WO2011033416A2

WO2011033416A2 - Hammer mill

Info

Publication number: WO2011033416A2
Application number: PCT/IB2010/054032
Authority: WO
Inventors: Werner Buschhoff
Original assignee: Th. Buschhoff Gmbh & Co.
Priority date: 2009-09-16
Filing date: 2010-09-07
Publication date: 2011-03-24
Also published as: DE112010003660A5; PL221771B1; PL398280A1; EA020274B1; DE202009011011U1; EA201270420A1; WO2011033416A3

Abstract

The invention relates to a hammer mill (10) for feed preparation having milling housing (11) forming a grinding chamber (12) that has two sieve zones (I, II) on a circumferential wall that have sieve perforations of differing diameters and a rotor (20) in the grinding chamber, equipped with hammers (19), which can be driven. In order to be able to create feed of varying grain size using one and the same hammer mill without modification steps, according to the invention the rotor (20) can be driven in opposing rotation directions and the hammers (19) each have two impact surfaces (28a, b), of which one is effective in one rotation direction and the other is effective in the opposite rotation direction.

Description

description

Title of Invention: HAMMERMILL

The invention relates to a hammer mill for feed processing, with a

Mahlkammer forming mill housing, which on a peripheral wall with two

Sieve zones is provided, which have Sieboochungen with different sized hole diameters, and with a rotatably driven in the grinding chamber, equipped with hammers rotor.

Hammer mills of this type are used in the processing of cereals or other agricultural products of plant origin, in order to prepare feed for the rearing of animals. The impact hammers arranged on the motor-driven rotor crush the cereal grains, plant parts and the like located therein in their circulation in the grinding chamber. until the shot produced thereby is smaller than the diameter of the sieve holes in the sieve zone used in each case. In order to obtain shot structures of diameters of different sizes, it is known from DE 20 2007 014 607 to provide the hammer mill with at least two screen zones on its drum peripheral wall, which have different hole diameters, wherein each of the screen zones can be closed with shutters and in operation Closing flaps of the zone with the desired screen hole diameter are opened, while the other screening zones remain closed.

The well-known hammer mill has proven itself well in operation. However, it sometimes happens that parts of the broken cereal or the like. Place in gaps between the tail flaps and the mesh zones and then make it difficult to reliably close or open the flaps. It is therefore relatively often necessary to clean the hammer mill in these areas of scrap remains.

Mostly in the generic hammer mills a need only for two different sized grain sizes of the processed feed. Thus, for example, it is necessary for pigs on farm farms to prepare the feed on the one hand for small piglets, on the other hand for adult fattening animals, the piglets needing a small grain size, while the fattening animals need feed with a coarser structure.

[5] The object of the invention is, in particular for such applications, to provide a hammer mill with which, without conversion measures, it is possible to produce feed with a small grain size as well as with a coarser structure.

This object is achieved with the invention in that the rotor is driven in opposite directions of rotation and that the hammers with two

Faces are provided, one of which in one direction of rotation and the others are effective in the opposite direction of rotation.

It has surprisingly been found that the direction of rotation of the rotor of a generic, provided with two sieve zones hammer mill has a very decisive influence on the grain structure of the produced feed, because the majority of the escaping from the screens screenings done by the direction of rotation in each case foremost screening zone. It is thus possible by changing the direction of rotation of the rotor without further technical measures to determine whether a large part of the ground feed is now in the small piglets or the like. required fine structure is produced or a feed is produced which has a predominantly coarser freeness. Since the hammers each have two impact surfaces, which are preferably arranged symmetrically to each other and thus equally effective in both directions, so can be changed by simply switching the direction of rotation of the sieve of the produced feed crucial, without it being required by additional technical measures, cover individual areas of the screen, which, as explained, often requires a cleaning of the machine.

Of course, also in the invention similar to the known machine of

Drive for the rotor to be controlled or regulated, so that the rotational speed of the rotor can preferably be varied continuously, whereby the grinding result or the desired degree of grinding can also be influenced.

