Grain Wetting Equipment

Abstract

The grain wetting device (1) of the aforementioned type comprises a vessel having a vessel inlet (11) and a vessel outlet (12) arranged in such a way that the grain flowing into the vessel inlet reaches the vessel outlet under the action of gravity. A number of nozzles (36, 37) serve to wet the grain inside the vessel. The wetting device further comprises a flow guide device inside the vessel, for example formed by an impingement element, which shapes the grain flow entering the vessel inlet and falling downwards. The nozzles (36, 37) are arranged in such a way that liquid and / or steam exiting therethrough strikes the grain below the flow guide device while the grain is in free fall.

Description

[Technical field]

[0001] The present invention relates to an apparatus for wetting grain for subsequent further processing into a milled product.

[0002] In the milling equipment, the cereal product is sprayed (humidified / wetted) with water for further processing. The moistening procedure is necessary so that the grain husk is detached to an improved extent from the endosperm. This leads to a more uniform milling and a higher yield. According to the state of the art, here, following the spraying, the best possible mixing of the grain with the water is generally achieved by mechanical treatment in a conveying screw. For this purpose, the respective moistening device in the grain mill usually comprises a horizontally placed rotating shaft equipped with various mixing facilities. The grain flows continuously into this equipment. At the same time, a defined amount of water is metered into this equipment. The grain is mixed with the free water by the rotating shaft as well as the stirring and mixing elements of the rotating shaft. Following moistening, the grain is conveyed to a so-called thermoregulation cell and left there for some time, usually several hours, before it can be further processed.

[0003] Such wetting devices, in terms of their function and their structure, should not be confused with washing equipment, which are used in modern industrial mills in the preliminary process and have, among other things, the purpose of removing contaminants in the grain by separating the wash water in which the contaminants are dissolved.

[0004] In fact, apart from good wetting properties, further features are placed on the important method step of wetting in grain mills. Germ contamination of cereals by field bacterial flora, which inevitably enters into the milling procedure with grain mills, is unavoidable. The interior of the wetting device provides microorganisms and bacteria with ideal breeding conditions for growth. For this reason, the ability to clean the interior of the wetting device, as in the case of other devices of the milling installation, is an essential requirement.

[0005] Wetting devices according to the state of the art require mechanisms for mechanical mixing of the grain, but have the disadvantage that they are difficult to clean: in particular, cleaning of the mixing elements and mixing spaces, in which the elements and spaces are wet and therefore correspondingly sticky grain and further residues are constantly located during operation, requires a great deal of effort and is therefore often neglected.

[0006] The object of the present invention is therefore to provide a method and an apparatus for wetting grain which overcomes the drawbacks of the state of the art. The wetting apparatus should in particular be simple in its construction and therefore require as low as possible manufacturing costs and in particular as low as possible maintenance costs. Additionally or alternatively it should be easy to clean. The wetting method should accordingly allow for as simple as possible construction of the wetting apparatus.

[0007] This object is achieved by a wetting device, a method and a milling installation as defined in the claims.

[0008] The invention is based on an approach in which a (defined) falling stream of grain is generated inside a vessel and, as it falls, this grain is sprayed with liquid and / or steam (i.e. with water or water steam, and, if necessary, with water enriched with additives in both cases).

[0009] The temperature of the water during the spraying procedure can be set to any value depending on the requirements, i.e. from 0 ° C to 100 ° C. The temperature and pressure of the steam are likewise not set to a fixed operating point but can vary.

[0010] The fact that the grain is exposed to the spray and / or steam "as it falls" means that the liquid or steam in the form of fine droplets does not strike the grain as it falls and does not strike it until, for example, the grain hits the substrate.

[0011] In contrast to spraying of grains, which form a mass of grain particles (bulk grains) that are in a stationary state or are transported and / or mixed by mechanical means and in contact with each other, essentially all grains are in direct contact with the wetting fluid (liquid and / or steam) that has already been sprayed and / or exposed to steam. Therefore, no subsequent mechanical thorough mixing of the grains is necessary. Mechanical mixers, such as conveying screws, which require a lot of effort to inspect and clean, can be omitted. In contrast, the wetting device can include no actively driven parts that contact the grains and mechanically move them.

[0012] The temperature of the water is between 0 ° C and 100 ° C during the spraying procedure. If wetting is carried out at least partially by steam treatment, the temperature and pressure of the steam are not fixed at the operating point but can vary as well.

[0013] The milling installation can be constructed in such a way that the grain reaches the temperature-regulating cell directly from the moistening device, in particular only due to the influence of gravity if the temperature-regulating cell is below the moistening device, or simply by air pressure means if the temperature-regulating cell is above or at the same height as the moistening device, although under certain circumstances after a short residence time in the vessel, and in any case without subsequent thorough mechanical mixing.

[0014] In particular the falling flow of grain can be curtain-like and locally spread, i.e. form a flat profile in horizontal cross section, thus wetting of essentially all grains can be achieved, for example by spraying from two sides and / or by steam treatment.

