Description:

The invention relates to a device for disinfecting leaf-shaped products such as, for example, leafy-vegetable and/or herb leaves.

US2015/0305396 discloses a device for sanitizing and packaging foodstuffs such as blueberries. The foodstuffs to be treated by the known device are, inter alia, fruit and vegetables, but the device known therefrom is not, or in any case less, suitable for disinfecting leaf-shaped products such as leafy-vegetable and/or herb leaves.

Leaf-shaped products such as leafy-vegetable and/or herb leaves have a surface area per unit weight that is much greater than most vegetables such as root vegetables or fruiting vegetables, and also in relation to fruit, for example, as a result of which the orientation thereof on the conveyor belt is difficult to predict and/or to adjust.

The device known from US2015/0305396 comprises a sanitizing station through which the blueberries are progressed in a conveying direction by means of a conveyor belt. The sanitizing station has pulsed UV light sources in order to produce a disinfecting effect on the blueberries conveyed through the sanitizing station. In order to maximize the use of pulsed UV light, the use of reflectors or reflective surfaces in the known sanitizing station is proposed without further details or indications being given. Ultraviolet (UV) light is electromagnetic radiation just outside the part of the spectrum that is visible to the human eye. The wavelength of ultraviolet is between 100 and 400 nanometers. US2015/0305396 does not describe the use of UV-C light sources. UV-C light has a wavelength between 100 and 280 nm and is also referred to as shortwave radiation with a limited penetration depth. Because of the limited penetration depth together with the unknown orientation of leaf-shaped products on a conveying device, shadow cast in relation to the UV-C light sources plays an important limiting role in achieving a high level of disinfection and/or a high level of uniform disinfection in leaf-shaped products.

An object of the present invention is to provide a device that disinfects leaf-shaped products by means of UV-C light efficiently and/or effectively in an energy saving manner and/or in a structurally relatively simple manner. This object is achieved by virtue of the features of a device as defined in claim 1.

The device is provided with a housing and with at least one conveying device by means of which the leaf-shaped products are conveyed between an inlet and an outlet of the housing, wherein one or more UV-C light sources are arranged above the conveying device at a height from the conveying device when viewed from a base surface on which the device is positioned, wherein at least one portion of inner wall portions of the housing that are directed toward the conveying device is designed to reflect UV-C light by more than 50%.

In order to be able to perform by means of the one or more UV-C light sources effective disinfection of the leaf-shaped products, which are typically oriented irregularly with respect to the one or more UV-C light sources, when the device is in operation, at least one portion of inner wall portions of the housing that are directed toward the conveying device is designed to reflect UV-C light from the one or more UV-C light sources by more than 50%. In this way, it is possible for the conveying device, and in particular the product thereon, to be illuminated by UV-C light from more directions, as a result of which the possible irregular orientation or unfavorable orientation of the product with respect to the one or more UV-C light sources on the conveying device now has less or even no effect on achieving a desired disinfection result on the leaf-shaped products. By virtue of the UV-C-reflective inner wall portions of the housing, no, or in any case fewer, UV-C light sources have to be positioned next to, along and/or under the conveying device because the UV-C-reflective inner wall portions reflect the UV-C light from the one or more UV-C light sources so as to disinfect the product on the conveying device as if one or more UV-C light sources were positioned on the side next to, along and/or under the conveying device. Furthermore, the use of the inner wall portions of the housing directed toward the conveying device requires no, or only minimal, structural modification and requires no additional UV-C reflectors or other components with a UV-C-reflective surface to be added to the device, thereby providing a relatively simple and compact device in which a UV-C disinfection process of leaf-shaped products can be implemented efficiently and effectively. An additional advantage is that the relatively limited number of UV-C light sources needed uses relatively little power in operation, as a result of which the device is relatively economical to run without this being to the detriment of the disinfection result on the leaf-shaped products. In one aspect, the at least one portion and/or another portion of the inner wall portions of the housing that are directed toward the conveying device are/is designed to reflect UV-C by more than 70% in order to increase the effectiveness of the UV-C reflection in the UV-C disinfection process of the leaf-shaped products. A given portion of the inner wall portions may therefore have a UV-C reflectivity of at least 50%, while the other portion may have a UV-C reflectivity of at least 70%. The at least one portion and/or another portion of the inner wall portions may be made of or coated with a highly UV-C light-reflective material such as, for example, aluminum (UV-C reflection > 70%) and/or polytetrafluoroethylene (PTFE) (UV-C reflection > 90%). It is advantageous to position the UV-C light sources at a height, for example at least 30 cm, above the conveying device so as to reduce or even eliminate the risk of the relatively lightweight leaf-shaped products such as herbs/leaves, which therefore might flutter around in the device, ending up on the UV- C light sources and at least partly covering them, which might negatively affect the disinfection process performed in the device using UV-C light. By choosing a minimum height, such undesired shading of the UV-C light sources may be prevented, or at least minimized, in a relatively straightforward manner. In this way, it is also possible to reduce, or even possibly virtually eliminate, the risk of leaf-shaped products that have been on the UV-C light sources for a short or long time falling back onto the conveying device and thereby forming undesired contamination in the end product. The device is particularly suitable for disinfecting dried, or virtually dried, leaf-shaped products or, if the leaf-shaped products have been washed beforehand, dry, or virtually dry, leaf shaped products.

