EP2931023A1

EP2931023A1 - Irradiation device for irradiating plants

Info

Publication number: EP2931023A1
Application number: EP13802595.2A
Authority: EP
Inventors: Oliver Weiss; Sven Linow
Original assignee: Heraeus Noblelight GmbH
Current assignee: Heraeus Noblelight GmbH
Priority date: 2012-12-12
Filing date: 2013-12-06
Publication date: 2015-10-21
Also published as: JP2016507220A; JP6033458B2; CN105142391A; US9426947B2; WO2014090693A1; US20150313090A1; DE102012112192B3

Abstract

Known irradiation devices (1) for irradiating plants (3) have a carrier element (2) for cultivating the plants, said carrier element defining a cultivation plane (E), a plurality of radiation sources (4a, 4b, 4c) for irradiating the plants with visible and/or ultraviolet radiation (5) and a plurality of infrared emitters (8) for irradiating the plants with infrared radiation (6). In order, proceeding therefrom, to specify an irradiation device for irradiating plants which ensures uniform irradiation of the plants with infrared radiation alongside irradiation of the plants with ultraviolet and/or visible radiation, and which furthermore requires a small number of infrared emitters relative to the cultivation area, the invention proposes that the infrared emitters are designed for a temperature of 800°C to 1800°C and each have a cylindrical emitter tube (303) having an emitter tube length in the range of 50 mm to 500 mm, and that the emitter tubes extend parallel to one another in an emitter zone (Z) located above the cultivation plane (E), wherein the infrared emitter occupation density relative to the area of the cultivation plane is in the range of between 0.2 m^-2 and 1.0 m^-2, and irradiation regions of adjacent infrared emitters on the cultivation plane overlap in such a way that the average irradiance on the cultivation plane is between 10 watt/m² and 100 watt/m² with a variation range of a maximum of 50%, and that a reflector (302) facing a structural space (B) is assigned to a top side of the emitter tube.

Description

Irradiation device for irradiation of plants

description

The present invention relates to an irradiation device for irradiating plants, comprising a support element defining a cultivation plane E for cultivating the plants, a plurality of radiation sources for irradiating the plants with visible and / or ultraviolet radiation and a plurality of infrared radiators for irradiating the plants with infrared radiation. Furthermore, the present invention relates to a radiator module for the irradiation of plants with infrared radiation for use in an irradiation device.

State of the art

In the rearing and cultivation of plants, for example in greenhouses and in the cultivation of floors artificial light sources are used. The emission spectrum of these light sources is usually adapted to the absorption spectrum of the green leaf pigment of chlorophyll and carotene.

The term chlorophyll and carotene summarizes several natural dyes that are involved in photosynthesis. The absorption spectra of these dyes dissolved in solvents have two pronounced absorption maxima, namely an absorption maximum in the violet and blue spectral range between 400 nm and 500 nm and a further absorption maximum lying in the red spectral range between 600 nm and 700 nm of the visible light.

In order to ensure efficient irradiation of the plants, the emission spectrum of artificial light sources for the irradiation of plants has large radiation components in the two above-mentioned wavelength ranges.

As light sources, for example, gas discharge lamps or light emitting diodes (LEDs) are used. Gas discharge lamps consist of one with a filling gas filled discharge chamber in which two electrodes are arranged. Depending on a voltage applied to the electrodes, a gas discharge takes place in the discharge chamber, which is connected to the emission of optical radiation. The wavelength of the emitted radiation can be influenced by a selection of the filling gas and adapted to the absorption spectrum of the chlorophyll, for example by a corresponding doping of the filling gas. LEDs, on the other hand, only emit light in a limited spectral range, so that several LEDs of different wavelengths have to be combined to produce an emission spectrum adapted to the absorption spectrum of the chlorophyll. Thus, for example, US 2009/0251057 A1 discloses an artificial light source with a plurality of LEDs, in which light emitting diodes with different emission spectra are combined to produce artificial sunlight.

However, efficient rearing of plants depends not only on the stimulation of photosynthesis, but also on the transport of water and nutrients in the plant and on carbon dioxide assimilation. Both water and nutrient transport in the plant and carbon dioxide assimilation are affected by the plant's stomata. Through the stomata of the plant, the plant regulates the gas exchange with the ambient air, in particular the absorption of carbon dioxide from the air and the release of oxygen into the air. In addition, the water balance of the plant is influenced by the opening width of the stomata. Thus opened stomata lead to an increased evaporation of water, which generates a transpiration suction, so that overall the water and nutrient transport (sap flow) is increased from the root to the leaves.

The opening width of the stomata can be regulated by a number of factors including, for example, temperature, availability of water, carbon dioxide concentration in the leaf interior and absorption of light. By targeted irradiation with infrared radiation, the gap opening width and thus the effectiveness of photosynthesis can be regulated. WO 2010/044662 A1 proposes an irradiation device for plants with a chamber in which, in addition to radiation sources for irradiating the plants with visible or ultraviolet radiation, a plurality of infrared radiators arranged on a side wall of the chamber are provided for irradiating the plants with infrared radiation. The infrared heaters heat the leaves of the plants in such a way that the stomata open, so that a stimulation of the exchanges of the plant with its environment is achieved.

Due to the lateral arrangement of the infrared radiators, the individual plants, depending on their planting position on the cultivation level, each have a different distance from the infrared radiators and are therefore irradiated unevenly. In particular, it has been found that the outer areas of the cultivated area are exposed to higher irradiation intensities compared with the inner areas of the acreage. In order to ensure an efficient rearing of the plants, a uniform growth of the plants and thus a homogeneous irradiation of all plants are basically desirable.