[9] The screening zones are preferably at least approximately symmetrical to each other in the

Mill housing arranged and adjacent to the lower bottom portion of the grinding chamber preferably at their lowest point together. It is also possible to provide a partition on the outlet side between the two screening zones or to assign separate collection containers to the two screening zones if mixing of the fine fraction emerging through the fine screen with the coarser result in the coarse screening is to be kept to a minimum.

The grinding chamber may for example be cylindrical, but it may also have a substantially oval cross-section, for example, similar to the combustion chamber look at a rotary engine. In a particularly advantageous embodiment of the invention, the rotor with eccentricity to the grinding chamber is arranged in this, that the average distance of its axis of rotation of the screening zone with the Sieblochungen smaller diameter is less than from the screening zone with the Sieblochungen larger diameter. This achieves a smaller distance of the radially outer flapping surfaces of the impact hammers of the finer sieve, so that the material to be ground in this screening zone with the Sieblochungen smaller hole diameter is very quickly crushed when the rotor rotates in a direction of rotation, in which the fine sieve in Rotation direction after the material inlet is reached first. Because of the then forming thicker gap between the Schlaghämbehöpfen and the coarse sieve of the hammers entrained, not yet passed through the sieve holes of the fine sieve part of the ground material in the Grobsiebes not further crushed / squeezed, but taken with the hammers in their circulation, until they get back into the sphere of action of the finer sieve.

In known manner, the rotor may be provided with evenly distributed over its circumference arranged pivot axes on which the hammers are pivotally mounted. In this case, the arrangement is preferably made such that a plurality of hammers are distributed over the width of the housing at each pivot axis.

The striking surfaces are expediently formed on the front and rear longitudinal sides of the hammers in the direction of rotation of the rotor at their radially outer end regions (hammerheads). They are preferably formed by arranged on the hammers hard metal elements, which have a high strength and are subject to little wear. In particular, if the material to be ground is very abrasive, it is advantageous if the striking surfaces are formed by exchangeable attached to the hammers wear pieces, because then the hammers must not be completely replaced when their striking surfaces have reached the wear limit, but it is sufficient just replace the wear pieces.

The rotor can be provided with circumferentially before and / or behind the pivot axes, the pivoting movement of the hammers limiting attacks, whereby the effectiveness of the machine is further increased. The

Screening zones may be formed by screen inserts or sheets interchangeably arranged in the mill housing, which not only can be replaced when worn, but also allow replacement with another screen insert with larger or smaller holes to alter the degree of grinding. Preferably, the screen zones each extend over a peripheral region of about 60 ° to 140 ° of the peripheral wall of the grinding chamber.

The mill housing is preferably constructed substantially symmetrical. For this purpose, it can be provided with an upper inlet for regrind, which opens symmetrically to the sieve zones below into the grinding chamber.

In particular, when shredding (dry) grain such as oats or wheat can lead to a strong dust. To address this problem, it has proved to be useful to provide a suction device connected in the upper region of the grinding chamber for sucking off the fine fraction (dust) of the ground material to be ground during the grinding process. Further features and advantages of the invention will become apparent from the following description of schematically illustrated embodiments. It shows:

[17] FIG. 1 shows a hammer mill according to the invention in a side view looking into the grinding chamber; and

[18] Fig. 2 shows the subject matter of Fig. 1 in a transverse view and partly in section.

The drawings show a hammer mill designated in its entirety by 10 in a partially simplified representation, wherein components that are immaterial to the invention, were not partially shown.

[20] The hammer mill 10 intended for feed preparation has a mill housing 11 in which a grinding chamber 12 is formed. The grinding chamber 12 has a substantially cylindrical shape and has an inlet 13 arranged at the top, which widens like a funnel with two guide plates 14 into the actual grinding chamber of the grinding chamber. Adjacent to the guide plates 14, the mill housing 11 or the grinding chamber 12 formed by this has a peripheral wall 15, which extends over an angle of about 270 ° in total. The peripheral wall 15 is essentially formed by two screen plates 16, 17, which adjoin one another at the lowest point 18 of the grinding chamber. In this case, the arrangement is such that the arranged in Fig. 1 in the right half of the housing screen plate 16 with sieve holes of a larger diameter - for example 12 mm - is provided, while in Fig. 1 located in the left half of the housing screen plate 17th smaller sieve holes, for example, have a diameter of 5 mm.

