EP0964748B1 - Method and device for fragmenting bulk materials - Google Patents

Abstract

The invention relates to a method and a device for fragmenting bulk materials. A rotor (4) having beating elements (5) is positioned in the milling chamber of said device and surrounded by a sieve (6) which has several deflecting elements (7, 9) on its surface (6a). The milling process is characterized by a pulsing motion, whereby the direction in which the product is fed to and drawn away from the beating elements alternates, which separates the fines from the total flow.

Description

The invention relates to a method and an apparatus for comminuting Bulk goods, especially cereals, which are used in the compound feed industry and in used in the milling industry.

A large number of grinding devices are known, in which in a housing a rotor with striking organs, the whole circumference or only partially is surrounded with a sieve is arranged. In these devices that will Material fed into a work zone, i.e. a zone between the striking organs and the inner surface of a chamber (sieve, baffle plate) which encloses the rotor and crushed there. Since the striking organs are located directly in the layer of the moving crushed material, the grinding is dominated by the grinding principle, which ultimately results in the over-crushing of the particles, in too high Energy consumption and intensive wear of the striking organs and the rotor.

A device of the type mentioned above is known from DE 1 250 721. This discloses a beater mill, in which revolving impact elements with in one The strainer basket interacts between the friction plates or baffle jaws. A particularly high energy consumption arises when the embodiment is used 4 with a two-armed cross beater and three rubbing jaws.

In GB 1 411 085 a hammer mill is disclosed, in which by special Conical design of the rotor end the flow of the in the grinding chamber material that has reached the mill is affected. This can prevent excessive wear of the rotor can be reduced.

The US-PS 2225095 discloses a sieve for hammer mills with radial product feed. The sieve surrounding the rotor has internally distributed around the circumference, triangular deflection elements. These are fixed. A similar arrangement shows US-PS 2465056, with additional elements also on the Sieve are distributed, which have approximately the thickness of the sieve mantle and are perforated analogously to the sieve.

The aim of the present invention is to reduce energy consumption in grinding, in increasing the uniformity of the grain of the finished product and in increasing the lifespan of the work organs and the sieve.

The device according to the invention has a housing with inlet and outlet connections, a racket rotor and a sieve with several deflecting elements, which the Surrounded by beater rotor. The baffles on the periphery of the screen are the same or varying distance from the rackets. The deflection elements have smooth surface with an inclination of 20 to 80 degrees to the radius and form a distance from the rotor whose minimum width is not greater than the diameter of the grains to be processed.

The deflection elements are rotatable in relation to the radius executed, i.e. rotatable about a pivot point on the screen surface in the direction of this Screen surface or in the opposite direction.

According to a preferred embodiment, the deflection elements are arranged radially and form a triangular prism, the lateral one, in a manner known per se Edges are directed towards the sieve.

The deflection elements can be adjusted along the screen circumference. By the possibility the sliding design of the deflection elements along the circumference of the Uniform wear of the sieve is achieved during operation, since this covers already worn segments of the sieve.

On the other hand, it is possible to use screens with alternately arranged screens Segments of different perforations, due to the joint displacement of the pin-shaped Working elements along the sieve surface with the same sieve segments Cover perforation. This allows the granulation of the end product to be predetermined become.

The device shown above is ground or ground in one Working zone between the deflection elements and the striking elements of the Rotor and goes beyond the so-called impact principle. Each time the product stream is fed a single blow to the flying product is carried out to the striking organs. This separates the particle stream into coarse and small particles. The coarse particles with high kinetic energy fly directly to the next one Percussion organ, whereas the small ponds with less kinetic energy, below Influence of the air flow generated by the rotor fly around it and its Continue motion along the perforated chamber surface and the chamber leave. This separates the fine fraction without the common one Impact of the next impact organ of the rotor takes place. So that will Product flow after its delivery into the grinding chamber a pulsating Character added with multiple changes of supply and discharge to the Blow organs.

It is also pointed out that the efficiency of the process increases, when the material is fed to the rotor at a certain angle. This angle varies with the radius in the range of 20-80 degrees.

Fig.1

schematische Darstellung der Schlagmühle in Längsansicht,

Fig.2, 2a

schematische Darstellungen der Schlagmühle in Seitenansicht bei Verwendung von radial angeordneten Ablenkelementen,

Fig.3

Draufsicht des Siebes mit Segmenten verschiedener Lochung,

Fig.4

schematische Darstellung der Mühle in Seitenansicht bei Verwendung von verstellbaren Ablenkelementen, und

Fig.5

schematische Ansicht eines Siebdetails mit verstellbaren Ablenkelement.