With a lateral arrangement of the infrared radiators, a large number of radiators is required in addition with respect to the cultivated area, which in order not to damage the plants in the outer area of the acreage by excessive heating, must have a low power. However, infrared radiators typically have high power; Spotlights low power are expensive to produce and have only a limited life.

In addition, the lateral arrangement of the infrared radiator also contributes to an irradiation and heating of the other components provided in the irradiation device, for example the electric lines and mounting elements for the radiation sources, as well as the radiation sources provided in the irradiation device, wherein the lifetime of the latter is due to the irradiation Components is shortened. A lateral arrangement of the infrared radiator is therefore associated with high operating costs. Technical task

The invention is therefore based on the object of specifying an irradiation device for the irradiation of plants, which has a long life and, in addition to irradiation of the plants with ultraviolet and / or visible radiation uniform irradiation of the plants with infrared radiation guaranteed without the irradiation with ultraviolet and / or visible To unnecessarily affect radiation, and which also requires a small number of infrared radiators in relation to the acreage.

Furthermore, the object of the invention is to provide a radiator module for irradiating plants with infrared radiation, which is designed for optimum use in an irradiation device for irradiating plants.

Finally, the invention is based on the object of minimizing losses in the conversion of the electrical energy into infrared radiation, losses in the steering of the infrared radiation to the plants to be irradiated, mutual shading of light sources and other energy losses.

General description of the invention

With regard to the irradiation device, this object is achieved, starting from a device of the type mentioned in the present invention that the infrared radiators are designed for a temperature of 800 ° C to 1800 ° C and each have a cylindrical radiator tube with a radiator tube length in the range of 50 mm 500 mm, and that the radiator tubes extend parallel to one another in a radiator zone Z located above the cultivation plane E, wherein the infrared radiator occupancy density relative to the surface of the mounting plane E in the range between 0.2 m ^"2 and 1, 0 m ^{" 2} is located, and irradiation areas of adjacent infrared radiators on the mounting plane E overlap such that the average irradiance on the mounting plane E between 10 watts / m ² and 100 watts / m ² with a maximum variation of 50%, and that a top of the Radiator pipe to a space B assigned associated with the reflector.

Sunlight, which plants need to grow under natural conditions, has radiation components of ultraviolet, visible, and infrared radiation. For simulating natural growth conditions, therefore, the artificial irradiation device also has infrared radiators in addition to radiators for generating ultraviolet and / or visible radiation (hereinafter also referred to as UV and VIS radiators for short). Through the use of these types of radiators, the plants are supplied under artificial rearing conditions on the one hand with the required for photosynthesis radiation and on the other hand, via the infrared radiation, the opening width of the stomata of the leaves are regulated so that adjusts an optimal water and mass transfer within the plant. These measures ensure rapid plant growth and high productivity.

In order to ensure the most uniform possible plant growth, it is, however, necessary to irradiate the plants as uniformly as possible, that is to say with an almost constant irradiation intensity. This applies in particular to the irradiation of the plants with infrared radiation. A locally too high infrared irradiance leads to damage of the affected plants. At too low irradiance, however, loses the effect of infrared radiation on the opening width of the stomata; it leads to low plant growth.

In the case of the irradiation device according to the invention, the infrared radiators are arranged in a radiator zone Z situated above the cultivation plane E. It is important that the infrared radiators produce an overall uniform irradiation surface on the cultivation plane E. On the side of the irradiation surface arranged infrared radiator can thus be dispensed with.

In order to achieve an overall uniform irradiation surface on the cultivation plane E, the infrared radiators in the radiator zone Z are arranged relative to one another and uniformly distributed so that their radiator tube longitudinal axes run parallel to one another. Due to the parallel arrangement of the radiator tubes is a areal radiation of the infrared radiation ensures, which is particularly suitable for the uniform irradiation of a plane, such as a defined plant growth by the plant level or the cultivation level.

Due to the uniform distribution of the infrared radiators in the emitter zone Z, it should not be accepted that the UV and VIS emitters experience shading at the cultivation level. The aim is thus not only a uniform infrared radiation, but also a minimization of shading of the UV and VIS radiation at the cultivation level E.

Above the radiator tube, the irradiation device according to the invention has a construction space B. In this space, a plurality of components are arranged, which are required for the operation of the irradiation device, such as electric cables or mounting elements for the infrared radiator or other radiation sources. It is therefore basically desirable to avoid excessive heating of the components of the installation space by infrared / thermal radiation.

An excessive heating of the installation space and the components therein is inventively reduced in that the radiator tube has on its upper side a reflector which reduces the propagation of the emitted infrared radiation in the direction of the installation space. However, since such a reflector could at the same time adversely affect the radiation propagation of the UVA / IS radiation emanating, for example, from the UV and VIS emitters in the emitter zone Z, the greatest possible radiation propagation of the UV and VIS emitters is ensured by the fact that based on the Mounting level E as small as possible number of infrared radiators is used, and that the reflector is formed so that a shading of the UVA / IS radiation is reduced.

In addition to a low shielding of the UVA / IS radiation, the radiation characteristic of the infrared radiator plays an important role. Its purpose is to ensure that the infrared radiation is not simply reflected downwards but distributed over a wide irradiation area. A uniform irradiation of the cultivation plane E with at the same time the smallest possible number of infrared radiators is inventively achieved in that the reflector above the radiator tube is shaped so that the infrared radiation emitted from the region above the horizontal through the center of the heating coil in areas further away from the radiation module is distracted.

