Feeding device and roller type installation

Abstract

The invention relates to a feed device (1) for a roller installation for food processing, having a collecting space (12) into which processed objects can be fed via a feed opening (11). The feeding roller (14) is used for conveying the machined objects existing in the collecting space (12) out of the collecting space. For this purpose, the feed roller is arranged on the lower side on the collecting space (12) and can be rotated about an axis. The feeding device comprises a first conveying device (17) above the feeding roller, and the first conveying device is used for conveying the machined objects in the collecting space in the axial direction. The feeding device is characterized in that the second conveying device (18) is used for conveying the processed objects conveyed by the first conveying device in the direction different from the conveying direction of the first conveying device. As a result, a particularly uniform distribution of the workpiece along the axis of the feed roller (14) is ensured.

Description

Technical Field

[0001] The invention relates to a feed device for a roller-type facility for food processing, such as a roller mill or a flaking mill, and a roller-type facility having the feed device. Background Art

[0002] Rolling mills according to the prior art often have a centrally arranged inlet for the ground material to be ground. The ground material accumulates in a collecting space and is conveyed from there by a feed roller into the grinding space, where it is reduced in size between the grinding rollers. The axis of the feed roller is generally parallel to the axis of the grinding roller, and the collecting space extends in the longitudinal direction over the entire length of the feed roller.

[0003] According to the prior art, the distribution of the collected ground material over the length of the feed roller is achieved, for example, by gravity, in that the collecting space is large enough to form a loose material cone whose width corresponds to the length of the feed roller. Technological developments require rolling mills with longer and longer grinding rollers, and therefore also longer and longer feed rollers. For this purpose, the inlet must be designed higher and higher to ensure a sufficiently wide loose material cone. However, this has its limitations, which is why the weight distribution is no longer sufficient at a certain point in time from a certain roller length - this depends on the properties of the ground material, which define the angle of the loose material cone.

[0004] Therefore, solutions are known in the prior art in which the ground material is actively conveyed outward by means of a conveyor shaft above the feed roller. The conveyor shaft is driven by the drive of the feed roller. In order to be able to adapt to the different characteristics of the ground material, the paddles of such conveyor shafts, which are configured as paddle shafts, have adjustable paddle angles. With this solution, the feed device can also be adapted to large roller mills with a grinding roller length of more than one meter and / or products with poor fluidity. However, the disadvantage of this solution is that the paddles can only be adjusted when the operation is interrupted in the case of an empty collection space. In addition, it is difficult to find the optimal adjustment in practice. Therefore, it must also be tolerated that the distribution over the length of the feed roller is not completely uniform, but that the feed roller conveys less ground material at its outer end, or that the ground material accumulates at the end of the conveyor shaft, which over time will bring about the risk of machine defects or permanent unhygienic adhesion of the ground material. If different products with different flow characteristics are ground, the feed device also needs to be readjusted repeatedly. This is difficult to do in practice, which is why the feed device is often operated in a non-optimized mode, accompanied by an uneven distribution of the ground material over the length of the roller. A further disadvantage of the solutions according to the prior art is that the paddle shafts with adjustable paddles are potentially unhygienic since they comprise open threads and screws in the collecting space and are therefore in direct contact with the grind.

[0005] Therefore, in EP 3 572 152 a feed device is proposed, in which the ground material inlet and the first filling level sensor are arranged at one end of the feed roller and the conveyor shaft, and the second filling level sensor is arranged at the other end of the feed roller and the conveyor shaft. According to this solution, the speed of the conveyor shaft is designed to be closed-loop controlled independently of the speed of the feed roller. This solution should ensure that the feed roller is always supplied with ground material over its entire length. However, it requires a relatively complex sensor system and a relatively complex closed-loop control and is sensitively dependent on the intact function of the filling level sensor; in the event of a malfunction, the ground material accumulated at the other end must leave the collection space via the feed gap. When eliminating the malfunction, there is a risk that the product cannot be discharged for a short time in some sections. In addition, in the event of a malfunction, compression of the ground material may occur at the end of the conveyor shaft. Due to the lateral ground material inlet, the feed device also needs to be adapted to the existing grain mill during installation, because such grain mills are generally designed for roller mills with a centrally arranged inlet.

[0006] Another topic in the context of rolling mills and their feed devices is suction. Generally speaking, an overpressure prevails in the collecting space, since air also flows in with the ground material. If this pressure is not reduced, this will cause an escape from the collecting space; in addition, air can flow out of the collecting space into the feed gap. For this reason and also to reduce dust and humidity, it has been proposed to extract the air from the collecting space via connections provided specifically for this purpose. According to a first solution (external suction), this is achieved by connecting a separate air pipe with its own fan. This leads to additional costs and requires a greater installation effort (duct construction).

[0007] Another possibility provides that the suction point in the collecting space is connected to a pneumatic conveying line via a suitable pipe. The pneumatic conveying line that is already present is used to transport the ground material away after it has passed through the grinding gap and has been collected by a hopper. The connection to the pneumatic conveying line avoids the need to provide a separate suction system or, if such a suction system already exists for other grinding machines, enables a smaller design of the suction system and avoids the construction of additional pipes. However, it requires additional pipes that are difficult to clean and maintain and are also relatively expensive.

[0008] According to another solution (internal suction), it is proposed to arrange a correspondingly short duct between the collecting space lateral to the feed roller and the grinding space in order to achieve pressure compensation. In this solution, since the air flow is guided through the level of the ground material and the duct is arranged close to this level in terms of design, the air flow can suck fine particles into the duct. This can cause deposits on the duct and even lead to blockages. Summary of the invention

[0009] The object of the invention is to provide a feeding device for a roller plant for food processing and such a roller plant, in particular a roller mill, which overcome the disadvantages of the prior art. Another object is to feed the processed material into a processing space, such as a grinding space, uniformly and in a well-controlled manner using processing rollers, such as grinding rollers, wherein the feeding should be reliable in the case of different properties of the processed material. Another object is to provide a solution to the suction problem.

