DK201870289A1

DK201870289A1 - A food grating apparatus

Info

Publication number: DK201870289A1
Application number: DKPA201870289A
Authority: DK
Inventors: Simonsen Steen
Original assignee: Siccadania A/S
Priority date: 2018-05-14
Filing date: 2018-05-14
Publication date: 2020-01-03
Also published as: WO2019219140A2; WO2019219140A3; DK180024B1

Abstract

A food grating apparatus (1) comprises a housing (2), a grating roller (7) arranged rotatable about its axis (8) below a top wall (9) of an upper housing part of the housing (4), which top wall (9) has an inlet (3) for receiving food objects to be grated, and a bottom housing part (6) below the grating roller (7) is configured for receiving grated food objects, characterized in that the food grating apparatus (1) comprises a sieve component (31) arranged in the bottom housing part (6) below the grating roller (7), which sieve component (31) has a curvature conforming to the curvature of the grating roller (7).

Description

The present invention relates to a food grating apparatus comprising a housing, a grating roller arranged rotatable about its axis below a top wall of an upper housing part of the housing, which top wall has an inlet for receiving food objects to be grated, and a bottom housing part below the grating roller is configured for receiving grated matter.

A food grating apparatus may be constructed to downsize food objects into pulp and/or to destroy the cell structure of the food objects in order to harvest valuable components. Such components can be soluble, suspended or dispersed inside the cells of the food object. For example a food grating apparatus may be constructed for grating root crops, such as for recovering and producing starch from food objects, such as potatoes or manioc roots. In the production of starch, starch grains in the cells of the food objects are to be released by grating, separated, washed and dried. When the starch grains are to be released, the food objects are disintegrated by means of a food grating apparatus.

European patent no. EP 1796839 Bl describes a food grating apparatus of the above-mentioned kind.

This known food grating apparatus comprises an essentially square housing, seen in cross-section, which provides an axially extending radial wedge-shaped gap between the interior face of the housing and the grating surface of the grating roller at both parallel vertical sides of the food grating apparatus. During operation of the food grating apparatus the food objects to be grated are thrown in direction of one of these wedge-shaped gaps and are wedged between the interior face of the housing and the grating surface of the grating roller and are thereby pressed against the grating roller. Due to the square design of the known food grating apparatus, the axially extending radial wedge-shaped gap between the interior face of the housing and the grating surface of the grating

DK 2018 70289 A1 roller is large, and at the initial part after the inlet little guidance of the food objects are provided. This means that the effective portion of the radial gap is relatively short, thus where the food objects to be grated are grated by being pressed between the interior face of the housing and the grating surface of the grating roller. This also means that a large part of the food objects to be grated are thrown back into the space above the grating roller without being grated, at least in the first instance, hence resulting in a reduced production capacity of the food grating apparatus.

Furthermore, the known food grating apparatus comprises a simple and relatively large inlet to the housing for introducing the food objects, such as potatoes. When the food objects are introduced into the apparatus through the inlet they tend to bounce against rasping blades on the rotating grating roller instead of being initially grated, and some of the food objects are even thrown back towards and up the inlet.

Furthermore, the above-mentioned patent describes a grating roller for the food grating apparatus. The known grating roller has circumferential spaced axially extending grooves for holding radially protruding rasping blades, and axially extending partitions between said axially extending grooves, wherein the width, seen in the circumferential direction, of the grooves, increases at a short part of a groove depth of the axially extending grooves. The partitions have their predetermined minimum width in a depth which is positioned less than 60% of the groove depth from the periphery of the grating roller. However the closer the minimum width is located to the periphery of the grating roller the less goods of partitions to counter-act the centrifugal force when the grating roller rotates. So the closer the minimum width is located to the periphery of the grating roller the more vulnerable the partitions are for keeping the rasping blades in position during rotation of the grating roller.

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In a main aspect of the present invention is provided a food grating apparatus of the kind mentioned in the opening paragraph with an increased grating capacity compared to conventional food grating apparatuses.

In a further aspect is provided a food grating apparatus of the kind mentioned in the opening paragraph, which is simple to maintain and has a high level of maintainability.

In a further aspect is provided a food grating apparatus of the kind mentioned in the opening paragraph, wherein the food objects are being guided towards and forced into a grating gap.

In a further aspect is provided a food grating apparatus of the kind mentioned in the opening paragraph, wherein the grating roller offers improved properties in terms of space and guidance for insertion and attaching the rasping blades in the grooves of the grating roller.

In a further aspect is provided a food grating apparatus of the kind mentioned in the opening paragraph, wherein the partitions between the axially extending grooves of the grating roller has high strength to keep the rasping blades inside the grooves when the grating roller rotates.

In a further aspect is provided a food grating apparatus of the kind mentioned in the opening paragraph, wherein the discharge, output and/or yield of grated food objects and derivable constituents of the food objects are improved compared to conventional food grating apparatuses.

The novel and unique whereby these and other aspects are achieved according to the present invention consist in that the food grating apparatus comprises a sieve component arranged in below the grating roller, which sieve component has a curvature conforming to the curvature of the grating roller. The sieve

DK 2018 70289 A1 component is arranged the bottom housing part below the grating roller so that the cavity of the sieve component faces the grating roller.

Within the scope of the present invention a “food grating apparatus is to be understood as an apparatus for reducing a food object, such as a potato, in size to small shreds or particles by contacting a grater, such as a grating roller, preferably to derive valuable constituents, such as starch, from the grated food objects.