[0015] In particular, the falling stream is vertical, which allows the falling stream to be particularly easily controllable, especially given the larger particles throughout, but also in the case of smaller particle throughputs, the wetting works without the need for horizontal impact on the grain.

[0016] The spraying and / or steaming can be carried out by suitably positioned nozzles, in particular these can be arranged so that essentially the complete falling stream is wetted.

[0017] In particular, the falling stream can form a hollow cylinder, for example it can be essentially a hollow annular cylinder with radially outwardly projecting leaf projections. Such a falling stream is star-shaped in horizontal cross section and thus a circular ring with a plurality of radial structures projecting radially outward therefrom, and therefore has a particularly large surface area for spraying and / or steaming simultaneously from the inside and outside.

[0018] Very generally, a divided falling flow can be generated by designing the flow guide device with radially extending dividing elements, for example by forming a plurality of radially extending radial structures in a horizontal cross section. This allows the surface to be particularly large and in particular the nozzles acting from the outside and distributed along the circumference of the vessel to be wetted in a particularly efficient manner, for example by being arranged circumferentially (azimuthally) between the segments. For this purpose, there can be at least three outer nozzles distributed along the circumference, i.e. the outer nozzles are each located at at least three different azimuth positions. In particular, at least one outer nozzle can be present in each intermediate space between two outer (radial) impingement elements.

[0019] The wetting device can include inner and outer nozzles regardless of the exact shape of the falling stream. The inner nozzles can be located, for example, approximately on the axis of the vessel. The outer nozzles can be located in several planes along the vessel wall, for example on the feed conduit, forming one or more horizontal peripheral rings.

[0020] Such an arrangement with an inner and an outer nozzle has the advantage that the construction is particularly simple and no elements protrude into the interior which could potentially block the falling flow, and the interior in the plane of spray can be completely free except for the centrally located inner nozzle and the elements for its supply.

[0021] However, other arrangements of the nozzles are possible, for example on a frame which holds the nozzles in a position optimized for the desired requirements.

[0022] The nozzle may in particular possibly be an inner nozzle, but under certain circumstances the outer nozzle may also be designed as a fan spray nozzle in order to allow a relatively wide spray angle.

[0023] In particular, the contoured falling stream is shaped by a flow guide device arranged inside the vessel, generally above the nozzle. The grain stream entering the vessel through an inlet, which can be closed in a conventional manner by an inlet slide or inlet flap, is shaped in the desired surface-optimized manner by the flow guide device. The flow guide device retards and shapes the vertical grain stream so as to create a falling stream with a large surface area (lateral surface area) and as favorable wetting as possible. The falling stream is sprayed below the flow guide device at the position where the grain falls freely.

[0024] The flow director thus subdivides the interior of the vessel into a collection area above the flow director and a drop area below the flow director.

[0025] For this reason, the following cases are possible:

[0026] The particles are only sprayed while falling downwardly below the flow director, and not while, for example, hitting the flow director or sliding any significant distance along it.

[0027] The particles are deflected only on the plane of the flow guide, from where they fall through the interior of the vessel without further deflection. Thus, in contrast to an arrangement with, for example, cascaded guide surfaces, no spaces can be present that are blocked by the flow guide, which would require a significant effort to clean. In particular, the wetting device can be designed in such a way that the grains falling freely downwards from the flow guide do not strike directly against the vessel wall that separates the vessel to the bottom, or, depending on the throughput, against already collected and stacked grains, but against further deflecting elements, screens, etc.

[0028] The buffer space can be formed below the collection area and the drop area, for example in the central part of the container following the drop area, which can be merged into the buffer space without a defined or visible clear separation. The container is delimited at the bottom by an outlet, which can likewise be closed in a manner known per se by an outlet slide or an outlet flap.

[0029] Such a flow guide device may firstly comprise a central collision element, the dimensions of which are adapted to the inlet in such a way that essentially all grains entering through the inlet strike the central collision element (or, in case of accumulation, the already accumulated grains) and are prevented from falling directly through the inlet downwards through the vessel without being braked. In some cases, the central collision element is below the inlet at the fall line and is dimensioned and arranged to cover this entire cross-sectional area (projection along the vertical). The upwardly facing collision surface may in particular be convexly curved and, for example, rotationally symmetrical about the vertical axis in order to deflect the grains uniformly on all sides.

[0030] The flow guide can further comprise radially extending dividing elements (outer impingement elements) in the outer zone structure, which divide the falling stream in the circumferential direction, so that the above-mentioned radial structure forms a horizontal cross section. These outer impingement elements can further be arranged to rise towards the outside, thus forming a base that tapers downwards towards the axis, towards the center and interrupted by intermediate spaces between the impingement elements. For this reason, especially when there is a large grain flow and the accumulation caused by this, the radius of the radial structure automatically expands, which is why the flow guide acts self-regulating: when there is a larger grain flow, the side of the falling stream increases, but the grain density and the thickness of the falling stream profile remain the same and the efficiency of wetting is not impaired.

