EP0994751A1

EP0994751A1 - Method and device for grinding grains

Info

Publication number: EP0994751A1
Application number: EP98939600A
Authority: EP
Inventors: UND MÜHLENBAU WITTENBERG GmbH MASCHINEN-
Original assignee: MASCHINEN- und MUEHLENBAU WITTENBERG GmbH; MASCH und MUEHLENBAU WITTENBE
Current assignee: MASCHINEN- und MUEHLENBAU WITTENBERG GmbH; MASCH und MUEHLENBAU WITTENBE
Priority date: 1997-07-09
Filing date: 1998-07-01
Publication date: 2000-04-26
Anticipated expiration: 2018-07-01
Also published as: PL337945A1; ATE227163T1; RU2181308C2; TR200000155T2; EP0994751B1; AU8805398A; WO1999002267A1

Abstract

The invention relates to a method for grinding grains, as well as to a device for implementing such a method. According to this method, the grains are humidified with a liquid, and compression and shear forces are applied to the grains with a first pair of rollers (4), so that the grain core internal structure (endosperm) is modified and the grain skin undergoes little or no damage. The grains are then transferred to another pair of rollers (5) having a ribbed surface for grinding. This is followed by grinding by another pairs of rollers (6) and/or sieving of the ground products, so that the final product is substantially in the form of flour. The inventive method is a low grinding method.

Description

Process for grinding cereals and device for carrying out the

Procedure description

The invention relates to a method for grinding cereals and an apparatus for carrying out the method (flat grinding method).

According to WO 92/10296, the prior art includes a flat grinding process (deep milling) in which the endosperm is separated from the husk in the case of wheat grains. According to this method, the wheat grains are flattened between two rollers of a first pair of rollers. For this purpose, the rollers are designed with a smooth surface. The gap is chosen so that the wheat grains are pressed flat.

The flattened wheat grains are fed to two further pairs of rollers without intermediate sieving. These pairs of rollers have corrugated rollers, the first pair of rollers having approximately eight corrugations per centimeter and the second pair having approximately eleven corrugations per centimeter.

The rollers of the first corrugated pair of rollers have different speeds of rotation. Likewise, the rollers of the second corrugated pair of rollers have different speeds of rotation.

After the grains have passed through these three pairs of rollers, the ground products are fed to a plan sifter. Bran parts are sifted out and used for other purposes. Flour products are either fed directly to another use or fed to a further roller mill with two pairs of rollers, the first pair of rollers having corrugated rollers and the second pair of rollers being equipped with smooth rollers. The product obtained in this way is in turn fed to the plan sifter, and the parts which have been screened off, that is to say which have fallen through, are likewise fed to further use. The transitions are in turn fed to the last roller mill.

With this state-of-the-art process, a 72-75% flour yield is achieved.

The technical problem on which the invention is based is to provide a method and a device for grinding cereals in which the cereals are comminuted more quickly and in which proportionally more flour is obtained in the first grinding step and in which the total flour yield is more than 75% is.

This technical problem is solved by the features of claim 1 and by the features of claim 15.

By feeding the cereals after wetting with a liquid to a first pair of rollers, in which the internal structure of the endosperm is changed by the action of the shear forces, a high overall flour yield is obtained, and the grains are obtained in the subsequent grinding in the subsequent roller mills shredded faster. For this reason, only a few roller mills are required.

In addition, the flour yield after the first grinding step is significantly greater than with the prior art method. It is quite possible to get a share of 30 to 40% of flour after the first grind. The yield of light flour is also essential borrowed higher than the prior art methods.

To obtain flour, the flour body (endosperm) of a cereal grain must be separated from the bran (husks and germs). For this purpose, the cereal grains are wetted with water so that the skins soften and can then be peeled off.

This method is used not only for cereal grains, but also for other cereals in which the husk is to be separated from the core. These are, for example, legumes, rice, corn, beans, also coffee beans, cocoa beans and the like.

Therefore, the term cereals is to be understood to mean all fruits which have a core and a hard or soft skin or skin surrounding the core.

According to the invention, the cereals are wetted with water so that the shells absorb the liquid and obtain a rubbery consistency. The wetting takes place according to the invention in such a way that the shells have a greater moisture content than the endosperm. This ensures that the shear forces only act in the endosperm. The rubber-like shell is not or hardly attacked by the shear forces. The internal structure of the endosperm is unlocked differently.

Basically, the shell and endooperm have a certain basic moisture content, for example 13%. Moisture in the shell is increased to 16%, for example, by wetting with liquid. Basically, the method according to the invention also works if the endosperm also absorbs liquid. The main thing is that the shell has a greater moisture content than the endosperm.

In the following, an endosperm that only has the basic moisture content and has absorbed no or hardly any other liquid through the wetting is referred to as dry or approximately dry.

