EP0598022B1 - Process for wetting grain with a liquid and device for implementing the process and the application of the process - Google Patents

Abstract

PCT No. PCT/EP92/01843 Sec. 371 Date Feb. 17, 1994 Sec. 102(e) Date Feb. 17, 1994 PCT Filed Aug. 12, 1992 PCT Pub. No. WO93/03843 PCT Pub. Date Mar. 4, 1993.A process for the wetting of cereals with a liquid, wherein the cereal/liquid mixture is exposed for a short time (2 to 15 seconds) to strong vibration (shaking at approximately 80 Hz), with the result that the cereals directly absorb the liquid into themselves and immediately become transportable and can be further processed, for example can be ground, without a substantial storage time. (FIG. 1).

Description

The invention relates to a method for wetting cereals, in particular cereal grains, with a liquid, hereinafter referred to simply as water, and a device for carrying out the method.

For example, for flour production, the flour body (endosperm) of a cereal grain must be separated from the husk (bran and germ). For this purpose, the cereal grains are wetted with water, so that their husk softens and can then be better separated during the grinding process.

According to the prior art, the cereal grains are mixed with water in a screw conveyor and mixed in the process.

In order to mix the cereal grains well with water, the screw conveyor must be made very long. In order to be able to use a shorter screw conveyor, FR-A 2 540 746 provides for the screw conveyor to be designed as a roller with protruding plates arranged helically on the roller. When the roller is rotated, the cereals are only slowly transported to the outlet opening, because some of the cereals can fall through between the plates and are not transported forward, so that the residence time of the cereal-liquid mixture in the mixing device is long-lasting. Such wetting usually causes an even distribution of water on the surface of the grain. This uniform water distribution is not sufficient, as has been shown, for example, to separate the flour body from the shell in a subsequent grinding process. Therefore, after the cereals have been wetted with the water, the cereal-liquid mixture is left for 10 to 24 hours, depending on the quality of the grains, so that the water can soften their skin and penetrate into the interior of the core. These long standstill times are of great disadvantage because a large space capacity is required for storage during the standstill time. The maximum production capacity of a mill is often limited by this necessary space capacity.

In addition, the long standing time has a disadvantageous effect on the quality of the flour, since mold and yeast and / or bacteria (for example enterobacteria C) often form and multiply during the long storage period because of the moisture in the grain. For this reason, the snail, which has a length of between three and eight meters, or is designed in accordance with FR-A 2 540 746 is a good source of germs for mold and / or bacteria, so that the snails have to be cleaned frequently, which leads to interruptions and greatly interferes with the continuous process. In particular, the screw conveyor according to FR-A 2 540 746 is difficult to clean because of the protruding plates.

In order to completely soften cereal grains and to loosen the husk at the core so that they can be rubbed off, it is also known to hurl the already wetted cereals against sharp-edged or rough friction elements during transport. This measure is intended to injure the shell, that is, to provide holes through which the water penetrates the grains and in particular the core more quickly than at the uninjured areas. With this procedure, the liquid primarily migrates from the injured area into the shell. This results in an uneven moistening of the shell. Therefore, as has been shown, the core still adheres firmly to the places on the shell where the shell is not yet sufficiently moist so that the shell cannot be rubbed off the core satisfactorily.

In transference to a grinding process of the cereals, this means that the separation of grain and shell at these points does not succeed.

According to FR-A 2 234 040, cereals are wetted with water for the production of a malt in the production of beer. The whole of the grains, i.e. the kernel and shell for the production of the malt, should absorb a very high water content so that the grains start to germinate. The penetration of the water into the shell and from the shell into the core is promoted in that the Shell of each grain is in turn wetted as evenly as possible, so that the water can penetrate into the shell and the core from all sides. For this purpose, the cereals are moved forward on a conveyor table by swinging the table and are sprayed with water with the aid of a plurality of nozzles arranged along the conveyor table, so that the cereals are mixed well with the water and, so to speak, a water film is placed around each grain.

This measure brings about a good mixing of the water with the grains, but not the rapid penetration of the water into the bowls of the grains. Therefore, according to this document, a longer standing time is required after the wetting of the cereals, because the water does not penetrate the shell of the cereals quickly enough.