[0031] In particular, the outer impact element may have the shape of an upwardly arched wing or a wing tapering upwardly towards its edge, the width of said wing increasing radially outward and its apex rising radially outward.

[0032] In particular, the impact element is arranged in the wetting device so that it does not have the function of peeling off the husks (i.e. the wetting procedure is carried out gently and at an impact speed against the impact element) and is shaped and arranged so that the impact speed of the grains at the collection surface in the lower region of the wetting device, where the grains fall after wetting, is correspondingly moderate and so that practically no mechanical processing of the grains takes place.

[0033] In particular, the vessel may be cylindrical, for example in the region having a circular cross section. It may, for example, comprise a central cylindrical region, which includes, inter alia, the region where the spray mist of spray liquid or steam impinges on the falling stream of grain. Conical inlet and outlet regions may be present at the top and bottom, respectively, which continuously taper towards the inlet and outlet, respectively.

[0034] The inlet and / or outlet may be centrally located, i.e. their respective medial axes may coincide with the (vertical) medial axis of the vessel, which in this document may be referred to simply as the "axis".

[0035] Independently of the cross-sectional shape of the vessel, the wetting device can be designed such that there are no internal surfaces to which the grains may remain attached, in particular such that the vessel does not form any upwardly facing surfaces (such as shoulders) and, apart from the impingement elements which, for example, only comprise curved and / or inclined surfaces, there are no elements in the vessel interior with further upwardly facing surfaces.

[0036] However, optionally, one can envisage a moistening device that is controlled so that the moistened grain is accommodated in the lower part of the container for a short period of time (typically a few seconds, e.g. 8-30 seconds), which can have a moisture equilibration effect, if necessary, in addition to the moisture equilibration in the subsequently placed temperature regulating cell.

[0037] The filling of the lower part of the container can be achieved with the help of an accumulation closed-loop control device (accumulation closed-loop control element). What is described here by "accumulation closed-loop control device" is a shut-off element that can be switched between two states ("open" and "closed") as well as closed-loop controlled in terms of allowing the setting of different throughputs. Examples of such accumulation closed-loop control devices are accumulation closed-loop control flaps or outlet slides.

[0038] The accumulation closed-loop control device is especially configured for closed-loop control of the mass flow of moistened grain as a function of the accumulation level. In particular, the accumulation closed-loop control flap, in contrast to the outlet slide, can be advantageous under certain circumstances by preventing the grain from flowing out of the container asymmetrically, so that in the accumulated product there are areas that stay in the container for a significant time and where only a part of the mass flow falls out of the container. In one example, an accumulation closed-loop control flap is used with two (or possibly three or more) flap wings, said flap wings in the closed state each closing a part of the flow cross section. By using several flap wings, a particularly uniform discharge of the grain is ensured even with only partial opening of the accumulation closed-loop control flap.

[0039] For the purpose of closed-loop control of the accumulation, there may furthermore be at least one level sensor, by means of which the reaching of the grain level to a level above the accumulation closed-loop control device can be determined. The at least one level sensor may allow the measurement of the level or may act discretely, i.e. for example, to determine the reaching of a certain predefined level. In both cases, there may also be several level sensors, and in the second case, various level sensors are installed to determine different level heights.

[0040] The accumulation closed-loop controller can be integrated into a control loop together with at least one level sensor, which close-loop controls the level according to specifications by setting the throughput by the accumulation closed-loop controller (the position of the flap or flap wing gives the accumulation closed-loop control flap), which specifications can depend on parameters (e.g., product characteristics, desired wetness, temperature, etc.) and / or settings performed by the user.

[0041] The accumulation closed loop control flap (or the outlet side) can be clamped between two fastening flanges, which allows the flap or slide to be disassembled at any time.

[0042] Providing an accumulation closed-loop control device is also an option (especially together with a level sensor and especially together with the closed-loop control described in this specification) for very general wetting devices, i.e. wetting devices for grain having a container (having a container inlet and a container outlet) and at least one nozzle for wetting the grain inside the container.

[0043] The container can be in two parts, for example with a container top and a container bottom. The container top and container bottom can be fastened to each other via a flange connection. In particular in embodiments where a cleaning device is present, it is generally not necessary that the container top and container bottom can be separated from each other with little effort.

[0044] Optionally, but often particularly advantageously, the cleaning device comprises, for example, a number of cleaning spray balls and / or cleaning lances. Such cleaning spray balls or cleaning lances can be fixedly positioned or, in particular in the case of cleaning lances, each can be extended into the interior of the vessel and comprise an element supporting at least one cleaning nozzle. The cleaning lances can be designed such that the extension is automatically performed by the water pressure as soon as the cleaning lance is supplied with cleaning water. Instead of automatic extension by water pressure, pneumatic actuation or another extension mechanism is also conceivable. Retraction after cleaning has been performed can be performed automatically, for example by spring force or air pressure.

