Frost protection system for plants

Abstract

A frost protection system (10) for plants (3), characterized by an energy source (12) designed as a module and burning without residues, which consists predominantly of carbon; an electronic ignition device (24) which is located in a recess (26) of the module and which is triggered when a predetermined minimum temperature is undershot, so that the module burns without residue.

Description

[0001] The invention relates to a frost protection system for plants. State of the art

[0002] German patent DE 32 38 44 C2 discloses pyrotechnic smoke compositions that produce impenetrable smoke in the visible and infrared ranges. Cesium or rubidium compounds are also added to the smoke compositions, which are dispersed during combustion and absorb radiation in the infrared range.

[0003] The German translation DE 69805912 T2 of European patent EP 0 878 125 B1 discloses a method and device for frost and hail protection of crops such as grapevines. The protection for the grapevines consists of two tarpaulins and a plastic cover that protects two rolls of the tarpaulin. The tarpaulins are wound up using a spring system located at each end of a metal tab.

[0004] DE 10 2017 116 571 A1 discloses a planting system, such as a viticulture system, for fruit plants arranged in rows, which can be attached to a wire frame. A heating device is provided, which comprises a heating cable as the heating device. The heating cable is guided in a hollow profile. This is attached to the fastening wire, wherein the heating cable comprises an electrically conductive heating conductor and an electrically conductive PTC thermistor.

[0005] International patent application WO 2021 / 052700 A1 relates to a burn pot for frost protection of agricultural crops. A container contains a fuel and a wick for the fuel. The container contents can be ignited using a spark plug body that can be inserted into the container. A receiving space arranged between the spark plug body and the container is for molten fuel. Furthermore, it is possible to insert a new spark plug body into a previously used container, thus eliminating the need to dispose of the container.

[0006] US Patent No. 3,615,287 A describes an inexpensive igniter for smear pots and the like, which can be ignited by a conventional battery such as those used in a car or truck, or by a corresponding moderate-voltage power source. The smear pots are suitable for use in or on orchards.

[0007] Patent specification DD 236 443 A1 discloses a method and product for protecting plants and crops from the effects of frost. For this purpose, a circular sheet of charcoal dust and wood flour is set ablaze.

[0008] French patent application FR 2 424 958 A2 discloses a combustible torch for outdoor use, particularly for frost protection of vines, early vegetables, fruit trees, etc. The candle has a slow-burning body made of a mixture of cellulose material impregnated with a flammable substance such as paraffin. To facilitate ignition, a pellet of pyrotechnic material is attached to the body.

[0009] US Patent No. 4,519,774 A relates to an igniter divided into at least two separate chambers (compartments). One of these compartments is filled with a freezable liquid, and another contains an ingredient that induces combustion in the presence of a selected ingredient. At subzero temperatures, the freezable liquid in the capsule compartment freezes and expands, causing all components of the capsule to rupture essentially simultaneously and resulting in a combination of the first and second ingredients, resulting in immediate combustion.

[0010] The diploma thesis at the Karl-Franzens University of Graz entitled “Frost Defense in Fruit and Viticulture” from June 2018 reveals in the chapter “Methods of Frost Control and Their Effectiveness”, among other things, the use of incense, paraffin candles or heating wires.

[0011] The final report from April 2018 from the Bavarian State Ministry of Food, Agriculture and Forestry reveals: "Investigations into damage mitigation from late frosts in Franconian vineyards." Active heat can be applied, for example, using frost protection candles or a heating wire.

[0012] A combination of early bud break and a cold snap can cause significant damage to viticulture, fruit growing, and ornamental plants. The state-of-the-art devices and methods mentioned above are used to attempt to mitigate the risk of late frosts on plants. This is particularly true for late frost damage to vines in the climates of southern Germany, Austria, Switzerland, parts of France, and Italy. After the young, green tissue has emerged in spring, temperatures below -2°C are sufficient to cause frostbite on the vine (or buds). The extent of the damage depends on various factors, particularly the duration of the frost exposure, the air humidity, the development stage of the vine, and the grape variety. The resulting economic damage can threaten the existence of individual businesses.