Within the scope of the present invention the term “axially extending means parallel to the rotation axis of the grating roller.

Within the scope of the present invention the term “radially extending means following a radius of the cross-section of the grating roller.

Within the scope of the present invention the term “conform used in relation to the sieve component having a curvature “conforming to the curvature of the grating roller means that the curvature of the sieve component follows the curvature of the grating roller. E.g. the cross-section of the grating roller may be a circle concentric with the larger circle including the sector of a circle taken through the curved sieve component.

Depending on the choice of mesh of the curved sieve component, said curved sieve component can serve several different or combined purposes. One function is to separate the desired products from the residues of the grating product, e.g. pulp, that cannot pass through the sieve component but leaves the sieve component at the end of said sieve component, seen in the rotational direction of the grating roller, at which end the

DK 2018 70289 A1 residues pass further down the bottom housing part in view of leaving the grating apparatus via the outlet.

The sieve component may have a larger radius than a radius of the grating roller.

A final grating step may in some embodiments, even take place in the narrow radial gap between the grating roller and the sieve component due to the action of the rotating rasping blades passing the sieve component. It should however be emphasized that rasping blades are out of direct contact with the sieve component. Said narrow radial gap may thus define a maximum size of finally grated matter, which are allowed to pass along the sieve component and leave the food grating apparatus via the outlet.

The sieve component may be pivotably hinged at one end to the housing. In this way the sieve component can be pivoted between an operation position in close proximity of the grating roller and a cleaning, maintenance, and/or setup position, where it is swung away from the grating roller. Further, it is possible to replace the sieve component or at least part of it, and to clean the grating roller. In the alternative the sieve component can be demounted in full for maintenance of the food grating apparatus and cleaning of the sieve component.

In a preferred embodiment the sieve component may comprise a first curved sieve component part pivotable hinged at one end to a second curved sieve component part, and a curved sieve part inserted between the first curved sieve component part and the second curved sieve component part. So in addition to the sieve component being pivotably hinged below the grating roller, e.g. by being hinged to the housing or a separate frame part, the first curved sieve component part and the second curved sieve component part are also pivotably hinged to one

DK 2018 70289 A1 another thereby facilitating that the curved sieve part can be taken out for cleaning or replacement in case of clogging.

The first curved sieve component part and the second curved sieve component part may include, but are not limited to, together constituting a rib-shaped holder for the curved sieve part. Spaced apart parallel curved ribs along the length of the first curved sieve component part and the second curved sieve component part suffice for supporting the curved sieve part and leaves space for passing of matter through the mesh of the curved sieve part. In case the sieve part is a bendable netting or filter the curved rib-shaped holder provides the sieve part with a corresponding requisite curvature that makes the sieve part conform to the grating roller.

Advantageously the sieve part can have mesh openings of between 0.5 and 20 mm, preferably 1 - 15 mm and more preferred between 1.5 - 10 mm. Any specific diameter in the range between 1.5 mm and 10 mm can be a specific mesh diameter or mesh width. The mesh size may however differ, need not be uniform, and be selected in accordance with the particle size allowed to pass through. For example the sieve component may only allow liquid, solubles and dispersions to pass, and not pulp.

The sieve component may for some crops quickly be blocked by grated mash or even worn, and in order to keep costs down for replacing the sieve component and for maintenance, it may, as described above, be preferred that the sieve component is comprised of a sieve part and a rib-shaped holder for supporting the sieve part and for keeping the sieve part from deflection when subjected to radial forces during operation of the food grating apparatus. The rib-shaped holder keeps the sieve part in place and close to the grating roller.

The rib-shaped holder may be pivotably hinged at one end to the housing and the sieve part be arranged more or less loose in

DK 2018 70289 A1 relation to the rib-shaped holder, or the sieve part can be attached or be attachable to the rib-shaped holder. For example the sieve part is simply a sieving sheet confined between two opposite curved rib-walls of the first curved sieve component part and the second curved sieve component part, respectively, of the rib-shaped holder. In this way only the sieve part needs to be replaced. So the sieve part may be flexible and the ribshaped holder rigid to be used to provide the sieve part its curvature along the grating roller. Yet an advantage is that sieve parts of different kinds, structure, material, flexibility and mesh size can be accommodated in the same ribshaped holder.

The above described sieve component principle may be used in other apparatuses, and are thus not limited to use in the food apparatuses of the present invention.

The grating roller may have a first grating surface facing an interior face of the top wall of the housing to delimit an axially extending radial gap between said first grating surface and said interior face. When the top wall is curved the axially extending radial gap becomes narrow faster than in known grating apparatuses.

So if the top wall has a summit wall section including an axially extending maximum radial gap, the summit wall section can extend into a continuously curved wall section where said axially extending radial gap continuously decreases, wherein the continuously curved wall section converges towards the first grating surface towards an axially extending minimum radial gap.

