EP0122402A2 - Grist mill - Google Patents

Abstract

Grist mill with grindstones (7, 8), in the usable grindstone areas of which air grooves (15, 15a, 15b; 16, 16a, 16b) are staggered in the grindstone depth and introduced with an air groove width based on the staggered depth that the progressive wear of the grindstones ( 7, 8) air furrows (15, 15a, 15b; 16, 16a, 16b) are always exposed at the grinding gap (17) without reworking.

An adjusting device (12, 13, 14) for the width of the grinding gap (17), a metering device for the ground material, a sieving device (43, 44) with a return device (41, 46, 47) for coarse grit is disclosed.

Reinforcing inserts and bristle inserts are advantageously provided in the millstones (7, 8), and a crushing device can be mounted centrally in the millstones (7, 8) on the axis (1a).

Description

The invention relates to a grist mill with two end faces, coaxially and axially displaceable relative to one another for setting a grinding gap, at least one of which is driven and at least one carries an air groove or air groove group on the grinding side and is made from stone grains and binders.

It is known to provide grinding stones on their grinding surface with so-called air furrows running from the inside out, in which the ground material and the meal or flour are distributed radially over the grinding surface by the grinding movement and conveyed to the outside. As the grindstones are subject to constant wear, the depth of the air furrows continuously decreases and their effect diminishes accordingly, so that the grinding performance and quality deteriorate. It is therefore necessary to remove the millstones from time to time and to look up the air grooves.

It has also been proposed in DE-PS 16 20 516 to store wires beneath one another under the furrows, which are gradually torn out as stone wear progresses, as a result of which the furrow becomes deeper. This type of rework also requires removal and installation of the millstones.

It is an object of the invention to disclose a grist mill with novel grindstones which are simple to manufacture and which perform uniformly throughout the at least the same service life and do not require any reworking.

The solution to the problem is that in at least one of the millstones from the grinding side axially in depth and at an angle to one another there are several air furrows, preferably air furrow groups, the air furrow width being selected in relation to their depth gradation so that at least one Air furrow group with progressive wear of the grindstone is on the respective grinding side, and the entire usable grindstone depth is interspersed with air furrows.

In order to ensure that the millstones are filled and used as far as possible, it is advantageous to guide the air grooves to their outer edges. Since in this configuration and if the grinding gap is set relatively wide to achieve high performance, regrind can also emerge unground, it is advantageous to arrange a grinder after the grinder, from which the coarse, non-passing grist or unground into the Mill is returned, so that fine grist with high performance and consistent quality is produced.

Another advantageous embodiment for maintaining a uniform, high performance of the millstones is given by the fact that bristles are axially embedded in the millstones, preferably in the form of thin steel wires, so that they constantly roughen the opposite grinding surface. The bristles or wires are expediently embedded so deeply that they are still fixed even when the grinding stone is completely worn. This represents an independent idea of the invention.

In order to give the millstone increased breaking strength over its long service life and with extreme performance, large-mesh mats made of glass fiber or metal wire are advantageously used in the remaining area stored below the wear area. The axial bristles or wires can also be anchored to these, for example by looping, so that no pieces of wire can escape into the meal.

The grinding stones of the type mentioned can be used advantageously in mills with horizontal and vertical grinding gap. It is also possible for the air furrows and the axial bristles to be introduced alternately in each case only in one millstone.

The return of the coarse grist from the screening device can be done in a very simple manner by means of scrapers which circulate with the grinding stone and spend it in a radial, for example sector-shaped recess in the fixed grinding stone.

A further increase in performance and extension of the life of the grist mill can be achieved by connecting a crushing device in a known manner. In an advantageous embodiment, this is arranged centrally in the grinder and driven directly with the same axis. This is a separate idea of the invention, since this type of construction is very simple and compact in comparison to previously known ones and is nevertheless more powerful.