[0013] However, there are no reliable forecast models for the occurrence of the frost period and there may be years in which no measures are required.

[0014] Similar risks exist in all fruit-growing areas in Central Europe, some of which are cultivated on slopes and in low mountain ranges or in the foothills of the Alps.

[0015] Depending on the conditions, the mechanism of frost is based on two active components: heat loss from plants and soil due to overflowing cold air (< 0°C), or radiant heat loss, predominantly through IR radiation into the cold and clear night sky. Radiant heat loss is less pronounced under cloudy conditions. Radiant heat loss predominates under clear night skies.

[0016] To prevent or mitigate such frost damage, various known methods are generally used, each of which presents specific difficulties in implementation regarding costs or efficiency. The known methods include: use of a fog machine, sprinkling, turbulence by helicopter, electric heating, hot air blowers, frost protection candles, extensive application of inhibitors to delay bud break, or resolving the damage through insurance as part of a risk assessment. The disadvantages of current systems and / or methods are: release of pollutants, impairment of the plant development cycle, costly logistics or installation, open flames that must be ignited and monitored manually, expensive equipment, electrical power source, or lack of scalability from small cultivation areas (< 1 hectare) to larger areas. Overview of the invention

[0017] The invention is based on the object of creating a frost protection system for plants that is cost-effective, pollutant-free, can be used without user involvement and requires little logistics and installation effort.

[0018] The above object is achieved by a frost protection system for plants comprising the features of claim 1.

[0019] In one embodiment, a frost protection system for plants comprises an energy carrier formed as a compact and combustible residue-free. During a statistically occurring frost event, the frost protection system releases sufficient heat to prevent damaging freezing of the spring-emerging plants in a planting area. An ignition device is assigned to the compact, which, depending on the temperature, triggers ignition and enables the compact to burn. For this purpose, the ignition device is triggered at a threshold value, causing the compact to burn as an energy carrier, which then releases heat in the form of warm gas and infrared radiation within a predetermined time.

[0020] The frost protection systems are deployed in a suitably selected number and pattern on the planting area to be protected, preferably in spring, shortly before the beginning of the first growth phase of the plants to be protected. Each individual frost protection system is designed so that, firstly, the ambient temperature for activation is appropriately selected (e.g., -1°C), and secondly, the fuel supply of the compact burns out completely along with the ignition device. The frost protection system can be a modular, disposable item, and collection after the energy release is not required.

[0021] According to one embodiment, the residue-free burning energy source of the pressed body consists predominantly of carbon.

[0022] In one embodiment, the compact has a recess into which the ignition device for the compact can be inserted. The compact is thus designed to be detachable from the ignition device. This ensures that the ignition device cannot be accidentally ignited, which would pose a fire hazard.

[0023] In one embodiment, the compact has slots or channels for the supply of atmospheric oxygen. By supplying atmospheric oxygen, the combustion behavior of the compact (solid fuel) can be favorably influenced by suitable slots or channels.

[0024] In one embodiment, inhibitors (passive layers) or promoters (oxidizers) are pressed into regions of the compact to influence the burning behavior of the compact. For example, the compact can have regions containing an increased concentration of oxidizer (promoter) to vary the burning rate of the compact.

[0025] According to various embodiments, the frost protection system can be applied to the planting area that is to be protected from frost. One possibility is that the press body is provided with a rod with which the frost protection system can be pushed into the ground. The frost protection system or the press body is held above the ground. Another possibility is that the frost protection system or the press body is provided with a hanger in order to suspend the frost protection system from a holder above the ground. The hanger can be designed as a hook, for example. This hook variant is used, for example, for easy hanging in branches or in existing guy wires or similar in the planting area. Another possibility for applying the frost protection system is that the press body is applied directly to the ground. A holder can be provided, for example, for secure positioning on the ground.