The at least one portion of the inner wall portions of the housing that are directed toward the conveying device may comprise at least the inner wall portions that are arranged under the one or more UV-C light sources, in particular inner wall portions of side walls of the housing that run between the inlet and the outlet (of the housing). What is meant by the inner wall portions under the one or more UV-C light sources is the inner wall portions running from the one or more UV-C light sources in the direction of the base surface and potentially inner wall portions of the housing bottom. In this way, maximum reflection of UV-C light toward the conveying device in the device can be achieved. In particular, the side walls of the housing between which the elongate conveying device runs form the largest surface of the housing under the UV-C light sources. In this way, inner wall portions of these side walls may contribute substantially to maximum UV-C reflection for an effective disinfection process of leaf- shaped products in the device. The at least one portion of the inner wall portions of the housing that are directed toward the conveying device, in particular the side walls thereof, may be designed to maximize UV-C reflection in the direction of the product on the conveying device when in operation. For example, the at least one portion of the inner wall portions of the housing that are directed toward the conveying device, in particular the side walls of the housing, may be configured so as to be at least partially curved and/or have at least one kink so that, by virtue of the design of the inner wall portions, UV-C light is maximally reflected toward the leaf-shaped products on a conveying surface of the conveying device. Additionally, the inner wall portions of the housing bottom and/or of the housing top may comprise a design, such as at least one bend and/or at least one kink, for maximizing reflection of UV-C light toward the leaf-shaped products on a conveying surface of the conveying device in the device.

The one or more UV-C light sources may be arranged at a height from the conveying device that is at least 25% of the width of a substantially longitudinally running conveying surface of the conveying device, and preferably at least 40% of the width of the conveying surface of the conveying device. Such a height related to the width of the substantially longitudinally running conveying surface of the conveying device ensures that the UV-C light sources, together with the inner wall portions of the housing that are directed toward the conveying device that are described above, distribute UV-C light in a relatively uniform and homogeneous manner over the width of the conveying surface so as to carry out a relatively effective and efficient disinfection process of the leaf-shaped products on the conveying surface. Additionally, by virtue of such a height difference between the UV-C light sources and the conveying surface of the conveying device, the undesired shading of the UV-C light sources caused by leaf-shaped products as already described above may be prevented, or at least minimized, in a relatively straightforward manner.