At least in the rotation direction of said grating roller the top wall is thus configured as an arc that delimits a continuously reduced distance to the grating roller. During rotation of the grating roller the food objects pass into the

DK 2018 70289 A1 direction of rotation along the axially extending radial gap from the inlet via the axially extending maximum radial gap further along the axially extending radial gap between said first grating surface and said interior face and into the axially extending minimum radial gap. During the passage the food objects are compacted more and more the closer the food objects get to the axially extending minimum radial gap. The result is an optimizing of contact of food objects with the grating roller, and improved and fast initial crushing of the food objects, which crushing becomes finer the closer the crushed mass gets to the axially extending minimum radial gap. The food objects are thus transformed from solid objects into a course mash before being grated into a fine product the closer the food objects get to the axially extending minimum radial gap, so at to recover constituents, e.g. starch from potatoes. The continuously curved wall section has no sharp edges that increase the axially extending radial gap on the food objects path to the axially extending minimum radial gap. The level of compacting of food objects brought along by the rotation of the grating roller increases towards the axially extending minimum radial gap.

The continuously curved wall section provides the upper housing part with smaller cross-sectional area than the square crosssection or rectangular cross-section of the upper housing part of conventional food grating apparatuses. In particular the conventional food grating apparatuses have box-shaped upper housing parts with sharp interior corners. In contrast thereto the wall of the upper housing part of the food grating apparatus of the present invention has a continuous curvature that continuously and gradually reduces the axially extending radial gap between at least an angular sector of the top wall in the direction of rotation of the grating roller and the grating surface of said grating roller.

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An axially extending radial gap may be provided on both opposite sides of the grating roller and be tapering opposite the summit section towards a diameter of the grating roller which is parallel to a plane being tangent to the summit section. By changing the square corner (s) of the box-shaped conventional upper housing part to a curving corner, preferably a smoothly curving corner, the upper housing part is given a convex cross-sectional curvature wherein the axially extending radial gap becomes narrow much closer to the summit section than in the prior art, whereby food objects are guided faster and under more control down into the axially extending radial gap and are wedged between the grating surface and the interior surface substantially closer to the summit sections than wedging possibly can take place in a square upper housing part. The result is early and instantaneous crushing of food objects substantially at the inlet, or at least when the food objects leaves the summit wall section.

The tapering axially extending radial gap may be seen as having the shape of a wedge for improved wedging of food objects to be grated. Within the scope of the present invention the term wedge-shaped is thus to be understood as a shape where the distance between two opposing surfaces decreases, or in other words a shape involving two surfaces that converge towards each other .

In order to provide a lengthwise extended axially extending radial gap between the interior face of the housing and the grating surface of the grating roller, the continuously curved wall section may extend into a tangential wall section. The lengthwise extended axially extending radial gap serves to further squeeze and grate the pre-grated food objects due to the axially extending minimum radial gap being located between the interior face of the tangential wall section and the first grating surface. Extending the travel distance for food objects

DK 2018 70289 A1 through a long axially extending minimum radial gap at the tangential wall section prolongs crushing/grating time.

The cross-section of the upper top wall may have any appropriate shape, however it is preferred that it is U-shaped, semi-circular or semi-oval. If the cross-section of the upper top wall of the upper housing part is e.g. U-shaped the opposite tangential wall sections can be constituted by the free end of the legs of the U, the summit wall section be the bottom of the U, and the continuously curved wall sections be the curved parts of the U between the bottom and the legs. The length of the legs and the radius of the continuously curved wall section may decide the size of the axially extending radial gap. The continuously curved wall section may be circular so that when the grating roller is positioned below the summit wall section the center of the continuously curved wall section is off-center, such as above, the center of the grating roller when the food grating apparatus is placed on e.g. a horizontal or substantial horizontal surface.

In a system of co-ordinates placed in the upper housing part of a food grating apparatus situated at a horizontal surface the origio is at the axis of rotation of the grating roller, the zaxis is said axis of rotation of the grating roller, the y-axis is horizontal and the x-axis extends as normal to the horizontal surface through the inlet. In the first quadrant of system of co-ordinates the summit wall section may continue an angle from the y-axis of about 2-10°, and the continuously curved wall section may extend the subsequent 80-88. The corresponding configuration located in the fourth quadrant may be same or different.

The top wall of the upper housing part can be formed e.g. simply by bending a plate into a half cylinder and closing the ends, or be molded into shape.

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The axis of rotation of the grating roller may in such an arrangement be substantially parallel to a surface where the food grating apparatus is set up to operate, preferably horizontal.

The food grating apparatus may include at least one axially extending grating block that has a second grating surface facing the first grating surface. An axially extending grating gap may be delimited between the second grating surface and the first grating surface, wherein the at least one grating block may be arranged to provide an axially extending grating gap in extension of the axially extending minimum radial gap, which axially extending grating gap is smaller than the axially extending minimum radial gap to further downsize the crushed and grated food objects.

The food grating apparatus may preferably have two axially extending grating blocks; one at each opposite axially extending minimum radial gap so that choice of rotation direction is not a limiting parameter for a set-up. The axially extending grating gap, which is narrower than the axially extending radial gap, improves final downsizing of the pregraded food objects, which pre-grating took place at the axially extending radial gap wherefrom the grating gap receives pre-grated food objects to a level and degree that derives much more valuable constituents than possible with known food grating apparatuses.

The position of the axially extending grating block(s), and hence the axially extending grating gap(s) may be adjustable so that the food grating apparatus of the present invention can be adjusted for grating various kinds and sizes of food objects.

It is preferred that a rotation direction of the grating roller is reversible which means that the food grating apparatus is efficient irrespective of rotation direction. Opposing axially

DK 2018 70289 A1 extending radial gaps and axially extending grating gaps parallel to the axis of the grating roller can be used alternatively and as desired simply by setting the rotation direction. Reversal of the rotation direction may also be 5 useful if a grating gap is plugged or obstructed by incoming raw food objects. Yet an advantage is that the operational time of the food grating apparatus between replacement or turning of the rasping blades may be increased.