[0026] According to the embodiments described above, the frost protection system or compactor can be replaced as a "disposable" module. An unused compactor can be equipped with a "reusable" holder, which is attached to the compactor using a plug-in, hook, or clamp system. The holder for the frost protection system or compactor can thus be designed in various ways, depending on the specific application. Materials for the holder or hanger can be made from natural and / or easily decomposable materials, such as wood, bamboo, etc.

[0027] In one embodiment, the ignition device is integrated into the compact. In another embodiment, a recess is provided on the compact into which the ignition device can be inserted. The advantage of the separability of the combustible compact and the ignition device is that, for example, accidental ignition or damage to the ignition device can occur.

[0028] According to the embodiments of the antifreeze system, the ignition device can be designed as a thermochemical or electronic ignition device which ignites when a predetermined minimum temperature is undershot.

[0029] The thermochemical ignition system can, for example, consist of a small cartridge containing an aqueous solution that, when the temperature drops below freezing, bursts the cartridge due to expansion, releasing another liquid that initiates an ignition reaction. This ignition reaction releases sufficient heat energy to ignite the slow-burning energy carrier (compressed body) and burn with atmospheric oxygen, releasing heat. One possible variant of the ignition device includes water / glycerin / potassium permanganate. The mass and energy content of the igniter are significantly smaller than the mass and energy content of the energy carrier.

[0030] The electronic ignition system includes, for example, an electronic temperature switch that closes a contact when the temperature falls below a predetermined level. A battery heats a glow wire, which then ignites the energy carrier. To ensure reliable ignition, an easily ignitable environment can be placed directly next to the glow wire in the pressed body. The battery and the electronic ignition switch can be selected to be so small and made of materials that they combust with virtually no residue when the energy carrier or the pressed body burns.

[0031] It is also possible for the numerous frost protection systems in a planting area to be equipped with variable ignition devices. This means that the frost protection systems' ignition devices ignite at different ignition temperatures and are positioned in a suitable arrangement within the planting area to be protected. This allows for staggered effects that optimize the frost protection effect across the area and over time.

[0032] In one embodiment, the compact may be provided with channels or slots that allow the supply of atmospheric oxygen.

[0033] In one embodiment, the compact can have inhibitors and / or promoters pressed into certain areas to influence the combustion behavior. The temporal combustion behavior of the compact can be designed such that a faster initial phase transitions into a slow plateau phase.

[0034] In one embodiment, the compact has a cylindrical shape. To ensure that the thermal energy released by the combustion of the compact is transferred to the plants over a suitable timescale, the combustion rate should be designed to bridge at least one frosty night. Furthermore, the temperature at a distance of approximately 1 m should not become too high to avoid damage to plants. Likewise, the temperature and the geometric design of the frost protection system should be selected so that good IR radiation characteristics are achieved predominantly in the horizontal direction. The elongated, cylindrical design of the compact combustion body is advantageous for this purpose.

[0035] In one embodiment, a casing can surround the compact. The casing can be a water-repellent layer, such as a waxy one, to increase weather resistance. Fire protection can be achieved, for example, by wrapping or coating the compact with an inorganic material, such as clay. After the ignition process, no open flame develops; instead, the compact glows slowly. Further shielding by reducing the energy content on the exterior of the compact can reduce the surface temperature to such an extent that the ignition of combustible material (e.g., dead wood or leaves) is severely hindered.

[0036] The compacts are typically made of carbon-rich material and can weigh from 500g to 10kg. These compacts can be enriched with wood chips to adjust the burning behavior.

[0037] The main component of the compressed bodies is carbon. The advantages are that carbon is inexpensive, that it burns residue-free and without emitting hydrocarbons, that carbon can be compressed to retain its shape, that carbon's ignition and combustion behavior can be easily adjusted using oxidizing agents (e.g., KNO3), that the CO2 produced during the combustion process is harmless to plants, that CO2 is heavier than air, so an air / CO2 mixture with a certain heat difference remains at the bottom ("heat lake"), and that carbon can be extracted naturally (charcoal).

