EP2322856A2 - Device for processing biomass - Google Patents

Abstract

The device (20) has screw shafts (22a-22d) with screw spirals, and cutting knives staying along circumference of the screw spirals in a circumferential direction. A perforated strainer is provided with holes. The shafts are arranged at a frame (24) in such a manner that the shafts withdraw straw from bales of straw supplied to the milling device during operation and convey the straw in to a processing space. The processing space is defined by the shafts, the frame and the strainer. The straw is milled in the space still the straw is guided through the holes of the strainer.

Description

Field of the invention

The invention relates to a device for processing substantially hemi-shaped biomass, in particular straw and hay. In particular, the invention relates to a device for shredding straw or hay in the form of bales in order to feed the thus shredded straw or hay to a boiler.

Background of the invention

The term straw is a collective term for threshed and then dried stalks and stems, in the narrower sense of any crops (especially cereals), in the broader sense but also of legumes, oil and fiber plants. Most of the straw is incorporated into the soil of agricultural land as a source of humus and nutrients, either directly after harvesting the crops or - mixed with animal excrement as manure - after being used as litter. Some straws also serve as nutrient-poor feed.

However, straw can also be meaningfully used as fuel, since the calorific value of straw is not significantly lower than that of wood. In Germany, about 50 million tonnes of grain, grain corn and rapeseed straw accumulate each year. Long term left 25 percent of them use energy, which corresponds to an energy amount of 190 petajoules. Straw can be compressed into highly compressed bales (for example in the form of rectangular bales or round bales), which then have a calorific value of about 5000 kWh per tonne. A truck loaded with such bales can transport just as much energy as a wood truck. In this way, straw can be collected together with relatively little transport traffic. The quality of the straw (moisture, residues) is decisive for the burning properties and depending on the harvesting weather.

However, there are some technical challenges with straw combustion in heating plants. The feeding and dosing of the firing systems with straw is complex. In order to avoid slagging, the quality of the straw must be high, the combustion chamber must be specially designed and the electronic boiler control system adjusted. Although straw pellets, which can be used like wood chips, have been available for some time now, the amended "First Bundesimmision Protection Ordinance" has tightened the limits for small and medium-sized combustion plants. In order to retain nitrogen oxides and fine dust, costly flue gas filter systems are often necessary. Therefore, suitable ovens are more expensive compared to wood boilers and are more likely to be worthwhile at higher heat outputs. The use of straw for heating in small installations such. Pellet heating is still very difficult.

The efficiency or the efficiency of a straw-operated heating system depends inter alia on the form in which the straw is fed to the heating system and how this is dosed. Linka of Denmark has disclosed for this purpose a charging system with a single-shaft cutting device which comprises a shaft provided with knives and a perforated screen. In this known charging system, the straws are hardly crushed due to the lack of movement, but only pulled out of a bale, ie the straw remains substantially whole, is only treated in length and hardly broken, resulting in an unfavorable, as non-uniform dosage.

The object of the present invention is therefore to provide an improved apparatus for processing straw or hay in the form of a bale for a Heinzanlage.

Summary of the invention

The object is achieved by a crushing device for processing straw bales according to claim 1. The comminution device comprises a plurality of screw shafts, each having a helix, along the circumference of which a plurality of cutting blades protrude in the circumferential direction. Further, the crushing device comprises a perforated screen having a plurality of holes. In this case, the worm shafts are arranged in a frame such that the worm shafts in operation draw straw from a straw bale fed to the comminuting device, convey it into a processing space defined by the worm shafts, the frame and the perforated wire, and the straw in the processing space for so long crush until it can be removed through the holes of the perforated screen.

Preferably, the shredding device comprises four screw shafts, which are arranged in the frame substantially in such a way that their longitudinal axes are parallel and perpendicular to the feed direction of a straw bale, wherein the axes of the first, i. the upper, worm shaft and the third worm shaft lie in an imaginary vertical first plane and the axes of the fourth, i. bottom, worm shaft and the second worm shaft lie in an imaginary vertically extending second plane, which is offset horizontally from the plane. Preferably, the second worm shaft and the fourth worm shaft are spaced closer to the vertical perforated wire than the first worm shaft and the third worm shaft.

Preferably, the relative arrangement of the worm shafts in the frame is such that the cutting blades of a worm shaft and the cutting blades of an immediately adjacent worm shaft intermesh, so that the space between two immediately adjacent worm shafts, which is not detected by a cutting blade, is kept as small as possible is reduced to a minimum. This arrangement of the screw shafts ensures that the straw is cut out of the bales evenly and no large press strokes are torn out. The straws are spread out.