It is further preferred that the axially extending grating gap between the second grating surface and the first grating surface is substantially the same along the angular length of the second grating surface to obtain a degree of standardization of the grating process, a.o. in view of product quality and product parameters of the output product(s) from the axially extending grating gap, parameters such as texture and resulting particle size.

The inlet of the food grating apparatus may be an axially 20 extending opening provided in the summit wall section, which inlet can be provided with a food object supply inlet duct for guiding a flow from a food object supply line of food objects to be grated inside the upper housing part. The larger the inlet the more raw food objects can be supplied to the axially 25 extending radial gap, and by providing the inlet along the axis of the grating roller the raw food objects can be supplied and distributed directly into the axially extending radial gap.

The inlet duct may optionally have axially extending opposite 30 longitudinal side walls diverging from the inlet, thereby configuring the inlet duct as a hopper having an entry that expediently guides the raw food objects from the food object supply line towards the inlet.

The opposite end walls between the axially extending opposite diverging longitudinal side walls may optionally converge so

DK 2018 70289 A1 that these end walls can serve as baffles in the event that any raw food objects rebound from the rotating grating roller up the inlet for possibly being thrown out of the inlet duct, and so that the inlet to the inlet duct has a smaller crosssectional area than the inlet to the housing.

So the above efficiency of keeping the raw food objects from jumping up and down above the grating roller and guiding the raw food objects towards and inside the axially extending radial gap towards the grating gap may be further improved if

the inlet duct has sectional area than an	an outlet inlet end.	end having a	larger cross
In	contrast to	the	prior	art	apparatus the	food grating

apparatus of the present invention may thus utilize a simple mechanical obstacle for raw materials being grated from being thrown out of the inlet of the apparatus. In this way a grating process is achieved which is much more effective than hitherto known .

The above described inlet duct may be used in other food grating apparatuses regardless of whether the top wall is designed according to the present invention: with a summit wall section including an axially extending maximum radial gap, which summit wall section extends via a continuously curved wall section where said axially extending radial gap continuously decreases and where the continuously curved wall section converges towards the first grating surface towards an axially extending minimum radial gap, as described above or not. The design of the inlet duct can be, but need not, depend on the design of the food grating apparatus, and in particular not on functional features such as the compacting function of the axially extending radial gap and of the grating gap. The inlet duct may be used for other purposes and installations.

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Any known grating roller may be used for the food grating apparatus according to the present invention. The speed of the grating and level of downsizing can however be improved by using a grating roller that has circumferential spaced axially extending grooves for holding radially protruding rasping blades, and axially extending partitions between said axially extending grooves.

It has been realized that at least one of food grating quality, deriving of valuable constituent, rotational speed of the grating roller and duration of rasping blades can be improved or increased if the width of the axially extending partitions, seen in the circumferential direction, of the grooves, increases at least a part of a groove depth of the axially extending grooves to an extent where the minimum wall width, seen in the circumferential direction, of the axially extending partitions is positioned at least 70% of a total groove depth from a periphery of the grating roller. A further advantage is the large and sufficient space in the groove for mounting, turning and/or replacing of the rasping blades. In one embodiment the wall width can increase continuously towards the bottom of a groove.

In order to maintain the rasping blades in place in the axially extending grooves of the grating roller, the rasping blades may be clamped between and retained by two axially extending locking strips, one on each side of an axially extending rasping blade. The axially extending locking strips have a shape that fits into said grooves, thus providing good contact surfaces of the locking strips against the partition walls. Typically the outline of an axially extending locking strip closest to the periphery of the grating roll when inserted is complementary to the corresponding outline of an axially extending groove. The locking strips are preferably reversibly orientatable to be reused when rasping blades are replaced or reversed. On rotation of the grating roller, the axially

DK 2018 70289 A1 extending locking strips will be pressed outwards by the centrifugal force, but due to a combined largest width of the opposite locking strips, and the rasping blade being smaller than the width of an axially extending groove at the periphery of the grating roller, the axially extending rasping blades become clamped between the axially extending locking strips when subjected to the centrifugal force and are clamped radially by the axially extending partitions when forced against the walls of the axially extending grooves. No further means may be needed for preventing the axially extending rasping blades from being ejected from the axially extending grooves when the grating roller rotates.

The partitions end in the grating surface so that an exterior portion of a partition, thus an angular section of the periphery of the grating roller between consecutive axially extending rasping blades, is exposed to food objects to be grated. The exterior portions entrain foods objects between axially extending rasping blades.

The exterior portion may radially taper with a first tapering angle into an intermediate portion that radially may taper into a second tapering angle that is smaller than the first tapering angle, thus the radially extending sides of the partitions tapers towards each other and the angular distance reduces, which means that the adjacent grooves becomes wider angularly. At the same time the intermediate portion may extend into an interior portion solid, thus in one piece, with the grating roller and having an increasing width, seen in the circumferential direction. The exterior portion serves as the head of a somewhat mushroom-shaped partition to serve as a breast for keeping the axially extending rasping blades and surrounding axially extending locking strips inside the axially extending grooves.

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Both the interior portion and the exterior portion are wider than the intermediate portion, and because the minimum width is located as close as at least 70% of the depth of the axially extending groove, thus very close to the interior portion, a partition achieves a high strength and is not highly susceptible of rupture and breakage thereby prolonging life time of a grating roller.