[0045] A cleaning device of this type can in particular comprise at least one (generally several, for example three) cleaning lances or cleaning spray balls, possibly each with a cleaning nozzle in the (upper) collection area, and at least one (also generally several, for example three) cleaning lances with a cleaning nozzle in the drop area. Additional cleaning nozzles can possibly be provided for additional cleaning lances, if, for example, the area below the flow guide has corresponding dimensions. The vessel and the cleaning device can be adapted to one another in such a way that internal cleaning can be carried out without obstructed spray areas.

[0046] The container can be provided with a container-emptying connection in the lower region. Such a container-emptying connection can be closed by an outlet ball cock or an outlet flap in a manner known per se. The cleaning agent (typically cold or hot water) is removed from the container via the container-emptying connection. Additionally or alternatively, the container-emptying connection can be integrated into the outlet flap or outlet slide, which can, for example, be provided with an opening for residual cleaning water, said opening, for example, being provided with a perforation through which the cleaning water can be removed.

[0047] In particular, the wetting device may comprise a (specially designed) outlet flap that can be switched between a closed and an open state, in which case the cleaning fluid inside the container cannot flow through the container outlet, but which comprises a hollow shaft and an opening that in the closed state is open to the inside of the container and connected to the hollow shaft. Given a closed outlet flap, the cleaning fluid can drain from the inside of the container through the opening and the hollow shaft without flowing through the container outlet.

[0048] In particular, cleaning is performed during out-of-operation periods when particles are not being fed to the wetting device. This means that the wetting device is configured not to deliver cleaning fluid during a wetting operation when the wetting nozzle is in operation and particles are being fed through the vessel inlet. In contrast, the wetting device is configured to deliver fluid through the cleaning nozzle during a dedicated cleaning operation.

[0049] A cleaning device of the described type having a nozzle for spraying the inner walls of a container and / or other elements arranged inside the container, which nozzle is arranged inside the wetting device and / or can extend into the interior of the wetting device (especially with an outlet flap of the aforementioned type through which the cleaning fluid can be discharged), is also an option for a very general wetting device, i.e. a wetting device for grain with a container (having a container inlet and a container outlet) and with at least one nozzle for wetting the grain inside the container.

[0050] The wetting device operates in such a way that wetting is achieved with the desired amount of fluid. Thus, at any given time, there is no excess water being fed, and such excess must again be separated from the system. For this purpose, a control device (belonging to the wetting device or to a higher-level unit, e.g. a complete flour milling installation) can monitor the throughput of grain, and the amount of fluid or steam sprayed, and also the metered input of at least the latter. Here, the metered input is made exactly in the amount desired according to the requirements to be metered in. This generally contributes 0.5% to 12% (percent by mass) of the grain amount, and is therefore an order of magnitude smaller than, for example, a given grain cleaner.

[0051] In order to determine the metering according to requirements, installations with a wetting device can also be equipped with a measuring device for measuring the actual grain moisture of the respective grain charge separately from the wetting device. Such a measuring device detects the moisture content of the grain in-line before the wetting procedure by means of a measuring instrument (in-line moisture sensor). For this purpose, the control device calculates the required amount of water wetting.

[0052] Apart from the moistening device and the method for operating the moistening device, the subject of the present invention also includes a milling installation. Such an installation comprises devices of a type known per se (for example roller mills and sieving devices, as well as weighing and / or metering devices and conveying devices), as well as a moistening device of the type described herein. In addition, there may be a temperature-conditioning cell arranged after the moistening device. In particular, the milling installation may be designed in such a way that no mechanical mixing of the grain takes place and no mechanical conveying means with physical contact with the grain act between the moistening device and the temperature-conditioning cell (not excluding the presence of an optional pneumatic conveying (conveying with a gas flow)).

[0053] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following, examples of embodiments of the present invention will be described with reference to the drawings, in which the same reference numerals represent the same or similar elements, and in which the elements partially correspond to one another and are of different dimensions from one drawing to the next. [Brief description of the drawings]

[0054] [Figure 1] FIG. [Diagram 2] FIG. [Diagram 3] FIG. 3 is a view of the wetting device according to FIGS. 1 and 2, cut along the plane EE of FIG. 2. [Figure 4] FIG. 4 is a view of the wetting device according to FIGS. 1 to 3, cut along a horizontal plane above the impact element. [Diagram 5] FIG. 5 is a view of the upper part of the container of the wetting device according to FIGS. 1 to 4, cut along a vertical plane. [Figure 6] FIG. 6 is a perspective view of the horizontal pipe, the vertical pipe and the central impingement element of the wetting device according to FIGS. 1 to 5. [Figure 7] FIG. 1 is a schematic diagram of a humidification device having a temperature regulating cell. [Figure 8] FIG. 13 is a perspective view of a further wetting device; [Figure 9] FIG. 2 is a cross-sectional view of a further wetting device. [Figure 10] FIG. 10 shows a detail of the wetting device according to FIGS. 8 and 9. [Figure 11] FIG. 10 shows a detail of the wetting device according to FIGS. 8 and 9. [Figure 12] FIG. 10 shows a detail of the wetting device according to FIGS. 8 and 9. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0055] An example of a wetting device 1 is shown in a perspective view in Figure 1 and in a side view in Figure 2. The wetting device comprises a container formed by a container top 2 and a container bottom 3 connected to each other by a flange connection. The flange connection is formed by an upper flange ring 4 and a lower flange ring 5 which are screwed together in the ready-for-operation state. As will be explained below, the flange connection does not need to be released for cleaning of the wetting device.