Conventional reflectors, such as parabolic or hyperbolic reflectors, do not fulfill this function, since they reflect the radiation in particular in areas directly below the radiator tube. A small number of emitters is associated with a small number of reflectors. These can be dimensioned larger at the same low radiation shield, so that they can contribute better to a uniform irradiation in the cultivation level E. An optimal range for the number of infrared radiators in relation to the cultivated area is between 0.2 m ^"2 and 1, 0 m ^{" 2} . With a number of less than 0.2 infrared radiators per square meter, a uniform radiation distribution can only be achieved with great difficulty, for example with large reflectors, which then obstruct the radiation of the UV and VIS radiators also located in the radiator zone Z. With a number of more than 1.0 infrared radiators per square meter, there is a reduced efficiency of IR irradiation because very small infrared radiators have a significantly lower conversion efficiency of electric energy into infrared radiation. In addition, the assembly and maintenance costs increase with the number of units.

In addition, a small number of emitters relative to the cultivation level enables the use of small but powerful infrared emitters, which have a higher conversion efficiency compared with larger and less powerful infrared emitters, thus lower heat loss and a longer service life. For this reason, the length of the cylindrical radiator tubes is in the range of 50 mm to 500 mm.

The longer service life of such lamps is achieved by the individual radiators with the highest possible voltages, for example in the range 24 V to mains voltage. operated. As a result, for example, only a small number of transformers is required, so that transformer-related heat losses are kept low. In this voltage range, however, larger but less powerful spotlights can only be operated at low currents, which necessitates the use of straight filaments with very small wire diameters (less than 0.4 mm), which typically have low mechanical stability, inhomogeneous temperature distribution and a short service life exhibit.

In order to achieve uniform irradiation of the growing plane, the use of a few emitters requires an overlap of the irradiation areas of adjacent emitters, so that the average irradiation intensity has a maximum fluctuation range of 50%. The fluctuation range is the maximum deviation of the actual irradiance at a point of the cultivation level E from the average irradiance. According to the invention, the actual irradiance deviates by a maximum of ± 50% from the mean irradiance at the cultivation level E. The deviation from the average irradiance at the cultivation level is preferably 20%, particularly preferably 10%. For optimal plant growth, the emission spectrum of the infrared radiators continues to be essential. The absorption spectrum of plants is characterized by high absorptions in the wavelength range below 700 nm and above 2.5 μιτι. In the range between 0.7 μιτι and 2.5 μιτι a basic absorption of about 5% and a nearly undirected scattering are observed. Radiation with wavelengths in this range is suitable for penetrating the uppermost layers of leaves of a plant; In principle, it is also available for irradiation of the lower leaf layers, but is absorbed only to small proportions. It has been found that optimum plant growth is achieved when the heating filament is designed for a temperature of 800 ° C to 1, 800 ° C, preferably for a temperature in the range of 850 ° C to 1, 500 ° C. Spotlights, which at nominal voltage have a filament temperature in the above

Have radiation, emit radiation having an intensity maximum in Wel- lenlängen in the range between 0.7 μιτι and 3.5 μιτι.

A distinction must be made between applications aimed at optimal irradiation of only the upper leaf levels and those at which the lower leaf levels are to be irradiated. The use of medium-wave thermal shear infrared radiators is advantageous if almost all the radiation is to be absorbed or reflected at the uppermost sheet layer. Such radiators have at nominal voltage a filament temperature in the range between 800 ° C and 1 .000 ° C. Short-wave thermal infrared radiators with a filament temperature at nominal voltage in the range between 1 .400 ° C and 2200 ° C, preferably between 1 .400 and 1 .800 ° C, are particularly suitable for penetrating the upper layers of sheets.

Radiation generated at filament temperatures in the transition region between 1000 ° C and 1400 ° C achieves a mixture of both mechanisms.

In a first advantageous embodiment of the device according to the invention 15 is provided that the average irradiance on the cultivation level 10th

Watt / m ² to 50 watts / m ² .

The necessary average irradiance at the cultivation level depends on the crop to be cultivated as well as other environmental conditions. It has been shown that, for many plant species, an irradiance in the range of 20 10 watt / m ² to 50 watt / m ² leads to accelerated growth and thus to a shorter average residence time of the plants in the rearing chamber.

In another equally preferred embodiment of the irradiation device according to the invention, it is provided that a plurality of infrared radiators are arranged one behind the other in the direction of their longitudinal axes, and that adjacent infra-red radiators are spaced apart in the direction of their longitudinal axis

0.9 m to 2.3 m, preferably between 1.1 m to 1.7 m.

In order to ensure uniform irradiation of the cultivation level with both ultraviolet / visible radiation and infrared radiation as inexpensively as possible, standing in conflict with each other or each other to optimize influencing properties, such as the radiator power, radiator size and radiator occupancy density. Basically, a low radiator density of the infrared radiator is desirable. However, a distance of neighboring infrared radiators of less than 0.9 m leads to a comparatively high radiation density, together with a low nominal power per radiator and high installation and operating costs. If adjacent infrared radiators have a distance of more than 2.3 m in the direction of their longitudinal axes, uniform irradiation of the cultivation plane with infrared radiation can only be achieved with great difficulty. Preferably, the infrared radiators are arranged in parallel rows, with adjacent rows extending in such a way that the infrared radiators of adjacent rows are arranged next to one another.

That is, the infrared radiator adjacent rows are just not offset from each other, set "gap", but they start and end - at the same length - at the same longitudinal positions of the illumination field within the radiator plane Z. In conjunction with the shape of the reflectors, this results in a less mutual interference and an optimal homogeneous irradiance on the plant level.

In this connection, it has also proven useful if adjacent infrared radiators arranged parallel to one another have a distance from one another of between 1 m and 3 m, preferably between 1.3 m and 2.5 m, particularly preferably between 1.5 m and 1 m , 8 m.