[21] In the grinding chamber 12, a rotor 20 equipped with impact hammers 19 is rotatably arranged. The rotor is mounted directly on the shaft 21 of a drive motor 22 flanged to the mill housing 11, wherein the drive motor is a variable speed motor whose output shaft on which the rotor 20 is seated can rotate in both directions of variable speed. Thus, the rotor 20 in the mill housing can rotate either clockwise or counterclockwise.

The rotor 20 is provided at its front and its rear end with annular support discs 23 which carry four evenly arranged on a pitch circle 24 hammer axes 25, on each of which six flat impact hammers 19 are pivotally mounted. For an additional support of the hammer axes provides a third, central support disk, wherein the arrangement is such that in each case between two support points formed by the support points three impact hammers 19 are arranged on a hammer axis. So that the distance between the impact hammers remains constant from each other, spacer bushes 26 are arranged between them and the support disks.

[23] It can also be seen in FIG. 1 that on the graduated circle 24 between two each The following hammer axes 25 are each two stop elements 27 are provided, which are formed by running between the support plates 23 bolts that additionally stabilize the rotor and limit the pivoting movement of the impact hammers 19.

[24] It can also be seen in FIG. 1 that the impact hammers 19 each have two

Impact surfaces 28 are provided, which are formed by the hammers in the circumferential direction of the rotor front and rear carbide elements 29, which are exchangeably attached as wear pieces on the hammers 19. Of the

Faces are in each case the lying in the direction of rotation of the rotor front of the hammers impact surfaces effective, i. upon rotation in a clockwise direction according to FIG. 1, the striking surfaces 28a, in a counterclockwise rotation, the striking surfaces 28b.

Finally, it should also be mentioned that the rotor is arranged in the mill housing 11 with an eccentricity e to the grinding chamber 12 in this, that the (average) distance of its axis of rotation 30 smaller of the screen zone II formed by the screen plate 17 with holes smaller hole diameter smaller is as of the screen zone I, which is formed by the screen plate 16 with the larger Siebiochungen.

[26] With the invention, described above with reference to the drawings

Hammer mill can produce cattle feed, such as cereals, with two different screening or scrap grades, without the need to rebuild the mill, for example, by replacing the screen plates. When the impact-driven rotor is rotated in a first direction of rotation in the housing, where the impact hammers (starting from the upper inlet) pass first the screen zone I (clockwise in FIG. 1), this is supplied via the inlet Ground stock of the hammers roughly cut and emerges from the comparatively large holes in the screen plate 16, from where it falls down through an opening in the machine base 31. Although it comes with this direction of rotation of the rotor also means that a part of the ground material to be processed in the screening zone II is further crushed and there from the smaller sieve holes of the

Sieve plate 17 exits; Surprisingly, however, the amount of this fine fraction in the direction of rotation of the rotor in the circumferential direction (Fig. 1) is small, since the material was ground to the desired extent already in the nearly half-round of the rotor with the hammers arranged thereon and thus the grinding chamber for predominantly in the area of the screening zone I emerges.

If you want to produce a finer shredded feed, it is not necessary to replace the screen plates consuming, but it is sufficient to change the direction of rotation of the rotor, ie to drive this so that the impact hammers 19 first sweep the screen zone II, in the screen plate 17 is provided with small holes (counterclockwise in Fig. 1). Because of the prevailing there, comparatively small distance of the screen plate from the radially outer end portions 32 of the percussion hammers on which the impact surfaces 28 are formed, the material is comminuted here between the percussion hammers and the fine screen plate quickly to the desired, small shot size, so that Here, too, a large part of the ground material has already been crushed and leaked out of the screen plate when the

Impact hammers reach their lowest position at 18, where then joins the coarser screen plate. Even when grinding with the finer degree of grinding thus discharged from the screening zone I coarse fraction remains low.