[0010] These objects are achieved by the invention as defined in the claims.

[0011] According to a first aspect of the invention, a feeding device for a roller facility for food processing is provided. The feeding device comprises a collecting space into which a workpiece can be fed via an inlet. The feed roller is used to convey the workpiece present in the collecting space out of the collecting space. To this end, the feed roller is arranged at the collecting space at the lower side and can rotate around an axis. Due to its rotation, the feed roller carries the workpiece and in particular conveys the workpiece through a feed gap, the width of which can be adjusted in a manner known per se, for example by an adjustable slide. Above the feed roller, the feeding device comprises a (first) conveying device for conveying the workpiece in the collecting space in an axial direction ("axial" refers to the axis of the feed roller) toward at least one end side. The feeding device is distinguished by a second conveying device, which is used to convey the workpiece conveyed by the first conveying device away from the end side in another direction.

[0012] The second conveying device can be configured, in particular, to convey the workpiece conveyed by the first conveying device in an axial direction opposite to the axial direction (the direction in which the first conveying device conveys).

[0013] In this context, the term "process material" generally refers to food, in particular cereal products, which are present as loose material to be processed in the roller system. If the roller system is a roller mill, the process material is ground material. If the roller system is a flaking machine, the process material consists of cereals or grains or granules to be flaked.

[0014] Therefore, the second conveying device is arranged so that it conveys the workpiece away from the end side, more precisely in the collecting space. No conveyed material will accumulate at the end side, but any workpiece that may be conveyed in excess to the end side will return to the following area, in which it can be caught by the feed roller or the first conveyor shaft.

[0015] The second conveyor device in particular conveys the workpiece conveyed by the first conveyor device back in the direction of its origin. If the feed device comprises a central feed opening into the collecting space, the conveying by the first conveyor device takes place in an axial direction towards the side, away from the center and outwards. Depending on the set conveying speed of the first conveyor device, the second conveyor device then conveys the portion of the workpiece conveyed outwards back inwards.

[0016] In the case of a non-centered feed opening laterally to the collecting space, the first conveying device conveys the workpiece from the side with the feed opening toward the other end side, and the second conveying device - also according to the adjusted conveying speed of the first conveying device - conveys the workpiece back, for example in the direction of the side with the feed opening.

[0017] The second conveyor device can also convey the workpiece from the end side or upward from the end side, where it falls again from the end side through the second conveyor device due to gravity, wherein at least the portion of the workpiece conveyed upward also moves back in the direction of its origin. In this variant, firstly an accumulation and compression of the workpiece at one or more end sides is prevented, and a certain degree of return conveyance of the workpiece in the direction of its origin is also achieved.

[0018] The problem described initially is solved by the second conveying device. The first conveying device can be operated with a certain conveying power which is sufficient in any case, even in the case of changing characteristics of the workpiece and independently of the presence of cavitation, etc., to reliably convey the workpiece to the outer end (in the case of a central feed opening) or the opposite end (in the case of a lateral feed opening). The conveying speed can, for example, depend only on the rotation speed of the feed roller, which is necessarily the case if the first conveying device is driven by the same drive as the feed roller (which can be an option). Therefore, the first conveying device can be operated in particular with a conveying power that is set slightly too high on average and thus conveys slightly more workpiece than is actually required. The second conveying device then ensures that the workpiece that may be over-conveyed does not accumulate and compact at the end side, but is conveyed back and distributed sooner or later along the axis of the feed roller. For this reason, the distribution along the axis of the feed roller becomes very robust and reliable by this solution.

[0019] Another advantage of the solution according to the first aspect of the invention is that the feed device can initially be operated with delivery and return delivery for a longer period of time until the collecting space is optimally filled and mixed. This is not possible with feed devices according to the prior art.

[0020] The second conveyor device is arranged in such a way that it conveys in particular the portion of the workpiece that is conveyed in excess. The second conveyor device can be arranged, for example, above the first conveyor device, i.e. vertically above the first conveyor device directly or also in a horizontally offset manner (e.g. parallel conveyor axes). However, depending on the geometry of the collecting space, the second conveyor device can also be located at a different position, for example close to the first conveyor device.

[0021] The first conveying device can be configured in particular as a conveying shaft. This is particularly suitable for environments that are partially filled with workpieces, because both ends can be well sealed to the outside and the shaft as a whole does not include areas that should not be covered by the workpieces. Such conveying shafts generally have a shaft core ("core") with a spiral conveying structure on the shaft core. Such a structure can be formed by discrete blades or, alternatively, by a continuous worm thread. In the latter case, the shaft can also be configured without a shaft core, as a so-called "shaftless" worm conveyor.

[0022] The second conveying device can also be, for example, a horizontally arranged conveying shaft, whose axis is therefore parallel to the axis of the feed roller. The same advantages as the first conveying shaft are obtained. In the case of a centrally arranged feed opening, the second conveying device can also be formed by two conveying shafts that are separated from each other and are respectively located at the two end sides. In particular, in this case, the conveying axis of the second conveying device can also be at an angle to the axial direction, for example inclined or even vertically upward.

[0023] Alternative conveying devices are, for example, running belts or rollers, for example, running in front of and / or behind the boundary of the collecting space, with conveying structures extending inwardly into the collecting space. Other alternative conveying devices are also not excluded, for example, as an option for the second conveying device, compressed air is used, by which the workpiece is blown back from one or more end sides above the first conveying device.

[0024] In the case of a central feed opening, at least the second conveyor device can be free of conveying structures in the central region below the feed opening. On the one hand, due to the dynamics existing in the collecting space, such conveying structures are not necessary at all in the central region, and on the other hand, undesirable compaction of the portions of the processed product conveyed in the opposite direction in the middle becomes impossible.