Preferably, the helix of a worm shaft consists of two helical sections with opposite accessibility, each extending from one end of the worm shaft to the center thereof.

More preferably, the cutting blades are each mounted at an angular distance of 90 degrees along the circumference of the helix of a worm shaft and have the shape of a triangle with two cutting edges for crushing the straw.

Preferably, the crushing device according to the invention is part of a feed system which comprises baleous biomass, e.g. Bales of straw, absorbs the biomass crushed and fed to a heating system in which the crushed biomass is used for heating.

Further advantages of the invention and preferred embodiments will become apparent from the following objective description, the features of the subclaims and the drawings.

Brief description of the drawings

• Figur 1 zeigt eine perspektivische Ansicht einer Beschickungslange mit einer erfindungsgemäßen Zerkleinerungsvorrichtung zum Verarbeiten von Strohballen gemäß einer bevorzugten Ausführungsform der Erfindung.
• Figur 2 zeigt eine Seiteansicht der Beschickungsanlage von Figur 1.

A preferred embodiment of the invention is illustrated in the accompanying drawings.

• FIG. 1 shows a perspective view of a feed length with a crushing device according to the invention for processing bales of straw according to a preferred embodiment of the invention.
• FIG. 2 shows a side view of the charging system of FIG. 1 ,

The FIGS. 3a and 3b show a perspective view and a side view from the front of the crushing device for processing straw bale according to a preferred embodiment of the invention.

The FIGS. 4a and 4b show a side view from behind and a cross-sectional view of the crushing device for processing bales of straw according to a preferred embodiment of the invention.

The FIG. 5a shows a further perspective view of the crushing device for processing bales of straw according to a preferred embodiment of the invention.

The FIG. 5b shows a detailed view of the four screw shafts and a part of the frame for supporting the screw shafts of the crushing device for processing bales of straw according to a preferred embodiment of the invention.

Detailed Description of a Preferred Embodiment

The invention will now be explained in more detail with reference to a preferred embodiment.

In the FIGS. 1 and 2 For example, a feeder length 10 is shown with a shredder 20 for processing straw bales in accordance with a preferred embodiment of the invention. The charging system 10 includes in addition to the Crushing device 20 for processing straw bales, a feed device 12 in the form of a table 13 and a feed, for example two feed chains 14a, 14b (preferably simplex chains) driven by a geared motor, guide means in the form of a guide frame 15 and a feed screw 16 for transporting the straw produced during the processing of a straw bale by the comminution device 20 and falls from above into a trough of the screw conveyor 16. In the feed chains 14a, 14b chain locks are preferably integrated with a one-sided angle bracket, so that the straw bales during transport along the table 13 and through the guide frame 15 can not slip. The deflection of the feed chains 14a, 14b by means of rollers at the end of the table 13 in the vicinity of the crushing device 20 and at the free end of the table 13, where the bales of straw are applied to the charging system 10. The feeder 12 is preferably clocked, the timing depending on the straw quality and the dimensions of the straw bales. For this purpose, the charging system 10 further comprises a control unit (not shown), which controls the operation of all components and monitored and is connected to the signal exchange with these components.

The crushing device 20 for processing straw bales and their components are described in detail in FIGS FIGS. 3a, 3b . 4a, 4b . 5a and 5b shown. As can be seen from these figures, the crushing device 20 comprises on its input side, ie the feeding device 12 and the guide tunnel 15 side facing four worm shafts 22a, 22b, 22c and 22d for pulling the straw from a bale of straw and for cutting the Straw. On the output side of the comminution device 20, that is, the side facing away from the feed device 12, a vertically arranged, flat perforated screen 26 is provided, which defines together with a cover 28 a discharge space, which leads into the trough of the screw conveyor 16. The cover 28 may comprise a transparent pane, such as a Plexiglas pane, which permits viewing the discharge space defined by the perforated screen 26 and the cover 28, but seals that discharge space so that no shredded straw passing through the perforated screen 26 escapes from the crushing device 20 but the screw conveyor 16 is supplied. The diameter of the holes of the perforated screen 26 is preferably between about 5 and 10 cm.