It has proved to be advantageous if the infrared radiators from the mounting plane have a distance in the range of 1, 0 m ± 0.5 m. For larger distances, all dimensions and performance data must be scaled accordingly.

The distance between the infrared radiators and the cultivation level influences the irradiance and its distribution on the cultivation level E. Depending on the plant species, a distance of the infrared radiators from the cultivation level of 0.5 m to 1.5 m has proven to be effective. At a distance of less than 0.5 m, only plants can grow up to be irradiated to a low stature height. A distance of the infrared radiators of more than 1.5 m affects a compact design of the irradiation device.

In a preferred modification of the irradiation device according to the invention, the reflector has-seen in the direction of the longitudinal axis-a length in the range between 70 mm and 650 mm, preferably between 250 mm and 450 mm and a width in the range between 50 mm and 160 mm, preferably in the range between 80 mm and 130 mm, on.

The length of the reflector is adapted to the length of the radiator tube. A reflector length of less than 70 mm with a radiator tube length of the infrared radiator of at least 50 mm is only conditionally suitable for reducing an emission of infrared radiation in the direction of the installation space. In such short emitter tubes, a large number of infrared emitters is also necessary, which increases the probability of failure, the installation costs and the operating costs. A reflector with a length of more than 650 mm with a maximum radiator tube length of 500 mm leads to an increased shielding of ultraviolet and / or visible radiation. In addition, the use of larger reflectors is disadvantageous because then larger, but low-power, with low amperage lamp emitter would have to be used, which in turn makes the use of straight filaments with very small wire diameters (less than 0.4 mm) necessary, which is typically a poor have mechanical stability, inhomogeneous temperature distributions and short lifetimes.

The reflector width between 50 mm and 160 mm represents for the same reasons a suitable compromise between the shielding of the infrared radiation upward and obstruction of the irradiation of the cultivation level with ultraviolet and / or visible radiation.

In an equally preferred modification of the irradiation device according to the invention, the reflector has a diffusely reflecting surface.

For example, a diffuse reflection of light occurs when light is rough Surface meets, which has several surface elements with different orientations. A light beam incident on a diffusely reflecting surface is reflected by the surface structure in many different directions, so that stray light is obtained. Scattered light is particularly suitable for generating uniform irradiation intensities, since maxima in the irradiance are attenuated and the difference between minimum and maximum irradiance on the cultivation plane E is reduced.

Here, it has proven to be useful if the surface has a mechanically embossed structuring, that is, for example, made of hammered aluminum. For example, the MIRO ^® -DESSIN materials ALANOD would be suitable for this purpose aluminum finishing GmbH.

A hammered aluminum surface has a diffuse reflective effect, low radiation losses due to its coarse surface structure, and is also easy and inexpensive to manufacture. In a further preferred embodiment of the irradiation device according to the invention, provision is made for a first reflector strip extending in the direction of the longitudinal axis to be applied on a lateral region of the lateral surface of the emitter tube.

A reflector strip applied to the lateral surface of the emitter tube prevents radiation of infrared radiation in this area of the lateral surface. As a result, not only the lateral radiation in the direction of the UV-A / IS radiation sources, which are also located in the emitter zone Z, but also the radiation in the direction of the installation space is reduced, depending on the size of the coverage angle. The application of reflector strips directly to the radiator tube allows a reduction of the reflectors above the radiator tubes with the same effectiveness, as far as the reduction of the propagation of the infrared radiation in the direction of the installation space is concerned. Smaller reflectors above the radiator tubes, moreover, less affect the optical radiation emitted by the UV / Vis radiators mounted in the radiator zone Z, so that a more uniform irradiation with ultraviolet and / or visible radiation is made possible. It has proved to be advantageous if the reflector strip is made of gold, opaque quartz glass (silicon dioxide) or ceramic (for example aluminum oxide).

Reflective strips made of these materials are characterized by a high IR reflectance, good chemical resistance and, in some cases, high temperature resistance. They can also be easily applied to the spotlight tube.

It has proved to be advantageous if the emitter tube has a circular cross-section, wherein the reflector strip covers a circular arc of the emitter tube having a horizontal angle through the filament midpoint between a -40 ° and + 40 °, preferably -30 ° and + 30 °.

A reflector strip with such a cover angle covers the radiator tube in the lateral direction above and below the horizontal. The coverage angle may be different above and below the horizontal, wherein optionally the amount of the coverage angle below the horizontal is preferably smaller than that above the horizontal. The fact that the reflector strip is arranged in the cover angle range above and below the horizontal, on the one hand, a radiation of infrared radiation with a horizontal relative to the flat radiation angle in the direction of space and the UV-A / IS radiation sources in the radiator zone and on the other hand, a lateral, Downward radiation of infrared radiation with a flat angle of radiation can be reduced.

In a preferred embodiment of the last-described embodiment of the irradiation device according to the invention, a further reflector strip is applied to the lateral surface, which is arranged mirror-symmetrically to a vertical line extending through a filament center to the first reflector strip.

A mirror-symmetrical to the first reflector strip applied further Re- Flektorstreifen contributes to a symmetrical and uniform irradiation of the cultivation level.

It has proven useful if the reflector strip has a diffusely reflecting surface. Such a reflector strip contributes to a homogeneous irradiation of the cultivation plane E.

In a preferred modification of the irradiation device according to the invention it is provided that additional reflectors are arranged in a respective reflector plane laterally of the radiator tube, wherein the reflector planes with the horizontal angle between 25 ° to 70 ° include and their dimensions and distance from the radiator tube are set such that They prevent a direct radiation of the infrared radiation emitted by the infrared radiation in a spatial region which is described starting from a filament center of the radiator tube by two planes, the len each len an angle between -40 ° and + 40 °, preferably between -30 ° and + 30 °.