[0025] There is also the option of providing the second conveyor device - for example if it is designed as a horizontal (second) conveyor axis - with a mixing structure in the area below the feed opening, which mechanically processes the process material in contact with it, rather than systematically conveying it in one direction or another. The advantages of the treatment method according to the invention - especially in the case of a "narrow" inlet discussed in this article - are thus further enhanced. For example, the combination of a powerful first conveyor device and a second conveyor device can effectively prevent separation when different process material components are fed through different feed sleeves. The additional mixing structure further enhances this positive effect.

[0026] Such a mixing structure can in particular protrude radially outward from the shaft core and extend from the shaft core. The mixing structure can be formed, for example, by radially extending rods or by mixing rods, ie (rods or plates) extending parallel to the axis.

[0027] In particular, if the second conveying device is a horizontal (second) conveying shaft, it is sufficient that the structures for conveying away from one or more end sides at the second conveying shaft (e.g. paddles or a continuous worm) are only present near one or more end sides. This leaves sufficient space for such mixing structures in the central area between the end sides.

[0028] Mixing structures of the type described effectively counteract bridge formation, especially in the case of poorly flowing and / or sticky ground material, and additionally mix the incoming product, ensure that the bulk angle is small, and have a positive effect on the product flow overall, since they prevent areas with stagnant product. In particular, the mixing structures also achieve a slightly greater power consumption if they are designed as mixing rods, which is why they can be present, in particular, as an option and can be reversibly releasably fastened to the second conveyor shaft, so that they can also be removed as required depending on the ground material.

[0029] As a supplement or alternative to the mixing structure on the second conveying device, a mixing structure on the first conveying device can also be an option. The mixing structure can also be arranged below the feed opening.

[0030] If the conveying device is designed as a conveying shaft with an axial core, the conveying structure (e.g. a paddle) can be fixedly connected (e.g. welded) to the axial core in contrast to the solutions according to the prior art. This results in that, due to the solution according to the first aspect of the invention, a mechanical adjustment of the conveying characteristics becomes superfluous. Thus, the described problems regarding hygiene in the case of open threads and screws in the collecting space can be elegantly solved.

[0031] In one set of embodiments, at least the first conveyor device comprises a separate conveyor device drive which is independent of the drive of the feed roller. In contrast to conveyor shafts driven by belt drives fixedly connected to the drive of the feed roller according to the prior art, the conveying speed of the conveyor device or devices can then also be adjusted independently of the feed roller during operation.

[0032] In particular, the feed device can thus be equipped in such a way that the delivery capacity can be adjusted by means of the first conveying device and, for example, also by means of the second conveying device, without the collecting space having to be emptied.

[0033] The independent drive comprises, for example, its own electric motor, which is independent of the electric motor of the feed roller drive.

[0034] The independent conveyor drive can comprise a single electric motor, which drives the first conveyor and, if necessary, also the second conveyor, for example via a belt, a gear or other elements. The electric motor can also comprise separate electric motors for the first conveyor and the second conveyor.

[0035] The feature of a separate conveying device drive is particularly advantageous in combination with the optional feature of a fixed connection between the conveying shaft and the conveying structure.

[0036] In one set of embodiments, the feed device is of the "narrow inlet" type, which means that the collecting space in the upper region is designed in the form of a chamber which is open downwards towards the conveying device and has a surrounding wall. The width (axial extension) is here significantly smaller than the axial length of the feed rollers and the conveying device. Unless otherwise expressly stated, the "axial length" of the feed rollers and the conveying device is always the extension within the collecting space without the part of the roller or shaft (or other device) which penetrates the boundary of the collecting space and is used to support and accommodate the drive.

[0037] In the present text, the chamber-shaped area - in an embodiment, it can also be essentially box-shaped with a rectangular contour - is referred to as the "upper sub-collection space". The area with the one or more conveying devices extends downwards as far as the feed rollers and the width of the area corresponds to the length of the feed rollers and the one or more conveying devices and is therefore referred to as the "lower sub-collection space". The lower sub-collection space is connected downwards to the upper sub-collection space and, in addition to the front and rear boundaries (walls and / or doors, each with a window if necessary) and lateral boundaries, also includes an upper boundary laterally in the upper sub-collection space. The upper boundary can be essentially horizontal, or it can be slightly inclined to the horizontal, for example at an inclination angle of a maximum of 10°, a maximum of 7° or a maximum of 5°.

[0038] This type of embodiment has the advantage, in particular, that, compared to a feed device with a wide collecting space extending upward, an easier and better control of the filling amount in the collecting space can be achieved. In addition, the mixing of the different process products is improved compared to a feed device with a wide bulk cone. For this reason, the controllability of the filling level and the reliable conveying of the process product along the entire length of the feed roller are often more demanding than in the case of a wide collecting space, which is why the process according to the invention, in particular with a separate drive for the conveying device, is particularly suitable for this type of embodiment.

[0039] The maximum width (width, i.e. axial extension of the internal volume) of the upper collecting subspace is derived from the available space usually present in a grain mill and from the requirement discussed later that in normal operation the collecting space should be sealed downwards with the process material, so that the operation can be easily controlled in a closed loop. The width measured at the widest point of the upper collecting subspace can be, for example, a maximum of 50 cm, a maximum of 45 cm or a maximum of 40 cm. Typically, this width is in any case less than half the axial length of the feed roller.

[0040] The surrounding wall of the upper sub-collecting space can be inclined vertically or at least partially slightly inclined to the vertical, for example with a maximum inclination angle of 10°, 7° or 5°.

[0041] According to a second aspect of the invention, which can be combined particularly well with the first aspect, a roller installation, such as a rolling mill, has a feed device of this type with an upper sub-collecting space and a lower sub-collecting space, and the roller installation has at least one suction channel between the upper sub-collecting space and the processing space with the processing rollers. The suction channel is a gas-conducting line, which can include a circular, rectangular or otherwise constructed cross-section that does not necessarily have to be constant along the channel. In particular, one or more of the suction channels can be guided along the surrounding wall of the upper sub-collecting space and from there further downwards, for example along the rear wall of the lower sub-collecting space, into the processing space.