The four worm shafts 22a, 22b, 22c and 22d are arranged in a frame 24 substantially one above the other such that their longitudinal axes are parallel and perpendicular to the feed direction of a straw bale. How this, however, in particular the FIG. 4b can be seen, the axes of the first, ie uppermost, worm shaft 22a and the third worm shaft 22c lie in an imaginary vertically extending first plane E1 and the axes of the fourth, ie lowest, worm shaft 22d and the second worm shaft 22b are in an imaginary vertically extending second Plane E2, which is offset horizontally from plane E1. Here, as seen from above, the second worm shaft 22b and the fourth worm shaft 22d, whose axes are in the vertical plane E2, are closer to the perforated screen 26 than the first worm shaft 22a and the third worm shaft 22c, whose axes are in the vertical one Level E1 lie.

As those skilled in the art will appreciate, the plane E1, in which the axes of the first worm shaft 22a and the third worm shaft 22c are located, and the plane E2, in which the axes of the second worm shaft 22b and the fourth worm shaft 22d are parallel, are parallel to that of the perforated screen 26 defined level. Preferably, the distance of the second worm shaft 22b and the fourth worm shaft 22d from the perforated screen 26 is approximately between 10 and 15 cm, and most preferably about 12.5 cm. Preferably, the spacing of the first worm shaft 22a and the third worm shaft 22c from the perforated screen 26 is approximately between 20 and 30 cm, and most preferably approximately 25 cm.

How this particular the FIGS. 4b . 5a and 5b A worm shaft 22a, 22b, 22c and 22d respectively has a plurality of cutting blades 23 for crushing the straw, which is processed by means of the worm shafts 22a, 22b, 22c and 22d. The cutting blades 23 are respectively mounted along the circumference of the helix of the worm shaft 22a, 22b, 22c and 22d so as to protrude in the circumferential direction. The cutting blades 23 are shaped and mounted on the helix of a respective worm shaft 22a, 22b, 22c and 22d, that in operation the cutting blade 23 for comminution of the shredder 20 supplied straw, for example in the form of a straw bale provide. For this purpose, the cutting blades 23 may preferably each be screwed at an angular distance of 90 degrees along the circumference of the helix of the screw shaft 22a, 22b, 22c and 22d and preferably have the shape of a triangle, so that a cutting blade 23 each has two cutting edges for crushing the straw ,

The relative arrangement of the worm shafts 22a, 22b, 22c and 22d in the frame 24 best suits the FIGS. 4b . 5a and 5b is preferably such that the cutting blades 23 of a worm shaft 22a, 22b, 22c and 22d and the cutting blades 23 of an immediately adjacent worm shaft 22a, 22b, 22c and 22d "intermesh" (of course without touching each other) so that the Space between two immediately adjacent screw shafts 22a, 22b, 22c and 22d, which is not detected by a cutting blade 23, is kept as small as possible or is reduced to a minimum. In other words, each two immediately adjacent worm shafts 22a, 22b, 22c and 22d are in a meshing arrangement with each other. However, it is also conceivable that in some embodiments, a tangential arrangement may be advantageous. As those skilled in the art will appreciate, this is determined by the diameter of the helices of a worm shaft 22a, 22b, 22c and 22d with the cutting blades 23 mounted thereon and the center distance of two immediately adjacent worm shafts 22a, 22b, 22c and 22d. Preferably, the center distance of two immediately adjacent screw shafts 22a, 22b, 22c and 22d is approximately between 20 and 30 cm and most preferably approximately 25 cm. At a most preferred center distance of two immediately adjacent screw shafts 22a, 22b, 22c and 22d of about 25 cm, the helix diameter of a screw shaft 22a, 22b, 22c and 22d is about 20 cm and the cutting blades are about 2 to 5 cm again from the helix. The pitch of the helices of a worm shaft 22a, 22b, 22c and 22d is approximately between 10 and 20 cm and most preferably about 15 cm.

Like this in FIG. 4b is indicated with the semicircular arrow R, rotate in operation, the four screw shafts 22a, 22b, 22c and 22d, preferably all in the same direction, in the clockwise direction in the side view of FIG. 4b in which, for example, the feeding device 12 is located to the left of the comminution device 20. However, it will be appreciated by those skilled in the art that in some embodiments, the worm shafts 22a, 22b, 22c, and 22d may all rotate counterclockwise and may also rotate individually in different directions, as long as the pitch of the worm shafts 22a, 22b, 22c, and 22d is selected accordingly ,