According to SU inventor's certificate 1,386,290, it is known for the conditioning of wheat kernels to heat the cooled kernel prior to the grinding of the variety and to moisten and soak the kernel, which are carried out under physical influence on the kernel. The grain is acted on the grain in each conditioning stage by vibration with an interference force of 400 to 495 kp and a frequency of 333 to 416 Hz over the course of 90 to 150 seconds.

A pressure of the wheat column on the vibrating sieve of at least 0.01 atm is required, which corresponds to a thickness of the wheat layer above the vibrating sieve of 0.5 to 0.6 meters.

This process of conditioning wheat kernels before grinding the varieties increases the Yield of flour of high quality grades by 5.0 to 5.5% achieved with a reduction in the ash content of the flour by 0.03 to 0.05%.

The grain is soaked several times over a long period in the course of conditioning. A soaking time of 10 hours is provided in the course of the first treatment stage, a soaking time of 4 hours in the course of the second treatment stage and finally a soaking time of 10 to 20 minutes in the course of the third treatment stage.

This method also requires a very long standby time. These long idle times have the disadvantages already described above.

Similar problems arise in the preparation of other cereals in which the husk is to be separated from the core, such as legumes, corn, rice, beans, including coffee beans, cocoa beans and the like. In the brewing process mentioned above, the problem of the long standing time of 80 to 100 hours and more arises in particular when producing a malt, since the wetted grains should absorb a particularly high proportion of water so that they start to germinate.

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.

Water can be used as the liquid for the treatment. For example, corn should be used as an extruder Popcorn are processed, sugar will be added to the liquid (water), so use sugar water. Molasses can be used as liquid for the treatment of cattle feed.

The object of the invention is to provide a wetting process for cereals, in which the cereals are wetted with liquid in such a way that the standing time is practically eliminated as a storage time, and in which the transportability of the cereals wetted with liquid is immediate, that is to say immediately or already after 10 to 30 minutes is given.

Transportability is understood to mean that the cereals, for example wetted with water, no longer have an outer water film which leads to sticking to the means of transport (belts, screws or the like).

This object is achieved by the characterizing feature of claim 1.

It has been found that when the cereals mixed with water are exposed to vibrations, that is to say they are shaken vigorously, for example at a frequency of 50 to 300 Hz, preferably 75 Hz, over a period of 2 to 20 seconds from the wall Accelerating forces exerted by the vibrating device on the cereal-liquid mixture allow all the water to penetrate so far into the cereals, at least into their shells, that the shells still feel moist on the outside, but a film of water on the cereals is no longer perceptible and also no longer is available.

This shaking process can be carried out gently, that is, in such a way that the husks of the cereals are not damaged, so that the liquid, evenly distributed, penetrates directly into the husk of each grain.

It has also been shown that the grindability of such a grain can be obtained after 30 minutes to 2 hours, depending on the addition of water, when using the process according to the invention, because in particular then the shell has the desired degree of moisture evenly distributed over the entire shell of each grain and can therefore be easily separated during the grinding process. Long storage of the cereals in order to obtain a uniform moisture content with the desired degree of moisture, as in the prior art, is not necessary.

According to the invention, therefore, the shell of the grain is first penetrated with moisture relatively quickly, and the moisture then penetrates from the shell into the interior of the grain relatively uniformly from all sides.

The advantage of the method according to the invention is therefore to be seen in the fact that the grain can be transported to its processing site immediately or after a short residence time after wetting, in order to be ground there, for example, and that there is no intermediate storage of the grain.

In addition, it has been found that, in order to obtain a grindable grain, the entire amount of water required can be supplied to the cereals, in particular the grain, in a single operation can, which saves considerable time for wetting the cereal grains. In the case of the methods belonging to the prior art, which work with a screw conveyor, several additions of water are required at intervals.

According to the invention, several additions of water are only necessary at intervals if the grain including its core is to absorb a great deal of water, for example up to 40 or 50 percent by weight, in order to start the germination process for the production of a malt in the malting plant.

The method according to the invention also has the advantage that, for example, a mesh screw for mixing the grain with the water is no longer necessary, since other simpler means are available, such as a simple agitator or a funnel arrangement according to subclaim 8. This results in greater cleanliness and thus achieved better hygiene. In addition, an energy saving is achieved since the drive of the line screw or similar devices requires considerably more energy than the vibrating device according to the invention.