[0056] The upper vessel part 2 forms the inlet 11, and the lower vessel part 3 forms the outlet 12, which are, for example, aligned with each other and arranged straight below each other in the fall line. The inlet and outlet in the illustrated embodiment example are each arranged centrally, i.e. their vertical axis coincides with the axis of the vessel. They are generally formed in such a way that a simple connection to elements of the milling installation arranged upstream and downstream, such as vessels, metering systems, pipe conduits, etc., is possible. For this purpose, inlet and outlet connection structures (for example suitable connection stubs in each case) can be present at the part of the inlet 11 or outlet 12, respectively. Furthermore, closing inlet and closing outlet flaps are present at the inlet and outlet, respectively, or at suitable slides or other shutoff elements. In the illustrated embodiment example, the inlet and outlet flaps 13 and 14 are each manually operable by means of suitable operating levers 15 and 16, respectively.

[0057] The vessel is formed by a vessel upper part 2 and a vessel lower part 3 and comprises a vessel wall forming a body of revolution with an essentially vertical axis 20. In the central region, the vessel wall is designed cylindrically and conically towards the inlet 11 and outlet 12.

[0058] As can be seen in Fig. 3, a central impact element 21 is arranged below the inlet 11. This forms an upwardly convexly curved impact surface 22. The outer impact elements 23, also shown in Figs. 4 and 5, are also located radially outward of the central impact surface and are each designed roof-like with a pair of inclined sections forming a peak, which extends radially and outwardly with a slight rise from which descending inclined sections extend on both sides. As is particularly visible in the plan view according to Fig. 4, the width of the impact elements increases radially outward, so that the intermediate spaces 24 between the impact elements form radially extending gaps whose width remains approximately constant with only a slight increase radially outward.

[0059] The wetting device further comprises a number of nozzles for spraying fluid onto the falling grain.

[0060] A first set of nozzles is formed by the inner nozzles 36 through which the fluid is sprayed radially outward from a substantially axial position. An inner nozzle 36 other than that of FIG. 3 can also be seen in FIG. 6. The inner nozzles in the illustrated example are formed in a vertical pipe 32 into which the fluid enters from the horizontal pipe 31. The vertical pipe also supports a central impingement element 21, which for this reason is fastened to the vessel lower part 3 in the embodiment described here, in contrast to the outer impingement element present in the vessel upper part. The horizontal pipe 31 runs across the vessel and conveys the vertical pipe 32, which is supplied with the fluid from one side through a vessel cutout. A branch 35, for example, is also located at the place where the vertical pipe 32 is fastened. A part of the fluid is led from there further through the horizontal pipe and, on the side opposite the vessel cutout, through a further vessel cutout into an arcuate transition pipe 33 (FIG. 2) and from there into the nozzle ring of the outer nozzles 37. Other routes of fluid guidance to the nozzles are also possible, e.g. no bifurcation, where the fluid then passes, for example, upwards through a vertical pipe to the inner nozzle and from there downwards again into the interior of the vertical pipe, or using a transition between the inner and outer nozzles in the vessel instead of the transition pipe 33, directing the fluid to the inner nozzle via the outer nozzle instead of the other way around, using separate fluid supplies for the inner and outer nozzles, etc. Many further routes of fluid guidance to the nozzles are also conceivable.

[0061] The inner nozzles 36 are designed as fan jet nozzles which spray the fluid at a wide angle, so that together they form an annular region (ring diameter: somewhat larger than the diameter of the central impingement element) around them in an essentially complete manner.

[0062] The outer nozzles 37 are arranged in a ring and spray from the outside to the inside. The outer nozzles can also be fan-injection nozzles, with a smaller spray angle than the inner nozzles, for example. The azimuthal position of the individual outer nozzles can be matched to the respective position of the outer impingement elements, in that each outer nozzle is in each case below the intermediate space between adjacent outer impingement elements and sprays the space through which the grain falls downwards.

[0063] Like the inner nozzle 36 , the outer nozzle 37 is also arranged approximately at the level of the flange connection between the upper vessel part 2 and the lower vessel part 3 .