The cereals are advantageously wetted with the liquid in a wetting device. For this purpose, the cereals are preferably mixed with liquid and passed through a tube which is set in a shaking motion. The cereal-liquid mixture is subjected to strong acceleration forces in the tube. Such wetting is known from DE-PS 41 27 290 C2.

By wetting the cereals with the liquid in the vibrating device, the cereals are prepared for the following grinding process. An optimally selected rest time ensures that the skin of the cereals is flexible, while the endosperm remains dry or almost dry. This so-called "glass transition" has the important function that the shell has maximum flexibility, while the endosperm remains dry. Depending on the quality of the product to be milled, the glass transition must be determined and the conditions for wetting and the rest time must be adapted to the product to be milled.

By the vibration of the cereal-liquid mixture or even by the vibration of the water In addition, the water molecules are changed so that they more easily penetrate the cell membrane and thus an optimal wetting of the grains is possible.

After wetting, the cereals are fed to a first pair of rollers, in which one roller is preferably smooth or approximately smooth, and in which the second roller preferably has a fine corrugation. This fine corrugation is preferably designed as very fine corrugation, for example with fourteen corrugations per centimeter or more. According to the invention, the reefing with a twist of plus / minus two to four degrees is selected. However, it is also possible to design the rollers differently. It is important that the first pair of rollers exert almost exclusively pressure and shear forces on the grains, and that the grains are only milled in the second and possibly subsequent pairs of rollers.

According to the invention, both rollers run at the same or approximately the same speed of rotation. It is conceivable to run the rollers in a ratio of 1: 1.05 or larger. The shear forces on the endosperm occur in that the moistened grain slips past the smooth roller with the rubber-like shell, while the grain is transported by the roller with the reefing, as is known per se. This means that the grain is hardly moved forward by the smooth roller, while the grain is simultaneously transported by the roller with the corrugation on the side opposite the smooth roller, so that shear forces occur in the grain and in particular in the endosperm.

According to the invention, the first roller is followed by one or more pairs of rollers, in which each roller has a reef lung, preferably with nine to twelve corrugations per centimeter. In these rollers, the corrugations preferably have a rounded corrugation surface. The so-called "Riffelgrund" is also rounded between the corrugations. The corrugated surfaces and the corrugated bases preferably have approximately the same rounding.

The rounding of the corrugated surfaces and the corrugated bases ensures that the proportion of flour which is obtained during grinding is significantly increased.

In a further embodiment of the invention, the second or one of the following pairs of rollers is followed by a pair of rollers, which is referred to as a "leveling roller pair". The rollers of this pair of rollers have a smooth or almost smooth surface. The purpose of this pair of rollers is to bring bran parts which have a curved shape and to which endosperm still adheres, into a flat shape. This in turn has the effect that the shell is rubbery due to the previous wetting, while the endosperm is dry and hard. The endosperm is at least cracked between the rollers or even partially detached from the shell.

After the second or one of the following pairs of rollers, the material to be ground is fed to a plan sifter, where the first flour is already sifted out and the remaining transition is fed to the next pair of rollers or the next pairs of rollers.

After the bran particles have been leveled, they are fed to a further one or more further pairs of rollers. A screening can then be carried out again, whereby coarse bran or fine bran is sieved off. The bran can be fed to a bran spinner in order to separate adhering endosperm particles.

The bran is then used again.

After the cereals have been ground in the device according to the invention, various types of flour are obtained after sieving, for example light flour, medium-dark flour or dark flour. Depending on the setting of the device according to the invention, atta flour or wholemeal flour is also obtained. Atta flour means that a 90 to 94% yield of the whole grain is achieved. Whole wheat flour contains 100% or almost 100% of the total grain. Depending on the setting of the device according to the invention, however, 3 to 5% of the products obtained can be removed as mist or semolina during the grinding process. These can be fed to a semolina cleaning machine or the like, for example.

The process according to the invention has the advantage that it requires only a very small number of roller mills and at the same time a very high proportion of flour, that is to say the highest possible yields. The yields depend on the correct addition of water when wetting and the optimal soak time. It is possible to achieve optimal yields with very few roller mills, i.e. with a simplified mill and a short diagram.

Depending on the guidance of the rollers, this process, which is part of flat milling, which primarily serves to produce flour, can also be used as a process which goes in the direction of semi-high milling. In this case you get more greetings and steam, which from the diagram can be screened in between, for example with the help of classifiers or semolina cleaning machines or other such machines.

According to the invention, a very simple, efficient and energy-saving method for grinding cereals is specified, namely a method in which flour is produced.

The advantage of the invention is that the grinding technique, in which pressure and shear forces act on the grain, brings about a completely different disintegration of the grain. In particular, the endosperm structure is demonstrably destroyed, in contrast to the methods belonging to the prior art.

In this way, aroma and odor substances are better exposed, in contrast to the conventional methods of high-level milling. Whole grain flours in particular show this better exposure of the aroma and odor substances. Bakers compare the quality of the flours produced by the method according to the invention with the flours of milling products, that is to say of products which have been ground on stone.