How this particular the FIGS. 4a . 5a and 5b In the preferred embodiment of the invention, the helix of a worm shaft 22a, 22b, 22c and 22d consists of two helical sections of opposite drive, each extending from one end of the worm shaft 22a, 22b, 22c and 22d to the center thereof. For example, in the back view of FIG. 4a or the perspective view of FIG. 5b the left or front portion of the helix of the worm shaft 22a to the middle of a left-handed helical section and the right and rear portion of the helix of the worm shaft 22a from the center of a right-handed helix section. The helix of the immediately underlying worm shaft 22b also has two helical sections with opposite accessibility, wherein the left or front portion of the helix of the worm shaft 22b to the middle of a right-hand helix portion and the right and rear portion of the helix of the worm shaft 22b from the Middle is a left-handed spiral section. The person skilled in the art will recognize that the mobility of the left or front portion of the helix of the worm shaft 22b (right-handed) thus also opposes the accessibility of the left or front portion of the helix of the worm shaft 22a (left-hand). How is this the FIGS. 4a and 5b can be seen, this pattern is continued at the two further underlying screw shafts 22c and 22d. In other words, the left and front portions of the helices of the worm shafts 22a, 22b, 22c and 22d to the center are left-handed, right-handed, left-handed and right-handed, and the right and rear portions of the helices of the worm shafts 22a, 22b, 22c and 22d, respectively from the middle are right-handed, left-handed, right-handed and left-handed.

Although the above-described relative arrangement and configuration of the worm shafts 22a, 22b, 22c and 22d lead to particularly advantageous results in the processing of straw with the comminution device 20 according to the invention, the present invention of course also covers such embodiments in which the individual helices of the worm shafts either are only right-handed or only left-handed, wherein the passabilities of the helices of immediately adjacent worm shaft opposite to each other or may be equal if the axial distance of the worm shafts 22a, 22b, 22c and 22d is selected accordingly.

Preferably, the worm shafts 22a, 22b, 22c and 22d are driven by a 7.5 kW geared motor (not shown), which may for example be housed below the frame 24 in the shredding device 20. Having described the essential components of the shredding device 20 according to the invention for processing straw bales and a β-feeding length 10 comprising them, the following will describe how they can be used in particular for processing straw bales. Pressed straw bales are placed longitudinally at the free end of the table 13 of the feeder 12. If necessary existing ropes of the straw bale must be removed. By means of the feed, ie the feed chains 14a, 14b, the bales of straw along the table 13 to the guide frame 15 and thus the crushing device 20 are fed (see also the horizontally extending, dotted arrow in FIG FIG. 4b indicating the direction of movement of a bale of straw). As soon as a part of a bale of straw is caught by the cutting knives 23 of the first worm shaft 22a and / or the third worm shaft 22c, straws are drawn out of the bale of straw at the corresponding locations and between the worm shafts 22a, 22b, 22c and 22d and thereon mounted cutting blades 23 crushed. In this case, the worm shafts 22a, 22b, 22c and 22d, due to their relative arrangement and configuration described above, transport the straw to be processed from outside to the center, namely the first and third worm shaft 22a, 22c, and from the center to the outside, namely the second one and the fourth worm shaft 22b, 22d. This ensures that the straw to be processed is cut out evenly from a straw bale and no large press strokes are torn out. In particular, the straws are advantageously spread out. After the worm shafts 22a, 22b, 22c and 22d is the perforated screen 26. The worm shafts 22a, 22b, 22c and 22d define together with the perforated screen 26 and the frame 24 a processing space in which the straw is crushed until it is small enough to emerge through the holes of the perforated screen 26 from this processing space and enter the discharge space defined by the perforated screen 26 and the cover 28. In other words, by the size of the diameter of the holes of the perforated screen 26, the length of the crushed straw is determined. About the perforated screen 26, the straw falls into the trough of the screw conveyor 16 (see also the vertically extending dotted arrow in FIG. 4b , which indicates the direction of movement of the crushed straw after the perforated screen 26) and is there discharged from the screw conveyor 16, for example to a boiler.

The crushing device 20 according to the invention has the following advantages. In contrast to known devices shorter and longitudinally broken blades are made with destroyed wax layer on the surface, which are much better suited for a good dosage and combustion in the boiler plants. Furthermore, due to the inventive arrangement of provided with cutting blades 23 screw shafts 22a, 22b, 22c and 22d, the cutting blades 23 in comparison to the prior art process the straw much more often and thus significantly better cut and destroy especially the straw structure. By means of the comminuting device 20 according to the invention, a more meterable and combustible raw material is produced than in the case of known devices.