The two side of the radiator tube arranged additional reflectors are straight or formed as a conic. The lateral reflectors reflect the radiation from the region of a circular arc of the radiator tube, which forms an angle between -40 ° and + 40 °, preferably -30 ° and + 30 ° with a horizontal extending through the center of the filament. The side reflectors are at an angle between 25 ° to 70 ° to the horizontal.

The coverage angle may be different above and below the horizontal, wherein optionally the amount of the coverage angle below the horizontal is preferably smaller than that above the horizontal. The fact that the lateral reflectors cover the angular range above and below the horizontal, on the one hand, a radiation of infrared radiation with a relative to the horizontal flat beam angle in the direction of space and the UV-A / IS radiation sources in the radiator zone On the other hand, the lateral, downward radiation of infrared radiation can be regulated by adjusting the reflector angle to the horizontal, or by the type and shape of the conic section.

In a preferred embodiment of the last-described embodiment of the irradiation device according to the invention, the lateral reflectors have a diffusely reflecting surface.

In another preferred modification of the irradiation device according to the invention it is provided that two side wings are connected to the reflector, wherein the side wings with the horizontal in each case enclose an angle in the range between 20 ° to 40 °.

The side wings reduce in particular a radiation of infrared radiation in the direction of the installation space. In addition, the side wings can also reduce lateral radiation of infrared radiation in the direction of the UV-A / IS radiation sources in the radiator zone. They therefore contribute - as stated above - to a high energy efficiency of the irradiation device.

It has proven useful if the reflector has a mirror symmetry to a reflector mirror plane, wherein the shape of a symmetry half of the reflector is described by a conic section in sectional view perpendicular to the reflector mirror plane, wherein the reflector towards the center tapers towards the radiator tube ,

A conic section is a section of the surface of a circular cone or double circle cone with a plane. Conic sections are for example ellipses, parabolas or hyperbolas and defined by the equation y ² = 2Rx- (k + 1) x ² , where R is the radius of curvature, and k is the conic constant of the conic. It has been found that a uniform irradiation distribution on the cultivation plane can be achieved with such a reflector, in particular when irradiating a large irradiation area.

It has proved to be advantageous if at least a part of the surface of the radiator tube acts as a diffuser and scatters incident radiation diffusely. An incident radiation diffusely scattering surface basically leads to a more uniform, non-directional radiation propagation. A diffuser therefore contributes to a uniform irradiation of the plants in the irradiation device. In a preferred embodiment, the entire surface of the radiator tube is formed as a diffuser.

In view of this, the emitter tube preferably has a roughened surface Ra which acts as a diffuser and has a mean roughness Ra, the average roughness Ra being in the range between 0.3 μm and 10 μm, preferably between 0.8 μm and 3 μm. Roughened surfaces act as a diffuser, with their diffuser properties depending on the average roughness of the surface. The average roughness Ra is determined as a vertical measured quantity according to DIN EN ISO 4288: 1988. Roughened surfaces with such a roughness have a nearly Lambertian scattering. The rate of backward scattering of the radiation impinging on them is between 0% and 6%. A surface with an average roughness of less than 0.3 μιτι has a large proportion of backscattered radiation.

It has proved favorable if the irradiation device comprises a housing with side walls, wherein a reflector foil, for example of aluminum, is applied to at least one of the side walls. A reflective inner lining by means of a reflector film applied to the side walls of the irradiation device primarily reduces radiation losses and can contribute to a uniform distribution of the irradiation intensity relative to the cultivation plane. A particularly symmetrical, homogeneous radiation distribution is obtained if a reflector foil is applied to two opposite or all four side walls.

If a reflective inner lining is used, it is possible, in particular, to use infrared radiation modules whose reflector is designed in such a way that a portion of the radiation is generated in a horizontal plane in relation to the horizontal. Downwards in areas further away from the irradiation module is radiated, which contributes to an overlap of the irradiation areas, even with beyond the nearest neighbor extending parallel modules, and a uniform distribution of the irradiation intensity with respect to the cultivation level.

If no reflective inner lining is used, it is possible, in particular, to use irradiation modules whose reflector is designed so that the predominant part of the radiation is emitted into areas below the irradiation module, so that an overlapping of the irradiation areas is mainly associated with the next neighboring module arranged parallel thereto given is.

With regard to the radiator module, the abovementioned object is achieved on the basis of a radiator module of the type mentioned in the introduction in that the infrared radiator is a cylindrical radiator tube with a radiator longitudinal axis, a radiator tube length of 50 mm to 500 mm, preferably 150 mm 350 mm and arranged therein, designed for a temperature of 800 ° C to 1 .800 ° C heating filament, wherein one side of the radiator tube is associated with a reflector.

The radiator module is intended for use in an inventive Bestahlungsvor- device. With regard to this irradiation device, reference is made to the above explanations.

The radiator module is designed for the irradiation of plants. In particular, infrared radiators with a cylindrical radiator tube with a radiator tube length of 50 mm to 500 mm, preferably 150 mm to 350 mm, have a good size ratio, with the good results are achieved with respect to a uniform irradiance on the cultivation level. They are capable of achieving a mean irradiance at the cultivation level of 10 W / m ² to 100 W / m ² .

In addition, it has been shown that optimum plant growth is achieved when the heating filament for a temperature of 800 ° C to 1 .800 ° C ausge- is laying. Emitters which have a filament temperature in the above-mentioned range at rated voltage emit radiation with an intensity maximum at wavelengths in the range between 0.7 μm and 3.5 μm. The emitted radiation is therefore both an irradiation of the upper and the lower leaf layers available.