• Fig. 1 Schrotmühle mit horizontalem Mahlspalt vertikal geschnitten,
• Fig. 2 wie Fig. l - horizontal geschnitten.
• Fig. 3 Schrotmühle mit vertikalem Mahlspalt, vertikaler Schnitt in Achsrichtung,
• Fig. 4 wie Fig. 3 - Schnitt senkrecht zur Achse.
• Fig. 5 Angetriebener Mahlstein im Schnitt,
• Fig. 6 wie Fig. 5 - Aufsicht.
• Fig. 7 Stehender Mahlstein in Aufsicht, mit Sektorausnehmung
• Fig. 8 wie Fig. 7 - im Schnitt,
• Fig. 9 Details zu Fig. 8.
• Fig. lo Mahlsteine mit Armierung durch Matten - axial geschnitten;
• Fig. 11 wie Fig. lo - radial geschnitten.
• Fig. 12 Mahlstein mit Borsteneinlagen - Aufsicht;
• Fig. 13 wie Fig. 12 - axial geschnitten.
• Fig. 14 Schrotmühle mit 3-Spindel-Mahlsteinverstellung und Schneckenförderer; vertikaler Schnitt.
• Fig. 15 Detail zu Fig. 14, 3-Spindelverstellung.
• Fig. 16 Zentrale Mahlsteinverstellung; vertikaler Schnitt.
• Fig. 17 Zentrale Mahlsteinverstellung und Schneckenförderer; vertikaler Schnitt.
• Fig. 18 Mahlsteinverstellung mit Anschlag; vertikaler Schnitt.
• Fig. 19 Schrotmühle mit zentraler Quetschmühle; axialer Schnitt;
• Fig. 2o wie Fig. 19, radialer Schnitt.
• Fig. 21 Schrotmühle mit Quetschwalze; radialer Schnitt;
• Fig. 22 wie Fig. 21, achsial geschnitten.

Various advantageous configurations are shown below with reference to the figures. The individual design features shown can be used in further combinations.

• 1 shot mill cut vertically with a horizontal grinding gap,
• Fig. 2 as Fig. L - cut horizontally.
• 3 grist mill with vertical grinding gap, vertical section in the axial direction,
• Fig. 4 as Fig. 3 - section perpendicular to the axis.
• 5 driven millstone in section,
• Fig. 6 as Fig. 5 - supervision.
• Fig. 7 Standing millstone in supervision, with sector recess
• 8 as Fig. 7 - in section,
• 9 details of FIG. 8.
• Fig. Lo grinding stones with reinforcement by mats - axially cut;
• Fig. 11 as Fig. Lo - cut radially.
• Fig. 12 grinding stone with bristle inserts - supervision;
• Fig. 13 as Fig. 12 - cut axially.
• Fig. 14 Grist mill with 3-spindle grindstone adjustment and screw conveyor; vertical cut.
• Fig. 15 detail of Fig. 14, 3-spindle adjustment.
• Fig. 16 Central millstone adjustment; vertical cut.
• Fig. 17 Central millstone adjustment and screw conveyor; vertical cut.
• Fig. 18 grinding stone adjustment with stop; vertical cut.
• Fig. 19 Grist mill with a central crushing mill; axial section;
• Fig. 2o like Fig. 19, radial section.
• Fig. 21 Shot mill with squeeze roller; radial cut;
• 22 as in FIG. 21, cut axially.

In Fig. 1 a grist mill with a horizontal grinding gap 17 is shown. The millstones 7, 8 are arranged coaxially in a cylindrical housing 4. The lower millstone 7 is fastened on the axis la of the motor 1, which is flange-mounted centrally on the underside 3 of the housing 4, and is thus rotatably mounted. The other grindstone 8 is mounted on the upper housing part with three spindles 13, which are arranged uniformly distributed around the central axis A and are seated with the spindle threads in threaded bushings on the grindstone 8, in an axially adjustable manner. The three spindles 13 carry sprockets which are connected to one another by a chain 14 or a toothed belt, so that they can be adjusted synchronously by means of a handwheel 12, as a result of which the grinding stone 8 can be displaced exactly parallel in a simple manner and the grinding gap 17 exactly to a predetermined depth t1 can be set so that a high grinding performance, a given grinding degree is given and little stone wear occurs.

The grinding stones 7, 8 have so-called air furrows 15, 16, in which the ground material, which is introduced axially into the central recesses 79, and the grist is distributed over the grinding sides 17a or discharged to the outside.

The ground material is fed via a funnel 5 via a metering device, which consists of a gap t2 between the lower funnel edge and an input plate Io, which is fastened on the end face on the motor axis la, and a height adjustment device of the funnel 5, which carries a test adjusting handle 11, which one passes through oblique slot 9a of a bearing bush 9 of the funnel 5, fed to the recess 79.