Above all, however, bacteria and fungi in particular have less opportunity to multiply due to the lack of storage time.

The device according to the invention expediently consists of a tube with a preferably vertically arranged axis, which is connected, for example, approximately in the middle to one or more vibrating motors. The cereals, mixed with liquid, for example water, can be filled into the tube at the top, and they run out again below. The flow rate can be regulated by measuring and control devices. In this way, the residence time of the cereal-liquid mixture in the tube can be regulated. In particular, a discharge element can be provided at the lower end of the tube, which takes the cereals in the desired amount either continuously or discontinuously from the tube. Such a discharge element can be formed, for example, by a cone which is introduced more or less into the pipe end and thus either completely interrupts the outflow of the cereals or optionally allows certain quantities of cereal / liquid mixture to escape. However, cellular wheel sluices, vibrating troughs, sliders of all kinds or screw conveyors can also be used.

In principle, the tube can also be arranged with a horizontal axis, so that the cereals are inserted from one side. This shaking may be appropriate when the grain-liquid mixture is to be shaken in batches.

The tube advantageously has smooth walls on the inside, so that, in particular, the shells of the cereals are not injured when shaken for the reasons mentioned at the outset, because, as already stated, if the shells are injured, the water penetrates the shell unevenly, namely first at the injury sites in order to penetrate further from here on the one hand into the shell and on the other hand into the core. As a result, the shell is moistened unevenly and therefore the desired exact separation of the shell and core is negatively influenced during the grinding process. Because at the points where the shell is not yet sufficiently moist, core pieces of the Grain still firmly on the bowl and stick to the bowl during the grinding process.

The tube can also have partition walls so that the maximum distance of each grain from one of the walls set in vibration remains small. This gives the cereal-liquid mixture high acceleration during the vibrating process, namely in the order of 5 g to 15 g (g = gravitational acceleration). Despite this high acceleration, the cereal-liquid mixture does not hit the walls hard since the grains mixed with liquid are arranged relatively compactly in the tube or in the tube chambers, i.e. the energy transfer to the cereal-liquid mixture does not take place by hard impacts on it Mixture, but by contact of the grains and possibly the liquid droplets on the pipe wall or an intermediate wall. With these acceleration forces, the liquid itself tears into the finest droplets, which are deposited directly on the husks of the cereals and penetrate into the husks.

A significant further advantage of the method according to the invention is seen in the fact that additives can be added to the liquid in a further embodiment of the invention. Enzymes such as proteinases, proteases or the like, vitamins such as ascorbic acid, nitrates, salts and / or sugars can be provided as additives. These additives dissolved in the liquid can change the properties of the cereals, such as raw fibers, starch, proteins, fats and / or mucilages, as well as the cell structures and thus, for example, the grindability of the grains.

• 1. Das Einbringen von Additiven in das Korn vor dem Mahlvorgang ist billiger, als das Einbringen von Additiven nach dem Mahlvorgang durch Zusatz zu dem Mehl, wobei das Additiv, zum Beispiel Vitamin C, nach dem Stand der Technik in Pulverform dem Mehl zugesetzt wird.
• 2. Das erfindungsgemäße Verfahren läßt sich zeitlich schneller durchführen, da beispielsweise bei der Herstellung von Mehl die Schalen oder das Mehl nach dem Mahlvorgang nicht mehr gesondert mit den pulverförmigen Additiven vermischt werden müssen.
• 3. Der Zusatz der Additive nach dem Stand der Technik in Pulverform kann gesundheitsschädlich sein, wenn die Additive zum Beispiel eingeatmet werden. Sie sind aber häufig auch nicht mit der Haut eines Menschen verträglich.
• 4. Die Vermischung von Mehl mit den Additiven nach dem Stand der Technik erfordert eine sehr gründliche Vermischung des Mehles mit den Additiven. Mit dem erfindungsgemäßen Verfahren wird auf einfachste Weise eine überaus gleichmäßige Verteilung der Additive in dem Mehl erreicht. Die Vermischung mit den Additiven ist also nicht mehr so kostenintensiv und so zeitaufwendig wie nach dem Stand der Technik.

