[0101] This allows for the use of very high air and liquid flow rates.

[0102] When room 2 is substantially airtight, the airflow circulating in the lining 11 has a flow rate between 1 and 10 m³ per hour per m³ of internal volume of the room, preferably between 5 and 10 per hour per m³ of internal volume of the room.

[0103] The liquid flow rate in the packing 11 is typically between 1 and 30 m³ / h.

[0104] This allows us to evaporate large quantities of product, for example 20 liters of product per day, and quickly reach the saturation concentration of the product in the atmosphere.

[0105] Alternatively, the packed evaporator is replaced by the machine sold under the name XEDAVAP, which is the subject of patent application number FR1255999. In this machine, the liquid to be evaporated is injected into a fabric swept by an airflow. The fabric has a surface area of ​​between 1 m² and 4 m². The airflow rate is between 1000 and 3000 m³ / hour. This machine can evaporate between 0.1 and 10 liters of liquid per day, for example, 1.2 liters / day of peppermint oil. This machine is designed for smaller spaces than the packed evaporator.

[0106] The operation of the entire treatment system with a packed evaporator is as follows.

[0107] The liquid to be evaporated is placed in reservoir 7. The transfer unit 19 forces the liquid into the ramp(s) 17, which project the liquid towards the packing 11. The atmospheric circulation unit 24 creates an upward gas flow. The atmosphere enters the treatment device 8 through the inlets 21 and flows upward through the packing 11. The liquid, meanwhile, flows downward through the packing 11, with some of the liquid evaporating upon contact with the gas flow and being carried away with the atmosphere as vapor. The fraction of the liquid that is not evaporated falls back into reservoir 7 and is recycled. The atmosphere laden with evaporated liquid passes through the droplet separator 25 and is forced by the circulation unit 24 to the outlet 23.

[0108] The treatment unit 8 discharges this vapor-laden atmosphere directly into the storage area, through outlet 23.

[0109] The liquid flow rate is, for example, 3 m³ / hour, and the air flow rate is approximately 2000 m³ / hour.

[0110] The invention also relates to a treatment method using at least one moderately volatile biocide and / or phytoprotectant product, with a boiling point between 150 and 280°C.

[0111] The process includes a treatment step in which a liquid containing a product or mixture of biocidal and / or phytoprotective products is evaporated and injected into the internal atmosphere of a room 2, the liquid being evaporated at a temperature below 50°C.

[0112] The concentration of product vapor in the internal atmosphere of room 2 is maintained above 10% of a saturation concentration of the vapor of said product in said atmosphere for a saturation period greater than or equal to 12 hours.

[0113] The product(s) are of the type described above for the entire treatment.

[0114] The premises typically contain plant products, for example cereals, stored for a DS storage period of more than one month, or plants in a greenhouse.

[0115] According to a first method of application, the treatment step includes a single injection of vapor of the product or mixture of products, the concentration of the product or each product in the internal atmosphere of the premises being maintained between 50 and 100% of the saturation concentration for a period of between 12 and 240 hours in order to obtain a complete sterilization effect of the plant products.

[0116] According to a second method of application, the treatment step includes a single injection, with a lower concentration of vapor of the product or product mixture, between 10 and 50% of the saturation concentration, being maintained in the internal atmosphere of the premises for most or substantially all of the storage period.

[0117] According to a third method of application, the treatment stage includes several injections of the same type as in the first method of application, carried out periodically, either when the increase in risk has been observed visually, or according to a predetermined schedule, for example 5 days of injection every month of storage.

[0118] These treatment methods are as described above relative to the overall treatment.

[0119] The room has an internal volume greater than 200 m³. It is of the type described above in relation to the treatment system.

[0120] Advantageously, the liquid is evaporated by contact with an airflow in a packing 11, the airflow containing the product vapors being injected into room 2.

[0121] The liquid is preferably evaporated in an evaporation device of the type described above relative to the treatment assembly.

[0122] In the first embodiment, room 2 is substantially airtight, the airflow circulating in the lining having a flow rate between 1 and 10 m 3< per hour and per m 3< of internal volume of the room.