Suitable modifications can be found in the above explanations concerning the irradiation device according to the invention.

embodiment

The invention will be described in more detail below with reference to exemplary embodiments. In detail shows in a schematic representation:

FIG. 1 shows a first embodiment of the irradiation device according to the invention for irradiating plants with a radiator zone,

FIG. 2 shows a raytracing simulation of the irradiation intensity for a second embodiment of the irradiation device according to the invention,

FIG. 3 shows an embodiment of a radiator module according to the invention for use in an irradiation device according to the invention

FIG. 4 shows a side view of a further radiator module according to the invention for use in an irradiation device according to the invention,

5 shows a cross-section of a further embodiment of the radiator module according to the invention with an infrared radiator, on the radiator tube to reduce the radiation emission in an angular range two reflector strips are applied, and Figure 6 shows in cross section a further embodiment of the radiator module according to the invention for use in an inventive radiating device with two additional reflectors at the side of the radiator tube, and

7 shows in cross section a further embodiment of the radiator module according to the invention for use in an irradiation device according to the invention with a reflector, in which two side wings are connected to the reflector.

FIG. 1 shows an irradiation device for the irradiation of plants, to which the reference numeral 1 is assigned overall. The irradiation device 1 is intended for floor cultivation and comprises a housing 15 with five plant modules (floors) arranged above one another for growing plants, of which only two plant modules 10, 20 are shown in FIG. 1 for the purpose of simplification. The plant modules, not shown, are identical to the plant modules 10, 20 formed. On both side walls 16, 17 of the housing in each case a reflector foil 18a, 18b is applied. The plant modules 10, 20 comprise a carrier element 2 and a space B arranged above the carrier element 2, which has electric lines and mounting elements, and the emitter zone Z arranged below the installation space. The carrier element 2 is filled with soil and planted with several plants 3. The surface of the planted support element defines an attachment level E. The radiator zone Z is located above the mounting plane E. In the radiator zone Z LED strips 4a, 4b, 4c are arranged, which emit substantially optical radiation 5 with wavelengths in the visible and in the ultraviolet range. In the radiator zone Z, a plurality of radiator modules 7 for irradiating the plants with infrared radiation 6 are likewise provided. The radiator modules 7 have an infrared radiator 8, wherein each infrared radiator 8 is assigned an irradiation area F on the cultivation plane, which is indicated by dashed lines 6, which symbolize the infrared radiation. The infrared radiators 8 are each designed for a nominal power of 100 watts at a nominal voltage of 15 volts. They have a cylindrical radiator tube of quartz glass with an outer diameter of 13.7 mm and a radiator tube length of 240 mm. The mounting plane E facing side of the radiator tube has an average roughness of 3.5 μιτι on; it acts as a diffuser. Within the radiator tube, a Heizfilament is arranged, which is operated at nominal power at a temperature of 900 ° C.

On the side of the infrared radiator 8 facing away from the mounting plane E, a reflector 9 is arranged, which reduces the propagation of the infrared radiation emitted by the respective infrared radiator 8 upwards in the direction of the installation space B and laterally in the direction of the LED strips 4a, 4b, 4c. The reflectors 9 each extend parallel to their associated infrared radiator 8 and have a length of 390 mm and a width of 120 mm. The reflector 9 has a mirror-symmetrical reflector base body, wherein the surface shape of a symmetry half is described in section through a parabola. With the reflector 9, two side wings 9a, 9b are connected. Both side wings 9a, 9b each enclose an angle of 30 ° with the horizontal. The surface of the side facing the infrared radiator 8 of the reflector 9 and the side wings 9a, 9b is made of hammered aluminum; it has a diffuse reflective effect.

In an alternative embodiment it is provided that a reflector strip of gold running in the direction of the longitudinal axis is applied to a lateral region of the lateral surface of the emitter tube, as well as another reflector strip being mirror-symmetrical thereto. These reflector strips reduce the radiation of infrared radiation 6 in the direction of the installation space and of the other radiation sources in the emitter zone. The reflector strip in each case covers a circular arc of the radiator tube cross-section which, with a horizontal line passing through the center of the filament, covers a coverage angle between 2 ° and + 25 °, wherein the smaller angular amount is assigned to the occupancy below the horizontal.

In the direction of the longitudinal axes of the infrared radiator 8 a plurality of identical radiator modules 7 are arranged one behind the other (not shown). Adjacent infra-red radiators 8 have a distance of 1.54 m in the direction of their longitudinal axis. The distance parallel, adjacent infrared radiators perpendicular to the direction of their longitudinal axes is 1.65 m. To the cultivation level E, the infrared radiators at a distance of 1, 0 m.

The infrared radiator 8 are in the emitter zone Z so ordered to each other, 10 that their radiator tube longitudinal axes parallel to each other; they are arranged side by side, in the sense that they begin and end on the same longitudinal position of the illumination field. The number of infrared radiators with respect to the surface of the cultivation plane amounts to 0.4 m ^2. In addition, the infrared radiators 8 are arranged in the emitter zone Z such that their areas of irradiation F laterally overlap so that the average irradiance on the cultivation plane 30 watts / m ² .

FIG. 2 shows a raytracing simulation of the irradiation intensity with infrared radiation of a second embodiment of the irradiation device 200 according to the invention for the irradiation of plants. FIG. 2 shows the irradiation intensity at the plant level at a distance of 1 m from the infrared radiators in W / mm ² .

