PROCEDURE FOR COLD-PEELING TUBEROUS VEGETABLES USING A SUITABLE INDUSTRIAL KNIFE PEELER

Description

2 drums are fitted. A number of knives are provided in the casing of the drum with which the potatoes are further peeled. However, when using such knife peelers, typically too much material is peeled off the potatoes, so that an undesirable amount of product is lost. The potatoes are also not always peeled evenly, so that it becomes clear that the potatoes have not been peeled by hand and so that the quality is lower. Moreover, when knives become blunter, they damage the potatoes instead of cutting them properly. A knife peeler with one or more peeling discs that can be rotated and arranged around a vertical axis is typically used for peeling tuber crops other than potatoes. It also appears that when similar knife peelers are used for peeling potatoes, too much material is peeled away, resulting in an undesirable amount of product being lost and the quality of the final product not being optimal.15 The purpose of the invention is therefore to provide an alternative method for the cold peeling of tuber crops, such as potatoes, whereby less material of the tuber crops is peeled away and the quality of the end product is better. 20 The purpose of the invention is achieved by providing a knife peeler with one or more peeling discs for peeling tuber crops, such as potatoes, where each peeling disc is rotatably arranged around vertical axes and is provided with knives for peeling tuber crops applied to an upper surface of the peeling disc, where these knives are arranged adjacent to corresponding openings, for the discharge through these openings and through the peeling disc of peels that are peeled from the tuber crops and where each knife is provided on a side wall of a respective opening, where a blade of the knife is located under a extending at an acute angle relative to the top surface, whereby a cutting edge of this 30 knife is positioned above the top surface.BE2024 / 5883 3 With this modified knife peeler, root vegetables, and more specifically potatoes, can now be peeled with less product material loss, while also achieving better quality of the final product. The pores of the root vegetables close better during peeling, so that the peeled surface matches hand-cut root vegetables, such as hand-cut potatoes, more beautifully. Each blade of such a modified knife peeler preferably extends through the respective opening and is preferably attached to the said side wall, for example by means of screws, bolts, or the like. In alternative design forms, it is possible to form blades by folding the peeling discs when forming the said openings in these peeling discs and thereby forming a cutting edge on parts folded upwards. However, it is preferred to provide knives as separate parts15 that are attached to the peeling disc.The materials from which both are manufactured can then be better optimized for the different requirements of the peeling discs and blades. When worn, blades can be easily replaced, while the peeling disc can continue to serve. More specifically, the peeling disc can, for example, be manufactured from stainless steel, but is preferably manufactured from inox so that breakage is avoided even during prolonged use and so that such a peeling disc is easily cleanable with standard cleaning products without damage occurring. Such a blade can, for example, be manufactured from stainless steel, but is preferably manufactured from carbide, so that it needs to be replaced less frequently than blades from existing peelers. Such a carbide blade can easily last longer than a year, whereas blades from existing peelers need to be replaced after only about 2 months.BE2024 / 5883 4 Each blade of a peeling knife adapted for the invention preferably extends further to below a lower surface of the peeling disc, which is positioned opposite the upper surface, this for the strength and durability of such a blade. The blades of a peeling knife adapted for the invention preferably extend radially into the peeling disc, to increase the efficiency of peeling. These knives preferably extend almost over the radius of such a peeling disc. Furthermore, all knives in such a peeling disc preferably have the same dimensions in order to limit costs and simplify maintenance, so that only one type of replacement knife needs to be available.10 The height over which the cutting edge of the knife extends above the top surface is preferably about 0.4 mm, but depending on the volume to be processed per hour and the types and quality of the tuber crops, the ideal conditions may vary. The cutting edge of each knife is therefore preferably positioned at an adjustable height above the15 top surface.This height can, for example, be made adjustable by providing such a blade with a mounting slot attached to the corresponding side wall using one or more spacers. By then placing one or more spacers between the blade and the side wall when attaching a blade, it can be ensured that the cutting edge can be adjusted to a lower or higher position. When the cutting edge is positioned lower, less peel will be removed, whereas more peel is removed when the cutting edge is positioned higher. Preferably, one or more stainless steel spacer plates are provided as spacers. In alternative designs, it is possible, for example, to provide such a blade with mounting slots to achieve a corresponding height adjustment. The angle at which the blade of a knife extends relative to the top surface is preferably between 50° and 65°, is more preferably between 30°, 55° and 60°, and is extremely