Introducing the additives directly with the liquid into the cereals during shaking has the following advantages, for example in flour production:

• 1. The introduction of additives into the grain before the grinding process is cheaper than the introduction of additives after the grinding process by addition to the flour, the additive, for example vitamin C, being added to the flour according to the prior art in powder form.
• 2. The method according to the invention can be carried out more quickly, since, for example, in the production of flour, the shells or the flour no longer have to be mixed separately with the powdery additives after the grinding process.
• 3. The addition of the additives according to the prior art in powder form can be harmful to health if the additives are inhaled, for example. However, they are often not compatible with a person's skin.
• 4. The mixing of flour with the additives according to the prior art requires a very thorough mixing of the flour with the additives. With the method according to the invention, an extremely uniform distribution of the additives in the flour is achieved in the simplest way. Mixing with the additives is therefore no longer as cost-intensive and as time-consuming as in the prior art.

In addition to the previously mentioned fields of application, the process according to the invention can, as already mentioned, also be used for the production of malt, as required by the brewer, by adding the cereals are expediently shaken several times with the addition of a liquid. As a result, more liquid, for example water, can be bound in the cereals in a short time, that is to say the percentage by weight of liquid in the grain can be increased far above the usual level, so that the cereal grains begin to germinate in a much shorter time. In this application, it is important that a lot of water is absorbed by the endosperm itself in order to germinate the grain.

Fig. 1

ein erstes Ausführungsbeispiel im Schnitt;

Fig. 2

einen Schnitt nach der Linie II-II der Fig. 1;

Fig. 3

ein geändertes Ausführungsbeispiel gemäß Fig. 2;

Fig. 4

ein geändertes Ausführungsbeispiel gemäß Fig. 2;

Fig. 5

ein geändertes Ausführungsbeispiel.

Exemplary embodiments of the invention are shown in the drawing, namely:

Fig. 1

a first embodiment in section;

Fig. 2

a section along the line II-II of Fig. 1;

Fig. 3

a modified embodiment of FIG. 2;

Fig. 4

a modified embodiment of FIG. 2;

Fig. 5

a modified embodiment.

1, cereal grains (100) are filled in the direction of arrow (101) in a funnel (102), in such a way that fewer cereal grains run out of the funnel opening (103) than are filled in above, so that the cereal grains are over the top edge (104) of the funnel swell and fall past it through the lower opening (105) of an outer funnel (106) surrounding the funnel (102). With the help of an inflow (107), water is supplied to the cereal grains in the area of the funnel (102).

A simple stirrer or other device can also be used to mix the cereals with the water.

The cereal grains thus mixed with water fall through an enlarged opening (110) of an approximately vertically arranged pipe (111). The tube (111) is supported by means of rubber buffers (112) on a fixed frame (113) in such a way that it can move in the direction of the arrow (115) and its upper part (111a) and the lower part (111b) can swing transversely to the axis AA of the tube in the direction of arrow (115). The tube (111) carries a sleeve (116) which is firmly connected to a vibrating motor (114). When the armature of the vibrating motor (114) rotates, the sleeve (116) and thus the middle part of the tube moves back and forth in the direction of the arrow (115), and the ends of the tube swing in the direction of the arrows (117 and 118) . As a result, a strong acceleration is imposed on the cereal grain-liquid mixture stored in the pipe (111) via the wall of the pipe (111), which tears the liquid into fine droplets through forced vibrations and distributes it quickly and evenly over the entire bowl and into the bowl and can penetrate the grain from here. During this process, the cereals mixed with the water trickle from the inlet opening (110) to the outlet opening (121). Here you will find a plug cone (120) which enters an outlet opening (121) can be introduced. Depending on the position of the cone (120) in the outlet opening, more or fewer cereals can fall past the cone (120). The position of the cone (120) and the length of the tube thus determine the residence time of the cereal-liquid mixture in the tube (111).

Instead of the cone, however, a cellular wheel sluice known per se, a slide mechanism, a vibrating trough or the like can also be suitably connected to the tube.

The grain can also be passed through in batches. In this case, the outlet opening (121) is closed and the tube is shaken for a predetermined time after filling in the cereal-liquid mixture. After opening the outlet, the wetted cereals flow out of the tube and the tube can be refilled.