[0042] In an embodiment, at least one suction channel can end, in particular, above the pair of processing rollers. A solution with a suction channel connecting the upper sub-collection space to the processing space above the processing rollers can be particularly advantageous: if the suction channel ends below the pair of processing rollers, the pressure resistance would be too high at best. If the suction channel starts below the upper sub-collection space, there is a risk of clogging.

[0043] The suction channel ensures that during operation, air continuously reaches the processing space from the feed opening and the upper sub-collection space, in which there is an overpressure, and in which there is a negative pressure due to the vacuum and pneumatic conveying of the processed material. Internal suction thus occurs. Since the upper sub-collection space is connected to the processing space, firstly, clogging of the suction channel can be prevented very effectively. Secondly, it is thus always ensured during operation that air and the delicate processed material entrained therewith cannot flow from the collecting space to any extent through the feed rollers along any path worth mentioning into the processing space.

[0044] The solution according to the second aspect of the invention can also in some cases make it possible to close the system with closed doors (e.g. grinding space door; if necessary, door leading to the collecting space), thereby also preventing moisture or spores etc. from entering the area with the processed material in an uncontrolled manner.

[0045] The roller installation according to the second aspect is in particular operated in such a way that the workpiece always seals the upper collecting subspace downwards, that is, in normal operation, the workpiece always occupies the entire cross-sectional area at least at the bottom in the upper collecting subspace. As a result, air cannot enter the processing space from the collecting space to any significant extent through the feed gap or through possibly unsealed locations, such as at the side, via the slide, and carry away the workpiece in an uncontrolled manner. The at least one suction channel according to the second aspect of the invention takes this into account without having to endure the disadvantages of external suction.

[0046] As known per se and as an option for all aspects of the invention, the feed device of the roller installation can include a filling level monitoring device. The filling level determined by the filling level monitoring device (i.e. the level of the process material in the collecting space) can be taken into account by the control device in order to control the rotation speed of the feed rollers and / or the conveying power of one or more conveying devices. In addition or as an alternative, the filling level can also be used to control the amount of process material fed in, for example by means of an inlet slide, an inlet baffle or another metering device.

[0047] According to a further third aspect of the invention, which can be combined particularly well with the first and / or second aspects, a feed device having a narrow inlet, that is to say an upper sub-collecting space with a surrounding wall and a lower sub-collecting space with at least one conveying device (e.g. two conveying devices if the feed device also corresponds to the first aspect), comprises an observation window which is present not only on the surrounding wall of the upper sub-collecting space but also extends downwards into the cover of the lower sub-collecting space. The width of the observation window is greater than the width of the upper sub-collecting space.

[0048] The viewing window can extend axially up to the end side close to the sub-collection space below. In the present context, "close to the end side" means that the ends of one or more conveying devices extending through the sub-collection space below can be well seen through the viewing window, which can, for example, mean that the viewing window extends to the end side on both sides, or ends laterally at a distance of up to about 10 cm from the end side.

[0049] The viewing window can be continuous or divided. However, a possible division should not, for example, prevent that all areas of the collection space can be viewed up to the lower limit of the viewing window.

[0050] Compared to the prior art, the viewing window makes visible not only the narrow area below the feed opening (upper collecting subspace), but also the area with one or more conveying devices, thereby enabling a visual assessment of the product distribution, product quality and product mixing in the feed device. Since the viewing window extends from the upper collecting subspace to the lower collecting subspace, a good assessment of the product flow through the feed device is enabled. Possible malfunctions, contaminations, mold formation, etc. can be seen through the viewing window without interrupting operation and opening the collecting space. The viewing window can be flipped open, thereby enabling easy access to the collecting space in order to identify malfunctions, contaminations, the onset of mold formation, etc.

[0051] According to all aspects of the invention, a roller installation in the form of a rolling mill can also be configured as a multi-roll mill with multiple pairs of grinding rollers, wherein two pairs of grinding rollers are arranged one after the other and can then be at least approximately at the same height. In embodiments of the second and / or third aspects of the invention and generally in embodiments with a "narrow" inlet according to the definition used herein, the rolling mill can be configured so that the upper sub-collection space does not have a conveying pipe passing through it. Possibly present conveying pipes can be guided laterally between the grinding roller pairs and between the feed rollers assigned to these grinding rollers and between the conveying devices, in the upper sub-collection space (which can be divided into two compartments, each compartment for the front and rear grinding roller pairs). If the width of the upper sub-collecting space (including a possible suction channel extending laterally therefrom according to the second aspect) does not exceed approximately 55 cm, which is very compatible with the dimensions of the width of the upper sub-collecting space already discussed above, then this type of arrangement is feasible for conveying pipes with typical diameters of, for example, approximately 90-100 mm, also for the shortest commonly used roller lengths of 1000 mm and for a total of up to four conveying pipes arranged side by side with each other and leading through the rolling mill. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Embodiments of the present invention are described below by means of the accompanying drawings. In the accompanying drawings, the same reference numerals represent the same or similar elements. The accompanying drawings are all schematic and not drawn to scale. These drawings show elements that partially correspond to each other, and the sizes of the drawings are different. Among them:

[0053] Figure 1 A diagram showing a feeding device is shown;

[0054] Figure 2 Shows Figure 1 A cross-sectional view of a feeding device;

[0055] Figure 3 A diagram showing an alternative feed device;

[0056] Figure 4 Shown according to Figure 3 The feed equipment, together with the conveying pipes and the marked filling level of the processed product,

[0057] Figure 5 A schematic diagram with a control device is shown;

[0058] Figure 6 A rolling mill with a suction channel is shown;