The radial lengths of the respective three portions of the partitions may be chosen so that the radial length of the exterior portion constitutes 30 to 45% of the total groove depth, the length of the intermediate portion constitutes 30 to 45% of the total groove depth and the length of the interior portion constitutes 20 to 30% of the total groove depth. The total of the length of the portions of the partitions altogether constitutes 100%. This design provides a strong partition for keeping the axially extending rasping blades and associated surrounding axially extending locking strips inside the associated axially extending grooves. The axially extending grooves have plenty of space and a configuration for easy mounting and/or replacing the axially extending rasping blades as well as for pulling out and inserting the axially extending locking strips from an end of the grating roller on opposite sides of the axially extending rasping blades.

It may be preferred that the first tapering angle, thus the angle between the radially extending sides of the exterior portion of a partition, is about 18 to 22°, preferably 20°, and that the second tapering angle, thus the angle between the radially extending sides of the intermediate portion of a partition, is about 0.5 to 2°, preferably 1°. Hereby is obtained a good fastening of the rasping blades with surrounding locking strips while there is good space at the bottom of the axially extending groove for mounting and/or replacing any of the axially extending rasping blades and/or the axially extending locking strips.

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In order to facilitate the insertion of the axially extending rasping blades and the axially extending locking strips into the axially extending grooves it may be preferred that at the bottom of the groove furthest away from the periphery of the grating roller the axially extending groove is configured with an axially extending narrow guiding track for guiding an axially extending rasping blade with surrounding axially extending locking strips during its axial insertion into the axially extending groove. The guiding track advantageously also take hold of an end of a rasping blade and keeps a rasping blade erected and in substantial same position and orientation, so that the axially extending locking strips on opposite sides of the rasping blade can be inserted very easily and fast. When the grating roller is in operation the rasping blade may leave its guiding track.

It may be preferred that an axially extending groove is symmetrical with respect to a radius of the grating roller which extends through the respective axially extending groove. Further it may be preferred that an axially extending rasping blade and an axially extending locking strip is symmetrical about its longitudinal axis. In this way, the versatility of use arrangements of axially extending rasping blades and axially extending locking strips is highly improved due to being less dependent on orientation. Axially extending rasping blades and axially extending locking strips may easily be reversed, so that a worn free tip or edge of an axially extending rasping blade can be turned inside the axially extending groove and a not worn tip or edge be exposed for grating food objects. Both tips or edges of the rasping blade can easily be used, thus increasing service life of axially extending rasping blades. Due to the special design of axially extending grooves and axially extending partitions replacing or reversing of axially extending rasping blade with surrounding axially extending locking strips takes place fast, at minimum effort and using minimum tools.

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The above described grating roller may be used in any kind of food grating apparatus, and its use is not limited to the food grating apparatus of the present invention.

The invention is illustrated in further details in the drawing and described below in relation to exemplary embodiments, wherein fig. 1 is a perspective view seen from above of a food grating apparatus according to the invention, fig. 2 shows the same from the side, fig. 3 is a cross sectional view according to line III-III in fig. 2 of the upper housing part of a food grating apparatus according to the invention, fig. 4 is a cross sectional view fig. 2 of the bottom housing part according to the invention, with different configurations, according to line IV-IV in of a food grating apparatus the sieve component in two fig. 5 is an exploded perspective view of the sieve component, fig. 6 is an enlarged scale view of the periphery of the grating roller seen from the end, and fig. 7 shows, in an enlarged scale view, a fragment of the periphery of the grating roller seen in fig. 6.

Below the food grating apparatus of the present invention is described by way of example for processing potatoes to derive starch.

Figs. 1 and 2 show a food grating apparatus 1 according to the invention.

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The food grating apparatus 1 comprises a housing 2 having an inlet 3 at an upper housing part 4 and an outlet 5 at a bottom housing part 6. A grating roller 7 (not shown), which will be described in further details below with references to figs. 36, is arranged inside the housing 2 for rotating about its horizontal axis 8.

The grating roller 7 is arranged rotatable about its axis 8 below a top wall 9 of the upper housing part 4 of the housing 2. The top wall 9 has the inlet 3 for receiving potatoes to be grated. The grating roller 7 is driven by a motor 10, such as an electric motor.

The grating roller 7 may be driven in both directions of rotation. The food grating apparatus 1 is supported on a frame structure 11 with leveling feet 12 for adjusting the axis 8 of the grating roller 7 to horizontal, as preferred.

The housing has an inlet duct 13 in communication with the inlet 3 .

The motor 10 can be any conventional motor having sufficient capacity to drive the grating roller 7 for grating food objects, and will not be described in further details below. The grating roller 7 is via a shaft 14 carried in bearings 15, which shaft 14 is connected to the motor 10 via a clutch 16 to rotate the grating roller 7 about its axis 8.

As seen best in figs. 3 and 4 an axially extending radial gap G is delimited between an interior surface 18 of the top wall 9 and the first grating surface 19 of the grating roller 7. The top wall 9 has a summit wall section 20 that includes the largest axially extending radial gap, thus the axially extending maximum radial gap G_max towards the bottom housing part 6 seen in fig. 4.

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The summit wall section 20 extends via a continuously curved wall section 21 where said axially extending radial gap G continuously decreases, and where the continuously curved wall section 21 converges towards a tangential wall section 22 having an axially extending minimum radial gap G_max.