In addition, the flours that were ground by the method according to the invention have much better processing criteria, such as an increase in water absorption. This means that a higher dough yield is achieved for the processor of the flour. The increase in water absorption is controlled by certain measures, for example by adding water when wetting and changing the standby time, as well as changing the roller guide, the roller corrugation, the swirl and the speed of rotation. In addition, the dough properties change. The dough gains more flexibility when using flour which is obtained by the method according to the invention. This is achieved in that the edge layers of the endosperm are exposed during the first reduction process and reach the main flour.

Another advantage of the method according to the invention is that the system according to the invention meets the highest hygiene requirements, since the short diagram means that only short transport routes are required.

Because only a few roller mills are required according to the invention, only a very small amount of energy is required, that is to say that only very few kilowatts are used per ton and hour.

According to the prior art, approximately 50 kilowatts per ton and hour are consumed, whereas according to the method according to the invention, less than 36 kilowatts per hour and ton have already been consumed.

In addition, the device according to the invention is very easy to use. This is particularly advantageous since the device according to the invention is to be used primarily in countries in which the high yield of flour is of primary importance. The grinding process according to the invention achieves high flour yields while maintaining the high quality of the end products.

Another advantage of the invention is that simple handling is possible. In addition, the method according to the invention arrives with the least use Electronics. It is even possible to drive the device according to the invention in manual mode. Fully automatic or semi-automatic operation is also possible.

The device according to the invention is of modular construction, that is to say that the actual core of the device with the wetting unit and the roller mills can be supplemented with special machines or a cleaning unit. This equipment with further modules is also possible subsequently, so that the device according to the invention can be easily retrofitted.

Another advantage of the invention is that only a few spare parts are required due to the low use of materials. In addition, according to the invention only three or four different types of rollers are provided, namely smooth rollers, rollers with fine corrugations and rollers with rounded corrugated surfaces or corrugated mirrors and corrugated bases provided between the rollers. For this reason, the procurement of spare parts is easy.

The rollers with worn mirrors are preferably used as the last pair of rollers in order to split off endosperm particles from the bran particles. These rollers, which have no or hardly protruding corrugations, but essentially longitudinal depressions, preferably run at different speeds, so that the endosperm particles are sheared off from the fine bran.

According to the invention, a cleaning unit is provided in front of the wetting unit. This cleaning unit takes on the tasks of pre-cleaning, pre-cleaning with stone selection, main cleaning with and without Stone selection, a main cleaning with and without ergot separation, an exclusive stone selection or an exclusive ergot separation.

This cleaning unit is designed such that several separation processes can be carried out according to density, sinking speed, mass or shape. This is achieved by an air flow generated by a fan of several and differently arranged work surfaces. The work surfaces are preferably designed as perforated sieves or special sieves or as wire mesh with different mesh sizes. The inclination of the work surfaces can be adjusted independently of each other.

In addition, a special preparation is connected upstream or downstream of the wetting device. This has the advantage that all types of grain, such as wheat, rye, barley, but also other cereals, such as rice, maize, dumour, sorghum, spelled, millet, malt and the like, can be ground. This is also of great importance for the countries in which a simple grinding process with a high yield and flexibility is important. In these countries, it is important to be able to grind wheat one day, barley the next day, and corn the third day using the same device.

In the combined grinding of different types of grain, it is advantageous to provide roller mills, the roller pairs of which are individually controlled and driven. In this case, it is possible, for example, to mill only or almost only the upper pair of rollers when milling millet, only or almost only the lower pair of rollers when milling wheat and, for example, when milling barley, to use both pairs of rollers for milling. This is possible because the rollers of the roller pairs have different corrugations and rollers with different corrugations have to be used for different types of grain or cereals. For example, wheat is mainly milled with smooth rollers, while rye is mainly milled with corrugated rollers. This measure considerably shortens the diagram of the mill.

Depending on the product, a special machine is advantageously connected upstream of the actual grinding unit. For example, dry or wet disinfection can be provided for corn, while a peeling, scouring, sanding or polishing machine is provided as a special machine for barley or oats.

According to the invention, the wetting unit is preceded or followed by a thermal cabinet. In countries with extreme temperatures it is necessary to bring the grain to a temperature, preferably between 18 and 20 ° C, before wetting and / or grinding.

According to the invention, the cereals are exposed to microwaves after wetting with the liquid and before grinding. Microwave treatment of cereals is known from GB-PS 1 379 116 and from GB-PS 1 571 710.

On the one hand, this produces aroma substances, similar to a roasting process. On the other hand, a kind of cooking process is carried out in the inner core. This opens up the strength more or less. Treatment of the cereals with microwaves has an advantageous effect on the ground products obtained. It is also possible to treat the ground products yourself with microwaves. This will upgrade the products.