Furthermore, the conveying device may be a conveyor belt which is, for example, provided with an endless belt wrapped around rollers. The conveying device may comprise a conveying surface and at least one moving mechanism that is provided in order to intermittently move at least one portion of the conveying surface on which the leaf-shaped products are conveyed in a direction that is substantially transverse to the conveying surface in a direction away from the base surface in order to move, mix (scramble together) and/or turn the leaf-shaped products conveyed by the conveying device off the conveying surface. By means of the moving mechanism, the conveyed product may be intermittently moved substantially vertically. By virtue of the moving mechanism, it is possible to prevent, in the case of leaf-shaped products lying on the conveying surface in bulk with many leaves potentially lying on top of one another, resulting in substantial shading, that not only the uppermost leaves are treated with (reflected) UV-C light. By virtue of the intermittent vertical movements of the conveying surface of the conveying device, the leaf-shaped products are thrown upward with a certain frequency so that the (reflected) UV-C light may treat all sides of the leaf-shaped products during the upward movement. Additionally, the leaves may be turned over by this movement produced by the moving mechanism so that both the upper side and underside of the leaf may be illuminated in turn by UV-C light. The moving mechanism may comprise, for example, a beater moving longitudinally and intermittently in the vertical direction or arranged at an angle with respect to the conveying direction of the conveying device, for example at right angles with respect to the conveying direction, or a rotating beater, or a rotating vibration motor or a vibration motor moving in the longitudinal direction. By adjusting the frequency, amplitude and angle of the moving mechanism to produce the previously mentioned intermittent vertical movement of the leaf-shaped products, a mixing of the leaf-shaped products may also take place such that those leaf-shaped products which are at the bottom of a bulk flow on the conveying surface can be moved to the top of the bulk flow and vice versa, and such that even mixing takes place and uniform treatment by (reflected) UV-C light is promoted. A movement of the leaf-shaped products in a direction that is substantially transverse to the conveying surface in a direction away from the base surface provided by the moving mechanism and/or the frequency of the moving mechanism for the intermittent movement may be adjustable by means of a controller, wherein the controller is manually settable and/or can be communicatively connected to at least one sensor to, at least partly, automatically adjust the moving mechanism. The sensor may, for example, visually recognize the type of leaf-shaped products such as the type of herbs or the type of leaves and/or the distribution and/or quantity and/or concentrations on the conveying surface and/or orientation of the product on the conveying surface of the conveying device and transmit this information to the controller for automatic adjustment of the moving mechanism.

In one aspect, a maximum movement of the leaf-shaped products provided by the moving mechanism in a direction that is substantially transverse to the conveying surface and away from the base surface with respect to the conveying surface is at most 40% of the width of the substantially longitudinally running conveying surface, and preferably at most 25% of the width of the conveying surface. By limiting the maximum movement heightwise with respect to the conveying surface, the process of the vertical movement of the leaf-shaped products can be better controlled and predicted so that a maximum surface area of each leaf-shaped product can be effectively disinfected by means of UV-C. In addition, limiting the substantially vertical movement of the leaf-shaped products with respect to the width during operation prevents the UV-C light sources from being able to be reached by the leaf shaped products and/or reduces the risk of at least some of the leaf-shaped products falling next to the conveying surface, which is obviously undesirable. Lastly, by limiting the movement of the leaf-shaped products in a vertical direction with respect to the conveying surface as provided by the moving mechanism, the device may be made relatively compact.

In another aspect, a conveying surface of the conveying device is provided with perforations and/or gaps so that UV-C light can pass through the conveying surface, and in particular the conveying surface is formed by a mesh strip. UV-C light that passes through the perforations and/or gaps may be reflected by, for example, UV-C-reflective portions of the housing bottom in the direction of the leaf shaped products carried on the conveying surface. In this way, a larger surface area of the leaf-shaped products can be disinfected by means of UV-C light. The reflection of UV-C passing through the conveying surface can be further maximized by providing a reflector between the base surface and a conveying surface of the conveying device, by means of which UV-C light can be reflected directly or indirectly via the UV-C- reflective inner wall portions in the direction of the conveying surface. Such a reflector may be provided a short distance beneath the conveying surface, and may be designed with at least one kink or at least one curved reflective surface, for example, to direct UV-C light (directly or indirectly) toward the leaf-shaped products on the conveying surface.

Instead of the moving mechanism described above or in addition thereto, it is possible, in the housing of the device, for the conveying device to be provided with conveying device sections in line with one another, wherein an end of a first conveying device section of the conveying device sections is arranged higher with respect to the base surface than a beginning of a second conveying device section of the conveying device sections in order to convey the leaf-shaped products conveyed by means of the first conveying device section in a conveying direction to the second conveying device section under the effect of gravity. In this way, the falling leaf-shaped products can turn over between the transport sections so that all sides of the product are treated with UV-C light as it falls. By turning, another surface of the leaf-shaped products can come to rest on the conveying surface of the next transport section, allowing a relatively effective further UV-C treatment of another surface of the leaf-shaped products to take place. Also in this way, in the case of a bulk flow, advantageous mixing as already described above may be provided.