The invention is illustrated below with reference to drawings and exemplary embodiments. show it:

Fig.1

schematic representation of the impact mill in longitudinal view,

Fig. 2, 2a

schematic representations of the impact mill in side view when using radially arranged deflection elements,

Figure 3

Top view of the sieve with segments of different perforations,

Figure 4

schematic representation of the mill in side view when using adjustable deflection elements, and

Figure 5

schematic view of a sieve detail with adjustable deflector.

The impact mill in Figure 1 consists of a housing 1 with an inlet nozzle 2 and an outlet nozzle 3. Inside the housing 1 there is a rotor 4 with the striking elements 5. The rotor is surrounded by a sieve 6, on the Surface 6a a plurality of deflection elements 7.9, preferably with a triangular Cross section, are arranged. The screen 6 is on its circumference in screen segments divided by the deflection elements 7, 9, which go from the sieve to the rotor inside are directed and a smooth work surface inclined in the direction of rotation of the rotor exhibit. The angle of inclination (in relation to the radius is in the range 20 to 80 degrees and the distance h between the ends of the striking elements 5 and the deflection elements 7.9 not less than the grain diameter of the starting product is.

2, 2a show a radial design of the deflection elements 9 with side edges, which to the screen 6 or whose surface 6a is an inward form a triangular prism.

3 shows the screen 6, which is in segments A and B with different perforations is alternately divided, the triangular prisms being the segments cover the same perforation.

4 shows an adjustable arrangement of the deflection elements 7 and FIG. 5 shows the directions of rotation of the deflection element 7 to and from the screen 6 by one at the Screen surface 6a arranged pivot point 80. The direction of rotation of the rotor 4th can be done both clockwise and counterclockwise.

The deflection elements 7, 9 are in a ring 10 along the circumference of the sieve 6 movable, cf. in particular Fig.2a arranged.

The mill works as follows:

The starting product (uncrushed grain) is through the inlet nozzle 2 in Figure 1 fed from two sides to the rotor 4 and comes under the influence of Centrifugal forces Z on the curved rotor track on the screen surface 6a or to a sieve section S (see Fig. 2), which by two successive Deflection elements 7 and 9 is limited. It should be noted that the Starting product within the rotor 4 of the partial crushing under the Exposure to the impact organs 5 is exposed. While moving along of the screen 6 in Fig.4, the product comes on the smooth inclined surface of the Deflection element 7, changes its direction of movement and thus comes under one single blow of the impactor 5 of the rotor 4. When the product collides on the striking organ 5 it is broken down into particles of different sizes, which, under the influence of the inertial forces which are given to them when struck, arrive on the next screen section S, which the deflection element 7 in the Direction of rotation of the rotor 4 follows. While moving along the screen surface 6a under the influence of centrifugal forces and the air flow through the rotor is generated, the product is separated according to size. particles which have passed through the perforation of the sieve 6 are over the outlet nozzle 3 transported out of the mill as a starting product (finished product). The coarser particles and a certain number of small particles, those who had no time to pass through the sieve reach the next deflecting element 7 that lies in the direction of movement of the product.

A similar process as described above follows, but with the difference that that along the surface of the deflecting element 7, 9 there is a product flow moving, which consists of particles of different sizes, coarse particles, which have a large supply of kinetic energy leave the surface at an angle in the range of 20 to 80 degrees to the radius and meet in free flight on a single impact of the rotor 4. The fine parts, which over less energy has curves around the deflecting element 7.9 and thus get without Impact to the next sieve section S. The small ones arrive Particles immediately behind the deflector 7.9 to the screen surface 6a, while Larger particles arrive at the back in the direction of rotation. To this In this way, the fine particles make a larger path along the screen surface 6a until the next movement with the deflection element 7.9, i.e. the probability increases that they pass the perforation of the sieve. simultaneously the coarser particles have only a short contact with the sieve surface 6a. which helps reduce its wear.

Each subsequent product conveying for shredding with the help of the deflection elements 7.9 differs from the previous one in that the product quantity is constantly decreasing because the particles of required size are continuously passing through the Perforation of the sieve 6 can be removed.