The foregoing objective description of the invention is for explanatory purposes only. The invention is by no means based on the described embodiment but may be adapted by a person skilled in the art in a manner which appears expedient to him to individual operating requests, which may deviate from the described operating conditions. The shredding device according to the invention for processing straw bales can be advantageously used, for example, both in the industrial or commercial area and in the non-commercial area. Those skilled in the art will further appreciate that instead of the four auger shafts provided in the described preferred embodiment, the present invention may be practiced with more or fewer auger shafts, such as six auger shafts for larger straw bales, depending on the size of the straw bales being processed. Finally, those skilled in the art will recognize that the terms used herein, such as "front,""top,""bottom,""outside," and the like, are not intended to indicate the orientation of the In this way, the elements according to the invention which are specified in greater detail are restricted in any way, but merely serve to distinguish these elements from one another. For example, the charging system could also be designed so that the direction of movement of the straw bales to be processed instead of horizontally vertically as described above.

LIST OF REFERENCE NUMBERS

10

stoker

12

feeding

13

table

14a, 14b

feed chains

15

guide frame

16

Auger

20

comminution device

22a-d

auger

23

cutting blade

24

frame

23

strainer

28

cover

R

Rotation direction of the worm shafts

E1, E2

first and second vertical plane

Claims (10)

Comminution device (20) for processing substantially hemi-shaped biomass, in particular straw bales, comprising: a plurality of worm shafts (22a, 22b, 22c, 22d) each having a helix, along the circumference of a plurality of cutting blades (23) protrude in the circumferential direction; and a perforated screen (26) having a plurality of holes; wherein the worm shafts (22a, 22b, 22c, 22d) are arranged in a frame (24) such that the worm shafts (22a, 22b, 22c, 22d) pull straw from a straw bale fed to the crusher (20) during operation Processing space, which is defined by the screw shafts (22a, 22b, 22c, 22d), the frame (24) and the perforated screen (26), and the straw in the processing space until it breaks through the holes of the perforated screen (26 ) is discharged. Crushing apparatus (20) according to claim 1, wherein the perforated screen (26) together with a cover (28) defines a discharge space leading into the trough of a conveyor screw (16). Crushing device (20) according to claim 2, wherein the cover (28) comprises a transparent disc, preferably a plexiglass disc, which allows to view the discharge space defined by the perforated screen (26) and the cover (28) but seals this discharge space, so that no comminuted straw emerging through the perforated sieve (26) escapes from the comminuting device (20), but is fed to the conveying screw (16). Comminution device (20) according to claim 1, wherein the comminution device (20) comprises four screw shafts (22a, 22b, 22c, 22d) which are arranged in the frame (24) substantially one above the other such that their longitudinal axes are parallel and perpendicular to the feed direction of a straw bale, the axes of the first, ie the upper, worm shaft (22a) and the third worm shaft (22c) lie in an imaginary vertically extending first plane (E1) and the axes of the fourth, e. Lowermost, worm shaft (22d) and the second worm shaft (22b) lie in an imaginary vertically extending second plane (E2), which is offset horizontally from the plane (E1). A crushing apparatus (20) according to claim 4, wherein the second worm shaft (22b) and the fourth worm shaft (22d) are closer to the vertically extending perforated screen (26) than the first worm shaft (22a) and the third worm shaft (22c). Crushing device (20) according to claim 5, wherein the distance of the second worm shaft (22b) and the fourth worm shaft (22d) from the perforated wire (26) is between about 10 and 15 cm, preferably about 12.5 cm and the distance of the first screw shaft (22a) and the third screw shaft (22c) from the perforated screen 26 is approximately between 20 and 30 cm, preferably about 25 cm. Crushing apparatus (20) according to claim 1, wherein the relative arrangement of the worm shafts (22a, 22b, 22c, 22d) in the frame (24) is such that the cutting knives (23) of a worm shaft (22a, 22b, 22c, 22d) and the cutting blades (23) of an immediately adjacent worm shaft (22a, 22b, 22c, 22d) intermesh, so that the space between two immediately adjacent worm shafts (22a, 22b, 22c, 22d), which is not detected by a cutting blade (23) , is kept as small as possible or is reduced to a minimum. A crushing apparatus (20) according to claim 1, wherein the helix of a worm shaft (22a, 22b, 22c, 22d) is composed of two helical portions of opposite drive, each from one end of the worm shaft (22a, 22b, 22c, 22d) to the center thereof run. Crushing device (20) according to claim 1, wherein the cutting blades (23) are each mounted at an angular distance of 90 degrees along the circumference of the spiral of the worm shaft (22a, 22b, 22c, 22d) and the shape of a triangle with two cutting edges for comminuting the Having straw. A feeder (10) for processing straw bales and feeding the processed straw bales to a heating device, comprising: a crushing device (20) according to one of the preceding Arisprüche.

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