Furthermore, at least the first conveying device section may be arranged at an angle a with respect to a horizontal surface so that the end of the first conveying device section is arranged higher than a beginning of the first conveying device section, and preferably the angle a is between 10-30 degrees, even more preferably between 15-20 degrees. With such an embodiment, the falling of the leaf-shaped products can be achieved in a compact embodiment of the device, because the required (installation) height for such an arrangement of the conveying device sections in the housing is limited. The end of the first conveying device section of the conveying device sections may be arranged 20-70 cm higher with respect to the base surface than the beginning of the second conveying device section, and preferably 30-60 cm higher. Tests show that such a height is particularly suitable for rotating the leaf shaped products as they fall and for achieving effective mixing so that the surface of each leaf-shaped product can be disinfected by UV-C light effectively and efficiently.

In one particular aspect, the inlet is formed by a feed hopper and/or the outlet is formed by a discharge hopper, wherein the inner wall portions of the feed hopper and/or the discharge hopper are designed to be at least 60% UV-C-light absorbent, for example by making or coating the inner wall portions of or with a UV-C- light absorbent material such as, for example, stainless steel and/or glass. In such a way, it is possible to create an operator-safe environment around the device since UV- C light cannot or virtually cannot escape from the device through the UV-C-absorbent inner wall portions of the feed hopper and/or the discharge hopper. In addition, the design of the feed hopper and/or the discharge hopper may contribute to no UV-C light that is harmful to humans escaping from the device.

In another aspect, the UV-C light sources may be elongate and/or point like UV-C light sources arranged at a distance from one another, wherein the horizontal distance between two outermost UV-C light sources across the width of the elongate conveying device is equal to or greater than the width of the conveying device. By virtue of such an arrangement, homogeneous UV-C illumination can be achieved over the entire width of a substantially longitudinally running conveying surface of the conveying device. The two outermost UV-C light sources may be arranged at a lower height with respect to the base surface than UV-C light sources arranged centrally between the two outermost UV-C light sources. The UV-C light sources arranged at a distance from one another may substantially follow a pattern in the form of a portion of a cylinder wall profile with respect to the conveying device. Such a pattern, together with the UV-C-reflective inner wall portions or other features of the device as described above, provides a device by means of which a relatively high output of leaf-shaped products completely or virtually completely disinfected by UV-C light is achieved. By virtue of the pattern and the UV-C-reflective inner wall portions, the radiation dose may be distributed more uniformly over the total surface of the conveying surface and over the leaf-shaped product. In one structurally relatively simple embodiment, elongate UV-C light sources arranged at a distance from one another run substantially in the conveying direction. With such an arrangement, the advantageous pattern mentioned above is relatively straightforward to achieve.

Lastly, the invention also relates to the use of a device for disinfecting leaf-shaped products such as, for example, leafy-vegetable and/or herb leaves as described and shown herein.

The aspects described in this document will be explained below by means of exemplary embodiments in combination with the figures. However, the invention is not limited to the exemplary embodiments described below. Rather, a number of variants and modifications are possible which likewise use the inventive idea and thus fall within the scope of protection. In particular, the possibility of combining the features/aspects which have only been mentioned in the description and/or illustrated in the figures with the features of the claims or features shown in other figures insofar as compatible is mentioned.

Reference will be made to the following figures, in which:

Fig. 1A schematically shows a longitudinal section of a portion of a first embodiment of the device for disinfecting leaf-shaped products such as leafy- vegetable and/or herb leaves;

Fig. 1 B schematically shows a front view of the device shown in figure 1A; Fig. 2A schematically shows a longitudinal section of a portion of a second embodiment of the device;

Fig. 2B schematically shows a front view of the device shown in figure

2A;

Figs. 3A-C show various cross sections of various shapes for a housing of various embodiments of the device;

Fig. 4 shows a perspective view of a portion of a fifth embodiment of the device;

Fig. 5 schematically shows a longitudinal section of a portion of a sixth embodiment of the device.