Thus an axially extending radial gap G provides a tapering space between the interior surface 18 of the top wall 9 and the first grating surface 19 of the grating roller 7. The extending radial gap G becomes more and more narrow along at least the continuously curved wall section 21 thereby compacting the potatoes in rotational direction of the grating roller 7 along the axially extending radial gap G much more than possible with known food grating apparatuses, and hereby, the production capacity of the food grating apparatus 1 is increased relative to the known food grating apparatuses.

The cross-section of the continuously curved wall section 21 of the top wall 9 is in the exemplary embodiment a circular sector. The radius of curvature of this circular sector is greater than the radius of curvature of the grating roller 7. The radius of curvature of the grating roller 7 is in the shown embodiment e.g. 550 mm whereas the radius of curvature of the continuously curved wall section 21 is 590 mm. The center of the circular sector offset vertically from the axis 8 of the grating roller 7 with a distance of 200 mm.

Due to the tangential wall section 22 the cross-section of the top wall 9 is an inverted U-shape.

The food grating apparatus 1 has opposite axially extending grating blocks 23a,23b arranged at both sides of the grating roller 7. The grating blocks 23a,23b has a second grating surface 24a,24b facing the first grating surface 19. The grating blocks 23a,23b delimit axially extending grating gaps

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25a,25b in extension of the axially extending minimum radial G_min. The axially extending grating gaps 25a, 25b are smaller than the axially extending minimum radial gap G_min.

In order to facilitate service on and maintenance of the food grating apparatus 1 the housing 2 comprises a gate 4a on at least one side of the upper housing part 4.

During operation of the food grating apparatus 1 the potatoes, are introduced into the inlet duct 13 through the inlet 3 and the potatoes (not shown) drops towards the grating roller 7 to be carried along by the rotation of the grating roller. When the potatoes hit the grating roller 7 they are thrown in any possible direction but the top wall 2 serves for their rebounding towards the grating roller 7, and the further the potatoes get along the axially extending radial gap G towards the grating blocks 23a,23b the more they are crushed and grated by being pressed against the grating roller 7.

The crushed and grated potatoes are maintained in the axially extending radial gap G until the mass is destroyed and the size reduced to an extent that the mass is able to proceed passing by the grating block 23a or 23b depending on the direction of rotation through the narrow gap 24a or 24b between the grating roller 7 and the grating block 23a or 23b. When passing through the narrow gap 24a or 24b between the second grating surface 24a or 24b and the first grating surface 19 the potato mash is further grated by the action of the second grating surface 24a or 24b and the first grating surface 19.

The inlet 3 of the food grating apparatus 1 is an axially extending opening 26 provided in the summit wall section 20. The inlet duct 13 to the opening serves for guiding a flow of potatoes inside the axially extending radial gap G of the upper housing part 4.

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Since the axially extending opening 26 that constitutes the inlet 3 is rectangular an outlet end 27 of the inlet duct 13 may be similarly rectangular, but the opposite inlet end 28 of the inlet duct 13 is, as seen best in fig. 1, circular to easily connect to a food object supply line (not shown) . To that aspect the inlet duct 13 has axially extending opposite longitudinal side walls 29a,29b diverging from the inlet 3 and opposite converging end walls 30a,30b between the axially extending opposite diverging longitudinal side walls 29a, 29b.

The potatoes or other food objects to be grated in the food grating apparatus 1 are conveyed to the inlet duct 13 by means of a food object supply line, which e.g. comprises a screw conveyor and a pipeline (not shown).

The bottom housing part 6 below the grating roller 7 is configured for receiving and separating grated food objects.

An axially extending sieve component 31 is arranged pivotable about a first pivot axis Pl in the bottom housing part 6 below the grating roller 7 between an operating position, as indicated by arrow A, where the sieve component 31 is just below the grating roller 7 and a cleaning and/or setup position, as indicated by arrow B.

To be pivotable the axially extending sieve component 31 is hinged at one end 31 to the housing 2 below an axially extending grating block 23b. In the cleaning and/or setup position 33 the axially extending sieve component 31 is swung away from the grating roller 7.

As seen in greater details in fig. 5, the sieve component 31 comprises a sieve part 32 and a rib-shaped holder 33. The rib shaped holder has a first sieve component part 33a facing the grating roller 7 and an opposite second sieve component part 33b facing away from the grating roller 5. In operation of the

DK 2018 70289 A1 food grating apparatus 1, the sieve part 32 inserted between first sieve component part 33a and the second sieve component part 33b, thereby being attached to the rib-shaped holder 33, constituted by said sieve component parts 33a,33b, which are pivotably hinged together at one end 34 of said sieve component parts 33a,33b to create a second pivot axis P2. When the sieve part 32 are inserted between sieve component parts 33a,33b, said sieve component parts 33a,33b are pivoted away from each other, the sieve part 32 are inserted and the sieve component parts 33a, 33b are closed again. This action can be done while the sieve component 31 is mounted to the housing 2 or when the sieve component 31 is taken off the housing. In this way the time and costs for replacing the sieve part 32 and for cleaning the grating roller may be kept down. The second pivot axis P2 and the first pivot axis Pl are e.g. coaxial when the sieve component 31 is mounted to the housing 2. The sieve part 32 is confined between opposite hinged together first sieve component part 33a and second sieve component part 33b, i.e. the ribshaped holder parts 33a,33b, that serve to shape e.g. a flexible sieve part 32 in accordance with the curvature of a rigid rib-shaped holder 33 and of the grating roller 7.