[0038] The application of frost protection systems outdoors or in greenhouses has the advantage, during the period in which frost only occurs statistically sporadically, that a plant population in vulnerable growth phases (e.g. bud formation or flowering), which arose during previous warm periods, can be quickly and easily protected from frost.

[0039] A combination of the self-triggering frost protection systems (heat sources) applied in the planting area with other protective measures, such as heat shielding by partially covering with foil, or air turbulence measures, increases the desired protection effect against frost.

[0040] For the successful implementation of frost protection measures, the required energy quantity and the required frost protection systems should be estimated. To estimate the effective protection, we assume 1 hectare of cultivated area and 12 hours of necessary application. For simplification and as an example, we assume that the critical energy loss range (cooling at night) is reached when 1 kg of water freezes per square meter. With the latent heat of water fusion (333 kJ / kg), this results in a heat loss of approximately 1,000 kWh / ha. From this roughly estimated value, it is clear that electrical heating of 1 hectare over one night (approximately 12 hours) requires a connected load of approximately 80 kW to reliably compensate for the heat loss.

[0041] Surprisingly, it is particularly cost-effective to distribute a carbon-based system consisting of several frost protection systems across the area (cultivated area) instead of electrical heating, e.g., via heating wires or warm air blowers, or instead of heating candles. This system operates primarily via radiant heat. The above-mentioned energy quantity required for 1 hectare over 12 hours corresponds to the calorific value of approximately 113 kg of carbon. If such carbon-based frost protection systems (modules) with approximately 1 kg to 5 kg each are used, for example, 100 modules can be distributed in a grid pattern over one hectare. Each frost protection system is coupled with a self-triggering, temperature-dependent ignition device.

[0042] Typically, each antifreeze system is triggered when the temperature drops below a given minimum (e.g., -1°C) and then burns off completely and residue-free over a timescale of 6-24 hours, typically 12 hours. The independence of the individual ignition devices results in a self-organizing distribution of the ignition sequence, and the temperature is optimally homogenized throughout the cultivated area. Due to normal (production-related) fluctuations in the ignition temperature and spatial fluctuations in the temperature on the cultivated area to be protected, the antifreeze systems in the coldest positions and those with the highest ignition temperature ignite first. Neighboring antifreeze systems will not ignite initially due to temperature stabilization. This results in a suitable and self-organized ignition sequence in the overall ensemble of antifreeze systems distributed across the entire area.

[0043] The big advantage is that human intervention or monitoring is not required. Short description of the drawings

[0044] The invention and its advantages are described in more detail below with reference to the attached schematic drawings. Fig. 1 shows a schematic view of the placement of several of the frost protection systems according to the invention in a growing area of ​​the plants to be protected against frost. Fig. Figure 2 shows a schematic cross-section through a possible embodiment of the frost protection system. Fig. 3 shows a plan view of the compact in which an ignition device is inserted. Fig. 4 shows a schematic view of the compact with a receptacle for the ignition device. Fig. 5 shows a schematic view of the compact from Fig. 4 with the ignition device inserted. Fig. 6 shows a schematic view of another embodiment of the compact, wherein the receptacle for the ignition device is arranged differently than in Fig. 4 is formed on the pressing body. Fig. 7 shows a schematic view of the compact from Fig. 6 with the ignition device inserted. Fig. 8 shows a plug-in version of the frost protection system for insertion into the ground. Fig. 9 shows a variant of the frost protection system for hanging on a bracket Fig. Figure 10 shows a variant of the frost protection system that is positioned directly on the ground of the cultivation area. Fig. 11 shows a top view of the compact, which is provided with channels to positively influence the supply of atmospheric oxygen. Fig. 12 shows an embodiment of the compact which has at least one promoter (oxidizing agent) compressed to influence the burning behavior. Fig. 13 shows another embodiment of the compact which has a promoter (oxidizing agent) and an inhibitor (passive layer) pressed in to influence the burning behavior.