In the figures, identical parts are provided with the same reference numerals.

Figures 1-5 schematically show the components of the device for a person skilled in the art in order to clarify the operation of the device 1 ; 101; 201 ; 301 ; 401; 501 for disinfecting leaf-shaped products. The device 1 ; 101 ; 201 ; 301 ; 401 ; 501 is an industrial device for disinfecting leaf-shaped products on an industrial scale. The device 1; 101; 201 ; 301 ; 401; 501 is provided with a housing 5; 205; 305; 405; 505 and with at least one conveying device which, in the figures, is formed by (but not limited to) a conveyor belt 7; 407; 507, by means of which the leaf-shaped products are conveyed between an inlet 9; 409; 509 and an outlet 11; 511 of the housing in a conveying direction P1 , wherein, viewed from a base surface (not shown) on which the device is positioned, various UV-C light sources 13; 113 are arranged above the conveyor belt 7; 407; 507 at a height with respect to the conveyor belt 7; 407; 507, wherein at least one portion of the inner wall portions 15; 215; 315; 415; 515 of the housing that are directed toward the conveyor belt 7; 407; 507 is designed to reflect UV-C light by more than 50%. The conveyor belt 7; 407; 507 is provided with an endless belt 10; 510a, 510b, 510c wrapped around rollers 6, 8; 506a, 508a. Instead of the conveyor belt shown, another suitable conveying device may be chosen.

By virtue of the UV-C-reflective inner wall portions 15; 215; 315; 415; 515 of the housing, no UV-C light sources are positioned next to, along and/or under the conveyor belt 7; 407; 507. Furthermore, the use of such inner wall portions 15; 215; 315; 415; 515 requires no, or only minimal, structural modification, thereby providing a relatively simple and compact device in which a UV-C disinfection process of leaf-shaped products can be implemented efficiently and effectively. The UV-C disinfection process can be further promoted if the at least one portion and/or another portion of the inner wall portions 15; 215; 315; 415; 515 of the housing that are directed toward the conveyor belt 7; 407; 507 are/is designed to reflect UV-C light by more than 70%. The at least one portion and/or another portion of the inner wall portions may be made of or coated with a highly UV-C light-reflective material such as, for example, aluminum (UV-C reflection > 70%) and/or polytetrafluoroethylene (PTFE) (UV-C reflection > 90%).

The UV-C light sources 13; 113 are individually arranged at a height, for example at least 30 cm, above the conveyor belt 7; 407; 507. Advantageously, the UV- C light sources 13; 113 may, as described in this document, be arranged at a height H1 with respect to the conveyor belt 7; 407; 507 that is at least 25% of the width B1 of a substantially longitudinally running (in the direction shown by the arrow P1) conveying surface 18; 418; 518a-c of the conveyor belt 7; 407; 507, and is preferably at least 40% of the width B1.