A cutting mill is advantageously arranged downstream of the first pair of rollers and / or one of the subsequent pairs of rollers and / or a plan sifter. According to the invention, the cutting mill has a cutting head and / or a micro-cutting head. In particular, by crushing the cereals with a micro cutting head, it is possible to considerably shorten the diagram of the mill.

The use of the cutting mill is advantageous, among other things, in the production of wholemeal flour. It is possible to use the cutting mill to finely comminute the constituents of the cereals, in particular the shell, so that a very fine and good whole grain flour can be produced in a mill diagram which is also very short.

Using the cutting mill, it is also possible to produce very fine flours (for example 40 μm), which is hardly possible with normal mills or only with great effort.

According to the invention, a flat grinding method is specified. The diagram of this flat grinding process can be shortened considerably with a cutting mill. However, the use of the cutting mills in the high-level mill also brings about a considerable shortening of the diagram, so that this use is also very advantageous.

According to the invention, it is possible to obtain flour using the flat grinding method with a very short diagram. As already mentioned, this diagram is shortened by using one or more granulators.

The roller pairs are arranged according to the invention in such a way that the device has single roller mills or multiple roller mills.

According to the invention, each roller mill has vibration monitoring. This vibration monitor monitors the decibel values of the roller mill. Each roller mill has special decibel values that depend on the type of product, the quantity and the quality of the product. The individual setpoints are specified in a controller, that is, the vibration value is set to a setpoint between a minimum and a maximum value. If the minimum or maximum value is exceeded for an unmanned mill, the mill is automatically switched off. Floors or departments can also be equipped with decibel monitoring.

The rollers of one or more roller mills can run at a speed of 1000 to 1500 revolutions per minute.

Further details of the invention can be found in the subclaims.

An exemplary embodiment of the invention is shown in the drawing, namely:

1 shows a device according to the invention;

Fig. 2 shows the first pair of rollers of Figure 1 in section. Fig. 3 shows the second pair of rollers of Figure 1 in section.

FIG. 4 further roller pairs downstream of the device from FIG. 1;

Fig. 5 shows a roller of the last pair of rollers of Fig. 4 in section;

Figure 6 shows part of the last pair of rollers of Figure 4 in section;

7 additional devices of the device according to the invention;

8 shows a cleaning unit in section;

9 shows a roller mill in section;

Fig. 10 is a section along the line X-X of Fig. 9;

11 shows a device according to the invention with a cutting mill;

12 shows a cutting head of a cutting mill in cross section;

13 shows a micro cutting head of a cutting mill in cross section.

1 shows a device (1) with a wetting device (2), a stand - off cell (3), roller pairs (4, 5; 6, 7) and a plan sifter (8). The cereals to be ground are fed in the direction of arrow (A) to the wetting device (2). The wetting device (2) consists of a vertically arranged tube (9) which is arranged with a vertical axis. The tube (9) is set in a shaking motion by a motor, not shown, so that the cereals which have been mixed with a liquid in the tube or in front of the tube are exposed to strong acceleration forces in the tube.

The shaken cereal-liquid mixture is fed to the stand-off cell (3). The grains remain here for a certain time in order to achieve optimal wetting.

The cereals are then fed to the actual grinding process. For this purpose, the cereals are fed to the first pair of rollers (4) and immediately thereafter to the second pair of rollers (5).

The first pair of rollers (4) consists of two rollers (10, 11), the roller (10) being designed as a smooth roller and the roller (11) having a fine special reefing.

Due to the wetting, the cereals have a rubber-like skin and a dry or almost dry endosperm.

2, the rollers (10 and 11) are shown. The rollers (10, 11) run at the same or approximately the same speed of rotation. A grain of grain (12), which has a shell (13) and an endosperm (14), is located between the rollers (10, 11). The roller (11) transports the grain (12) in the direction of the arrow with ribs (15). les (B). Due to the smooth surface of the roller (10), the rubber-like shell (13) of the grain (12) slips past the roller (10) and is not transported at the same speed as by the roller (11). As a result, shear forces occur within the grain (12), which primarily affect the endosperm (14), since the rubber-like shell (13) is flexible, while the internal structure in the endosperm (14) is changed by the shear forces .

1, the cereals are then fed to the second pair of rollers (5) with the rollers (16, 17).

3, the rollers (16, 17) have asymmetrically shaped corrugations. The surfaces (20) of the corrugations (18, 19) are referred to as "backs". The rollers (16, 17) are arranged such that the backs (20) of the corrugations (18) and the backs (20) of the corrugations (19) are arranged opposite one another. The rollers (16, 17) are arranged so to speak "back to back". The corrugated surfaces or corrugated mirrors (69) are rounded, as are corrugated bases (70) between the corrugations (18, 19).