On the side of the housing 4 there is an outlet opening for the shot, to which an outlet nozzle 6 with a flap 19 and a coarse sieve 43, which serves as a protective grille, is connected in a known manner.

An exchangeable sorting screen 44 is arranged in the outlet opening in the cylindrical surface of the housing 4.

Due to the centrifugal effect of the running millstone 7, an air flow from the supply air opening 23 through the grinding gap 17 to the outlet opening, which also conveys the grist through the sorting screen 44, arises in particular also through the air furrows. Coarse shot parts are picked up by the scraper 41, which is laterally attached to the rotatable millstone 7 and runs past the sorting sieve 44, and into the return opening 46, which is drawn with the central recess 79 via a radial recess 47 or - shown in broken lines - an inclined one Recess 47a, which forms a return channel, is connected, conveyed and fed to a new grinding cycle.

Fig. 2 shows a section in the plane II-II. The details of the design of the millstones 7, 8 will be discussed later with reference to FIGS. 5 to 8.

3 shows a grist mill with a vertical grinding gap 17. The rotatable grinding stone 7 is fastened to the axis of the motor 1, and the grinding stone 8a held in the slot guide 48 in a rotationally fixed manner is axially displaceably supported by adjusting means. These consist of a central spindle 50 with a handwheel 36 and a locking clamp 51, which engages in a central thread of the plug axis of the grinding stone 8a. A relatively long guidance of the thru axle ensures an exact parallel guidance and exact adjustment of the depth t 1.

The ground material is introduced through a funnel 29 into the central recesses 79, 79 a of the grinding stones 7, 8 a, the amount being determined in each case by adjusting the gap t 2 a between the lower funnel edge and the hub of the rotating grinding stone 7, which is extended up to this. The funnel 29 is guided through a radial recess 47 of the rotationally fixed grinding stone 8a, which is widened in a sector shape. A supply air opening 45 and an exchangeable sorting sieve 44 are arranged in the casing 4 on the casing side, behind which the outlet connection 3o connects.

In front of the sorting sieve 44, on the rotatable millstone the scraper 41 runs at the edge of the coarse meal into the return opening 46 into the funnel 29 and partly also into the sector-shaped recess 47, where it runs on the inlet side 47a which runs obliquely downwards to the central recess 79a , runs back to the center together with the incompletely ground material coming in and from there is distributed again via the air furrows 16, 15e in the grinding gap.

Fig. 4 shows a section along the plane IV-IV, from which the position of the sorting screen 44 and the sector-shaped recess 47 and their size can be seen.

5 and 6 show a section in plane VV and the end view of a rotatable grinding stone 7, and in FIG. 7 the end view of a fixed grinding stone 8a with a radial sector recess 47 is shown, to which FIGS. 8 and 9 show sections in Play level VIII-VIII or along the air channels GI, GII, GIII.

The millstones 7, 8a are built on a plate 7b, on which the central fastening bush or thru axle is fastened with a flange or in which the bushes of the spindles 13 (FIG. 1) are seated, or fastened thereon. A central, conical recess 79, 79a runs from the grinding side 17a through the entire usable, ie wearable, area of the grinding stones 7,8a. In each case tangentially from this recess 79, 79a, the air groove groups G!, GH, GI! I with the air grooves 15, 15a, 15b and 16, 16a, 16b each offset by an angle w in several planes. The levels are staggered according to the width or diameter of the air furrows in the usable millstone area to the depth t3, t4, t5, so that as wear progresses, at least one air furrow is always exposed and thus effective, as is the case in the direction of the furrow running cuts Fig. 9 can be seen.

In the example, the air furrows 15, 16, etc. run only up to the vicinity of the edge 8 ₀ , so that an edge zone of the width b remains, in which no furrows run, so that practically only finely ground shot from the Grinding gap 17 can emerge. The entire surface of the grinding side 17a is used only to a limited extent, which means a certain limitation of the grinding capacity. In Fig. 3, an alternative advantageous embodiment is shown in which the air grooves 15c, 15d, 15e and the corresponding air grooves of the other grindstone are guided to the edge 8 _0. This ensures full use of the grinding surface. The coarse shot parts or the regrind that has not been gripped by the gap and emerges from the air furrows at the edge are, as described, returned to the central recess 79, 79a.