[0064] The grain led into the moistening device from the inlet 11 falls onto the central collision element 21 and is deflected radially outwards from there. The grain stream is then divided in the outer region by the outer collision elements 23. The grain stream is thus shaped by the intermediate spaces between the collision elements 21, 23. In horizontal cross section, the stream has the shape of a ring with radially outwardly protruding radial structures, as can be particularly well seen in FIG. 4, so that, overall, a mass stream with a star-shaped cross section results. Here, the ring and the radial structures are relatively thin, so that grain grains cannot be significantly shielded from the nozzle by other grain grains.

[0065] The slight outward rise of the tops of the outer collision elements ensures a controlled radial distribution even in the most variable cases of flow rate and different velocities of the incoming grains striking the central collision element. When larger mass throughputs are given, a constant accumulation can also be formed. This is automatically controlled by the larger filling of the collection area above the collision elements, in the case of more grains being accumulated, the cross section of the mass flow below the collision elements increases. This is automatically done by the area exposed to the through flow extending further radially outwards, when more grains are accumulated by the collision elements and the area tapering slightly conically towards the center starts to fill above the collision elements 21, 23. It is thus guaranteed that even when a large mass throughput is given, the particles are always distributed in such a way that they form only a very thin particle flow curtain. The spraying by the fluid therefore reaches essentially all the grains, independent of the mass throughput. As a result, no mechanical mixing after spraying is necessary, even when a large mass throughput is given.

[0066] The milling installation can therefore be designed such that the temperature conditioning cell 101 immediately follows the moistening device 1, which is shown diagrammatically in Figure 7. The temperature conditioning cell 101 can be located directly below the moistening device 1 or alternatively, for example aerodynamics (with at least one fan / compressor etc.) acting directly on the grain can transport the grain flow from the moistening device outlet to the temperature conditioning cell inlet. In any case, there are generally no screw conveyors or the like between the moistening device and the temperature conditioning cell, which require significant efforts for maintenance and cleaning.

[0067] During operation of the milling installation, the grain passes from the storage through the moistening device into the temperature conditioning cell and from there (after a suitable temperature conditioning time of several hours, selected according to requirements, for example 8-16 hours) into the further elements of the mill, in particular the roller mill, the sieving device, etc.

[0068] A (optional) particularity of an embodiment of the wetting device according to the invention is the presence of an integrated cleaning device. The integrated cleaning device comprises a number of cleaning lances 41, 42, in particular a number of upper cleaning lances 41 for the space above the impact elements 21, 23 and a number of lower cleaning lances 42 for the space below the impact elements 21, 23. The cleaning lances can each be extended into the interior of the vessel and comprise a nozzle element, each having at least one cleaning nozzle. The extendable nozzle elements can optionally be designed to extend inwards automatically under the action of the water pressure, for example against a spring force, as soon as water is introduced into the cleaning lance. Their arrangement is such that, given the extended nozzle elements, they are essentially completely inside the vessel to be sprayed when cleaning water is introduced with sufficient pressure.

[0069] For cleaning purposes, for example, at least the outlet flaps are closed, water under pressure is directed into the cleaning lances 41, 42, the nozzle elements are extended and the cleaning nozzles at the inner ends of the nozzle elements spray the cleaning water, so that the entire interior of the vessel including the surface of the impingement element is sprayed. The cleaning water is discharged together with the washed-out grain residues via the (closable) vessel emptying connection 51 (outlet stub).

[0070] Even if the connection 51 for emptying the container is arranged directly above the outlet flap 14, a small amount of residual water remains on the outlet flap 14 even after emptying. Insofar as this amount of water is of concern to the user, the wetting device can be configured to remove this amount of residual water as well. For this purpose, for example, the shaft on which the outlet flap or the wings of the outlet flap are attached can be a hollow shaft with perforations in the upper part. The residual water can then be removed via the hollow shaft.

[0071] A further embodiment of the wetting device is shown in Figures 8 and 9. The manner in which the central and outer collision elements 21 and 23 as well as the flow guiding device with sprays function is similar to the embodiment of Figures 1 to 6.

[0072] The moistening device 1 of figures 8 and 9 is provided with a mechanism that allows a controlled accumulation of moistened grain in the lower part of the vessel, so that moisture balance between the grains can be achieved if required. For this purpose, in the embodiment shown, there is an accumulation closed-loop control flap 72. Closed-loop control via an outlet slide is also possible.

[0073] A cross section of the accumulation closed-loop control flap 72 is shown in FIG. 11. In this figure, the closed-loop control flap is shown in the closed position. The accumulation closed-loop control flap 72 comprises essentially identical, symmetrically arranged flap wings 73 (flap halves) which uniformly close-loop control the entire mass flow of particles. The flap wings 73 are adapted to the contour and their position is set by a servo motor (servo-actuated drive 72). When opened, the flap wings 73 rotate from the horizontally closed position in the opposite direction, up to 90° downwards (depending on the opening set) to the outlet, about their flap axis, which is shown by a concentric circle in the cross section according to FIG. 11.

[0074] The symmetrical location of the flap halves avoids zoning or irregular mass flow of particles towards the center of the outlet.