[0059] Figure 7 shows a top view of a twin-roll mill with a narrow entry;

[0060] Figure 8 The structure of the delivery device with an additional mixing structure is shown;

[0061] Figure 9-Figure 17 An alternative possible solution for the design of the second conveying device is shown;

[0062] Fig.18 An alternative design of the feed device is shown with Figure 2 a similar cross-sectional view; and

[0063] Fig.19 A first conveying device and a second conveying device with a mixing rod are schematically shown. DETAILED DESCRIPTION

[0064] Figure 1 and Figure 2 A feeding device 1 according to a first embodiment is shown. The feeding device comprises at the upper side Figure 1The feed opening 11, which is only schematically shown, and the collecting space 12 formed by the housing 2. The collecting space 12 is closed at the bottom by a feed roller 14, which interacts with an adjustable slide 15 in order to convey the workpiece in the collecting space through a feed trough 16 so that the workpiece enters the processing space (grinding space), where it is reduced in size between the grinding rollers.

[0065] The feed opening 11 is located centrally (with respect to the axial direction) above the feed roller 14 and the conveying shafts 17, 18 described in more detail below. As known per se, the feed opening can comprise one or more sleeves to which a pipeline with the fed process product can be connected.

[0066] Due to the central arrangement of the feed port, the workpiece needs to be distributed outward in the axial direction so that it is evenly distributed in the grinding gap ( Figure 1 and Figure 2 To a certain extent, this is achieved by the accumulation of a cone of the workpiece below the feed opening 11. However, this is generally not sufficient, which is why the workpiece is actively transported in the axial direction to improve the axial distribution.

[0067] For this purpose, the feed device comprises a first conveying device, i.e. a first conveying shaft 17, for conveying the workpiece in the axial direction outwards, i.e. in two opposite directions from a central region 31 below the feed opening, as indicated by the double arrows. For this purpose, paddles 19 or other conveying structures, e.g. structures extending at least partially in a spiral manner, are oriented in opposite ways in the two outer regions, i.e., are arranged, for example, mirror-symmetrically.

[0068] Furthermore, the feed device comprises a second conveying device, namely a second conveying shaft 18, for conveying the workpiece in the opposite axial direction, i.e., inwardly. The second conveying shaft 18 is arranged above the first conveying shaft, so that the portion of the workpiece that would otherwise accumulate from the end of the first conveying shaft 17, i.e., axially outward, is mainly captured by the second conveying shaft. In the example shown, the second conveying shaft 18 is arranged above the first conveying shaft 17, but also slightly offset horizontally, more precisely offset to the rear (see Figure 2 ). Such a slightly offset arrangement has the advantage that the vertical distance between the conveyor axes can be slightly smaller than in the case of a direct vertical arrangement of the two conveyor axes above one another. For example, a reduced vertical distance that is slightly smaller than the sum of the radii of the blades 19 can be advantageous, since lateral accumulation of the workpiece can thereby be particularly well prevented.

[0069] In order to transport the workpiece by the second transport axis 18 in the axial direction opposite to the first transport axis, as shown in FIG. Figure 1The conveying structure shown (paddle 19) can be arranged inversely, ie mirror-symmetrically, compared to the first conveying shaft 17. Alternatively, the second conveying shaft can also be designed identically to the first conveying shaft, but rotated in the opposite direction.

[0070] The paddles 19 present as conveying structures on the two conveying shafts 17, 18 are known per se. In the case of a rotational movement of the respective conveying shaft, the paddles convey the workpiece in a fixed direction by pushing the workpiece in front of them or by pulsing the workpiece in a defined conveying direction depending on the rotational speed. The paddles 19 or other conveying structures extending helically in certain areas, such as worm threads, can be fixedly welded to the actual shaft or fastened to it in another way, which overcomes the hygiene problems described initially.

[0071] The upper conveying shaft 18 and, in the embodiment shown, the lower conveying shaft 17 comprise a central region 31 which is free of paddles 19. Therefore, no transport of the workpiece takes place in this central region.

[0072] also, Figure 1 The possibility is shown that the conveyor shafts 17, 18 include a conveyor shaft drive 21, which is independent of the feed roller drive 22 by virtue of having its own electric motor. This has the advantage already mentioned that the speed of the conveyor shafts 17, 18 can be adjusted independently of the speed of the feed roller and can also be changed during operation. In the embodiment shown, the first conveyor shaft 17 and the second conveyor shaft are coupled to each other or to the conveyor shaft drive 21, so that they always rotate at a fixed speed ratio, for example 1:1 (i.e. at the same speed) in a manner driven by the conveyor shaft drive 21.

[0073] Alternatively, the conveying shaft can also be driven by the drive of the feed roller, for example via a suitable belt. On the contrary, it is not excluded that the first conveying shaft 17 and the second conveying shaft 18 can each have their own drive and their rotational speed can be adjusted independently.

[0074] Figure 1 Also shown is a conveyor shaft supply unit 23 separate from a feed roller supply unit 24; in practice, the supply units can also optionally be integrated into a common electronic unit.

[0075] The feed device also comprises a filling level monitoring device which, in the embodiment shown, is formed by a radar sensor 27, as taught in Swiss patent application 448 / 2022 of April 14, 2022. Other filling level monitoring devices which determine the filling level, for example by means of capacitive sensors, weight measurement and / or optically and / or in another way, are likewise an option.