A control device (130) is provided for the continuous passage of the cereals. The control device (130) receives measured values from a sensor (131) which indicates the flow rate of the cereals into the tube (111). The device (130) regulates the refilling of the funnel (102) with cereals and water. A measuring device (132) measures the outflow quantity of the cereals from the tube (111). The measuring device (130) controls this outflow quantity and thus the residence time of the cereals in the tube. The cereal-liquid mixture lies compactly in the tube during the shaking process, so that it does not hit the tube wall too strongly when shaking, but rather is only exposed to high acceleration forces.

A tube filling usually requires 2 to about 15 seconds or more of shaking time, i.e. the cereals which have entered above should be shaken in the tube for about 2 to 15 seconds or more, regardless of whether they are filled and shaken in batches in the tube or run continuously through the pipe. The length of the tube is dimensioned accordingly. A tube of one meter length is usually sufficient.

The cereals emerging from the bottom of the tube (111) fall through a guide tube (140) onto a distribution plate (141) and from there into a collecting container (142). The emerging cereals are immediately transportable, so that they can be transported with the aid of conveyor belts, snails and the like, without sticking to these parts due to adhesive forces, to a processing location without time-consuming intermediate storage.

The tube (111) can have a circular, elliptical or rectangular, also square, cross section. It is only intended to ensure that the cereals receive their acceleration energy from the inner wall of the tube to a sufficient extent during the shaking process.

The diameter of the tube (111) can be increased in order to allow larger quantities to pass through. However, the vibrating effect is reduced towards the inside of the pipe, since the energy transfer of the cereal-liquid mixture from grain to grain to the center of the pipe is reduced. 3, longitudinal walls (150) are provided in a further exemplary embodiment in the interior of a tube (122), which further Form energy transfer walls for the grain-liquid mixture passing through.

Another solution to this problem is shown in FIG. 4. Three tubes (151, 152, 153) are provided here, which are firmly connected to one another and can be shaken together.

Fig. 5 shows the tube (123) with retracted partitions (124), so that rectangular spaces (125) are formed in the tube over the length of the tube, the transverse walls being at a relatively short distance from one another, so that the rectangular spaces become very narrow. If one shakes such a tube with a frequency of 75 to 80 Hz, the tube walls give the grain-liquid mixture an acceleration of five to fifteen times the acceleration due to gravity, whereby the liquid tears and the grains evenly wet, so that the liquid directly into the bowls that penetrates grains. This penetration is promoted by the acceleration forces exerted on the cereals and also the further penetration of the liquid into the core of the cereals.

Reference numbers

100

Cereal grains

101

arrow

102

funnel

103

Funnel opening

104

upper edge

105

lower opening of 106

106

Outer funnel

107

Water inflow

110

extended opening

111

pipe

111a

upper part of the tube

111b

lower part of the pipe

112

Rubber buffer

113

Frame

114

engine

115

arrow

116

cuff

117, 118

Arrows

120

Locking cone

121

Outlet opening

122

pipe

123

pipe

124

Partitions

125

elongated, rectangular rooms

130

Control device

131

Sensor

132

Measuring device

140

Guide tube

141

Distribution plate

142

Collecting container

150

Partitions

151, 152, 153

Tube

A-A

Pipe axis

Claims (33)