The invention is not limited to the illustrated and described embodiment, but various changes or additions are possible without departing from the scope of the invention. For example, it is possible that the

Mahlkammer not cylindrical, but has a substantially oval cross-section. The width of the grinding chamber in the axial direction of the rotor and the number of impact hammers received on the hammer axes can vary depending on the application and the size of the machine. For different types of regrind not only the direction of rotation of the rotor, but also the rotational speed is preferably infinitely adjustable, so that the peripheral speed with which the impact hammers act on the material to be ground, can be varied. The hammer mill may be formed as a stationary mill, but it may also be a mobile unit, which is transported by means of a transport vehicle to the respective place of need.

Claims

claims

1. Hammer mill for feed preparation, with a one

Grinder chamber (12) forming mill housing (l l), which is provided on a circumferential wall (15) with two sieve zones (I, II), the

Sieboochungen have different hole diameters, and with a in the grinding chamber (12) rotatably driven, equipped with hammers (19) rotor (20), characterized in that the rotor (20) is driven in opposite directions and that the hammers (19 ) are each provided with two impact surfaces (28), one of which (28a) in one direction of rotation and the other (28b) in the opposite direction of rotation are effective.

2. hammer mill according to claim 1, characterized in that the sieve zones (I, II) are arranged at least approximately symmetrical to each other in the mill housing (11) and at the lower bottom portion (18) of the grinding chamber (12) preferably adjoin one another at their lowest point.

3. hammer mill according to claim 1 or 2, characterized in that the grinding chamber (12) is cylindrical.

4. hammer mill according to claim 1 or 2, characterized in that the grinding chamber (12) has a substantially oval cross-section.

5. hammer mill according to one of claims 1 to 4, characterized in that the rotor (20) with eccentricity (e) to the grinding chamber (12) is arranged in this, that the distance of its axis of rotation (30) of the screening zone (II) is smaller with the Sieboochungen smaller hole diameter than from the screening zone (I) with Siebiochungen larger hole diameter.

6. hammer mill according to one of claims 1 to 5, characterized in that the rotor (20) distributed evenly over its circumference arranged Hämmerachsen (25) is provided, on which the hammers (19) are mounted pivotably.

7. hammer mill according to claim 6, characterized in that on each hammers axis (25) a plurality of hammers (19) are arranged.

8. hammer mill according to one of claims 1 to 7, characterized in that the striking surfaces (28) on the in the direction of rotation of the rotor (20) front and rear longitudinal sides of the hammers (19) at the radially outer end portions (32) are formed.

9. hammer mill according to one of claims 1 to 8, characterized in that the striking surfaces (28) of the hammers (19) arranged hard metal elements (29) are formed.

10. hammer mill according to one of claims 1 to 9, characterized in that the striking surfaces (28) of exchangeable to the hammers (19) fixed wear pieces (29) are formed.

11. hammer mill according to one of claims 1 to 9, characterized in that the rotor (20) arranged in the circumferential direction before and / or behind the hammers axes (25), the pivoting movement of the hammers (19) limiting stops (27) is provided.

12. hammer mill according to one of claims 1 to 10, characterized in that the screening zones (I, II) of exchangeable in the mill housing (12) arranged screen plates (16, 17) are formed.

13. Hammer mill according to one of claims 1 to 12, characterized in that the sieve zones (I, II) each extend over a circumferential range from 60 ° to 140 ° of the peripheral wall of the grinding chamber (12).

14. Hammer mill according to one of claims 1 to 13, characterized in that the mill housing (11) is provided with a top arranged inlet (13) for ground material, which opens symmetrically to the screen zones (I, II) in the grinding chamber (12) ,

15. Hammer mill according to one of claims 1 to 14, characterized by a suction device connected in the upper region of the grinding chamber for sucking off a fine fraction of the ground grinding material produced during the grinding process.