The raytracing simulation on which the irradiation device 200 has four juxtaposed plant tables 201, 202, 203, 204, which together define the cultivation level of the irradiation device. Everyone who

25 plant tables 201, 202, 203, 204 has a length of 6 m and a width of

1, 65 m. Above each plant table 201, 202, 203, 204, five radiator modules 205 each having an infrared radiator are arranged in a radiator zone Z. In relation to the cultivation level, the number of infrared radiators is about 0,5 m ^"2. The nominal power of the infrared radiator (at a nominal voltage of

30 1 15 V) is 96 W. The infrared radiator is characterized by a radiator tube length of 260 mm, a radiator tube outer diameter of 10 mm and by a disposed within the radiator tube heating filament. The distance between the infrared radiators and the cultivation level is 1, 0 m. The side of the radiator tube facing away from the mounting plane E is assigned a reflector according to FIG. At the same height of the emitter zone Z, a plurality of LED strips are arranged for emitting radiation in the ultraviolet and visible range (not shown). In order to ensure a homogeneous irradiation intensity, a reflective inner lining 206, 207 are respectively provided on two side walls of the irradiation device 200. Diagram 209 also shows, as viewed in the longitudinal direction of plant table 202, the course of the irradiation intensity in W / mm ² along a center axis 208 of plant table 202. Diagram 21 1 shows the course of the irradiation intensity along a center axis 210 of irradiation device 202. The mean irradiation intensity based on the total cultivation level E is 27 W / m ² , with a minimum irradiation intensity of 20 W / m ² and a maximum irradiation intensity of 32 W / m ² .

FIG. 3 shows an embodiment of a radiator module 300 for irradiating plants with infrared radiation for use in an irradiation device according to the invention. The radiator module 300 comprises an infrared radiator 301 with a radiator longitudinal axis 305 and a reflector 302.

The infrared radiator 301 has a cylindrical radiator tube 303 made of quartz glass and a heating filament 304 arranged inside the radiator tube 303. The infrared radiator features a radiator tube length of 270 mm and an outside diameter of 10 mm. The heating filament 304 is made of tungsten wire. The length of the heating filament 304 is 240 mm. The

Nominal power of the radiator is 96 W, at a nominal voltage of 1 15 V.

The reflector 302 has a length of 350 mm in the direction of the longitudinal axis of the radiator 305 and a width of 94 mm perpendicular thereto. The reflector 302 is mirror-symmetrical. The reflector surface of a mirror half has a curvature whose course can be described by a conic with the equation y ² = 2Rx- (k + 1) x ² . (The conic constant k is -1, the radius of curvature R is 132 mm.) The distance B of the reflector to the central axis of the radiator tube 303 is 7.5 mm 6 are the same reference numerals as used in Figure 3, so are identically constructed or equivalent components and components referred to, as explained in more detail above with reference to the description of the embodiment of the lamp unit according to the invention according to FIG.

The radiator module 400 comprises an infrared radiator 301 with a radiator tube 303 and a heating filament 304 disposed therein, and a reflector 302. The length A of the heating filament 304 is 240 mm. The radiator tube 303 has a roughened surface an average roughness Ra of 3.5 μιτι on. Figure 5 shows a cross section of a radiator module 500 according to the invention with an infrared radiator 501, on the radiator tube two reflector strips 503a, 503b are additionally applied.

The infrared radiator 501 has a cylindrical radiator tube 503 made of quartz glass and a heating filament arranged inside the radiator tube 503 (not shown). The nominal power of the infrared radiator (at a nominal voltage of 1 15 V) is 96 W. It has a radiator tube length of 260 mm and an outside diameter of 10 mm. On the radiator tube 503 two reflector strips are applied in the form of a gold coating, which extends in the direction of the radiator tube longitudinal axis. The width of the reflector strip 503b is designed so that it covers a circular arc, which is described by an angle range α between - 5 ° and + 22 °, starting from a horizontal axis 510, which is associated with the angle 0 °. The reflector strip 503a is arranged mirror-symmetrically to the reflector strip 503b; it covers a circular arc with an angular range α between 158 ° and 185 °. By the two reflector strips 503a, 503b, the radiation is infrared Reduces radiation in the direction of the installation space and laterally in the direction of the UV-A / IS radiation sources in the radiator zone, which, for example, a longer life of the radiation sources arranged there is ensured. FIG. 6 shows a cross section of a radiator module 600 according to the invention with an infrared radiator 601 with two additional reflectors 603a, 603b mounted on the side of the radiator tube.

The infrared radiator has a cylindrical radiator tube of quartz glass and an inside, disposed at the bottom of the radiator tube heating filament 604 on. The nominal power of the infrared radiator (at a nominal voltage of 1 15 V) is 96 W. It has a radiator tube length of 260 mm and an outside diameter of 10 mm. The two lateral reflectors 603a, 603b are arranged so that they cover with a horizontal through the center of the filament an angle α of 28 ° above the horizontal and thus minimize the radiation upward in the non-covered by the upper reflector 602 angle range. The angle of the lateral reflectors 603a, 603b to the horizontal is 55 °, the distance of the side reflectors 603a, 603b from the radiator tube is at the shortest point 3 mm. The distance from the central axis of the radiator tube to the upper reflector 602, whose outer dimensions are 120 x 390 mm ² , is 15 mm. The shape of the upper reflector is described by a parabolic conic, with a radius of curvature of 1 15 mm.