1. Process for wetting grains with a liquid, in which the grains are mixed with a liquid and vibrated in a container (111) during a transport movement, characterized in that the grains run continuously or batchwise through the container of the vibrating device after or during the mixing with the liquid in such a way that the walls of the tubular container transmit their kinetic energy to the grain-liquid mixture, in such a way that the grains and the liquid are subjected to strong acceleration forces.
2. Process according to claim 1, characterized in that the grain-liquid mixture is vibrated with a frequency of 50 to 300 Hz, preferably 75 Hz.
3. Process according to claim 1, characterized in that the vibrating time is approximately 2 to 20 seconds.
4. Process according to claim 1, characterized in that the grain-liquid mixture is vibrated by mechanical, electrical and/or magnetic energy and/or by exposure to sonic waves.
5. Process according to claim 1, characterized in that the grains are arranged compactly in the container or run through it.
6. Process according to claim 1, characterized in that the grains and the water are brought together in a mixing device upstream from the vibrating device and are fed from this mixing device direct to the vibrating device.
7. Process according to claim 1, characterized in that the grains are fed to a hopper in such a quantity that they trickle out of the lower hopper opening on the one hand and fall over the top edge of the hopper on the other hand, that the liquid is directed into the intake opening of the hopper, and that the grains moistened in this way are directed or fall into the vibrating device.
8. Device for implementing the process according to claim 1, whereby a container (111) with its longitudinal axis (A-A) is positioned in the direction of the product flow and connected with at least one motor (114) setting the container in vibratory movement, characterized in that the container consists of at least one pipe (111) whose longitudinal axis (A-A) is positioned horizontally or vertically, whereby the motor (114) generating the vibratory movement engages approximately at the centre of the at least one pipe, so that the latter is vibrated transversely to its longitudinal axis.
9. Device according to claim 8, characterized in that the pipe is positioned with the axis approximately vertical, that the mixing device (102, 107) for the grains with the liquid is provided above the pipe (111), and at the lower end of the pipe (111) a device (120, 121) regulating the throughput and/or quantity of grains removed.
10. Device according to claim 9, characterized in that the device (120, 121) regulating the discharge of the grains from the pipe (111) consists of a conical body (120) more or less insertable into the pipe end (121), whose tip points into the pipe end.
11. Device according to claim 9, characterized in that the device (120, 121) is formed by a rotary vane batcher, a worm rotatable about its axis at controllable speed, a vibratory trough connected with the pipe end or a valve device.
12. Device according to claim 8, characterized by a device (130, 131) measuring and controlling the intake quantity of the grains and of the liquid into the container of the vibrating device.
13. Device according to claim 9, characterized by a device (132, 130) measuring and controlling the discharge quantity of the grains.
14. Device according to claim 12 and claim 13, characterized by a control device (130) regulating the retention time of the grain-liquid mixture in the vibrating device.
15. Device according to claim 9, characterized in that a distributing plate (141) is mounted downstream from the device (120, 121).
16. Device according to claim 8, characterized in that the pipe (111) has a circular or elliptical cross section.
17. Device according to claim 8, characterized in that the pipe has a rectangular or square cross section.
18. Device according to claim 8, characterized in that the pipe (122) has several partition walls (124, 150) dividing the internal space in longitudinal direction.
19. Device according to claim 18, characterized in that the spaces (125) formed by the walls (124) have an approximately flat rectangular cross section.
20. Device according to claim 8, characterized in that several pipes (151, 152, 153) are connected with one another.
21. Device according to claim 8, characterized in that the diameter of the pipe (111, 151, 152, 153) is approximately ten centimeters.
22. Process according to claim 1, characterized in that the acceleration exerted on the grain-liquid mixture is approximately 10 to 15 g (g = gravitational acceleration).
23. Process according to claim 1, characterized in that under grains, fruits with a hard and soft husk are understood, such as cereal grains, pulses, corn, rice, and polished rice and the like, and beans, such as coffee beans, cocoa beans or the like, as well as fruits which can be extruded.
24. Process according to claim 1, characterized in that water, sugared water, molasses or the like is used as the liquid.
25. Process according to claim 1, characterized in that at least one additive soluble in the liquid is added to it, such as enzyme, vitamin, nitrate, salt and/or sugar, which changes at least one characteristic of the grains, such as crude fibres, starch, proteins, fats, mucocelluloses or the like, or else aromatic agents, colouring agents and the like.
26. Process according to claim 1, characterized in that the grains mixed with the liquid are vibrated from one another several times at intervals.
27. Process according to claim 26, characterized in that the interval is approximately 30 minutes to 5 hours.
28. Application of the process according to claim 26 in the brewery for the production of malts, such as wheat malt, barley malt, millet malt, sorghum malt or the like, characterized in that the grains are vibrated from one another at intervals under respective addition of liquid.
29. Process according to claim 1, characterized in that the grains are vibrated without damage to their surface.
30. Device according to claim 8, characterized in that the pipe (111) has smooth walls and/or partition walls internally.
31. Process according to claim 1, characterized in that the grains are provided in such a way that an osmotic pressure effect is exerted on them on passing through the pipe.
32. Process according to claim 1, characterized in that the grains are processed into flour subsequent to the vibrating process.
33. Process according to claim 1, characterized in that the grain-liquid mixture is used for the production of extruder products subsequent to the vibrating process.

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