preferably approximately 57°.BE2024 / 5883 5 Each opening is preferably bounded opposite the mentioned side wall by a second side wall, which extends at a sharp angle relative to the top surface. In this way, such an opening is executed tapering from the bottom surface to the top surface, whereby it is executed narrower at the top surface than at the bottom surface. Because the opening widens towards the bottom, peels can be discharged more easily downwards. For production purposes, the angle at which this side wall extends is preferably equal to the angle at which the first-mentioned side wall extends. With a knife that has a constant thickness at the height of the blade, when this knife is attached to this first-mentioned side wall—possibly with one or more spacers of constant thickness between them—the blade will also extend at this same angle. Each peeling slice of a peeler blade adapted for the invention is preferably provided with one or more relief elements to form a height difference between blades relative to the top surface.Such a relief element can be specifically designed as a relief plate attached to the top surface. Such a relief element is preferably provided with a rising rolling surface so that, when rotating the respective peeling disc, the tubers are rotated against this rolling surface by this relief element during rolling. With such a relief element, a height difference between 1.5 mm and 3 mm is preferably realized relative to the top surface, and more preferably a bearing of approximately 2 mm, so that the tubers remain rounder during peeling. 25 A particularly good result for the cold peeling of tuber crops, such as potatoes, is achieved when they are first scraped with the aid of a scraping machine and then peeled with a knife peeler adapted for this purpose described above, in accordance with the invention. This invention is therefore more specifically achieved by providing in an assembly of a scraping machine for the30 scraping of tuber crops and a knife peeler described above for the BE2024 / 5883 6 peeling of the tuber crops after scraping them.For this purpose, a roller scraper is preferably used as a scraping machine, such as, for example, a roller scraper described above that is commercialized by the firm DeBruyne NV. 5 The objective of the invention is further achieved by providing a method for the cold peeling of tuber crops, such as potatoes, with the aid of a knife peeler with one or more peeling discs adapted for the invention described above. Preferably, the tuber crops, such as potatoes, are first scraped for this purpose10 with the aid of the said scraping machine from the assembly mentioned above, before they are peeled with the aid of a knife peeler. More specifically, raw tubers, such as potatoes, are preferably washed first without further treatment, then scraped with a scraping machine and subsequently cut with a knife peeler. Furthermore, it is also possible to further cut the tubers, such as potatoes, for example with the aid of a water knife, which cuts a tuber into fries.Such a water knife is a liquid pump internally equipped with a knife, with which potatoes pumped into water by the liquid pump are cut using this knife. The tubers, whether or not in further cut form, are then preferably brought into contact with cold water at a temperature between 0 and 2°C. Afterwards, the cut tubers (whether or not in further cut form) can be packed in the desired quantities, for example per 5 or 10 kg. In this way, the tubers are neither brought into contact with steam, nor brought into contact with drying coolers or the like, but only brought into contact with water, cold cut and packed. This invention is now further explained on the basis of the detailed description below of some preferred forms of execution of a method for peeling tubers using a knife peeler with adapted peeling discs according to this invention.The purpose of this description BE2024 / 5883 7 is solely to provide clarifying examples and to indicate further advantages and particulars of this invention, and cannot therefore be interpreted as a limitation of the scope of application of the invention or of the patent rights claimed in the claims. 5 In this detailed description reference is made by means of reference figures to the drawings attached hereto, in which: -Figure 1 a knife peeler adapted with peeling discs for peeling tubers in accordance with the invention is schematically represented in perspective; 10 -Figure 2 a peeling disc from the knife peeler in Figure 1 is represented separately in perspective; -Figure 3 the peeling disc from Figure 2 is shown in top view; -Figure 4 shows a part of the peeling disc from Figure 2 in cross-section at the level of a knife attached to it.15 In this detailed description it is described how potatoes can be cold-peeled according to a design according to the invention.Mutatis mutandis this can also apply to other tuber crops. 