[0075] The filling level in the lower part of the container is controlled in a closed loop by a level sensor 75 which detects the already wetted and accumulated product. For this purpose, the control device (not shown) of the wetting device or of the higher-level unit is equipped with a control loop which controls the level in a closed loop according to specifications, for example by the position of the accumulation closed loop control flap 72.

[0076] The accumulation closed-loop control flap 72 in the example embodiment shown is clamped between two fastening flanges 74 so that the flap can be disassembled at any time (however, this is not essential to the function of the accumulation closed-loop control flap 72).

[0077] During cleaning, the accumulation closed-loop control flap 72 is, for example, fully open.

[0078] A further peculiarity of the embodiment of figures 8 and 9, which is independent of the accumulation closed-loop control flap, is the specially constructed outlet flap 14, which is specially designed for a wetting device with a washing device and can be used as such in general (and therefore also in the embodiments of the type shown in figures 1 to 6). In figure 8 a cross section through the outlet flap 14 is shown. With respect to the outlet flap 14, opposite the drive side, a hollow shaft 53 is the mounting shaft of the outlet flap 14, which is directly integrated in the flap with an opening 52 to the top. The washing water, as well as residual water which may be present in the closed state of the outlet flap 14, can be removed through the hollow shaft, which merges into a connection 51 that empties the container.

[0079] In normal operation of the moistening device, the outlet flap 14 is always open, the outlet flap is closed only for cleaning purposes. In the open state of the outlet flap, the entrance to the hollow shaft is protected by a small pipe protrusion so that moistened grain cannot escape out of the falling stream.

[0080] The embodiments of Figures 8 and 9 have the following differences / particularities in comparison with the embodiments of Figures 1 to 6, which can be realized independently of each other and independently of the design of the accumulation closed-loop control and the outlet flap, i.e. in each case by themselves or in combination or in partial combination, apart from the design of the accumulation closed-loop control and the outlet flap:

[0081] The upper vessel part 2 consists of two parts, in the example embodiment shown, a first part 111 tapering upwards and a second part 112 formed as a cylindrical intermediate piece.

[0082] The internal thread is located in the lower flange ring 5 so that a further nozzle ring 114 (in the illustrated example there are two nozzle rings 114) can be clamped between the upper flange ring 4 and the lower flange ring 5. Here, the lower flange ring 5 is fixedly connected to the vessel lower part 3.

[0083] Instead of manually operated levers, the inlet flap 13 and the outlet flap 14 each comprise a pneumatic drive 115 and 116, respectively. It is an option to provide only the inlet flap or only the outlet flap with a pneumatic drive or to provide the inlet flap and / or the outlet flap with an electromechanical drive, in particular the inlet flap can also be configured to control the throughput (with regard to the outlet flap this option is in particular also present in the absence of a separate accumulation closed-loop control flap, i.e. the outlet flap can be a regulating flap for closed-loop control of the optional accumulation function).

[0084] The central collision element 21 is held by three horizontal support struts 131 fastened to the vessel bottom 3 and by a vertical strut 132. One of the horizontal support struts 131 is designed here as a pipe through which the fluid reaches the inner nozzle 36. The inner collision element 21 with the holder is also shown in FIG.

[0085] The inner nozzles 36 and the outer nozzles 37 in the first outer nozzle ring (in the lower flange ring 5) are always supplied with fluid simultaneously by flexible or rigid connections for wet applications. Here, the fluid can enter directly, for example via the first nozzle ring, into a horizontal support column designed as a pipe.

[0086] The vertical position of the inner nozzle 36 is approximately at the height of the transition between the lower flange ring 5 and the remainder of the vessel lower part 3 , directly below the (lowest) outer nozzle 37 .

[0087] Instead of the upper cleaning lance 41 there is a fixedly installed cleaning spray ball 141, which protrudes into the interior of the vessel slightly above the outer impingement element 23. In contrast, the way in which the lower cleaning lance 42 functions corresponds to the way in which the embodiment of figures 1 to 6 functions, i.e. during cleaning water under pressure is directed to the cleaning spray ball 141 and to the cleaning lance 42, and the nozzle of the cleaning spray ball 141 remains rigidly positioned and the nozzle element of the cleaning lance extends.

[0088] Valid for all embodiments, in the wetting device, the inner nozzles 36 or the outer nozzles 37 can be adapted to the product in terms of type of jet and water throughput. In the simplest case, all the outer nozzles are identical. The application area of ​​the nozzles is optimized for a certain pressure range, for example from 3 bar to 10 bar. In this pressure range, water is precisely specified throughout. If a larger water throughput is required for the wetting procedure than is possible via the fixedly installed nozzles (in the illustrated example, the inner nozzles 36 and the outer nozzles 37 present in the lower vessel part 3), the area of ​​the water throughput can be increased by one or more additional nozzle rings 114, as shown enlarged in Fig. 8 and Fig. 9. The maximum number of additional nozzle rings is not limited. The additional nozzle rings 114 can be supplied with water separately in an external manner. The structure of the additional nozzle rings is shown identically in Fig. 8 and Fig. 9.