The device 1 shown in figures 1A,B and 3A differs from the device 101 shown in figures 2A,B only in that the UV-C light sources are elongate 13 or point-like 113 UV-C light sources arranged at a distance from one another. What is meant by point-like in this document is a UV-C light source with relatively small dimensions and the point-like UV-C light sources 113 are here only shown as an alternative to the elongate UV-C light sources 13. Elongate UV-C light sources 13 are also shown in the device 401 shown in figure 4. Figure 5 also has elongate UV-C light sources similar to those in figure 4, but these UV-C light sources are not shown in figure 5. Figures 2A, 2B show a pattern of the UV-C light sources 113 that is similar to the pattern shown for the elongate UV-C light sources 13. The elongate UV-C light sources 13 may, for example, be known fluorescent tubes that emit UV-C. However, it is also possible for the elongate UV-C light sources 13 to be formed by UV-C LEDs. The UV-C light sources 113 may likewise be UV-C LEDs. It is further possible to position the elongate UV-C light sources transverse to the conveying direction P1 (not shown), resulting in a similar pattern as in figures 2A and 2B, but then with at least one elongate UV-C light source that runs as indicated by the arrow A1 in figure 2B, wherein, viewed in the conveying direction, at least a second and a third elongate UV-C light source may be arranged at a distance therefrom in order to simulate UV-C illumination that is similar to the arrangement shown in in figures 2A, 2B. The UV-C light sources described in this document further comprise reflectors known per se in order to direct the UV-C light downward, and in this document more particularly in the direction of the conveyor belt 7; 407; 507. The horizontal distance A1 across the width of the elongate conveyor belt between two outermost UV-C light sources 13; 113 viewed from the conveying direction P1 is equal to or greater than the width of the conveyor belt 7; 407. By virtue of such an arrangement of the UV-C light sources 13; 113, homogeneous UV-C illumination can be achieved over the entire width of the substantially longitudinally running conveying surface 18; 418; 518a-c of the conveyor belt. As visible in the figures, the two outermost UV-C light sources (between which the distance A1 is shown in the figures) are arranged at a lower height with respect to the base surface/conveying surface than UV-C light sources arranged centrally between the two outermost UV-C light sources. The UV-C light sources 13; 113 arranged at a distance from one another substantially follow a pattern (crescent) in the form of a portion of a cylinder wall profile with respect to the conveyor belt 7; 407. This crescent pattern is clearly visible in figures 1 B, 2B, 3A-C and 4. By virtue of such a pattern, together with the UV-C-reflective inner wall portions, leaf-shaped products can be disinfected by UV-C light effectively and efficiently. By virtue of the elongate UV-C light sources 13 preferably arranged at a regular distance from one another, the pattern shown can be produced in a structurally relatively straightforward manner and maintenance on the device is minimal because of the relatively limited number of UV-C light sources 13.

The conveyor belt 7; 407; 507 comprises the conveying surface 18; 418; 518a-c on which the leaf-shaped products lie when in operation and at least one moving mechanism 20A-D; 420A,B that is provided in order to intermittently move at least one portion of the conveying surface on which the leaf-shaped products are conveyed in a direction that is substantially transverse to the conveying surface 18; 418; 518a-c in a vertical direction away from the base surface in order to move, mix (scramble together) and/or turn the conveyed leaf-shaped products off the conveying surface 18; 418; 518a-c. Figures 1A and 2A show four moving mechanisms 20A-D and three moving mechanisms 20A-D, respectively, merely to show that the number of moving mechanisms may be variable. To obtain a uniform (vertical) movement of the leaf-shaped products on the conveying surface 18; 418 in order to give an even UV-C radiation dose to the leaf-shaped products when in operation, the moving mechanisms can be arranged at a regular distance with respect to one another under the conveying surface 18; 418 in the housing 5; 205; 305; 405; 505 as shown in figures 1A and 4. Although not shown in figure 5, the conveyor belt, and more particularly each conveyor belt section 507a-c, can be provided with moving mechanisms. By means of the moving mechanisms, the conveyed product may be intermittently moved substantially vertically. By virtue of the moving mechanisms, it is possible to prevent, in the case of leaf-shaped products lying on the conveying surface in bulk with many leaves potentially lying on top of one another, resulting in substantial shading, that not only the uppermost leaves are treated with (reflected) UV-C light. By virtue of the intermittent vertical movements of the conveying surface, the leaf-shaped products are thrown upward with a certain frequency so that the (reflected) UV-C light may treat all sides of the leaf-shaped products during the upward movement. Additionally, the leaf shaped products may be turned over by these movements produced by the moving mechanisms 20A-D; 420A,B so that both the upper side and underside of the product to be treated may be illuminated in turn by UV-C light. By adjusting the frequency, amplitude and angle of the moving mechanisms 20A-D; 420A,B to produce the previously mentioned intermittent vertical movement of the leaf-shaped products, a mixing of the leaf-shaped products may also take place such that those leaf-shaped products which are at the bottom of a bulk flow on the conveying surface 18; 418; 518a-c can be moved to the top of the bulk flow and vice versa, and such that even mixing takes place and uniform treatment by UV-C light is promoted. The moving mechanisms may be adjustable by means of a controller 425. Such a controller is only shown in figure 4, but may be provided in each device 1 ; 101; 201 ; 301 ; 401 ; 501. The controller 425 can communicate with at least one sensor 430 which is again shown only in figure 4, but such a sensor may be present in all of the devices shown. The sensor 430 may, for example, visually recognize the type of herbs or leaves and/or the distribution and/or quantity and/or concentrations on the conveying surface and/or orientation of the product on the conveying surface of the conveying device and transmit this information to the controller for automatic adjustment of the moving mechanism 20A-D; 420A,B.