The appropriate Sektorausnehmung 47, which serves inter alia the recirculation has, as shown, an opening angle of about 6 ° _0. An equivalent, radial or inclined recess 47 or 47b is shown in FIG. 2 for use with a horizontal grinding gap 17.

FIGS. 10 and 11 show axial and radial sections of grinding stones 7, 8, in the supporting area of which, which lies below the wearable area through which air grooves (not shown) pass, coarse-meshed mats 77a, 77b made of glass fiber, metal wire mesh, for example steel wire Reinforcement are stored. The mesh size and the distance between the mats are expediently a multiple of the largest grain diameter of the grit of the grinding stone. The mats are expediently used, for example, with a texture rotated by 45 ° relative to one another, so that attacking mass forces and compressive forces are absorbed and distributed evenly in all directions. This enables the stones to be operated at a very high grinding capacity and at high speed.

12 and 13 each show a top view and a section of a grindstone 7, in which bristles 85 made of plastic or metal, preferably steel, are axially embedded, which brush through brushing at the height of the grinding gap 17, cleaning the grinding gap and the Roughly projecting opposite grinding side from the grinding side 17a.

A statistically homogeneous distribution of the bristles 85 is shown in the lower half of the drawing, and in the other embodiment according to the upper half of the drawing, a brush-like compacted storage is carried out in the zones 86 between the air furrows 15 to 15b.

The bristles 85 extend into the load-bearing area so that as the grindstone wears down, no longer pieces of wire fall out and get into the shot. As shown in FIG. 13 below, the bristles expediently extend into the mat 77a of the reinforcement and are preferably connected to it by means of a loop.

The protruding bristle ends prevent the millstones from being placed close together, which prevents extreme wear. It is expedient and simplifies the production of a millstone set, air furrows and bristles to be arranged only on one of the millstones, preferably on opposite ones. It is preferred to introduce the air furrows in the non-rotatable grinding stone 8,8a and the bristles 85 and possibly reinforcement with mats 77a in the rotating grinding stone 7, since the latter hardly shows any imbalance with increasing wear and withstands high speeds.

Fig., 14 shows a grist mill with a vertical grinding gap 17 between the grinding stones 7, 8, of which the non-rotatable is axially adjustable via a 3-spindle drive, within which a screw conveyor 63 is arranged. The outlet of the funnel 29 is axially angled and mounted so that there is a metering gap between its end and the distributor plate 10. The shift can be made with an adjusting handle 11a, which can be fixed with a lock nut 11b.

In Fig. 15, the actuator with three spindles 13 of Fig. 1 and 14 is drawn out again in supervision.

16 shows a further very simple variant of the central spindle 5o for shifting the plug-in axis of the rotationally fixed grinding stone 8a, in which the plug-in axis is pressed against the spindle 5o only by the grinding pressure and contains no thread. Furthermore, a funnel outlet 29a is shown, which is bent into the central recesses 79, so that the grinding stock is guided into the grinding gap 17 even with progressive wear of the grinding stones 7, 8a.

Fig. 17 shows a further arrangement of the adjusting means 36,5 ₀ , 51 for the central setting of the grinding gap, in which the plug axis of the grinding stone 8 is designed as a tube 81, in which the screw conveyor 63 and around it the displaceable metering device at the outlet of the funnel 29, adjustable with the handle 11, is mounted.

A further addition to the adjusting means 12, 13, 14 is shown in FIG. 18. A tube is axially attached to the rotationally fixed grinding stone 8 and is led out of the housing 4, which is designed as a gauge 7o on a scale; with which the position of the grindstone 8 is determined relative to the housing 4. At this gauge 7o there is a lock 67, by means of which the axial displacement of the grindstone 8 by the spindles 13 in the direction of the rotatable grindstone 7 is limited in accordance with the setting. The stop 67 is supported in the end position on the housing 4 or a concentric tube 69 connected to it to limit the grinding gap 17.

19 shows an advantageous embodiment of the grist mill, in which the power is additionally increased by a squeezing device 54, 60. On the axis la, a crushing roller 6o is fastened in the central recesses 79, 79a, around which a bush 54 is arranged eccentrically, with a surface line almost touching it, in a rotationally fixed manner. In the narrowest zone, a pinch gap 55 is formed between the bush 54 and the crushing roller 6 ₀ , behind which an outlet opening for the crushed material is provided with a sieve insert 57. In the furthest zone there is the connection 56 for the feed of the ground material. The dosing device for the regrind is in the form of an adjustable slide 35 in front of the squeezing device.