[0076] Figure 3 An alternative embodiment is shown, which is similar to Figure 1 and Figure 2 The difference in the embodiment of the present invention lies in the shape of the collecting space 12. The collecting space 12 is divided into a chamber-like upper sub-collecting space 41 with a surrounding, approximately vertical wall 51 and a lower sub-collecting space 42 extending along the entire length of the feed roller. The upper sub-collecting space can have a box shape with a generally rectangular contour, or can also have a generally circular or slightly elliptical contour. On the upper side, a feed opening 11 in the form of at least one pipeline (usually a plurality of, for example four pipelines, for which the housing 2 respectively includes connecting sleeves or the like) opens into the upper sub-collecting space 41. The width (axial extension) of the upper sub-collecting space is significantly smaller than the axial extension of the feed roller 14. Thus, in addition to the front and rear side boundaries and the lateral boundaries 52, the lower sub-collecting space 42 also includes a horizontal upper boundary 53, which is located laterally of the first sub-collecting space 41 and in some cases also in front of and / or behind the upper sub-collecting space.

[0077] The viewing window 44 indicated by the encircling dashed line is arranged and designed such that it is not only present on the surrounding wall 51 of the upper sub-collection space, but also extends downward into the cover of the lower sub-collection space 42, so that at least the upper conveying shaft 18 is visible through the window. The viewing window can be vertical or approximately vertical at least in sections.

[0078] The observation window extends axially to the end side close to the sub-collection space below, that is, it basically extends to the position corresponding to the axial ends of the conveying shafts 17, 18 and the feed roller 14 (more precisely expressed as: the axial end of the part of the conveying shaft / feed roller that contacts the workpiece).

[0079] In particular, in Figure 3 In the embodiments shown in the following figures and with a relatively narrow upper collecting subspace 41, a conveyor shaft drive 23 which is independent of the feed roller drive 22 is particularly advantageous. It has been shown that, in particular in these embodiments, the best results can be achieved if the speed ratio of the feed roller and the conveyor shaft or shafts is not constant but can be adapted to the workpiece and possibly other parameters.

[0080] Figure 4 A further optional feature of the feed device is shown with an upper sub-collecting space 41 and a lower sub-collecting space 42, the lower sub-collecting space having at least one conveying axis 17, 18. Figure 4 In the example, for illustration reasons, no viewing window is shown, but a viewing window having the aforementioned features is also considered as a device for having a through Figure 4 Describes the features of the equipment options.

[0081] first, Figure 4 It is shown that the surrounding wall of the chamber forming the upper subcollection space 41 does not have to be vertical, but can be slightly inclined to the vertical direction. The inclination angle α of at least a part of the surrounding wall, i.e. one of the side walls, the front wall or the rear wall can in particular be between 0° and a few degrees, for example between 0° (vertical) and 10°, in particular between 0° and 7° or between 0° and 5°. In the case of a rectangular profile, in particular at least one wall or two walls opposite to each other, for example Figure 4 As shown, the two side walls or the front wall and the rear wall can be inclined relative to the vertical. A slight inclination of at least one region of the surrounding wall can be advantageous in order to prevent so-called product bridges, due to which relatively large air pockets can form within the product - although this is generally not a problem due to the active product transported by the transport device.

[0082] Secondly, Figure 4 The conveyor pipes 71 leading through the roller mill are shown. These conveyor pipes are used to convey the processed products or other items between the equipment and / or storage locations of the grain mill, and they do not necessarily have to be connected to the corresponding roller mill. For example, after running through the roller mill, the conveyor pipes can, for example, pneumatically carry away the processed products.

[0083] Roller mills are often built as multi-roller mills (four-roller mills or eight-roller mills with roller pairs arranged one above the other). In this regard, for reasons of space, it is often necessary to guide a conveyor pipe through the roller mill, regardless of whether the conveyor pipe is used to discharge the processed product from the respective roller mill or only to connect other elements of the grain mill to one another. Since the collecting space extends further to the rear in the upper region (see Figure 2 , where the front side is on the right in the figure), so according to the prior art a solution must be found in which the delivery tubes are guided through the collecting space itself, or these delivery tubes must be restricted by recesses or the like for the delivery tubes. In terms of design, this is often unsatisfactory. The measures discussed in this article enable an embodiment in which the delivery tubes are arranged in the axial direction close to the upper sub-collecting space 41 and thus do not affect the collecting space.

[0084] In particular, the width of the upper sub-collecting space 41 can be selected so that even in the case of a minimum roller length of 1 m, there is still space on both sides for two feed pipes each having a pipe diameter of, for example, 95 mm, so that the width b of the upper sub-collecting space at the lowest point is, for example, a maximum of about 550 mm, for example a maximum of about 500 mm, and in particular in the absence of a possible suction channel guided laterally through the actual upper sub-collecting space 41, a maximum of about 450 mm.

[0085] third, Figure 4 The following principle is shown, namely that the process products always seal the volume in the upper sub-collection space downwards, since at least the lowermost process product in the upper sub-collection space always occupies the complete cross-sectional area. For this purpose, the feed device or the device in which the roller device with the feed device is embedded is configured to always control the filling level 61 of the process product in a corresponding closed loop during operation. The opening angle σ of the bulk product cone varies depending on the process product and has a value between 90° and 120°. Therefore, the control device of the feed device (see Figure 5 ) is configured, for example, to adjust the filling level in the upper collecting subspace 41 so that a seal is always ensured in the case of the steepest bulk cone (σ=90°) and in the case of a certain lateral offset of the bulk cone, wherein the maximum lateral offset for ensuring the seal can be, for example, up to 30 mm, up to 50 mm or even up to 100 mm. For typical filling levels to be achieved, the width b of the upper collecting subspace 41 is also 500 mm at most, in particular up to about 450 mm at most, as a standard.