1. Vorzerkleinerung des Ausgangsproduktes (ganzer Getreidekörner), welches dem Innenraum des Rotors 4 zugeführt wird und seine gleichzeitige Beschleunigung bis zu einer bestimmten Geschwindigkeit,

2. Weiterleitung des vorzerkleinerten Produktes unter einem bestimmten Winkel und mit vorgegebener Geschwindigkeit auf das Sieb 6,

3. Produktbewegung entlang des Siebes 6 bzw., Sieboberfläche 6a, welche den Rotor 4 umschliesst, mit gleichzeitiger Trennung der Feinfraktion und der Zuführung der ungenügend zerkleinerten Fraktion unter Einwirkung der geneigten Ablenkelemente 7, welche am Sieb 6 angeordnet sind, zum weiteren Schlag durch die Schlagorgane 5,

4. mehrmalige Wiederholung des Zuführzykluses der noch zu wenig zerkleinerten Fraktion zum Rotor 4, ihre Zerkleinerung und Weiterleitung zur Sieboberfläche 6a.

The process for shredding bulk goods is based on the following principles.

1. Pre-comminution of the starting product (whole grain), which is fed to the interior of the rotor 4 and its simultaneous acceleration up to a certain speed,

2. forwarding the pre-shredded product to the screen 6 at a certain angle and at a predetermined speed,

3. Product movement along the sieve 6 or, sieve surface 6a, which encloses the rotor 4, with simultaneous separation of the fine fraction and the supply of the insufficiently comminuted fraction under the action of the inclined deflection elements 7, which are arranged on the sieve 6, for further blow by the Percussion organs 5,

4. repeated repetition of the feed cycle of the fraction which has not yet been comminuted sufficiently to the rotor 4, its comminution and forwarding to the screen surface 6a.

In addition, the crushing principle of the impact mill is based on the crushing without direct interaction of rotor 4 and sieve 5, which is in Reduction of energy consumption and an increase in the lifespan of the Striking organs.

It should be noted that the perforated surface of the chamber from the rotor by the distance necessary to prevent the Rotor can hit the product as it passes.

The process has the best efficiency when the product feed to the rotor takes place at a certain angle. This angle must be in the area with the radius from 20 to 80 degrees.

Reference numeral Directory

1

casing

2.3

Inlet and outlet nozzle

4

rotor

5

blow organs

6

scree

6a

screen surface

7.9

deflectors

8th

engine

10

Ring on the circumference of the sieve

80

Pivotal point of the deflection element to the screen surface

A

work zone

G

crushed good

H

Distance between the deflection elements and the striking elements of the rotor

S

screen sections

α

Angle of inclination of the deflection element with respect to the radius

P1, P2

Double arrows indicate the deflection of the material to and from the blow organs

Z

centrifugal

β

Angle that determines the product feed to the rotor

Claims (10)

1. A device for comminuting bulk material with a casing (1) having inlet and outlet nozzles (2, 3), with a rotor (4) surrounded around its entire or only partial periphery by a sieve (4), and deflectors (7, 9) arranged on the sieve, characterized in that the deflectors (7) are rotatably arranged relative to the radius, and that the deflectors (7) can also rotate around a pivot (80) on the sieve surface (6a) in the direction of the sieve surface (6a), and in the opposite direction.
2. The device according to claim 1, characterized in that the deflectors (7) exhibit a smooth working surface with angle of inclination α ranging from 20 to 80 degrees relative to the radius.
3. The device according to claims 1 and 2, characterized in that the distance between the deflectors (7, 9) and beaters (5) of the rotor (4) does not exceed the diameter of the grain size of the starting product.
4. The device according to one of claims 1 to 3, characterized in that the deflectors (7, 9) are moveably arranged along the sieve periphery (6).
5. The device according to claim 1 or 4, characterized in that the sieve (6) exhibits segments with a different perforation.
6. The device according to claim 4 and 5, characterized in that the side edges of the triangular prisms cover the segments with an identical perforation.
7. The device according to claim 4, characterized in that the deflectors (7, 9) can be shifted along a ring (10) on the periphery of the sieve surface (6a).
8. The device according to one of the preceding claims, characterized in that it is a beater and deflector mill.
9. A procedure for comminuting bulk material, characterized in that

   a) The pre-comminuted product is routed at a specific angle and preset speed to the sieve (6);

   b) The product is moved along the sieve, while simultaneously separating the fine fraction and routing the insufficiently comminuted fraction during exposure to the deflectors (7, 9) for subsequent impact by the beaters (5);

   c) The feed cycle of the as yet inadequately comminuted fraction to the rotor (4) is repeated several times, it is comminuted and routed on to the sieve surface (6a).
10. The procedure according to claim 9, characterized in that the angle β can vary from 20 to 80 degrees relative to the radius.

Images