[0045] In the following, exemplary embodiments will explain the invention and its advantages in more detail with reference to the accompanying figures. The proportions in the figures do not always correspond to the actual proportions, as some shapes are simplified and others are shown enlarged relative to other elements for better illustration. Detailed description of the drawings and embodiments

[0046] Fig. 1 shows a schematic view of the placement of several of the frost protection systems 10 according to the invention in a cultivation area 1 of the plants 3 to be protected against frost. The majority of the frost protection systems 10 are distributed in a grid-like manner over the cultivation area in order to achieve the most homogeneously distributed heating of the cultivation area.

[0047] Fig. 2 schematically shows a cross-section perpendicular to the longitudinal axis L of a possible embodiment of the frost protection system 10. The frost protection system 10 consists of a pressed body 20, which represents the energy source 12 of the frost protection system 10. In the embodiment shown here, the pressed body 20 is surrounded by a casing 22 in the direction of the longitudinal axis L. The casing 22 of the pressed body 20 can, for example, be a coating with an inorganic material, such as alumina, in order to reduce the surface temperature of the pressed body 20 and / or be a water-repellent coating in order to increase the weather resistance of the pressed body 20.

[0048] Fig. 3 shows a top view of the compact 20 of the antifreeze system 10, with an ignition device 24 inserted into the compact 20. The ignition device 24 can be installed during the manufacture of the compact 20. It is also conceivable that the ignition device 24 is inserted into the compact 20 only shortly before the antifreeze system 10 is used.

[0049] Fig. 4 and Fig. 5 show schematic sectional views of the compact 20 in the section plane AA (see Fig. 3) along the longitudinal axis L. The compact 20 has a central recess 26 into which, as indicated by the arrow, an ignition device 24 can be inserted. The representation of the Fig. 5 shows the ignition device 24 inserted into the recess 26.

[0050] Fig. 6 and Fig. 7 show schematic sectional views of another embodiment of the compact 20 in the sectional plane AA (see Fig. 3) along the longitudinal axis L. Here, the formation 26 is formed laterally on the pressing body 20. The representation of the Fig. 7 shows the ignition device 24 inserted into the recess 26.

[0051] Fig. Figure 8 shows a plug-in version of the frost protection system 10 for insertion into the ground 5. The pressed body 20 sits on a rod 7, over which the pressed body 20 is positioned above the ground 5. This plug-in version is designed to be advantageous for the respective application. The pressed body 20 and thus the energy carrier 12 are covered with the casing 22 for protection and to reduce heat radiation. The ignition device 24 is also located beneath the casing.

[0052] Fig. Figure 9 shows a variant of the frost protection system 10 for hanging on a bracket 29. The compressed body 20 is connected to a hanger 28. With the hanger 28, the frost protection system 10 can be easily hung on branches or existing guy wires, etc.

[0053] Fig. Figure 10 shows another variant of the frost protection system 10, which is positioned directly on the soil 5 of the cultivation area. A ground support 30 is provided for the compactor 20, allowing the compactor 20 to be distributed directly on the soil 5.

[0054] After the compact 20 has burned down, the rod 7, the hanger 28, or the base mount 30 can be configured as a "disposable" mount or a "reusable" mount. The "disposable" or "reusable" mount can be attached to the compact 20 using a plug-in, hook, or clamp system.

[0055] Fig. Figure 11 shows a top view of the compact 20, which is provided with channels or slots 27. The channels or slots 27 serve to supply atmospheric oxygen to the compact 20 in order to positively influence the combustion behavior of the compact 20.

[0056] Fig. Figure 12 shows an embodiment of the compact 20, which has at least one promoter 23 (oxidizing agent) pressed into the compact. The promoter 23 can be introduced into specific areas of the compact 20 in order to influence a specific combustion behavior of the compact 20.