Instead of, as shown, the bushing 54 can also be fastened to the housing 4 in the rotationally fixed grinding stone 8a, in particular when the grinding stone is mounted on a 3-spindle. Height adjustment for specifying the pinch gap width can be provided in a known manner by means of a spindle, wedge or eccentric device.

In Fig. 2o a section perpendicular to the axis in the plane XX-XX is shown by the squeezing device, which illustrates the eccentric gap and the grist and discharge.

21 shows a further embodiment with an upstream squeezing device in which the crushing roller 6o is fastened on the axis la, which is extended into the central recess 79a of the rotationally fixed millstone. Parallel to the axis, in addition to the crushing roller 6o, the bush 54a is rotatably mounted on an eccentric 61, preferably on ball bearings 62, so that a pinch gap 55a is formed between the crushing roller 6 ₀ and the bush 54a, which can be changed in the seat 4 in the seat by adjusting the angle of the eccentric 61 .

22 shows a section in the plane XXII-XXII through the breaking device, from which it can be seen that the axial extension of the bush 54a is only provided in the area of the millstone 8a, otherwise a collision with the rotating millstone 7 would occur. In the arrangement according to FIGS. 19, 20, the bush 54 can protrude beyond the grinding gap 17 and produce higher performance. In an equivalent manner, the bushing 54 can also be rotatably supported in this embodiment in a sleeve 61a which is eccentrically recessed for setting the gap, with the regrind being fed from one side in one half and discharged on the other side in the other half. A corresponding thread-like profile of the crushing roller 6 ₀ serves the axial conveying movement. A separation of the two conveying areas is easily possible thanks to side covers and a fixed separator.

Similarly, further combinations and exchanges of the features and components shown can be carried out or equivalent means can be used to accomplish the task. The objects of the features can also be separated under certain circumstances, as can happen, for example, with the bristles 85, which can also be arranged in the form of a brush in a sector cutout 47 instead of in the stone mass. Here, however, only the cleaning effect of the opposite grinding side is achieved, but not the additional effect of securing the distance.

Furthermore, a gear, preferably with a selectable transmission ratio, can be arranged between the axis 1 a and the driving motor 1 in order to optimize the grinding performance with different regrind and grinding degree. Such additions are within the skill of the art.

Furthermore, a connection possibility for a mains-independent auxiliary drive can be provided, for example in the form of a pulley, so that the grist mill can be used as a catastrophe mill, for which it is well suited because of the high grinding quality.

Combinations of the objects are also possible in such a way that the grinding gap is not, as shown in FIG. 1, horizontal or, as shown in FIG. 3, vertical, but is arranged obliquely. The threaded sleeves and threaded spindles can also be arranged in reverse as shown and the spindle drive and the spindle bearing can be interchanged between the housing and the grinding stone.

Claims (11)