So the sieve component 31 has a curvature conforming to the curvature of the grating roller 7, preferably conforming by the sieve component 31 having a larger radius than a radius of the grating roller 7. After final grating the grated potato mass and other matter that has passed through the mesh openings of the sieve component 32 and between the ribs 36 leaves the bottom housing part 6 via the outlet 5 and out of an outlet duct 35.

During operation of the food grating apparatus 1 the potatoes, which have passed the grating blocks 23a,23b through the narrow gap 25a,25b continues to the sieve component 31 where the mass are filtered and/or sieved by being forced against and through

DK 2018 70289 A1 the sieve part 32 due to gravity and the action of the rotating grating roller 7.

Although fig. 5 does not show the mesh openings described above it is to understand that such are part of the sieve part 32.

When the sieve component 31 is in its operation position A in close proximity of the grating roller 7, the sieve component 31 is locked in this position by means of a locking device 37.

The grated food objects leaving the food grating apparatus via outlet duct 5 may be conveyed to the next process step by means of a not shown conveyor device.

A fragmentary sectional view of the grating roller 7 is shown in fig. 6.

The grating roller 7 has circumferential spaced axially extending grooves 38 for holding radially protruding rasping blades 39. The axially extending grooves 38 are circumferentially separated by axially extending partitions 40.

The width, seen in the circumferential direction, of a groove 38, increases at least along 70% of the groove depth d due to the minimum wall width w_min, seen in the circumferential direction, of an axially extending partitions 40 is positioned at least 70% of the total groove depth d from a periphery of the grating roller 7.

To keep a rasping blade 39 secured in a groove 38 the rasping blade 39 is mounted between two locking strips 41a,41b. The locking strips 41a,41b have a shape selected to clamp the rasping blade inside the groove. The locking strips 41a,41b and the rasping blades 39 may be of conventional kind, with the proviso that the locking strips should have a portion that is wider than the opening 42 of the groove 38, so that a rasping

DK 2018 70289 A1 blade 39 is maintained in place in the axially extending grooves 38 of the grating roller 7.

Fig. 7 shows, in an enlarged scale view, a fragment of the periphery of the grating roller seen in fig. 6.

A partition 40, as seen from the periphery of the grating roller 7, has an exterior portion 43 exposed to food objects to be grated. The opposite sides of the exterior portion 43 of a partition tapers radially with a first tapering angle (X of about 20° into an intermediate portion 44 that has opposite sides that radially tapers into a second tapering angle ß of about 1°. The intermediate portion 44 extends into an interior portion 45, which is solid with the grating roller 7 and having an increasing width, seen in the circumferential direction, compared to the exterior portion 43. The circumferential distance w_max between two adjacent partitions 40 is greatest at the transition 46, which is located at least 70% of the groove depth d, between the intermediate portion 44 and the interior portion 45, so a groove 38 is widest at said transition 46 placing the minimum width w . also at the transition 46.

A groove 38 is configured with a guiding track 47 at its bottom furthest away from the periphery of the grating roller 7 for guiding the rasping blade 39 with surrounding locking strips 41a,41b during its axially insertion into the groove 38.

A groove 38 is symmetrical with respect to a radius of the grating roller 7. A rasping blade 39 may also be symmetrical about its longitudinal axis.

An exemplary grating roller 7 has a length of 600 mm and a diameter of 1090 mm. For such a grating roller 216 grooves 38 are presented for rasping blades 39. Fewer or more grooves can be provided. The groove 38 has a depth d of 20 mm. For such a

DK 2018 70289 A1 groove the partitions have an exterior portion 43 and an intermediate portion 44 that each are about 7,5 mm, and the interior portion 45 are about 5 mm. A rasping blade 39 extends about 18 mm into the groove 20 during rotation of the rating roller, thus leaving a space of a height about 2 mm below the rasping blade 39. This space comprises the guiding track 47 for guiding the rasping blade 39 during e.g. inserting the locking strips 41a,41b into the groove 38. This space suffice to provide proper room for replacement or reversal of the rasping blade 21 with surrounding locking strips 22.

The bottom of the grooves 38 may have rounded convex corners at the exterior portion 43 of the partitions 40 to avoid that the partitions 40 constitute points of fracture and to smoothly guide the rasping blades into the guiding tracks.

The bottom housing part 6 has a door or cover 48 which may be removed in order to provide access to the interior of the food grating apparatus 1. This may be relevant in connection with replacement of the sieve part 32, emptying the bottom housing part 6 from food residues, and/or for cleaning purpose of the food grating apparatus 1 and grating roller 7.

The food grating apparatus may e.g. be available in widths of the grating roller 7 from 400 up to 600 mm and motor sizes up to 315kW, having a capacity of up to 55 ton/h. The housing can be made of 25 mm solid stainless steel.

Claims

1. A food grating apparatus (1) comprising a housing (2) , a grating roller (7) arranged rotatable about its axis (8) below a top wall (9) of an upper housing

part of the housing (4), which top wall (9) has an inlet (3) for receiving food objects to be grated, and a bottom housing part (6) below the grating roller (7) is configured for receiving grated matter, characterized in that the food grating apparatus (1) comprises a sieve component (31) arranged in the bottom housing part (6) below the grating roller (7), which sieve component (31) has a curvature conforming to the curvature of the grating roller (7).