[0086] Figure 5 A control device 81 is shown, which can correspond to the control device of the entire rolling mill (this applies similarly to other rolling facilities) and can be integrated into the control device of the entire system or connected to the system via a suitable communication channel. The control device receives the signals of the radar sensor 27 and / or one or more other sensors for detecting the filling level and controls the conveyor shaft drive 21 and the feed roller drive 22 and, in some cases, also influences the flow rate of the fed process material, which is Figure 5 , an optional control device for the inlet slide 85 is shown in FIG. In an embodiment, the control is implemented using a relatively narrow upper sub-collection space 41, so that the above-mentioned condition is met, according to which the processed product always faces the volume of the sealed feed inlet below, for which a separate conveyor shaft-drive 21 is advantageous. In particular, when integrated into the control device of the rolling mill, the speed of the grinding roller can also be controlled accordingly (grinding roller-drive 82). The user interface 84 allows information and commands to be input and / or output by or to the user, for example manually influencing the speed of the feed roller and / or the conveyor shaft. Figure 5 Also shown is the option of adjusting the feed gap in a motorized and controlled manner (feed gap adjustment 83 via an adjustable slide 15), wherein in many embodiments the feed gap is adjusted mechanically and with the feed device stationary, wherein, however, the feed gap can also be adjusted during operation.

[0087] By automatically adjusting the rotation speed of the conveyor shaft and / or feed roller as a function of the fill level measured by the radar sensor 27, the sensors, control devices and drives of the conveyor shaft and / or feed roller form a closed control loop, wherein the fill level of the workpiece serves as an adjustable target value, for example.

[0088] Figure 6 A rolling mill is shown as an example of a roller installation and, in addition to the feed device 1, a grinding space 93 with a pair of grinding rollers 91 is shown, between which a grinding gap 92 is formed, into which the workpiece conveyed by the feed rollers 14 enters. In the example shown, at least one suction channel 94 is present between the upper region of the upper subcollection space 41 above the filling level 61 and the grinding space 93, in particular the region above the grinding rollers 91. Figure 6 As shown, such a suction channel can be guided along the rear side of the collecting space 12. Additionally or alternatively, suction channels guided laterally along the upper collecting space and, for example, behind the lower collecting space are also conceivable.

[0089] Figure 7 Very schematically, a "narrow" inlet, i.e. with Figure 3 and Figure 4 1. A top view of a twin-roll mill with a feed device of the type shown in FIG. The feed opening 11 comprises connections for four pipes. In the vicinity of the upper sub-collecting space 41, on both sides, suction channels 93 extend respectively along the side walls of the upper sub-collecting space. The dashed line indicates the division between the front chamber and the rear chamber of the upper sub-collecting space, whereby the workpiece is already divided in the upper sub-collecting space into the portions of the front grinding roller pair (e.g. Figure 7 The lower half of the middle roll mill) and the rear grinding roll pair (e.g. Figure 7 The suction channel extends below the upper collecting subspace, between the lower collecting subspace for the two grinding roller pairs and the associated feed rollers and the conveying shaft. A conveying pipe 71, which does not necessarily belong to the rolling mill, also extends between the lower collecting subspace for the two grinding roller pairs and the associated feed rollers and the conveying shaft.

[0090] exist Figure 8Schematically, the following possible solution is shown in FIG: the second conveying device (here the second conveying shaft 18) is provided with a mixing structure, i.e. a structure that moves the processed products and mixes them without systematically conveying them in one or another axial direction. The mixing structure can be formed, for example, by rods extending outwards from the shaft core, or by any other structure suitable for the mixing process. These mixing structures are located in the central area below the feed opening. The same possible solution also exists for the first conveying device (first conveying shaft 17).

[0091] In the following Figure 9-Figure 17 The following possibility is depicted very schematically, namely how the second conveying device can be designed as an alternative to a one-piece shaft with a shaft core and conveying structures arranged opposite to each other on both sides, as has already been schematically depicted in the previous examples.

[0092] according to Fig. 9 The second conveying device can be a multi-piece device, that is, Fig. 9 The conveyor is in two parts, with a second conveyor shaft on each side, wherein the second conveyor is interrupted in the area below the feed opening. Fig. 9 In the embodiment, the drive is realized by means of a suitable transmission, for example at least one belt, via a conveying shaft drive 21 .

[0093] However, in Fig. 9 The solution shown is as follows Fig.10 As shown, the second conveying axes 18 can also each comprise their own drive 112 .

[0094] Fig.11 The second conveying axis or the second conveying axis 18 is not extended in the axial direction, but is at an angle to the axis of the feed roller and the first conveying axis. Fig.11 In the embodiment, the second conveyor axis is vertical so that it conveys the workpiece conveyed to the end side upwards, from where it can fall laterally again and be caught by the first conveyor axis or conveyed through the feed gap and in no case accumulate at the end side.

[0095] Fig.12 A possible solution is schematically shown in which the second conveying device is not formed by a conveying shaft, but by a periodically moving plunger 118 which presses the accumulated workpiece inwards.

[0096] As another possible solution, Fig.13 A second conveying device in the form of a pivot plate 119 is shown, which likewise moves the accumulated workpieces.

[0097] according to Fig.14The second conveying device uses a compressed air nozzle that blows the workpiece accumulated on the end side inward.

[0098] Fig.15 A possible solution for a second conveying device is shown very schematically, which, although present as a second conveying shaft 18, is not arranged above (and / or laterally) the first conveying shaft, but as a "shaftless" (or "coreless") screw conveyor, which can accommodate the first conveying shaft in its interior, i.e., the screw conveyor can be approximately coaxial with the first conveying shaft.

[0099] Fig.16 Also shown very schematically are rollers 122 with a conveying structure which can be arranged vertically or horizontally in order to convey workpieces accumulated on the end side away from the end side.

[0100] Fig.17 A wraparound belt with a conveying structure is shown, which can be arranged such that, for example, at one side (for example at Fig.17 In the region above the first conveyor device (above the dotted line in FIG. 1 ), the first conveyor device is connected to the region above the first conveyor device, while in the region not in contact with the workpiece (in the Fig.17 Stretch is returned in the example below the dotted line in .

[0101] Fig.18 A design scheme of the collection space 12 is shown, which is consistent with the design scheme according to Figure 2 The design of is different in that the rear wall of the collecting space forms a shoulder 121 at the narrowest point directly above the feed roller. This shoulder 121 - in the form of a vertically extending wall section of the inclined rear wall - effectively counteracts bridge formation in the case of poor flowability of the grinding material.