[0123] In one variant, the device used to evaporate the liquid operates continuously. The vapor concentration of each biocide and / or plant protection product in the room increases rapidly until it reaches saturation. Evaporation then stops naturally, although the evaporation device continues to operate. The vapor concentration of each biocide and / or plant protection product is maintained close to 100% of saturation at all times.

[0124] According to a second variant, the amount of biocide and / or plant protection product evaporated follows a pre-programmed time diagram, corresponding to the desired treatment strategy. This diagram indicates the desired evolution of the amount of product vapor evaporated over time.

[0125] According to a third variant, the vapor concentration of the product(s) in the room's atmosphere is continuously measured. The amount of biocide and / or plant protection product evaporated is chosen to maintain the product vapor concentration measured by sensor 27 within a pre-programmed time frame corresponding to the desired treatment strategy. The time frame indicates the desired change in product vapor concentration over time.

[0126] The process is designed to be implemented by the processing unit 8 described above. Conversely, the processing unit 8 described above is particularly well-suited for implementing the process.

[0127] A second embodiment of the storage system of the invention will now be described, with reference to the figure 2Only the points by which the second embodiment differs from the first will be detailed below. Identical elements or elements performing the same functions will be designated by the same reference numerals in both embodiments.

[0128] In the second embodiment, room 2 is a grain silo having an air inlet 41 communicating with the outside and an air outlet 43 communicating with the outside.

[0129] The silo includes a forced ventilation 45 designed to ensure air circulation from the air inlet 41 to the air outlet 43 through the grains 47.

[0130] The forced ventilation 45 is intended to ensure the drying and / or cooling of the grains 47.

[0131] An air distribution manifold 49 is provided in the silo 2, under the grain. The forced ventilation 45 includes an air circulation device 51 such as a fan, the suction of which is connected to the air inlet 41 and the discharge to the manifold 49.

[0132] Air outlet 43 is typically located in the upper part of the silo.

[0133] In normal operation, the circulation unit 51 draws in outside air, forces it into the collector 49, the air circulating to the air outlet 43 through the grains 47 from the collector 49.

[0134] Forced ventilation 45 is likely to be switched off during the injection of the biocide and / or plant protection product(s).

[0135] The evaporation device 8 is located outside the silo 2. It is arranged to draw in outside air and expel air laden with product vapors from an area near the air inlet 41 towards the air outlet 43.

[0136] For example, the injection is made at the bottom of the chamber receiving the grains 47, in the collector 49.

[0137] The injection is done at a low air flow rate.

[0138] For example, the airflow circulating in the lining 11 has a flow rate of between 1 and 6 m³ per hour and per 100 m³ of internal volume of the room, preferably between 2 and 4 per hour and per 100 m³ of internal volume of the room.

[0139] The liquid flow rate in the packing 11 is typically between 10 and 20 ml / m³ of air.

[0140] The injected air has a vapor concentration of the biocidal and / or phytoprotective product greater than 50% of the saturation concentration of the vapor of said product in the air, preferably greater than 80% of the saturation, and even more preferably greater than 90% of the saturation.

[0141] The vapor from each product is heavier than air and tends to accumulate at the bottom of the silo.

[0142] The vapor is forced towards the air outlet 43 by the continuous airflow from the evaporation device 8. After a period of filling the silo with vapor from the product(s), the vapor concentration in the silo is maintained above the desired limit, allowing continuous contact between the vapor and the grain. This prolonged contact leads to the desired biocidal or phytoprotective effect.

[0143] Preferably, a mesh screen (51) is placed over each air outlet of the silo to prevent insects present during grain processing from escaping and contaminating other parts of the installation. These screens are chosen to allow air to pass through but block insects.

[0144] The processing method corresponding to the second embodiment of the storage assembly will now be described. Only the points by which the method differs from that of the first embodiment of the storage assembly will be detailed below. Identical elements or those performing the same functions will be designated by the same reference numerals.

[0145] In this process, the forced ventilation 45 of the silo is stopped during the injection of the biocide and / or phytoprotectant product(s).