2. A food grating apparatus (1) according to claim 1, characterized in that the sieve component (31) has a larger radius than a radius of the grating roller (7).

3, characterized in that the sieve component comprises a first curved sieve component part (33a) pivotable hinged at one end to a second curved sieve component part (33b), and a curved a sieve part (32) inserted between the first curved sieve component part (33a) and the second curved sieve component part (33b).

5. A food grating apparatus (1) according to any of the preceding claims 1 - 4, characterized in that the first curved sieve component part (33a) and the second curved

DK 2018 70289 A1 sieve component part (33b) constitutes a rib-shaped holder (33) for the sieve part (32).

6. A food grating apparatus (1) according to any of the preceding claims 4 or 5, characterized in that the sieve part (32) has mesh openings of between 0.5 and 20 mm, preferably 1-15 mm and more preferred between 1.5 - 10 mm.

7 . A food grating apparatus (1) according to any of the preceding claims 1-6, characterized in that - the grating roller (7) has a first grating surface (19) facing an interior face (18) of the top wall (9)

of the housing (2) to delimit an axially extending radial gap (G) between said first grating surface (19) and said interior face (18),

- the top wall (9) is curved and has a summit wall section (20) including an axially extending maximum radial gap (G_max) ,

- the summit wall section (20) extends into a continuously curved wall section (21) where said axially extending radial gap (4G) continuously decreases, and

- which continuously curved wall section (21) converges towards the first grating surface (19) towards an axially extending minimum radial gap (G_min) .

8. A food grating apparatus (1) according claim 7, characterized in that the continuously curved wall section (21) extends into a tangential wall section (22), and the axially extending minimum radial gap (G) is located between the interior face (18) of the tangential wall section (22) and the first grating surface (19), preferably the cross-section of the top wall (29) is 13shaped, semi-circular or semi-oval.

DK 2018 70289 A1

9. A food grating apparatus (1) according to any of the preceding claims 1 - 8, characterized in that the food grating apparatus (1) includes at least one axially extending grating block (23a,23b) that has a second grating surface (24a,24b) facing the first grating surface (19), an axially extending grating gap (25a,25b) is delimited between the second grating surface (24a,24b) and the first grating surface (19), wherein the at least one axially extending grating block (23a,23b) is arranged to provide an axially extending grating gap (25a,25b) in extension of the axially extending minimum radial gap (G_min) , which axially extending grating gap (13 is smaller than the axially extending minimum radial gap (4b), preferably the food grating apparatus (1) has two axially extending grating blocks (12), one at each opposite axially extending minimum radial gap (4b).

10. A food grating apparatus (1) according to any of the preceding claims 7, 8 or 9, characterized in that the inlet (3) is an axially extending opening (26) provided in the summit wall section (20), which inlet (3) is provided with an inlet duct (13) for guiding an incoming flow of food object inside the upper housing part (4), optionally the inlet duct (13) has axially extending opposite longitudinal side walls (29a,29b) diverging from the inlet (3), optionally the opposite end walls (30a,30b) between the axially extending opposite diverging longitudinal side walls (29a,29b) converge.

11. A food grating apparatus (1) according to any of the preceding claims 1 to 10, wherein the grating roller (7) has circumferential spaced axially extending grooves (38) for holding radially protruding rasping blades (39), and

DK 2018 70289 A1 axially extending partitions (40) between said axially extending grooves (38), wherein the width, seen in the circumferential direction of the grooves (38) increases at least a part of a groove depth (d) of the axially extending grooves (38), characterized in that the minimum wall width (w . ) , seen in the circumferential direction, of the axially extending partitions (40) is positioned at least 70% of a total groove depth (d) from a periphery of the grating roller (7).

12. A food grating apparatus (1) according to claim 11, characterized in that a partition (40) has an exterior portion (43), which is exposed to food objects to be grated, the exterior portion (40) radially tapers with a first tapering angle (OC) into an intermediate portion (44) that radially tapers into a second tapering angle (ß) that is smaller than the first tapering angle (OC) , the intermediate portion (44) extends into an interior portion

(45) that is solid with the grating roller (7) and having direction an of increasing width, seen in the grating roller (7). the circumferential 13. A food grating apparatus (1) according to claim 12,

characterized in that the length of the exterior portion (43) constitutes 30 to 45% of the total groove depth (d), the length of the intermediate portion (44) constitutes 30 to 45% of the total groove depth (d) and the length of the interior portion (44) constitutes 20 to 30% of the total groove depth (d), wherein the total length of the portions (43,44,45) of the partitions altogether constitutes 100%.

14. A food grating apparatus (1) according to any of claims 12 or 13, characterized in that the first tapering angle (a)

DK 2018 70289 A1 is about 18 to 22°, preferably 20°, and the second tapering angle (ß) is about 0,5 to 2°, preferably 1°.

15. A food grating apparatus (1) according to any of the

3. A food grating apparatus (1) according to claims 1 or 2, characterized in that the sieve component (31) is pivotably hinged at one end (34) to the housing (2).

4. A food grating apparatus (1) according to claims 1, 2 or

5 preceding claims 11 to 14, characterized in that at a bottom of the groove (38) furthest away from the periphery of the grating roller (7) the groove (38) is configured with a guiding track (47) for guiding a rasping blade (39) during its axially insertion into the groove (38).