The rollers (16, 17) are finely fluted rollers with nine to fourteen flutes per centimeter. The rollers preferably have a diameter of 250 mm. The roller

(17) has a higher rotational speed than the roller (16). For example, the amount of the rotational speed of the roller (17) is 2.5 times greater than the amount of the rotational speed of the roller

(16). The fast roller (17) preferably runs at 450 to 500 revolutions per minute. 1, the cereals are fed to the plan sifter (8) after passing through the pair of rollers (5). The ground products are sieved in the plan sifter (8). For this purpose, the plan sifter (8) has a plurality of sieves (21, 22, 23). The transition of the screen (21) is fed to the pair of rollers (6). The transition of the sieve (22), which is referred to as coarse bran, is fed to a bran spinner (24), and the transition of the sieve (23), which is referred to as fine bran, to a bran spinner (25).

The diarrhea (26, 27, 28) of the sieves (21, 22, 23) can be separated again. The diarrhea (26, 27, 28) contains a large proportion of flour (29), a small proportion of haze and semolina and a further proportion (31) of ground products that can be processed further.

According to the invention, the small proportion of haze and semolina, such as the grinding products (31), is fed to further grinding processing. However, it is also possible to feed this small proportion of haze and semolina to a semolina cleaning machine (30).

The transition of the screen (21), as already stated, is fed to the pair of rollers (6). The pair of rollers (6) has smooth rollers (32, 33) which crack the endosperm parts adhering to the shells, so to speak. The shell parts are predominantly curved. Endosperm parts hang on these shell parts. The shells are wet from wetting, that is, they have a rubbery consistency, while the endosperm parts are dry and rigid. Because the shells with the endosperm parts are passed through the smooth rollers, the shells are, at least for a short time, brought into a flat shape. The endosperm parts cannot understand this movement, so that they are cracked or already partially released.

Downstream of the pair of rollers (6) are the pair of rollers (7) with the rollers (34, 35), which carries out a further grinding process with the product prepared in the pair of rollers (6).

The ground products are then fed back to the plan sifter (8), where the sieving process described above is carried out again.

The ground products (31) can be fed to further pairs of rollers (36, 37, 38, 39). The pair of rollers (36), like the pair of rollers (5 or 7), is finely corrugated (see FIG. 3). The pair of rollers (36) has the task of not carrying out a grinding process, but rather of optimally preparing the product for the pair of rollers (38) underneath.

4, the ground products are then fed to a plan sifter (40) in which the ground products are sifted. The screening is carried out analogously to the screening described in FIG. 1.

A transition from the plan sifter (40) is fed to the roller pairs (38, 39). It is also possible to feed transitions of the underlying sieves to the roller pairs (38, 39). These transitions can also be subtracted as bran, for example.

The pair of rollers (38), like the pair of rollers (36) and the pair of rollers (5), consist of corrugated rollers. The pair of rollers (38) and the pair of rollers (39) have corrugations (43) (FIG. 5) which are flattened. The corrugations (43) were obtained from worn corrugations (44) (shown in broken lines). The depth (71) and the removed imaginary projection (72) have a ratio of 60:40.

6, the operation of the rollers (41, 42) of the pair of rollers (39) is shown. Part of a grain (45) with endosperm residues (46) is arranged between the rollers (41, 42). The roller (42) runs at a greater rotational speed than the roller (41). For example, the rotational speed of the roller is 1.5 times greater than that of the roller (41).

The grinding gap (47) is chosen to be relatively narrow, so that the bowl (45) lies in recesses (48) between the corrugations (43). Because the rollers (41, 42) run at different speeds of rotation, the remaining endosperm parts (46) are detached from the shell (45).

This grinding process according to the invention gives a very high yield of flour with very few rollers.

Fig. 7 shows a diagram of special devices that are upstream or downstream of the wetting device (2). The special devices include the cleaning device (49) with which a pre-cleaning or also a main cleaning of the material to be ground is carried out.

According to FIG. 8, the cleaning device (49) has work surfaces (50, 51, 52) which are used as perforated screens or Special sieves or wire mesh with different mesh sizes are formed.

An air flow is generated in the cleaning device (49) such that the material to be cleaned is transported on the work surfaces (50, 51, 52). The material to be cleaned is passed in the direction of arrow (C) through a material feed into the cleaning device (49). The product inlet is closed by a pendulum flap for sealing against the negative pressure in the cleaning device (49).

The goods to be cleaned reach the work surface

(50). Particle stratification occurs in the flowing material flow on the wire mesh of the work surface (50). Heavy cargo

(53) is led away, for example in the direction of arrow (D), by a corresponding inclination of the work surface

(50). Light and large admixtures of the material to be cleaned are passed over the screen surfaces. Dust and chaff go with the exhaust air (73) into a dust separator (filter, cyclone). The lighter material to be cleaned, for example cereal grains, is transported in the direction of the arrow (F) by an air flow directed in the direction of the arrows (E). Due to different mesh sizes of the work surface (50), which is larger in the area (54) of the work surface than in the area (55), the material to be cleaned falls on the next work surface, depending on the size

(51 or 52) and after a similar sorting on the work surfaces (51, 52) leaves the cleaning device (49) as separate light goods (56, 57, 58).