1. Grist mill with two mutually face-to-face, coaxial and for setting a grinding gap (17) axially displaceable grinding stones (7,8,8a), at least one of which is driven and at least one on the grinding side (17a) has an air groove (15, 16) or air furrow group (GI) and is made of stone grains and binders, characterized in that in at least one of the grinding stones (7,8) from the grinding side (17a) axially into the depth (t3, t4, t5) and in Angle (w) offset from one another a plurality of air furrows (15, 16; 15a, 16a; 15b, 16b), preferably air furrow groups (GI, GII, GIII), the air furrow width being selected in relation to their depth gradation so that at least one each Air furrow group (GI, GII, GIII) with progressive wear of the grinding stone (7,8) lies on the respective grinding side (17a), and the entire usable grinding stone depth is interspersed with air furrows (15,16 to 15b, 16b) . 2. Grist mill according to claim 1, characterized in that the air furrows (15c, 15d, 15e) to the outer edge (8 ₀ ) of the grinding stone (8) are executed. 3. Grist mill according to claim 1 or 2, characterized in that in at least one of the millstones (8,9) preferably in radially extending zones (86) compacted in a brush-like manner, axially bristles or wires (85) are preferably incorporated from steel, which enforce the entire usable grinding area and reach into the area below and are firmly embedded there. 4. Grist mill according to claim 1, 2 or 3, characterized in that preferably the driven grindstone (7) under the deepest air furrows (15, 16) is equipped with coarse-mesh reinforcement mats (77a, b), preferably made of metal wires or glass fibers, and the mesh size is several times the grain size of the stone grains and if necessary the bristles or wires (85) are held in the mat wires or fibers surrounding them. 5. Grist mill according to one of claims 1 to 4, characterized in that the rotationally fixed grinding stone (8a) is disc-shaped and has at least one radial, preferably rotationally fixed sector-shaped recess (47). 6. Grist mill according to one of the preceding claims, characterized in that the grinding gap (17) lies horizontally and the grinding stones (7, 8) are mounted in a cylindrical housing (4), on the underside of which a drive motor (1) is flanged onto which Axis of the rotatable millstone (7) is attached centrally, and on the upper side of an adjusting means (12,13,14) the rotatable millstone (8) is vertically displaceably mounted, and that this has a central recess (79) through which Ground material can be introduced into the grinding gap (17) and the air furrows (15, 16), which is preferably fed to this recess through a funnel (5) via a metering device, for example an adjustable gap (t2), and that the housing (4 ) preferably has an outlet opening on the side, possibly with an outlet connection (6) for the shot. 7. Grist mill according to one of claims 1 to 5, characterized in that the grinding gap (17) is vertical and the grinding stones (7,8a) are mounted in a cylindrical housing (48), on one end of which a drive motor (1) is flanged , on the axis of which the rotatable millstone (7) is attached centrally and on the other end face of an adjusting means (36.5 ₀ , 51; 12, 13, 14) the rotatable millstone (8a) is horizontally displaceably mounted, and that this one has a central recess (79) through which the Grist can be introduced into the grinding gap (17) and the air furrows (15, 16), which is preferably through a funnel (29) via a metering device, for example an adjustable gap (t2, t2a), either axially, preferably by means of a screw conveyor (63 ) or radially through the recess (47) in the fixed millstone (8a), which is directed upwards and has an opening angle (w2) of about 6 ₀ °, and that the housing (4) preferably on the jacket side, laterally if necessary, near the feed side (47a) of the recess (47) an outlet opening, if necessary with an outlet connector (3 _0). for the shot. 8. Grist mill according to claim 7 or 6, characterized in that the outlet opening with a sieve (43) and preferably an interchangeable sorting sieve (44), which is preferably located in the casing surface level, is closed and on the rotatable millstone (7) scrapers (41) between the grindstone (7) and the housing shell or the sorting sieve (44) are directed and designed so that they the coarse, stripped scrap or grist in a back. guides opening (46) on the funnel (29) and / or in the recess (47). 9. Grist mill according to claim 6 or 7, characterized in that the adjusting means (36,5o, 51; 12,13,14) a spindle guide with a central spindle (50) or with at least three spindles (13) which are concentric with the grinding stone ( 8) are arranged and synchronously adjustable via a chain or toothed belt drive (14), and the spindle drive can preferably be actuated via a handwheel (36, 12) and a clamp (51) can be locked and that preferably a gauge (70) with an adjustable stop (67) for displaying or limiting the grinding gap width (17) to a minimum distance on the grinding stone (8). lo. Grist mill according to one of the preceding claims, characterized in that the drive shaft (la) extends into the central recess (79, 79a) of the grinding stones (7, 8), if appropriate, and a crushing roller (60) is fastened thereon to be the eccentric, with a surface line of the crushing roller (6 ₀ ) forming a nip (55), a fixed bushing (54) is arranged, in which there is an outlet opening, preferably with a screen insert (57) in the direction of rotation behind the nip (55), and into the the side that forms a wide gap, the ground material, preferably coming from the metering device, is introduced. 11. Grist mill according to one of claims 1 to 9, characterized in that the drive shaft (la) extends into the central recess (79a) of the fixed millstone (8a) and there is attached to it a crushing roller (6 ₀ ), in addition to that in a Recess (47) axially parallel to a socket (54a) on an eccentric (61) is rotatably mounted at such a distance, preferably on the housing (4), that depending on the eccentric position, a suitable pinch gap (59) is formed, to which the ground material is fed via the metering device becomes.

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