20 Potatoes are stored raw in a silo. Preferably without further treatment, they are removed from the silo and washed with water. Washed potatoes are then preferably scraped with a scraping machine, for which a roller scraping machine can be chosen more specifically, for example a roller scraping machine commercialized by the firm De Bruyne NV. After the potatoes have been pretreated in this or an alternative equivalent way to remove the dirt, they are further peeled using a knife peeler (1) with peeling discs (2) adapted according to the invention. Less preferable, the potatoes could also be peeled directly with a similar knife peeler (1), after washing them, but without the BE2024 / 5883 8 scraper. However, a better result is obtained by first scraping the potato and then peeling it with a knife peeler (1).As a knife peeler(1), an existing knife peeler(1) can be chosen, however, the known peeling discs(2) are replaced by, for example, the 5 depicted peeling discs(2) or alternative designs according to the invention. Given that the construction of such a knife peeler(1) is otherwise known, and alternative knife peelers according to the state of the art are also known, this knife peeler(1) itself is only shown schematically here. 10 In a known knife peeler(1), tubers to be peeled, such as potatoes, are fed into a peeling tunnel(15) at the beginning of the knife peeler(1). In a known example of such a knife peeler(2), these tubers are fed over the peeling discs(2) for this purpose, for example, by an adjustable chain with carriers.15 In the schematic representation shown, this peeling tunnel(15) has been opened up to provide a view of the peeling discs(2). In practice, however, this peeling tunnel(15) is preferably constructed in a closed manner.In such a knife peeler(1), one or more peeling discs(2) are each rotatably arranged around a vertical axis(R). Depending on the quality of the tuber crops to be peeled, such as potatoes, these peeling discs(2) can be driven by motors to rotate between 400 and 850 revolutions per minute. Each peeling disc(2) is equipped with knives(5), as shown in figures 2-4, which are inserted through respective openings(9) in the peeling disc(2). Peeling waste can be discharged through these openings(9) and collected in a space(16) under the peeling discs(2) and transported from there to a side stream. The openings(9) are bounded on the first side by a first side wall30 (10) and on the second side by a second side wall(11), where these side walls BE2024 / 5883 9 (10,11) extend at an acute angle(α) relative to the top surface(3) of the shell disc(2). This angle(α) is between 50° and 65°, is more preferably bearing between 55° and 60° and is extremely preferably bearing about 57°.Each knife(5) is attached to a respective side wall(10) of the respective opening(9), for example by means of screws(12). One blade(7) of the knife(5) also extends at the same sharp angle(α) relative to the top surface(3) of the peeling disc(2). In an alternative design, the said side walls(10,11) do not both need to extend at the said angle(α), as long as the knife(5) can be attached to the opening(9) at the said angle(α). By widening the opening(9) downwards, peels from potatoes placed on the top surface(3) of the rotating peeling disc(2) can be more easily discharged downwards through the opening(9). As shown in Figure 4, stainless steel spacer plates (8) are preferably provided, 15 which allow the height (h) at which the cutting edge (6) of the blade (5) is positioned above the top surface (3) of the peeling disc (3) to be adjusted. For example, this height (h) is preferably 0.4 mm when one spacer plate (8) is placed between the blade (5) and the respective side wall (10).By omitting this spacer plate(8), the blade(5) can be positioned higher, for example at a height(h) of 0.6 mm above the top surface(3). By adding an additional spacer plate(8), the blade(5) can be positioned lower, for example at a height(h) of 0.2 mm above the top surface(3). Each blade(5) extends above the top surface(3) of the peeling disc(2) to extend with its cutting edge(6) above this top surface(3) and preferably also extends below the bottom surface(4) of the peeling disc(2). In the design shown, all blades(5) extend radially into the peeling disc(2) to peel the potatoes more efficiently. In alternative designs, blades(5) can also be positioned radially relative to the BE2024 / 5883. Each blade(5) preferably extends as far as possible over the radius of the peeling disc(2), whereby the length of the corresponding opening(9) is limited depending on the necessary strength for attaching the peeling disc(2) to incorporate it rotatably around the vertical axis(R) into the blade peeler(1).In alternative designs shorter blades(5)5 can also be provided, where possibly several blades(5) can be arranged spread over the radius of the peeling disc(2). Alternating with blades(5), the peeling disc(2) is preferably also provided with one or more relief elements(13). With such a relief element(13), a height difference(Δx) is formed relative to the top surface(3) of the peeling disc(2), in order to make potatoes placed on this top surface(3) roll. The relief elements(13) give potatoes an uncontrollable rotation, causing them to come into contact with blades(5) themselves at different points each time. This results in them being stripped of their skins with optimally set parameters.15 The height difference(Δx) is preferably between 1.5 mm and 3 mm above the top surface(3) and more specifically preferably about 2 mm.Such a relief element(13) preferably comprises a rising rolling surface(14) so ​​that when the peeling disc(2) rotates, the potatoes are rotated by this relief element(13) when rolling against this rolling surface(14), without damaging the potatoes. In the design shown, the relief element(13) is designed as a relief plate(13) which is attached with the help of screws(12) on top of the upper surface(3) of the peeling disc(2). In alternative designs, the relief element can optionally be formed integrally with the peeling disc, whereby this relief element can rise relative to the said upper surface, or alternatively can be provided as a cavity provided at the top of the peeling disc(2) which opens into the upper surface. Finally.