[0146] The airflow circulating in the lining 11 of the injection device 8 has a flow rate between 1 and 6 m 3< per hour and per 100 m 3< of internal volume of the room.

[0147] The treatment strategy is of the type in which the treatment step either comprises a single continuous injection phase or several continuous injection phases separated by waiting periods without injection of biocide and / or plant protection product. In both cases, each continuous injection phase has an injection duration (ID) greater than 12 hours.

[0148] Typically, each injection phase lasts between one and 15 days, preferably between two and 5 days.

[0149] According to a variant applicable to all embodiments, the liquid comprises several moderately volatile biocidal and / or phytoprotective products, having different respective vapor pressures at ambient temperature.

[0150] Advantageously, the respective vapor pressures of volatile biocidal and / or phytoprotective products at ambient temperature are spread over a pressure range between 1.3.10 -5< bar and 4.10 -3< bar.

[0151] Since the applicant has observed that there is an optimum vapor pressure range for achieving the desired maximum biocidal and / or phytoprotective activity, it is considered that the vapor pressure of ideal liquids should be between 0.01 and 3 mmHg (1.3 x 10⁻⁵ bar and 4 x 10⁻³ bar) at ambient temperature. If the vapor pressure is too low, the product evaporates slowly, and the vapor concentration in the room's internal atmosphere cannot reach a sufficient value to achieve the desired effect. If the vapor pressure is too high, losses to the outside of the room can be significant.

[0152] Using several products with stepped vapor pressures allows us to stay within the desired vapor pressure range for a wide range of temperatures around ambient temperature and to have a broader spectrum of activity compared to the activity of each product taken individually.

[0153] According to a variant applicable to all embodiments, the treatment unit 8 includes a heater 51 of the internal atmosphere of room 2. This heater is configured to heat said internal atmosphere during the injection of the product vapor, to a temperature between the normal temperature of room 2 and the normal temperature plus 5°C.

[0154] The normal temperature is the temperature at which room 2 is located in the absence of treatment.

[0155] The temperature is increased during the injection phases to raise the steam saturation concentration of each product. This allows for a higher steam concentration, leading to greater treatment efficiency. The temperature is returned to its normal value by stopping the heating during the standby phases, when no steam is injected.

Claims

1. Method of treatment by at least one moderately volatile biocidal and / or phytoprotective product, having a boiling temperature comprised between 150 and 280°C, the method comprising a treatment step during which a liquid containing a biocidal and / or phytoprotective product or mixture of products is evaporated and injected into the internal atmosphere of a room (2), the liquid being evaporated at a temperature lower than 50°C, the concentration in vapor of product in the internal atmosphere of the room (2) being maintained greater than 10% of a saturation concentration of the vapor of said product in said atmosphere at said temperature for a saturation duration greater than 12 hours, in which the room (2) has an internal volume greater than 200 m3 ; in which the liquid is stored in a reserve (7) and is evaporated in an evaporation device (8) comprising a packed evaporator (10) (11) by bringing into contact with a flow of air in said packing (11), the flow of air containing the vapors of product being injected into the room (2), said evaporation device (8) further comprising: - a device (12) for injecting a flow of the liquid into the packed evaporator (10); - a member (13) for circulating the flow of air in the packed evaporator (10), the reserve (7) being a tank placed vertically under the packing (11), the injection device (12) being arranged to inject the liquid above the packing (11).

2. Method according to claim 1, in which at least one of the products is selected from the following list of phytoprotective or biocidal products : essential oil; terpene; short-chain alcohol from C6 to C10 saturated or unsaturated, such as for example, octanol, 2-ethylhexanol; volatile synthetic product, such as for example, hexanal, dimethylnaphthalene and 3-decene-2-one; liquid organic acids with a high boiling point, such as pelargonic acid and parabenic acid; esters with biocidal activity such as for example isoamyl isovalerate.

3. Method according to claim 1 or 2, in which the room contains plant products, for example cereals, stored for a storage duration (DS), normally greater than one month.