Claims

1. 1. A moistening device (1) for grain comprising a vessel having a vessel inlet (11) and a vessel outlet (12), the vessel inlet (11) and the vessel outlet (12) being arranged such that grain flowing into the vessel inlet reaches the vessel outlet by the action of gravity, the moistening device being characterised by a flow guiding device inside the vessel comprising a number of nozzles (36, 37) for moistening the grain inside the vessel, the flow guiding device shaping a stream of grain flowing into the vessel inlet and falling downwards, the number of nozzles (36, 37) being arranged such that liquid and / or steam exiting through the number of nozzles (36, 37) impinges on the grain below the flow guiding device during free fall of the grain.

2. 2. The moistening device according to claim 1, wherein the flow directing device comprises a central impingement element (21) against which grain entering through the vessel inlet (11) impinges and which subsequently deflects said grain.

3. 3. The moistening device according to claim 1 or 2, wherein the flow guide device comprises a plurality of outer impingement elements (23) for dividing the flow of grain falling downwards from the flow guide device into at least a plurality of regions.

4. 4. The wetting device according to claim 3, wherein the outer impact elements (23) are arranged so as to rise outwards.

5. The wetting device of claim 1 or 2, wherein the flow director defines a throughflow cross-sectional area comprising a central ring and a plurality of radial structures extending radially outward from the central ring.

6. 3. The wetting device according to claim 1 or 2, wherein the plurality of nozzles comprises a plurality of inner nozzles having a spray direction from inside to outside and a plurality of outer nozzles (37) having a spray direction from outside to inside.

7. 7. The wetting device according to claim 6, wherein the inner nozzles (36) are arranged in a holder of a central collision element (21) and / or the outer nozzles (37) are arranged along the circumference of a partly annular cylindrical vessel wall of the vessel.

8. The wetting device according to claim 1 or 2, wherein at least some of the nozzles (36, 37) are designed as fan jet nozzles.

9. 3. Wetting apparatus according to claim 1 or 2, wherein the bin does not include an inner horizontal surface below the bin inlet (11) on which grain can rest.

10. 3. The wetting device of claim 1 or 2, which does not contain any elements that move during normal use.

11. 3. The wetting device according to claim 1 or 2, comprising a plurality of washing nozzles capable of introducing a washing fluid into the vessel for rinsing the vessel walls and the surfaces of the flow directing device.

12. 12. The wetting device of claim 11, comprising a plurality of cleaning spray balls (141) and / or a plurality of cleaning lances (41, 42) extendable into the vessel and each having a nozzle element with at least one of a plurality of cleaning nozzles.

13. The wetting device of claim 11 , wherein the plurality of cleaning nozzles comprises a plurality of top cleaning nozzles disposed above the flow directing device and a plurality of bottom cleaning nozzles disposed below the flow directing device.

14. 3. The moistening device according to claim 1 or 2, comprising an accumulation closed-loop control device arranged below the flow directing device and capable of closed-loop control of the flow of the grain through the vessel outlet (12).

15. 15. The moistening device of claim 14, comprising at least one level sensor (75) capable of determining when a grain level reaches a level beyond the accumulation closed-loop control device for the closed-loop control of throughput via the accumulation closed-loop control device.

16. The wetting device according to claim 14, wherein the accumulation closed-loop control device is an accumulation closed-loop control flap (72) having at least two flap wings (73).

17. 3. The wetting device according to claim 1 or 2, characterized by an outlet flap (14) having a hollow shaft (53) connected to at least one opening (52), the opening in the closed state of the outlet flap (14) opening into the interior of the container, and when a closed outlet flap (14) is provided, cleaning fluid can be removed from the interior of the container via the opening (52) and the hollow shaft (53) without flowing through the container outlet (12).

18. 2. A flour milling installation comprising a moistening device (1) according to claim 1 and a temperature-regulating cell (101), the temperature-regulating cell (101) being arranged such that the grain enters directly from the outlet (12) of the moistening device (1) into the temperature-regulating cell (101) without any mechanical treatment means intervening therebetween.

19. 20. The milling installation of claim 18, further comprising a grinding unit disposed downstream of the temperature conditioning cell.

20. 20. The wetting device of claim 1 or the milling installation of claim 18, comprising a control device for metering fluid in response to the measured humidity of the grain.

21. A method of operating a moistening device for grain, characterized in that the moistening device comprises a container, the grain flowing in through a container inlet (11) reaches the container outlet under the influence of gravity, and the grain is sprayed with liquid and / or steam as it falls.

22. 22. The method of claim 21, wherein a contoured falling stream of the grain is generated in the vessel, and the grain in the contoured falling stream falls downwardly while being sprayed with liquid or the steam.

23. 23. The method of claim 21 or 22, wherein the amount of liquid or steam is closed-loop controlled so that its mass accounts for between 0.5% and 12% of the mass of the sprayed grain.

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