FIG. 7 illustrates in cross section a further embodiment of a radiator module 700 according to the invention for use in an irradiation device according to the invention. The emitter module 700 comprises an infrared emitter 301 and a reflector 702, wherein two reflective side wings 703a, 703b are connected to the reflector 702. The two side wings 703a, 703b are arranged so as to enclose an angle of 30 ° with a horizontal. They have a width C of 84 mm. The width D of the reflector is 88 mm. Both the side wings 603a, 603b and the reflector 702 have a Length of 338 mm. The arrangement of the side wings 703a, 703b reduces the radiation of infrared radiation upward in the direction of the construction space and laterally in the direction of the UV-A / IS radiation sources in the emission zone

Claims

Patent claims

Irradiation device for irradiating plants, comprising a support element defining a cultivation plane E for cultivating the plants, several radiation sources for irradiating the plants with visible and / or ultraviolet radiation and several infrared radiators for irradiating the plants with infrared radiation, characterized in that the infrared radiators for a temperature from 800 ° C to 1,800 ° C and each have a cylindrical radiator tube with a radiator tube length in the range of 50 mm to 500 mm, and that the radiator tubes extend parallel to one another in a radiator zone Z located above the mounting level E, whereby the infrared radiator occupancy density based on the area of the cultivation level E is in the range between 0.2 m ^"2 and 1.0 m ^"2 , and irradiation areas of neighboring infrared radiators on the cultivation level E overlap in such a way that the average irradiance on the cultivation level E between 10 watts/m ² and 100 watts/m ² with a fluctuation range of a maximum of 50%, and that a reflector facing an installation space B is assigned to an upper side of the radiator tube.

Irradiation device according to claim 1, characterized in that the average irradiance on the cultivation level is 10 watts/m ² to 50 watts/m ² .

Irradiation device according to claim 1 or 2, characterized in that the infrared radiator heating filaments are designed for a temperature of 850 °C to 1,500 °C.

Irradiation device according to one of the preceding claims, characterized in that several infrared radiators are arranged one behind the other in the direction of their longitudinal axes, and that adjacent infrared Red radiators have a distance from one another between 0.9 m and 2.3 m, preferably between 1.1 m and 1.7 m, in the direction of their longitudinal axis.

5. Irradiation device according to one of the preceding claims,

characterized in that adjacent infrared radiators arranged parallel to one another are at a distance from one another between 1 m to 3 m, preferably between 1.3 m to 2.5 m, particularly preferably between 1.5 m to 1.8 m.

6. Irradiation device according to one of the preceding claims,

characterized in that the infrared radiators are at a distance from the cultivation level in the range of 1.0 m ± 0.5 m.

7. Irradiation device according to one of the preceding claims,

characterized in that the reflector - viewed in the direction of the longitudinal axis - has a length in the range between 70 mm and 650 mm, preferably between 250 mm and 450 mm and a width in the range between 50 mm and 160 mm, preferably in the range between 80 mm and 130 mm.

8. Irradiation device according to one of the preceding claims,

characterized in that the reflector has a diffusely reflecting surface.

9. Irradiation device according to claim 8, characterized in that the surface is made of hammered aluminum.

10. Irradiation device according to one of the preceding claims,

characterized in that a first reflector strip running in the direction of the longitudinal axis is applied to a lateral area of the lateral surface of the radiator tube.

1 1 . Irradiation device according to claim 10, characterized in that the reflector strip is made of gold, opaque quartz glass or ceramic.

12. Irradiation device according to one of the preceding claims 10 or 1 1, characterized in that the radiator tube has a circular cross section, wherein the first reflector strip covers a circular arc of the radiator tube, which has a coverage angle between -40 ° and + with a horizontal running through the filament center 40°, preferably between -30° and +30°.

13. Irradiation device according to claim 12, characterized in that a further reflector strip is applied to the lateral surface, which is arranged mirror-symmetrically to the first reflector strip to a vertical running through a filament center.

14. Irradiation device according to one of the preceding claims 10 to 13, characterized in that the reflector strip has a diffusely reflecting surface.

15. Irradiation device according to one of the preceding claims, characterized in that additional reflectors are arranged on the side of the radiator tube, each in a reflector plane, the reflector planes enclosing an angle of between 25 ° to 70 ° with the horizontal and their dimensions and distance from the radiator tube are set in this way that they prevent direct radiation of the infrared radiation emitted by the infrared radiator into a spatial area which, starting from a filament center of the radiator tube, is described by two planes, each of which forms an angle between -40° and +40°, preferably between -30°, with the horizontal and +30°.

16. Irradiation device according to one of the preceding claims, characterized in that two side wings are connected to the reflector, the side wings each enclosing an angle in the range between 20° to 40° with the horizontal.

17. Irradiation device according to one of the preceding claims,

characterized in that the reflector achieves mirror symmetry ner reflector mirror plane, with the shape of a symmetry half of the reflector being described by a conic section in a sectional view perpendicular to the reflector mirror plane, with the reflector tapering towards the center in the direction of the radiator tube.

18. Irradiation device according to one of the preceding claims,

characterized in that at least part of the surface of the radiator tube acts as a diffuser and diffusely scatters incident radiation.

19. Irradiation device according to claim 16, characterized in that the radiator tube has a roughened surface acting as a diffuser with an average roughness Ra, the average roughness Ra in the range between 0.3 μm and 10 μm, preferably between 0.8 μm and 3 μητι, lies.

20. Irradiation device according to one of the preceding claims,

characterized in that the irradiation device comprises a housing with side walls, with a reflector film being applied to at least one of the side walls.

21. Irradiation device according to one of the preceding claims, characterized in that the fluctuation range is a maximum of 20%, preferably a maximum of 10%, of the average irradiance.

22. Radiator module for irradiating plants with infrared radiation for use in a radiation device according to one of claims 1 to 18, comprising an infrared radiator, characterized in that the infrared radiator has a cylindrical radiator tube with a radiator tube longitudinal axis, a radiator tube length of 50 mm to 500 mm, preferably from 150 mm to 350 mm, and a heating filament arranged therein and designed for a temperature of 800 ° C to 1,800 ° C, with a reflector being assigned to one side of the radiator tube.