In order to achieve an effective air flow, flow straighteners are arranged under the front part of the upper work surface (50). In the lower part of the machine (not shown) there is at least one table level in addition to various guide floors, with which a separation according to grain density takes place. A complete stone selection can be carried out here, for example. If, for example, an ergot separation is to be carried out, a density selection can also be carried out with the lower part of the cleaning device (49).

For the return of mixed fractions, the composition of which does not correspond to any of the target fractions, a conveyor trough without its own drive is included, which brings the relevant flow of material to the point of machine loading for admixing in the load.

7, one or more special machines are arranged after the wetting device (2) and the stand-off cell (3). These can be a peeling machine or scrubbing machine (59), an impact blower (60), an emery - grinding or polishing machine (61), a read-out device (Trieur) (62), special grinding courses or special roller mills (64). The special grinding courses can be a peeling course, a pointed course or a scrubbing course or a polishing machine.

The special machines (59 to 64) can also be arranged in front of the wetting device (2) as required.

The special machines (59 to 64) are followed by a microwave device (74), in which cereals (12) are exposed to microwaves.

The microwave device (74) can also be arranged directly after the stand-off cell (3). Fig. 9 and Fig. 10 show a roller mill (68) with the roller (16). The material to be ground is fed to the roller mill (68) in the direction of the arrow (G).

After grinding, the ground material falls straight down over the entire width in the direction of the arrows (H) onto a transport device which is designed as a vibrating trough (65) or as a transport screw (not shown). The grinding products are fed from the vibrating trough (65) to a device (66) for sucking off the grinding products. From here, the ground products are fed to a tube (67) and from there are transported to further roller mills or to a plan sifter.

Due to the linear drop of the material to be ground down, "forced cleaning" is carried out, since the material to be ground cannot collect on obliquely arranged sheets or pipe surfaces. All or almost all of the regrind is taken up by the transport device.

According to the invention, the rollers consist of hard cast iron or gray cast iron, steel, plastic, porcelain, rubber, copper and / or stone.

Fig. 11 shows the first pair of rollers (4) with the rollers (10 and 11), which exerts pressure and shear forces on the cereals, and the second pair of rollers (5) with the rollers (16 and 17). Downstream of the second pair of rollers (5) is a cutting mill (75) which greatly comminutes the product of the pair of rollers (5). After passing through the cutting mill, the ground and crushed product is fed to the plan sifter (8). According to this exemplary embodiment, the proportion of flour (29) is significantly higher than, for example, according to the exemplary embodiment in FIG. 1 it is also possible to feed diarrhea from the plan sifter (8) to a cutting mill (76).

Fig. 12 shows a cutting head (77) with columns of vertical knives (78) mounted at intervals. Separators (79) are provided between the knives (78). A rotor (80) drives the product inside the cutting head (77)

(81) against the evenly arranged thin horizontal separators. The small product parts, which protrude between the separators (79), are cut off by the columns of vertical knives (78) which are mounted at intervals. The separated particles (82) are thrown outwards by the centrifugal force from the cutting head (77). The wall surface between the vertically arranged knives

(78) is concave to prevent the generation of frictional heat. This ensures that the cereals are not subject to such great evaporation.

FIG. 13 shows a micro cutting head (83) which has micro cutting plates (84). The product (85) is fed into a rotor (86) running at high speed and hits the exposed cutting edges (87) of the microcutting plates (84) at high speed. In this way, small parts are separated from the product until the shredding is finished. The particles are ejected through spaces (88) between the platelets (84). Due to the high speed, the product remains in the micro cutting head for a split second (83). The particle reduction progresses to a precise extent, and thus the end product has a uniform particle size. Reference numbers

1 device

2 wetting device

3 rest cell

4, 5, 6, 7 pairs of rollers

8 plansifters

9 pipe

10, 11 rollers

12 seeds

13 bowl

14 endosperm

15 corrugations

16, 17 rollers

18, 19 corrugations

20 backs

21, 22, 23 sieves

24 bran spinner

25 bran spinner

26, 27, 28 diarrhea

29 flour

30 Semolina cleaning machine

31 ground products

32, 33 rollers

34, 35 rollers

36, 37, 38, 39 pairs of rollers

40 plansifters

41, 42 rollers

43, 44 ripples

45 bowl

46 endosperm residues

47 gap

48 wells

49 cleaning device , 51, 52 work surfaces

Heavy goods, 55 areas, 57, 58 light goods

Peeling or scrubbing machine

Impact slingshot

Sanding or polishing machine

Readout device (door)