[0102] Fig.19 Finally, the principle of the mixing rod 122 on the second conveying shaft 18 is shown. Fig.19 In the drawing, the paddles 19 can also be seen, ie the means for transporting away from the end side are arranged only completely on the outside on the second conveying shaft, which may be sufficient to achieve the effects discussed in this context.

[0103] As an alternative to the embodiment shown, all aspects of the invention can also be realized if the feed opening is not arranged centrally but laterally.

Claims

1. A feeding device for a roller-type facility for food processing, comprising: a collecting space (12), into which the processed material can be fed via a feeding port; and a feed roller (14) having an axis, wherein the feed roller (14) is arranged on the collecting space at the lower side, and wherein the workpiece present in the collecting space (12) can be transported out of the collecting space by the feed roller (14), wherein the feeding device also includes a first conveying device above the feed roller (14), the first conveying device being used to convey the workpiece in the collecting space (12) toward at least one end side in an axial direction, and is characterized by a second conveying device being used to convey the workpiece conveyed by the first conveying device away from the end side.

2. The feeding device according to claim 1, wherein: The second conveying device is configured to convey the workpiece conveyed by the first conveying device in a direction opposite to the axial direction.

3. The feeding device according to claim 1 or 2, wherein: The second conveying device is arranged above the first conveying device.

4. A feeding device according to any one of the preceding claims, wherein The first conveying device is formed by a first conveying shaft (17) and the second conveying device is formed by a second conveying shaft (18).

5. The feeding device according to claim 4, wherein: The first conveying shaft (17) and / or the second conveying shaft (18) comprises a shaft core and a paddle (19), wherein the paddle is fixedly connected (for example, welded) to the shaft core.

6. The feeding device according to claim 4 or 5, wherein: The first conveyor shaft and the second conveyor shaft are coupled to one another and / or to a common conveyor shaft drive, so that they rotate at a fixed speed ratio.

7. A feeding device according to any one of claims 4 to 6, wherein: At least the second conveying shaft (18) is free of paddles (19) and other conveying structures in the area below the feed opening (11).

8. A feeding device according to any one of claims 4 to 7, wherein: The first conveying shaft (17) and the second conveying shaft (18) respectively comprise a first outer region and a second outer region having a conveying structure, wherein the conveying structures of the first outer region and the second outer region convey in opposite directions.

9. A feeding device according to any one of claims 4 to 8, wherein: The first conveying shaft and / or the second conveying shaft has a mixing structure (101, 102, 122) for actively mixing the process material in the area below the feed opening (11).

10. A feeding device according to any one of the preceding claims, wherein: The first conveyor device and the second conveyor device have a conveyor device drive which is independent of the drive of the feed roller.

11. The feeding device according to claim 10, wherein: At least the delivery performance of the first delivery device can be regulated.

12. A feeding device according to any one of the preceding claims, wherein The collecting space comprises a lower sub-collecting space and an upper sub-collecting space, wherein the upper sub-collecting space is formed by a downwardly open chamber having a surrounding wall and opens into the lower sub-collecting space at the lower side, wherein the extension of the chamber in the axial direction is smaller than the axial extension of the feed roller (14) and the conveying device.

13. The feeding device according to claim 12, wherein: The collecting space (12) comprises an observation window, which extends downward at least to the lower sub-collecting space (42).

14. A roller facility comprising: at least one processing space (93) with at least one pair of processing rollers (91), between which the workpiece can be reduced in size and / or pressed into sheets; and a feeding device (1) according to any one of the preceding claims, which is arranged so that the workpiece conveyed by the feed rollers (14) enters the processing space (93).

15. The roller installation according to claim 14, comprising a gas-conducting suction channel (94) between the upper region of the collecting space (12) and the processing space (93).

16. A roller installation having a feed device with a collecting space (12) and a processing space (93) with at least one pair of processing rollers (91), between which the processed material can be reduced in size and / or pressed into sheets, wherein: The collecting space (12) includes a lower sub-collecting space (41) and an upper sub-collecting space (42), wherein the upper sub-collecting space (41) is formed by a downwardly open chamber having a surrounding wall and opens into the lower sub-collecting space (42) at the lower side, wherein the extension of the upper sub-collecting space in the axial direction is smaller than the axial extension of the feed roller (14), wherein the workpiece can be fed into the upper sub-collecting space (41) via the feed port (11), wherein the feeding device also has a feed roller (14) with an axis, wherein the feed roller (14) It is arranged at the lower side at the lower sub-collecting space (42), wherein the workpiece in the lower sub-collecting space can be transported from the lower sub-collecting space to the processing space (93) by the feed roller, and wherein the feed device also has a first conveying device for conveying the workpiece in the lower sub-collecting space (42) in an axial direction, characterized in that the roller facility also has at least one gas-guiding suction channel (94) between the upper sub-collecting space (41) and the processing space (93).

17. The roller facility according to claim 16 has a control device (81) configured to operate the feed roller (14) and at least one of the conveying devices so that the workpiece always seals the feed port (11) toward the sub-collection space (42) below.

18. The roller installation according to claim 17, having a fill level monitoring device for determining the fill level in the collecting space, wherein: The control device is configured to take the determined filling level into account when regulating the amount of process material entering the collecting space through the feed opening and / or the rotational speed of the feed roller (14) and / or the conveying capacity of the first conveying device.

19. The roller installation according to any one of claims 16 to 18, wherein: The collection space (12) comprises an observation window, which extends downward at least to the lower sub-collection space (42).

20. The roller installation according to any one of claims 16 to 19, wherein The suction channel (94) or at least one of the suction channels is guided laterally or at the rear along the upper sub-collecting space (41) and at the rear along the lower sub-collecting space (42), and terminates above the pair of processing rollers (91).

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