[0057] Fig. Figure 13 shows another embodiment of the compact 20, which has a promoter 23 (oxidizing agent) and an inhibitor 25 (passive layer) pressed into it. This configuration also allows the burning behavior of the compact 20 to be influenced in the desired manner.

[0058] The Fig. 12 and Fig. The number and positioning of promoters 23 or inhibitors 25 in the compact 20 shown in Figure 13 is for descriptive purposes only and should not be construed as a limitation. List of reference symbols 1 growing area 3 plants 5 Floor 7 staff 10 Frost protection system 12 energy sources 20 compacts 22 Wrapping 23 Promoter 24 Ignition device 25 Inhibitor 26 Formation 27 channel, slot 28 trailers 29 Bracket 30 floor mount AA cutting plane L Longitudinal axis QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 32 38 44 C2

[0002] DE 69805912 T2

[0003] EP 0 878 125 B1

[0003] DE 10 2017 116 571 A1

[0004] WO 2021 / 052700 A1

[0005] US 3 615 287 A

[0006] DD 236 443 A1

[0007] FR 2 424 958 A2

[0008] US 4,519,774 A

[0009] Cited non-patent literature

[0000] Frost protection in fruit and wine growing” from June 2018 reveals in the chapter “Methods of frost control and their effectiveness

[0010] Final report from 04 / 2018 of the Bavarian State Ministry of Food, Agriculture and Forestry reveals: “Investigations on damage reduction during late frosts in Franconian vineyards

[0011]

Claims

[1] A frost protection system (10) for plants (3), characterized by an energy source (12) designed as a module and burning without residues, which consists predominantly of carbon; an electronic ignition device (24) which is located in a recess (26) of the module and which is triggered when a predetermined minimum temperature is undershot, so that the module burns without residue. [2] Antifreeze system (10) according to claim 1, wherein the module is a compact. [3] Antifreeze system (10) according to claim 2, wherein the ignition device (24) can be inserted into the molding (26) of the compact (20). [4] Antifreeze system (10) according to claim 2, wherein the ignition device (24) is integrated in the pressed body (20) or is located in a recess (26) formed on the pressed body (20). [5] Antifreeze system (10) according to one of the preceding claims, wherein slots or channels (27) for supplying atmospheric oxygen are formed in the module. [6] Antifreeze system (10) according to one of the preceding claims, wherein inhibitors (25) or promoters (23) are pressed into regions of the module in order to influence the combustion behavior of the module. [7] Frost protection system (10) according to one of the preceding claims, wherein the module is provided with a rod (7) with which the frost protection system (10) is inserted into the ground (5) and the module is held above the ground, or wherein the module is provided with a hanger (28) in order to suspend the frost protection system (10) above the ground (5) on a holder (29), or wherein the module stands on the ground (5) in a holder (29). [8] Antifreeze system (10) according to claim 7, wherein the holder (29) for the module is a disposable holder or a reusable holder. [9] Antifreeze system (10) according to one of the preceding claims, wherein the module has a cylindrical shape. [10] Antifreeze system (10) according to one of the preceding claims, wherein an enclosure (22) surrounds the module. [11] Antifreeze system (10) according to one of the preceding claims, wherein the modules of the carbon-based antifreeze system (10) each comprise approximately 1 kg to approximately 5 kg of carbon. [12] Frost protection system (10) according to claim 11, wherein, for example, 100 modules are distributed in a grid pattern per hectare and each of the modules is coupled to the self-triggering and temperature-dependent ignition device. [13] Antifreeze system (10) according to any one of the preceding claims 11-12, wherein each module burns off completely and residue-free on a time scale of 6 - 24 hours. [14] Antifreeze system (10) according to claim 13, wherein the module burns off completely and without residue within 12 hours. [15] Antifreeze system (10) according to any one of the preceding claims 11-14, wherein each antifreeze system is coupled to an individual, self-triggering and temperature-dependent ignition device, resulting in a self-organizing distribution of the ignition sequence and a homogenized temperature in the cultivation area.

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