Peeling, pointed, scrubbing or polishing machine

Special roller mills

Vibrating channel

Suction device

pipe

Roller mill

Corrugated mirror

Riffelgrund

deepening

Ripple height

Exhaust air

Microwave facility

Granulator

Cutting head

knife

Separators

rotor

Particles separated particles

Micro cutting head

Cutting tip

particle

rotor

Cutting edges 88 spaces

A, B, C, D arrows

E, F, G, H arrows

Claims

claims

1. Process for grinding cereals with one shell and one core each, d a d u r c h g e k e n n z e i c h n e t,

- That the cereals (12) are wetted with a liquid such that the shell (13) of the cereals

(12) has a greater moisture content than the core (endosperm) (14),

- That on the cereals (12) with a first pair of rollers (4) pressure and shear forces are exerted such that an inner structure of the core (14) changes and that the shell (13) of the cereals (12) is not or hardly damaged,

- The grains (12) are then fed directly to a second pair of rollers (5), which has a corrugated surface, and are ground by the pair of rollers (5) or fed to a cutting mill (75, 76) and crushed,

- That there is then further grinding by at least one further pair of rollers (7, 36, 37, 38) or in at least one further roller mill and / or a sifting of the ground products, such that essentially flour (29) is obtained as the end product.

2. The method according to claim 1, characterized in that the cereals (12) after the second pair of rollers (5) or after one of the subsequent pairs of rollers a pair of rollers (6) are supplied, in which a surface of the two rollers (32, 33) smooth or is approximately smooth so that endosperm parts (46) still adhering to the shell (45) are at least partially detached from the shell (45) when the pair of rollers (6) passes through.

3. The method according to claim 1, characterized in that the shell (13, 45) of the cereals (12) is wetted approximately uniformly.

4. The method according to claim 1, characterized in that the cereals (12) after or during the mixing with the liquid through a vibrating device (2) continuously or in batches such that the vibrating device (2) exposes the cereal-liquid mixture to strong acceleration forces.

5. The method according to claim 1, characterized in that the cereals (12) are cleaned before wetting with the liquid.

6. The method according to claim 1, characterized in that the cereals (12) are subjected to special preparation before or after wetting with the liquid.

7. The method according to claim 6, characterized in that the cereals (12) in the special preparation of a peeling machine (59), scrubbing machine (59), emery grinding machine (61), polishing machine (61), an impact sling

(60), a reading device (Trieur) (62), disinfection machines, special grinding courses and / or special roller mills (64) are fed and treated in these.

8. The method according to claim 1, characterized in that during or after grinding bran particles are supplied to a bran spinner (24, 25).

9. The method according to claim 1, characterized in that during the grinding of semolina and / or haze components (30) collected and fed to roller mills.

10. The method according to claim 1, characterized in that the cereals (12) are exposed to microwaves after wetting with the liquid and before grinding.

11. The method according to claim 1, characterized in that the ground products are exposed to microwaves.

12. The method according to claim 1, characterized in that the cereals (12) after the second pair of rollers (5) and / or after a further pair of rollers (7, 36, 37, 38) are crushed in a cutting mill (75, 76).

13. The method according to claim 12, characterized in that the cereals in a cutting mill (75, 76) with a cutting head (77) and / or a micro cutting head

(83) can be crushed.

14. The method according to claim 1, characterized in that the cereals are ground in a double roller mill or a multiple roller mill, the grinding being carried out by at least one pair of rollers of the roller mill.

15. A device for performing the method according to claim 1, characterized in that the device has a wetting unit (2) for wetting the cereals (12) with the liquid, that the wetting unit (2) is provided downstream of a first pair of rollers (4) , The first pair of rollers (4) being designed as a pair of rollers exerting pressure and shear forces on the cereals (12), that the first pair of rollers (4) is immediately followed by at least one further pair of rollers (5) with corrugated rollers (16, 17) for the first grinding of the cereals (12) and / or that at least one cutting mill (75, 76) is arranged after the first pair of rollers (4) and that the at least one further pair of rollers (5) or another further pair of rollers (7, 36, 37, 38) and / or the cutting mill (75, 76) is followed by at least one plan sifter (8, 40).

16. The apparatus according to claim 15, characterized in that the first pair of rollers (4) has the rollers (10 and 11), the roller (10) having a smooth or approximately smooth surface and the roller (11) has a corrugated surface.

17. The apparatus according to claim 15, characterized in that the rollers (10, 11) of the first pair of rollers (4) have an approximately equal rotational speed.

18. The apparatus according to claim 15, characterized in that the rollers (10, 11) of the first pair of rollers (4) have different speeds of rotation.

19. The apparatus according to claim 15, characterized in that the second roller (11) of the first pair of rollers (4) has at least nine corrugations (15) per centimeter.

20. The apparatus according to claim 15, characterized in that the second roller (11) of the first pair of rollers (4) has a twist of plus / minus two to four degrees.

21. The apparatus according to claim 15, characterized in that the second pair of rollers (5) or a subsequent pair of rollers is followed by a further pair of rollers (6), the rollers (32, 33) of this further pair of rollers (36) smooth, approximately smooth or roughened are trained.