Figures 3B, 3C and 4 show that inner wall portions of the housing 205; 305; 405 that are directed toward the conveying surface 18; 418 may be designed to maximize UV-C reflection in the direction of the product on the conveying surface 18; 418 when in operation. For example, the inner wall portions of the housing may be made curved as shown in figure 3C and/or be made with kinks as shown in figures 3B and 4 so that, by virtue of the design of the inner wall portions, UV-C light can be maximally reflected toward the leaf-shaped products on the conveying surface 18; 418. In addition, the inner wall portions of the housing bottom (not shown) and/or of the housing top (figures 3B, 3C and 5) may be designed similarly to maximize reflection of UV-C light toward the leaf-shaped products on a conveying surface. In the devices shown in the figures, a particular design of the housing bottom has a minimal effect because the distance between the conveying surface 18; 418 and the inner wall portions is minimal, even zero in the device shown in figure 4, resulting in very little or even no UV-C light reaching the housing bottom. If this distance is greater, the housing bottom can be provided with a suitable design in order to more effectively reflect UV- C light toward the conveyor belt directly or indirectly via the UV-C-reflective inner wall portions.

As shown in figures 1 B and 2B, a conveying surface 18 can be provided with schematically shown perforations/openings 30 so that UV-C light can pass through the conveying surface. UV-C light that passes through the perforations may be reflected by, for example, UV-C-reflective portions of the housing bottom in the direction of the leaf-shaped products carried on the conveying surface. The reflection of UV-C passing through the conveying surface can potentially be further maximized by providing a reflector (not shown) between the base surface and a conveying surface of the conveying device, by means of which UV-C light can be reflected in the direction of the conveying surface.

Instead of the moving mechanism described above or in addition thereto, it is possible, in the housing of the device 501 , for the conveying device 507 to be provided with conveyor belt sections 507a-c in line with one another in the conveying direction P1. In this case, an end 514a, 514b of a first/second conveyor belt section 507a, b is arranged higher with respect to the base surface than a beginning 516b, 516c of a second/third conveyor belt section 507b, c in order to convey the leaf-shaped products conveyed by means of the preceding conveyor belt section 507a, b in a conveying direction P1 to the next conveyor belt section 507b, c under the effect of gravity (represented by the arrow P2). In this way, the falling leaf-shaped products will be treated with UV-C light between the transport sections and turn over so that another surface of the leaf-shaped products can come to rest on the conveying surface 518b, 518c, allowing a relatively effective UV-C treatment of the surface of the leaf-shaped products to take place. Also in this way, in the case of a bulk flow, advantageous mixing as already described above may be provided. The conveying surfaces 518a, 518b, 518c run substantially horizontally. The height difference between the end and beginning of the next conveyor belt section 507b, c is 20-70 cm, preferably 30-60 cm.

Although not shown in the figures, at least a first conveying device section is arranged at an angle a with respect to a horizontal surface so that the end of the first conveying device section is arranged higher than a beginning of the first conveying device section, and preferably the angle a is between 10-30 degrees, even more preferably between 15-20 degrees. In this way, each beginning of a conveying device section can be arranged at virtually the same height with respect to a horizontal base surface. In one particular aspect which is shown only in figure 5, but which is applicable to each device 1; 101 ; 201 ; 301 ; 401 ; 501 shown, the inlet of the housing is formed by a feed hopper 509 and the outlet is formed by a discharge hopper 511 , wherein the inner wall portions of the feed hopper and the discharge hopper are designed to be at least 60% UV-C-light absorbent, for example by making or coating the inner wall portions of or with a UV-C-light absorbent material such as, for example, stainless steel and/or glass. In this way, it is possible to create an operator-safe environment around the device. In addition, the design of the feed hopper and the discharge hopper may contribute to no UV-C light that is harmful to humans escaping from the device.