4. Method according to claim 3, in which the treatment step comprises a continuous injection phase of duration greater than 50% of the storage duration (DS), preferably greater than 75% of the storage duration (DS) and still preferably greater than 90% of the storage duration (DS), during which the concentration in vapor of product in the atmosphere is maintained between 10% and 50% of the saturation.

5. Method according to any one of claims 1 to 3, in which the treatment step comprises a single continuous injection phase having an injection duration (DI) from 12 to 240 hours, or comprises several continuous injection phases separated by waiting phases without injection of biocidal and / or phytoprotective product, each continuous injection phase having an injection duration (DI) between 12 hours and 240 hours, the concentration in vapor of product in the atmosphere being maintained between 50% and 100% of the saturation during the or each injection phase.

6. Method according to any one of the preceding claims, in which the room (2) is a grain silo having an air inlet (41) communicating with the outside and an air outlet (43) communicating with the outside, the silo comprising a forced ventilation (45) provided to ensure a circulation of air from the air inlet (41) to the air outlet (43) through the grains (47), the forced ventilation (45) being stopped during the injection of the or of each biocidal and / or phytoprotective product.

7. Treatment set, the set (3) comprising: - a reserve (7) of liquid containing at least one moderately volatile biocidal and / or phytoprotective product or mixture of products, having a boiling temperature comprised between 150 and 280°C, - a device (8) for evaporation of the liquid stored in the reserve (7) and for injection of the evaporated liquid into the internal atmosphere of a room (2), the evaporation device (8) being configured to evaporate the liquid at a temperature lower than 50°C, - a controller (9) controlling the evaporation device (8), configured so that the concentration in vapor of the or of each product in the internal atmosphere of the room (2) is maintained greater than 10% of a saturation concentration of the vapor of said product in said atmosphere for a saturation duration greater than 12 hours; in which the room (2) has an internal volume greater than 200 m3; in which the evaporation device (8) comprises a packed evaporator (10) in which the liquid is evaporated by bringing into contact with a flow of air in said packing (11), the evaporator (10) being configured to inject the flow of air containing the vapors of product into the room (2), said evaporation device (8) further comprising: - a device (12) for injecting a flow of the liquid into the packed evaporator (10); - a member (13) for circulating the flow of air in the packed evaporator (10); the reserve (7) being a tank placed vertically under the packing (11), the injection device (12) being arranged to inject the liquid above the packing (11).

8. Treatment set according to claim 7, in which at least one of the products is selected from the following list of phytoprotective or biocidal products: essential oil; terpene; short-chain alcohol from C6 to C10 saturated or unsaturated, such as for example, octanol, 2-ethylhexanol; volatile synthetic product, such as for example the hexanal, dimethylnaphthalene and 3-decene-2-one; liquid organic acids with a high boiling point, such as pelargonic acid and parabenic acid, esters with biocidal activity such as for example isoamyl isovalerate.

9. Treatment set according to claim 7 or 8, in which the room (2) contains plant products, for example potatoes, stored for a storage duration (DS) greater than one month, the controller (9) being configured to carry out a continuous injection phase having an injection duration (DI) greater than 50% of the storage duration (DS), preferably greater than 75% of the storage duration (DS) and still preferably greater than 90% of the storage duration (DS), during which the concentration in vapor of product in the atmosphere is maintained between 10% and 50% of the saturation.

10. Treatment set according to claim 7 or 8, in which the room (2) contains plant products, for example cereals, the controller (9) being configured to carry out a single continuous injection phase having an injection duration (DI) from 12 to 240 hours, or several continuous injection phases separated by waiting phases without injection of biocidal and / or phytoprotective product, each continuous injection phase having an injection duration (DI) from 12 to 240 hours, the concentration in vapor of product in the atmosphere being maintained between 50% and 100% of the saturation during the or each injection phase.

11. Set for storage of plant products, the storage set (1) comprising: - a room (2), preferably containing plant products; and - a treatment set (3) according to any one of claims 7 to 10, configured to inject the evaporated liquid into the internal atmosphere of the room (2).

12. Storage set according to claim 11, in which the room (2) has an internal volume greater than 200 m3.