22. The apparatus according to claim 21, characterized in that the rollers (32, 33) of the further pair of rollers (6, 37) have the same or approximately the same rotational speeds.

23. The apparatus according to claim 15, characterized in that the at least one further roller pair (5, 36, 38) arranged after the first pair of rollers has different rotational speeds.

24. The device according to claim 15, characterized in that the at least one of the first pair of rollers (4) downstream roller pair (5, 36, 38, 39) has nine to sixteen corrugations (18, 19) per centimeter.

25. The device according to claim 15, characterized in that the corrugations (18, 19) of the rollers (16, 17) of the at least one roller pair downstream of the first roller pair (4) (5) corrugations with rounded corrugated surfaces and / or corrugations with one each have a rounded base between the corrugations.

26. The apparatus according to claim 15, characterized in that the first pair of rollers (4) and the at least one downstream pair of rollers (5) are designed as a multiple roller mill.

27. The apparatus according to claim 15, characterized in that the first pair of rollers (4), the at least one downstream pair of rollers (5) and the pair of rollers (6) with the rollers (32, 33) which have a smooth or approximately smooth surface , are designed as a multi-roll mill.

28. The apparatus according to claim 15, characterized in that the rollers (16, 17; 34, 35) of the roller pairs (5, 7) formed with a corrugated surface are arranged in such a way that when the rollers (16, 17; 34 , 35) the back (20) of the corrugation (18) of the one roller (16) and the back (20) of the corrugation (19) of the other roller

(17) are arranged to each other (back-to-back arrangement).

29. The device according to claim 15, characterized in that the rollers (10, 11, 16, 17, 32, 33, 34, 35) have a diameter between 200 mm and 300 mm.

30. The device according to claim 15, characterized in that the fast rollers have 450 to 500 revolutions per minute.

31. The device according to claim 15, characterized in that at least one of the last pairs of rollers (38, 39) has two rollers (41, 42) which carry corrugations (43) with worn mirrors (44).

32. Apparatus according to claim 15, characterized in that the rollers (41, 42) of the last pair of rollers (39) have a smooth or approximately smooth surface.

33. Apparatus according to claim 31, characterized in that the rollers (41, 42) at least one of the last roller pairs (38, 39) have different speeds of rotation.

34. Device according to claim 15, characterized in that the device (1) in front of the wetting unit (2) has a cleaning unit (49).

35. Apparatus according to claim 34, characterized in that the cleaning unit (49) is designed as a cleaning unit (49) working with an air flow, and in that the cleaning unit (49) surfaces (50, 51, 52) made of perforated sieves, special sieves and / or wire mesh with different mesh sizes.

36. Apparatus according to claim 35, characterized in that the work surfaces (50, 51, 52) are independently adjustable in their inclination.

37. Apparatus according to claim 15, characterized in that the wetting unit (2) has a vibrating device which consists of a tube arranged with an approximately vertical axis, which is connected to a motor which sets the tube in vibrating motion.

38. Apparatus according to claim 15, characterized in that a wetting cell (3) is arranged downstream of the wetting unit (2).

39. Apparatus according to claim 15, characterized in that the wetting unit (2) or the stand-off cell (3) is followed by a test device for the surface moisture.

40. Apparatus according to claim 15, characterized in that the wetting unit (2) is a special preparation unit (59 to 64) upstream or downstream.

41. Apparatus according to claim 40, characterized in that the special preparation unit is a sterilization machine, a peeling machine (59), a scrubbing machine (63), an emery grinding machine (61), a polishing machine (61), an impact blower (60), a read-out device (62 ), Special grinding courses and / or special roller mills (64).

42. Apparatus according to claim 15, characterized in that one or more pairs of rollers are designed as roller mills (68).

43. Apparatus according to claim 42, characterized in that one or more pairs of rollers are driven in the roller mill (68) during the grinding process.

44. Apparatus according to claim 42, characterized in that the roller mills (68) have a lower outlet, the outlet being designed in such a way that the ground product falls in a straight line.

45. Apparatus according to claim 42, characterized in that a transport device (65) is arranged below the roller mills (68).

46. Apparatus according to claim 42, characterized in that the roller mills (68) are designed as vibration-monitored or decibel-monitored roller mills.

47. Apparatus according to claim 15, characterized in that the wetting device (2) is upstream or downstream of a device regulating the temperature of the cereals (12).

48. Apparatus according to claim 15, characterized in that the stand-off cell and / or the at least one special processing unit (59 to 64) is followed by a microwave device.

49. Apparatus according to claim 15, characterized in that the last roller mill and / or the last plan sifter is followed by a microwave device.

50. Apparatus according to claim 15, characterized in that the second pair of rollers and / or the further pairs of rollers (5, 7, 36, 37, 38) a cutting mill (75, 76) with a cutting head (77) and / or a micro cutting head ( 83) is connected downstream.